Policy changes for preventing and recognizing overwork-related cardiovascular diseases in Taiwan: An overview.
Chang Heng-Hao,Lin Ro-Ting
Journal of occupational health
OBJECTIVE:Overwork-related cardiovascular and cerebrovascular disease (CVD) has a large impact on workers' rights and labor standards across East Asian countries. This article describes the background and impact of policies regarding overwork-related CVD in the past decades in Taiwan. METHODS:We reviewed government policies, guidelines, literature, and news addressing the problems and impact of policy changes to prevent and recognize overwork-related CVD since the 1990s, and collected data on overwork-related CVD cases in Taiwan from 2006 to 2017. RESULTS:In 2017, overwork-related CVD accounted for 13% of all cases of occupational diseases, but 79% of all deaths due to occupational diseases. Guidelines for recognizing overwork-related CVD cases were established in 1991; however, under-recognition exists in Taiwan due to poor exposure data on working hours and psychological factors and because most medical expenses are covered by the national health insurance system. Amendments on the guidelines, and stricter policies on overwork prevention were enforced following calls from labor unions, nongovernmental organizations, and legislators, but health disparities were introduced when certain industries were exempted from restrictions. CONCLUSIONS:Long working hours and other work characteristics increase the risk of overwork-related CVD. By reviewing the changes in policy for preventing overwork and recognizing overwork-related disease, we identified the need for clearly defined guidance on evaluating overwork-related CVD, with specific criteria for working hours and other risk factors regarding work characteristics. National policies that lead to better working conditions and prevent overwork-related diseases must be developed.
Mediation analysis for new recognition criteria, working hours and overwork-related disease: a nationwide ecological study using 11-year follow-up data in Taiwan.
Lin Sheng-Hsuan,Chou Meng-Ying,Lin Ro-Ting
OBJECTIVES:Taiwan revised its criteria for overwork-related cerebrovascular and cardiovascular disease (CCVD) in 2010. A new definition of overwork increased the number of recognised cases. Meanwhile, actual average working hours decreased. We estimated the effects of the revised criteria on the number of overwork-related CCVD cases and the mediation effect through reduced working hours. METHODS:From the Labor Insurance of Taiwan, we collected data on the total number of overwork-related CCVD cases from 2006 to 2016 and average monthly working hours for 13 industry groups. We conducted causal mediation analysis to investigate the mechanism of the effect of new criteria on CCVD mediated by working hours. RESULTS:From 2006 to 2016, 594 overwork-related cases of CCVD were recognised across 13 industry groups. After introducing the new criteria, overwork-related CCVD increased by 8.40 cases (per one million person-years) (95% CI 4.53 to 15.05), which resulted from a decrease of 1.54 (95% CI 0.22 to 3.82) cases due to reduced working hours (mediation effect) and an increase of 9.93 (95% CI 5.24 to 18.17) cases related to the effect of the criteria change and other covariates excluding working hours (alternative effect). CONCLUSIONS:Working hours are an important mediator of the effect of policy on the rate of overwork-related CCVD. Introducing new criteria for recognising overwork-related disease might raise awareness and prompt reductions in working hours, which also help to reduce CCVD. Our findings suggest that understanding mediation effects is important to evaluating national health policies.
The Uncounted Casualties of a Hidden COVID-19 Epidemic in China: Cross-sectional Study on Deaths Related to Overwork.
Wang Zhicheng,Lin Leesa,Guo Yan,Xiong Huayi,Tang Kun
Journal of medical Internet research
BACKGROUND:During the COVID-19 response, nonclinical essential workers usually worked overtime and experienced significant work stress, which subsequently increased their risk of mortality due to cardiovascular diseases, stroke, and pre-existing conditions. Deaths on duty, including deaths due to overwork, during the COVID-19 response were usually reported on web-based platforms for public recognition and solidarity. Although no official statistics are available for these casualties, a list of on-duty deaths has been made publicly available on the web by crowdsourcing. OBJECTIVE:This study aims to understand the trends and characteristics of deaths related to overwork among the frontline nonclinical essential workers participating in nonpharmaceutical interventions during the first wave of COVID-19 in China. METHODS:Based on a web-based crowdsourced list of deaths on duty during the first wave of the COVID-19 response in China, we manually verified all overwork-related death records against the full-text web reports from credible sources. After excluding deaths caused by COVID-19 infection and accidents, a total of 340 deaths related to overwork among nonclinical essential workers were attributed to combatting the COVID-19 crisis. We coded the key characteristics of the deceased workers, including sex, age at death, location, causes of death, date of incidence, date of death, containment duties, working area, and occupation. The temporal and spatial correlations between deaths from overwork and COVID-19 cases in China were also examined using Pearson correlation coefficient. RESULTS:From January 20 to April 26, 2020, at least 340 nonclinical frontline workers in China were reported to have died as a result of overwork while combatting COVID-19. The weekly overwork mortality was positively correlated with weekly COVID-19 cases (r=0.79, P<.001). Two-thirds of deceased workers (230/340, 67.6%) were under 55 years old, and two major causes of deaths related to overwork were cardiovascular diseases (138/340, 40.6%) and cerebrovascular diseases (73/340, 21.5%). Outside of Hubei province, there were almost 2.5 times as many deaths caused by COVID-19-related overwork (308/340, 90.6%) than by COVID-19 itself (n=120). CONCLUSIONS:The high number of deaths related to overwork among nonclinical essential workers at the frontline of the COVID-19 epidemic is alarming. Policies for occupational health protection against work hazards should therefore be prioritized and enforced.
Higher Number of Night Shifts Associates with Good Perception of Work Capacity and Optimal Lung Function but Correlates with Increased Oxidative Damage and Telomere Attrition.
Pavanello Sofia,Stendardo Mariarita,Mastrangelo Giuseppe,Casillo Valeria,Nardini Marco,Mutti Antonio,Campisi Manuela,Andreoli Roberta,Boschetto Piera
BioMed research international
Sleep deprivation and the consequent circadian clock disruption has become an emergent health question being associated with premature aging and earlier chronic diseases onset. Night-shift work leads to circadian clock misalignment, which is linked to several age-related diseases. However, mechanisms of this association are not well understood. Aim of this study is to explore in night-shift workers early indicators of oxidative stress response and biological aging [oxidized/methylated DNA bases and leukocytes telomere length (LTL)] and late indicators of functional aging [lung function measurements (FEV1 and FVC)] in relation to personal evaluation of work capacity, measured by work ability index (WAI). One hundred fifty-five hospital workers were studied within the framework of a cross-sectional study. We collected physiological, pathological, and occupational history including pack-years, alcohol consumption, physical activity, and night shifts, together with blood and urine samples. Relationships were appraised by univariate and multivariate ordered-logistic regression models. We found that workers with good and excellent WAI present higher FEV1 (p< 0.01) and number of night-work shifts (p<0.05), but they reveal higher urinary levels of 8-oxoGua (p<0.01) and shorter LTL (p<0.05). We confirmed that higher work ability was prevalent among chronological younger workers (p<0.05), who have also a significant reduced number of diseases, particularly chronic (p<0.01) and musculoskeletal diseases (p<0.01). The new findings which stem from our work are that subjects with the highest work ability perception may have more demanding and burdensome tasks; they in fact present the highest number of night-shift work and produce unbalanced oxidative stress response that might induce premature aging.
Evoked electrical and cerebral vascular responses during sleep and following sleep deprivation.
Schei Jennifer L,Rector David M
Progress in brain research
Neuronal activity elicits vascular dilation, delivering additional blood and metabolites to the activated region. With increasing neural activity, vessels stretch and may become less compliant. Most functional imaging studies assume that limits to vascular expansion are not normally reached except under pathological conditions, with the possibility that metabolism could outpace supply. However, we previously demonstrated that evoked hemodynamic responses were larger during quiet sleep when compared to both waking and rapid eye movement (REM) sleep, suggesting that high basal activity during wake may elicit blunted evoked hemodynamic responses due to vascular expansion limits. We hypothesized that extended brain activity through sleep deprivation will further dilate blood vessels and exacerbate the blunted evoked hemodynamic responses observed during wake, and dampen responses in subsequent sleep. We measured evoked electrical and hemodynamic responses from rats using auditory clicks (0.5s, 10 Hz, 2-13s random ISIs) for 1h following 2, 4, or 6h of sleep deprivation. Time-of-day matched controls were recorded continuously for 7h. Within quiet sleep periods following deprivation, evoked response potential (ERP) amplitude did not differ; however, the evoked vascular response was smaller with longer sleep deprivation periods. These results suggest that prolonged neural activity periods through sleep deprivation may diminish vascular compliance as indicated by the blunted vascular response. Subsequent sleep may allow vessels to relax, restoring their ability to deliver blood. These results also suggest that severe sleep deprivation or chronic sleep disturbances could push the vasculature to critical limits, leading to metabolic deficit and the potential for tissue trauma.
Flavanol-rich chocolate acutely improves arterial function and working memory performance counteracting the effects of sleep deprivation in healthy individuals.
Grassi Davide,Socci Valentina,Tempesta Daniela,Ferri Claudio,De Gennaro Luigi,Desideri Giovambattista,Ferrara Michele
Journal of hypertension
BACKGROUND:Sleep deprivation is a risk factor for cardiovascular disease. Cocoa flavonoids exert cardiovascular benefits and neuroprotection. Whether chocolate consumption may mitigate detrimental effects of sleep loss on cognitive performance and cardiovascular parameters has never been studied. AIM:We investigated the effects of flavanol-rich chocolate consumption on cognitive skills and cardiovascular parameters after sleep deprivation. METHODS:Thirty-two healthy participants underwent two baseline sessions after one night of undisturbed sleep and two experimental sessions after one night of total sleep deprivation. Two hours before each testing session, participants were randomly assigned to consume high or poor flavanol chocolate bars. During the tests were evaluated, the Psychomotor Vigilance Task and a working memory task, office SBP and DBP, flow-mediated dilation and pulse-wave velocity. RESULTS:Sleep deprivation increased SBP/DBP. SBP/DBP and pulse pressure were lower after flavanol-rich treatment respect to flavanol-poor treatment (SBP: 116.9 ± 1.6 vs. 120.8 ± 1.9 mmHg, respectively, P = 0.00005; DBP: 70.5 ± 1.2 vs. 72.3 ± 1.2 mmHg, respectively, P = 0.01; pulse pressure: 46.4 ± 1.3 vs. 48.4 ± 1.5 mmHg, P = 0.004). Sleep deprivation impaired flow-mediated dilation (5.5 ± 0.5 vs. 6.5 ± 0.6%, P = 0.02), flavanol-rich, but not flavanol-poor chocolate counteracted this alteration (flavanol-rich/flavanol-poor chocolate: 7.0 ± 0.6 vs. 5.0 ± 0.4%, P = 0.000001). Flavanol-rich chocolate mitigated the pulse-wave velocity increase (P = 0.001). Flavanol-rich chocolate preserved working memory accuracy in women after sleep deprivation. Flow-mediated dilation correlated with working memory performance accuracy in the sleep condition (P = 0.04). CONCLUSION:Flavanol-rich chocolate counteracted vascular impairment after sleep deprivation and restored working memory performance. Improvement in cognitive performance could be because of the effects of cocoa flavonoids on blood pressure and peripheral and central blood flow.
Lipid peroxidation in the descending thoracic aorta of rats deprived of REM sleep using the inverted flowerpot technique.
Nawi Afifah,Eu Koh Liew,Faris Asma Nadia Ahmad,Wan Ahmad Wan Amir Nizam,Noordin Liza
NEW FINDINGS:What is the central question of this study? Deprivation of rapid eye movement (REM) sleep is associated with increased oxidative stress, but its effects on the blood vessels are poorly documented. We investigated whether REM sleep deprivation induces oxidative stress and causes lipid peroxidation in the aorta. What is the main finding and its important? We demonstrate that REM sleep deprivation induces oxidative stress and mediates lipid peroxidation in the aorta. This can cause endothelial changes and increased blood pressure. These findings will contribute to the growing body of literature on the mechanism underlying the effects of sleep deprivation on cardiovascular disease. ABSTRACT:Oxidative stress-mediated lipid peroxidation is a known cause of endothelial injury or dysfunction. Deprivation of rapid eye movement (REM) sleep is associated with oxidative stress. To date, the pathogenesis of increased blood pressure after sleep deprivation remains poorly understood, particularly in the REM sleep phase. Our aim was to investigate the effects of REM sleep deprivation on blood vessels in the REM sleep-deprived rat model. Twenty-eight male Sprague-Dawley rats were divided into four equal groups: free-moving control rats, rats deprived of REM sleep for 72 h (REMsd), tank control rats and 72 h sleep-recovered rats after 72 h of REM sleep deprivation. The rats were deprived of REM sleep using the inverted flowerpot technique. Food consumption, body weight gain and systolic blood pressure were monitored. At the end of the experiment, the descending thoracic aorta was isolated for the measurement of oxidative stress markers. Despite a significant increase in food consumption in the REMsd group compared with the other groups, there was a significant reduction in body weight gain. Systolic blood pressure also showed a significant increase in the REMsd group compared with the other groups. Superoxide dismutase activity was significantly lower and malondialdehyde concentrations significantly higher in the REMsd group compared with the other groups. Increased levels of malondialdehyde are suggestive of lipid peroxidation in the blood vessels, and oxidative stress may be attributed to the initiation of the process. The changes after REM sleep deprivation revert during sleep recovery. In conclusion, the findings of the present study provide convincing evidence that REM sleep deprivation induced lipid peroxidation, leading to endothelial damage.
Insufficient sleep is associated with impaired nitric oxide-mediated endothelium-dependent vasodilation.
Bain Anthony R,Weil Brian R,Diehl Kyle J,Greiner Jared J,Stauffer Brian L,DeSouza Christopher A
BACKGROUND AND AIMS:Habitual short nightly sleep duration is associated with increased atherosclerotic cardiovascular disease risk and morbidity. Vascular endothelial dysfunction represents an important mechanism that may underlie this heightened cardiovascular risk. Impaired endothelium-dependent vasodilation, particularly NO-mediated vasodilation, contributes to the development and progression of atherosclerotic vascular disease and acute vascular events. We tested the hypothesis that chronic insufficient sleep is associated with impaired NO-mediated endothelium-dependent vasodilation in middle-aged adults. METHODS:Thirty adult men were studied: 15 with normal nightly sleep duration (age: 58 ± 2 y; sleep duration: 7.7 ± 0.2 h/night) and 15 with short nightly sleep duration (55 ± 2 y; 6.1 ± 0.2 h/night). Forearm blood flow (FBF) responses to intra-arterial infusion of acetylcholine, in the absence and presence of the endothelial NO synthase inhibitor N-monomethyl-L-arginine (L-NMMA), as well as responses to sodium nitroprusside, were determined by strain-gauge venous occlusion plethysmography. RESULTS:The FBF response to acetylcholine was lower (∼20%; p<0.05) in the short sleep duration group (from 4.6 ± 0.3 to 11.7 ± 1.0 ml/100 ml tissue/min) compared with normal sleep duration group (from 4.4 ± 0.3 to 14.5 ± 0.5 ml/100 ml tissue/min). L-NMMA significantly reduced the FBF response to acetylcholine in the normal sleep duration group (∼40%), but not the short sleep duration group. There were no group differences in the vasodilator response to sodium nitroprusside. CONCLUSIONS:These data indicate that short nightly sleep duration is associated with endothelial-dependent vasodilator dysfunction due, in part, to diminished NO bioavailability. Impaired NO-mediated endothelium-dependent vasodilation may contribute to the increased cardiovascular risk with insufficient sleep.
Regular aerobic exercise counteracts endothelial vasomotor dysfunction associated with insufficient sleep.
Stockelman Kelly A,Bain Anthony R,Dow Caitlin A,Diehl Kyle J,Greiner Jared J,Stauffer Brian L,DeSouza Christopher A
American journal of physiology. Heart and circulatory physiology
Insufficient sleep is associated with endothelial vasomotor dysfunction and increased cardiovascular risk. Regular aerobic exercise is an effective lifestyle strategy for improving endothelial function and, in turn, reducing cardiovascular risk. We tested the hypotheses that regular aerobic exercise would ) improve endothelial vasodilation and ) decrease endothelin (ET)-1-mediated vasoconstrictor tone in middle-aged adults who chronically sleep <7 h/night. Thirty-six healthy, middle-aged adults were studied: 16 with normal sleep duration (age: 57 ± 2 yr; sleep duration: 7.4 ± 0.1 h/night) and 20 with short sleep duration (age: 56 ± 1 yr; sleep duration: 6.2 ± 0.1 h/night). The 20 short sleepers completed a 3-mo aerobic exercise training intervention. Forearm blood flow was determined (via plethysmography) in response to intra-arterial acetylcholine (ACh), BQ-123 (ET receptor antagonist), ACh + BQ-123, and sodium nitroprusside. Forearm blood flow responses to ACh were lower (∼20%; < 0.05) in the short (from 4.2 ± 0.2 to 10.5 ± 0.6 mL/100 mL tissue/min) versus normal (4.2 ± 0.2 to 12.7 ± 0.6 mL/100 mL tissue/min) sleepers. In response to BQ-123, the short-sleep group had a significantly greater increase in resting forearm blood flow than the normal-sleep group (∼25% vs. ∼8%). ACh + BQ-123 resulted in a significant (∼25%) increase in the ACh-mediated vasodilation in the short-sleep group only. After exercise training, although nightly sleep duration was unchanged (6.4 ± 0.1 h/night), ACh-mediated vasodilation was significantly higher (∼20%), ET-1-mediated vasoconstriction was significantly lower (∼80%), and the vasodilator response to ACh was not increased with ET receptor blockade. Regular aerobic exercise, independent of changes in nightly sleep duration, can counteract insufficient sleep-related endothelial vasomotor dysfunction. Habitual insufficient nightly sleep (<7 h/night) is associated with increased risk of cardiovascular disease and events. Endothelial dysfunction, specifically reduced endothelium-dependent vasodilation and increased endothelin (ET)-1-mediated vasoconstriction, is considered to be a major contributing mechanism underlying increased vascular risk with insufficient sleep. In contrast to insufficient sleep, regular aerobic exercise enhances endothelial vasomotor function, reducing the risk of cardiovascular disease and associated events. In the present study, we determined the effects of aerobic exercise training on endothelium-dependent vasodilation and ET-1 vasoconstriction in adults who habitually sleep <7 h/night. After exercise training, although nightly sleep duration was unchanged, endothelium-dependent vasodilation was significantly enhanced and ET-1-mediated vasoconstrictor tone was significantly reduced in adults who sleep <7 h/night. Regular aerobic exercise training can mitigate insufficient sleep-related endothelial vasomotor dysfunction and, in turn, potentially reduce the cardiovascular risk associated with habitual insufficient nightly sleep.
Forensic Pathology Analysis of 363 Sudden Death Cases in Yunnan Province.
Sun Z C,Yang Q K,Jia P L,Xiong X,Qu P F,Qu Y Q,Lei P P
Fa yi xue za zhi
OBJECTIVES:To study the epidemiological and pathological features of sudden death （SD） in Yunnan Province and to provide scientific evidence for prevention and forensic identification of sudden death. METHODS:Totally 363 SD cases were collected from the autopsies between 2009 and 2017 in the Forensic Centre of Kunming Medical University. The related factors such as etiology, age, inducing factor, time interval between the onset of disease and death, morbidity season and pathological change were retrospectively analysed. RESULTS:The incidence of SD in males was significantly higher than that of females. The peak age was ≥35-55 years. The mortality rate was relatively high within 6 h after the onset of disease. The season order with descending number of deaths was spring, summer, winter and autumn. The top ten causes of SD were coronary heart disease, sudden unexplained death （SUD）, cerebral hemorrhage, acute hemorrhagic necrotic pancreatitis, aortic dissection rupture, cardiomyopathy, pneumonia, pulmonary thromboembolism, amniotic fluid embolism and allergy. Exercise, infusion, surgery, medication and minor injury were the most common predisposing factors of sudden coronary death. Consciousness disorder or coma, chest pain or chest tightness, and abdominal pain were the most common premortem symptoms of sudden coronary death. CONCLUSIONS:The SD is more common in middle-aged males, which is the key population for the prevention of SD. For the forensic identification and prevention of SD, the attention on SUD should be paid.
CO-related vasoconstriction superimposed on ischemic medullary brain autonomic nuclei may contribute to sudden death.
Jaster J Howard,Zamecnik Josef,Giannì Aldo Bruno,Ottaviani Giulia
Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology
INTRODUCTION:In 2015, a multinational randomized controlled phase IV clinical trial of adaptive servoventilation for the management of heart failure with central sleep apnea was halted in progress because more patients in the study group were dying than in the control group. One year later, another large clinical trial reported results on the effectiveness of continuous positive airway pressure (CPAP) in preventing sudden death and other cardiovascular events such as heart attack and stroke in patients with preexisting vascular disease as well as obstructive sleep apnea. BACKGROUND:Sudden unexpected death has been associated with many types of small and nonmalignant medullary brain lesions, like demyelination plaques - largely asymptomatic until they caused sudden death. Many such medullary lesions, typically without hemorrhage or mass effect, have in themselves been previously considered relatively harmless - in cases where they have been known to be present. DISCUSSION:Why did not the improved pulmonary ventilation and subsequently improved gas exchange provided during the CPAP and servoventilation clinical trials help to resolve any ischemic lesions that may have been present both in the heart and in the medulla, thereby tending to normalize interactions between the vagal neural structures and the heart? CO is a potent dilator of brain vasculature, thereby increasing blood flow to the brain. When ventilation is increased, even if only to improve it back toward normal from a depressed steady-state level, the alveolar partial pressure of carbon dioxide is decreased, likely resulting in a converse relative vasoconstriction in the brain, thereby reducing blood flow in the brain, especially in watershed areas like the solitary tract nucleus. In normal physiology, this is demonstrated impressively by the ability of hyperventilation to induce loss of consciousness. CONCLUSIONS:The findings of several clinical trials recently reported, taken together with neuropathology case studies reported elsewhere, suggest that additional research is warranted in regard to the mechanisms by which focal medullary autonomic brain ischemia may be related to sudden death in general medical illnesses - and how it may additionally be influenced by changes in arterial CO levels.
Sudden unexpected death with primary adrenal lymphoma.
Hata Yukiko,Ishizawa Shin,Nishida Naoki
Legal medicine (Tokyo, Japan)
An 82-year-old man was found dead on the road near his home with unwitnessed interval of 3 h from final witness. He had been diagnosed with hypertension and mild aortic stenosis (AS) 13 years before death, and was continuously followed up with medication. Although a recent medical check-up related to cardiac function was stable and consistent with moderate AS, he sometimes complained of general fatigue, anorexia associated with intermittent mild fever and rare vomiting in the weeks before death. At autopsy, no lethal injury or drug intoxication was found, but congenital bicuspid aortic valve (BAV) with central rache was found. Although calcification was found in a restricted area of one cusp, valvular structural deformity was clearly milder than in typical severe AS cases. Moderate left ventricular hypertrophy without coronary disease was found. A brownish-red, soft nodular lesion was found in both adrenal glands, but no other tumorous focus was evident in any other organs. Immunohistochemical examination showed that B-lymphocyte-derived markers (CD20, melanoma associated antigen (mutated) 1, and CD79a) were exclusively positive. Therefore, we diagnosed primary adrenal lymphoma (PAL), diffuse large B-cell lymphoma phenotype. We concluded that the cause of sudden unexpected death (SUD) was adrenal insufficiency associated with PAL, with a background of moderate AS related to BAV.
Effect of Cardiorespiratory Fitness on Risk of Sudden Cardiac Death in Overweight/Obese Men Aged 42 to 60 Years.
Jae Sae Young,Franklin Barry A,Kurl Sudhir,Fernhall Bo,Kunutsor Setor K,Kauhanen Jussi,Laukkanen Jari A
The American journal of cardiology
The purpose of this study was to examine the subject and combined associations of cardiorespiratory fitness (fitness) and body mass index (BMI) with the risk of sudden cardiac death (SCD) in middle-aged men. This prospective study was based on a population sample of 2,357 men aged 42 to 60 years, who were followed up in the Kuopio Ischemic Heart Disease cohort study. Fitness was directly measured by peak oxygen uptake (VO) during progressive exercise testing to volitional fatigue. Participants were divided into 4 groups (fit-normal weight, unfit-normal weight, fit-overweight/obese, and unfit-overweight/obese) based on the median values of fitness and BMI. A total of 253 (10.7%) SCDs occurred during an average follow-up of 22 years. After adjusting for potential confounders, the hazard ratio (HR) and 95% confidence interval (CI) for SCD was 1.80 (95% CI 1.21 to 2.68) for BMI ≥30.0 kg/m versus normal weight cohort, that is, BMI corresponding to 18.5 to 24.9 kg/m. However, these associations were no longer statistically significant after adjusting for VO (1.49, 95% CI 0.98 to 2.24). Compared with the lower levels of fitness, upper levels of fitness had a 39% lower risk of SCD (HR 0.61, 95% CI 0.40 to 0.92) after adjusting for potential confounders, including BMI. In the combined associations of fitness and BMI with the risk of SCD, unfit-overweight/obese men had 1.80 times (95% CI 1.06 to 3.06) increased risk of SCD, but fit-overweight/obese men were not at increased risk of SCD (HR 1.22, 95% CI 0.66 to 2.25) as compared with their fit-normal weight counterparts. In conclusion, both overweight/obesity and fitness were independently associated with the risk of SCD; however, fitness appears to attenuate the risk of SCD in overweight/obese men, suggesting that improving fitness may reduce the risk of SCD in this population.
Sudden death: Neurogenic causes, prediction and prevention.
Japundžić-Žigon Nina,Šarenac Olivera,Lozić Maja,Vasić Marko,Tasić Tatjana,Bajić Dragana,Kanjuh Vladimir,Murphy David
European journal of preventive cardiology
Sudden death is a major health problem all over the world. The most common causes of sudden death are cardiac but there are also other causes such as neurological conditions (stroke, epileptic attacks and brain trauma), drugs, catecholamine toxicity, etc. A common feature of all these diverse pathologies underlying sudden death is the imbalance of the autonomic nervous system control of the cardiovascular system. This paper reviews different pathologies underlying sudden death with emphasis on the autonomic nervous system contribution, possibilities of early diagnosis and prognosis of sudden death using various clinical markers including autonomic markers (heart rate variability and baroreflex sensitivity), present possibilities of management and promising prevention by electrical neuromodulation.
[Interaction between heart and brain in sudden cardiac death].
Fatar M,Akin I,Borggrefe M,Platten M,Alonso A
The heart and brain are constantly interacting under normal physiological conditions. This interaction is under the control of the autonomic nervous system with parasympathetic and sympathetic nerve fibers including the participating brain structures. Pathological conditions, such as epilepsy and ischemic cerebral stroke influence heart function, especially the frequency and may result in severe arrhythmia. An asymmetric influence of the left and right brain hemispheres on the heart rate is still under debate. Conversely, the influence of the heart in cases of acute cardiac arrest on brain function is equally relevant and a common clinical problem after resuscitation. We review the damaging cascade of global cerebral hypoxia and the value of different diagnostic procedures as well as the ethical problem of the point in time of termination of consciousness and the instruments for estimating the prognosis.
The electrical heart: 25 years of discovery in cardiac electrophysiology, arrhythmias and sudden death.
Saffitz Jeffrey E,Corradi Domenico
Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology
This review summarizes progress in the fields of cardiac electrophysiology, arrhythmias and sudden death made in the 25-year interval between 1992 and 2016 during which time Cardiovascular Pathology has been published. Organized along clinical lines, it considers the major heart rhythm disorders underlying atrial, atrioventricular and ventricular arrhythmias, and sudden cardiac death. There is a strong focus on the remarkable advances in understanding the genetic basis for cardiac rhythm disturbances and elucidating fundamental mechanisms of abnormal conduction and impulse formation. During this 25-year period, our understanding of how altered tissue structure (classical pathology) contributes to arrhythmias and sudden death has undergone continuous refinement as new insights have been gained about arrhythmia mechanisms and the dynamic interplay between anatomic substrates and triggers of the major heart rhythm disorders.
Sudden death due to spontaneous rupture in splenic artery atypical dissection with features of vasculitis: case report and review of the literature.
Desinan Lorenzo,Scott Cathryn Anne,Piai Iginio,Mazzolo Gionata Maria
Forensic science international
A case of sudden death in a 45-year-old man due to splenic artery dissection and rupture diagnosed at a medico-legal autopsy is described. The examination of the splenic artery revealed macroscopically the features of a ruptured intramural haematoma (no intimal tear, no lumen dilation) and histologically the characteristics of a lymphoplasmacytic vasculitis of the vasa vasorum associated with fibrinoid degeneration. The patient died at home after having been discharged from hospital where he had presented for modest abdominal pain with no evidence of the true nature of the disease found using echography. The Authors discuss the literature relative to splenic artery dissection (13 cases of which only one diagnosed in vivo), the present case being the only one due to vasculitis of the vasa vasorum and the forensic implications (autopsy was ordered to examine the causes of death, to verify whether diagnosis could have been reached during hospitalization with consequences on the outcome and if a hypothesis of malpractice could be prospected).
Is there an association between depression and cardiovascular mortality or sudden death?
Alboni Paolo,Favaron Elisa,Paparella Nelly,Sciammarella Massimo,Pedaci Mario
Journal of cardiovascular medicine (Hagerstown, Md.)
The results of many studies and recent meta-analyses strongly suggest that depression is a risk factor for total and cardiovascular mortality, both in the general population and in patients with known heart disease. By contrast, the association between depression and sudden death or cardiac arrest has received little attention. This issue has been investigated in three recent studies; two were carried out in the general population and showed depression to be a independent risk factor for sudden death. The other study was carried out in patients with acute myocardial infarction (AMI); the adjusted relative risk (RR) of sudden death was significantly increased in depressed patients but, after adjustment for dyspnea/fatigue (a common symptom for heart disease and depression), the RR was no longer statistically significant. However, when the cognitive-affective depressive symptoms were examined separately from the somatic ones (dyspnea/fatigue, etc.), there was a clear trend for an association between cognitive-affective symptoms and sudden death. Because a risk factor can be defined as 'independent' only in a multivariate analysis in which variables are dichotomized, the presence of common symptoms between heart disease and depression represents a very difficult problem. However, taken together, the results of studies carried out in the general population and in patients with AMI strongly suggest that depression is a significant risk factor for sudden death.
Symptoms preceding sudden cardiac death in the young are common but often misinterpreted.
Wisten Aase,Messner Torbjörn
Scandinavian cardiovascular journal : SCJ
OBJECTIVES:To identify patients at risk of sudden cardiac death (SCD) by analysis of clinical history. DESIGN:A retrospective study of the Swedish cohort of 15-35 year olds having suffered an SCD during 1992-1999 and having undergone a forensic autopsy (162 individuals). We sought information in forensic, police and medical records and from interviews with family members. RESULTS:Syncope/presyncope, chest pain, palpitations or dyspnoea were present in 92/162, unspecific symptoms such as fatigue, influenza, headache or nightmares in 35/162. Syncope/presyncope was most common (42/162). In 74 seeking medical attention, 32 had an ECG recorded (24 pathological). In 26 subjects there was a family history of SCD. CONCLUSIONS:The patient seeking medical advice before suffering an SCD is characterized by one to three of the following: 1) cardiac-related symptoms or non-specific symptoms often after an infectious disease, 2) a pathological ECG, 3) a family history of SCD. In 6 out of 10 a cardiac diagnosis was not considered. We conclude that symptoms preceding SCD were common but often misinterpreted.
Unexpected sudden death due to a spontaneous rupture of a gastric dissecting aneurysm: an autopsy case suggesting the importance of the double-rupture phenomenon.
Nishiyama Sayaka,Zhu Bao-Li,Quan Li,Tsuda Kohei,Kamikodai Yasunobu,Maeda Hitoshi
Journal of clinical forensic medicine
Gastric dissecting aneurysm is a very rare lesion with a potential risk of fatal rupture. Differentiating this from a traumatic lesion may be important in forensic casework. We report an autopsy case of sudden death due to a clinically overlooked spontaneous rupture of gastric dissecting aneurysm. A 91-year-old Japanese male visited a hospital with complaints of back pain and general fatigue, and then died at his home about 4 h later. Postmortem examination revealed massive hemoperitoneum and a subserosal hematoma originating from a vascular lesion at the lesser gastric curvature with a serosal tear. The histological findings were compatible with segmental arterial mediolysis (SAM). The pathological findings and clinical course suggested the possible 'double-rupture phenomenon' (delayed fatal rupture). This case suggested the importance of careful investigation such a vascular lesion in medico-legal practice, not only to differentiate from traumatic injury but also to investigate the process of dying.
The insula and cerebrogenic sudden death.
Cheung R T,Hachinski V
Archives of neurology
Sudden death is an "electrical accident" caused by fatal cardiac arrhythmias. While brain-heart control has physiological advantages, cerebrogenic sudden death and nonfatal cardiovascular disturbances can complicate stroke of all types, seizures and epilepsy, head injury, other neurological conditions, neurosurgical procedures, and intense emotional states. Cerebrogenic cardiovascular and autonomic disturbances include electrocardiographic changes, elevation of cardiac enzymes, cardiac arrhythmias, disturbances of blood pressure regulation, and cerebrogenic pulmonary edema. Evidence from experimental studies and clinical observations indicates a crucial role of the insula in cerebrogenic cardiovascular disturbances and sudden death. Future studies should focus on identification of at-risk patients, confirmation of a vulnerable period of cerebrogenic sudden death in those with different neurological conditions and intense emotional states, and clarification of the neurochemical mediators.
Depression and risk of sudden cardiac death after acute myocardial infarction: testing for the confounding effects of fatigue.
Irvine J,Basinski A,Baker B,Jandciu S,Paquette M,Cairns J,Connolly S,Roberts R,Gent M,Dorian P
OBJECTIVES:This study examined the impact of depressive symptoms and social support on 2-year sudden cardiac death (SCD) risk, controlling for fatigue symptoms. METHODS:Myocardial infarction (MI) patients (N = 671) participating in the Canadian Amiodarone Myocardial Infarction Arrhythmia Trial completed measures of depression, hostility, and social support. RESULTS:After controlling for significant biological predictors, psychosocial predictors of increased SCD risk in the survival analysis were greater social network contacts (RR = 1.04; 95% CI = 1.01-1.06; p < .007), lower social participation (RR = 0.98; 95% CI = 0.96-1.00; p < .05), and, in placebo-treated patients, elevated depressive symptoms (RR = 2.45; 95% CI = 1.14-5.35; p < .02). Fatigue was associated with SCD (RR = 1.31; 95% CI = 1.11-1.53; p < .001), and, when included in the model, diminished the influence of depression (RR = 1.73; 95% CI = 0.75-3.98; p = .20). When the cognitive-affective depressive symptoms were examined separately from somatic symptoms, there was a trend for an association between cognitive-affective symptoms and SCD in placebo-treated patients after controlling for fatigue (RR = 1.09; 95% CI = 0.99-1.19, p < .06). CONCLUSIONS:Symptoms of depression and fatigue overlap in patients with MI. The trend for the cognitive-affective symptoms of depression to be associated with SCD risk, even after controlling for dyspnea/fatigue, suggests that the association between depression and mortality after AMI cannot be entirely explained as a confound of cardiac-related fatigue. The independent contribution of social participation suggests a role of both depressive symptomatology and social factors in influencing mortality risk after MI.
[Labor status of anesthesia in general hospitals in Japan Committee on Human Resources, the Japan Society of Anesthesiology].
Yoshimura N,Asayama K,Tsushima M,Yanagawa T,Yoshikawa H,Tashiro C
Masui. The Japanese journal of anesthesiology
AIMS:Investigating the labor by anesthetists in general hospitals with more than 600 beds during the month of September 1995. METHOD:Using MS/EXCEL spread sheet soft wear, we have analyzed daily OR anesthesia activities in 33 hospitals based on personal attendance of anesthesiologists. We defined anesthesia performing hours i.e. actual working hours as the time between the onset and the end of anesthesia for each anesthetist. RESULTS:An average number of monthly anesthesia cases was 961 in the first 10 hospitals we surveyed. We obtained two frequency graphs on weekly 5-day working 138 anesthetists whose anesthesia performed, and their occupied hours were as shown in fig. 1 and 2. for those who worked other less than 5 days per week, they showed the shorter hours on the frequency distribution graph as shown in fig. 3 to 7. The 5-day working anesthetists have spent more than 5 hours giving anesthesia in the 93.2% of all anesthesia times in the first 10 hospitals, while 28.1% of the times in the last 10 hospitals. There were an average of 11.6 operating tables, in the first 10 hospitals. And we have analyzed ratios of the number of 5 day working persons to the number of operating tables. The ratio was 0.86 in the first 10 hospitals, while 0.21 in the last 10 hospitals. CONCLUSIONS:There must be overwork of 5-day working anesthetists, who are working for too many hours for anesthesia. It is necessary to have better quality service in the OR.
[Correlation of occupational stress with serum levels of immunoglobulins and complement in police].
Wu H,Jiang K Y,Zhou W H,Gu G Z,Wu Y Y,Yu S F
Zhonghua lao dong wei sheng zhi ye bing za zhi = Zhonghua laodong weisheng zhiyebing zazhi = Chinese journal of industrial hygiene and occupational diseases
OBJECTIVE:To investigate the correlation of occupational stress with the serum levels of immunoglobulins(IgG, IgM, and IgA) and complement(C3 and C4). METHODS:In May 2011, convenience sampling and cluster sampling were used to select 225 policemen from a local police station as study subjects. A questionnaire was used to investigate demographic features and occupational stress, and the immunoturbidimetric assay was applied to measure the serum levels of IgG, IgM, IgA, and complement C3 and C4. RESULTS:Positive affectivity was positively correlated with the concentration of IgG(r=0.084, P<0.01); positive affectivity, coping strategy, and sleep quality were positively correlated with the concentration of IgM(r= 0.146, 0.155, and 0.203, all P<0.05); negative affectivity was negatively correlated with the concentration of IgM(r=-0.185, P<0.05). Reward and sleep quality were positively correlated with the concentration of C3(r= 0.172 and 0.285, both P<0.05), and negative affectivity was negatively correlated with the concentration of C3 (r=-0.174, P<0.05); sleep quality was positively correlated with the concentration of C4(r= 0.173, P<0.05), and negative affectivity was negatively correlated with the concentration of C4(r=-0.164, P<0.05). The logistic regression analysis revealed that the risks for a reduced concentration of IgG in the groups with high scores of social support and positive affectivity were 0.460 and 0.495 times those in the groups with low scores, while the risk for a reduced concentration of IgM in the group with a high score of coping strategy was 0.482 times that in the group with a low score. CONCLUSION:Occupational stress is correlated with the serum levels of immunoglobulins and complement.
Nurse Work Environment and Stress Biomarkers: Possible Implications for Patient Outcomes.
Arnetz Judith,Sudan Sukhesh,Goetz Courtney,Counts Scott,Arnetz Bengt
Journal of occupational and environmental medicine
OBJECTIVE:To examine associations between nurse work environment, serum biomarkers, and patient outcomes in a large hospital. METHODS:A work environment questionnaire was administered in 2017 to the total sample of nurses in a Midwestern hospital. A subsample of nurses (n = 83) provided blood samples. Correlation analyses examined associations between work environment ratings, biomarkers (dehydroepiandrosterone-sulphate [DHEA-S] and interleukin-6 [IL-6]), and unit-level patient outcomes. RESULTS:Work stress was negatively correlated with DHEA-S (r = -0.23) and positively correlated with IL-6 (r = 0.31; P < 0.05). Psychological safety (r = 0.22) and competence development (r = 0.25) were both positively correlated with DHEA-S (P < 0.05). DHEA-S was negatively correlated with central line-associated bloodstream infections (rho = -0.61; P < 0.05). CONCLUSIONS:Work environment-associated physiological mechanisms might adversely impact patient safety, in addition to nurse health.
Work stress and hair cortisol levels among workers in a Bangladeshi ready-made garment factory - Results from a cross-sectional study.
Steinisch Maria,Yusuf Rita,Li Jian,Stalder Tobias,Bosch Jos A,Rahman Omar,Strümpell Christian,Ashraf Hasan,Fischer Joachim E,Loerbroks Adrian
Evidence on the association of work stress with cortisol levels is inconsistent and mostly stems from Western countries, with limited generalizability to other regions of the world. These inconsistencies may partly be due to methodological limitations associated with the measurement of cortisol secretion in saliva, serum or urine. The present study set out to explore associations of work stress with long-term integrated cortisol levels in hair among 175 workers of an export oriented ready-made garment (RMG) factory in Dhaka, Bangladesh. Work-related demands (WD), interpersonal resources (IR) and work-related values (WV) were assessed using a psychometrically evaluated interview. WD consisted of four items on physical demands, time pressure, worries about mistakes and exposure to abusive language. IR comprised five items addressing support, recognition, adequate payment, workers' trust in the management, and the management's trust in workers, as perceived by the workers. WV captured job security, promotion prospects and job latitude by three items. Hair cortisol concentrations (HCC) were analyzed by liquid chromatography-mass spectrometry. Stepwise multivariable linear regression models (backward elimination of predictors) were used to estimate associations of HCC with the three work stress components. For significant work stress component(s), further multivariable linear regression analyses were conducted to explore whether, and if so, which individual item(s) contributed most. The mean HCC equaled 3.27 (SD 2.58) pg/mg. HCC were found to be significantly associated with WV (beta=0.209, p=0.021). Additional analyses of the three WV items revealed that this association was largely driven the item on "promotion prospects" (beta=0.230, p=0.007) implying that the perception of good promotion prospects was associated with higher HCC. The finding of elevated HCC with good promotion prospects may initially seem counter-intuitive, but is supported by research documenting that job promotion may result in poorer mental well-being. Moreover, being promoted in the Bangladeshi RMG industry may represent a stressful experience: job promotions are rare in this setting and are associated with the need to meet exceptional job-related demands. Further research from ethnic and culturally diverse occupational settings is needed to test this hypothesis, to shed light on the reproducibility of our findings and to improve our understanding of the psychobiological implications of psychosocial working conditions across cultures and contexts.
Stress hormones in health and illness: the roles of work and gender.
Two neuroendocrine systems are of specific interest in the study of stress and health; the sympathetic adrenomedullary system with the secretion of epinephrine and norepinephrine, and the hypothalamic pituitary adrenocortical (HPA) system with the secretion of cortisol. These hormones have often been used as objective indicators of stress in the individual. However, through their bodily effects, they are also a link between the psychosocial environment and various health outcomes. From a series of studies of women and men, it was concluded that gender roles and psychological factors are more important than biological factors for the sex differences in stress responses. The stress responses have been important for human and animal survival and for protection of the body. However, in modern society, some of these bodily responses may cause harm rather than protection. The catecholamines have been linked to cardiovascular disorders such as hypertension, myocardial infarction and stroke, cortisol to cardiovascular disease, Type 2 diabetes, reduced immune function and cognitive impairment. An adequate balance between catabolic (mobilization of energy) and anabolic processes (growth, healing) is considered necessary for long term health and survival. In modern society, which is characterized by a rapid pace of life, high demands, efficiency and competitiveness in a global economy, it is likely that lack of rest, recovery and restitution is a greater health problem than the absolute level of stress.
Overwork Death of Chinese Physicians under High-Intensity Pressure, 2007-2018.
Iranian journal of public health
BACKGROUND:To summarize the cases of physicians overwork death between Jan 2007 and Dec 2018, the tragedy merits the attention of the authorities and policy-makers to increase their efforts to reduce death among physicians in China. METHODS:Data were extracted from medical databases, local mass media, official documents and medical Bulletin Board System (BBS), in which only included articles, reports and news listed in the retrieval strategy, and unpublished data were excluded. RESULTS:Overall, 110 cases (7 females and 103 males) were enrolled in this study. Most incidents have occurred since 2012, especially in 2017. Of these, 86 (78.18%) physicians worked in public tertiary hospitals, four times more than the number of cases taking place in secondary hospitals. Additionally, overwork death was the most common in surgery-related departments that account for up to 65 (59.1%). Notably, these events, taking place in first-tier cities and the southeastern coastal areas of China, included 27 chief physicians, 31 associate of chief physicians, 21 attending physicians, 10 resident physicians and 4 standardized training physicians. CONCLUSION:Overwork death among Chinese physicians is not only a contemporary health problem but also a critical social issue. The laws and regulations should be perfected to prevent the events. Meanwhile, the public should be aware of the need for more understanding and trust in physicians in China.
The impact of the introduction of new recognition criteria for overwork-related cardiovascular and cerebrovascular diseases: a cross-country comparison.
Lin Ro-Ting,Lin Cheng-Kuan,Christiani David C,Kawachi Ichiro,Cheng Yawen,Verguet Stéphane,Jong Simcha
Cardiovascular and cerebrovascular diseases (CVDs) related to overwork are common in Asia, as is death from overwork, known as karoshi. Japan was the first country in the world to introduce criteria for recognizing overwork-related CVDs in 1961. Taiwan followed Japan in putting in place new policies and then updating these in 2010. We aimed to investigate the effect of introducing the new criteria for recognizing overwork-related CVDs in both countries. We defined the baseline period as the 5 years before launch of the new criteria, then collected data to 5 years after the new criteria. We applied a Poisson regression model to analyze the longitudinal change in rates of overwork-related CVDs before and after, adjusting for indicators of working conditions. Implementation of the new criteria was associated with a 2.58-fold increase in the rate of overwork-related CVDs (p-value < 0.05). However, the examined policy framework in Taiwan still appears to miss a substantial number of cases compared to that are captured by a similar policy framework used to capture overwork-related CVD rates in Japan by a factor of 0.42 (p-value < 0.05). Accordingly, we make a case for enhancements of Taiwan's system for reporting and recognizing overwork-related diseases and deaths.
Regulatory mechanism of performance in chronic cognitive fatigue.
Tanaka Masaaki,Ishii Akira,Watanabe Yasuyoshi
Chronic cognitive fatigue is characterized by a sensation of long-lasting fatigue that impairs cognitive functions. Facilitation and inhibition systems in the central nervous system play primary roles in determining the output to the peripheral system, that is, performance. Sensory input from the peripheral system to the central nervous system activates the inhibition system to limit performance, whereas motivational input activates the facilitation system to enhance performance. The dysfunction of the facilitation system and central sensitization and classical conditioning of the inhibition system play important roles in the pathophysiology of chronic cognitive fatigue. Because the dorsolateral prefrontal cortex receives input from both the facilitation and inhibition systems to determine performance, metabolic, functional, and structural impairments of the dorsolateral prefrontal cortex induced by repetitive and prolonged overwork, stress, and stress responses contribute to the impaired functioning and cognitive performance that occur in people with chronic cognitive fatigue. This hypothesis of the regulatory mechanism of performance provides a new perspective on the neural mechanisms underlying chronic cognitive fatigue.
Effect of implementing an overwork-prevention act on working hours and overwork-related disease: A mediation analysis.
Lin Ro-Ting,Liang Ying-Wen,Takahashi Masaya,Eguchi Hisashi,Tsutsumi Akizumi,Lin Sheng-Hsuan
Journal of occupational health
OBJECTIVES:Overwork has been recognized as a risk factor for cerebrovascular and cardiovascular disease (CCVD). To our best knowledge, Japan is the first country in the world to implement an independent act (the 2014 Act) for the prevention of overwork-related disease, which was promoted through application of preventive measures, such as reductions in working hours. We assessed changes in working hours and overwork-related CCVD before and after introduction of the 2014 Act. METHODS:We calculated the overwork-related CCVD incidence rate and average monthly working hours for 10 industry groups in Japan with data from 2012 to 2018. We applied a causal mediation analysis to estimate the total effect of implementing the 2014 Act on the overwork-related CCVD and the effect mediated by working hours. RESULTS:An average of 271 for every 48 million employees developed overwork-related CCVD per year. After introducing the 2014 Act, the incidence rate ratio of overwork-related CCVD was 0.881-fold lower (95% CI 0.780-0.995) compared with before the policy change. The 2014 Act contributed to a decrease of 26% (78 cases per year; 95% CI 29-173) of the overwork-related CCVD incidence per year. Approximately 41% (32 cases per year) of this effect could be explained by reduced working hours. CONCLUSIONS:Our study highlights the impact of the 2014 Act in Japan on the reduction in working hours, which further contributes to the reduction in overwork-related CCVD. Policymakers should consider adopting our innovative approach to assess the mediation effect underlying the implementation of new policies.
Investigating the relationship between job stress, workload and oxidative stress in nurses.
International journal of occupational safety and ergonomics : JOSE
Occupational stress and workload are common risk factors among nurses that increase absenteeism, reduce the quality and quantity of patient care, increase care costs and increase the patient safety risk. The relation between these risk factors and oxidative stress levels has not been clearly defined. This study was conducted with 258 participants (126 nurses as the case group and 132 healthy adults as the control group). Information was collected using a demographic questionnaire, the nurses' occupational stress scale and the NASA task load index workload questionnaire. Blood samples were taken from the participants and then the levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase and total antioxidant capacity (TAC) were measured in the serum samples. Independent tests and one-way analysis of variance were used for statistical analysis. SOD and TAC were significantly higher and MDA was significantly lower among the case group compared to the control group. TAC levels significantly decreased with increased stress. MDA levels showed negative associations with stress and workload. Nurses experience high levels of occupational stress and workload. Biomarkers such as SOD, TAC and MDA are the most important predictors of work stress and overwork in this study.
The association between long working hours and health: a systematic review of epidemiological evidence.
Bannai Akira,Tamakoshi Akiko
Scandinavian journal of work, environment & health
OBJECTIVES:Many studies have investigated the association between long working hours and health. By focusing on differences in the definition of long working hours and the influence of shift work, we attempt to explain why the results of these studies remain inconclusive. METHODS:We defined long working hours as working time greater than around 40 hours per week or 8 hours per day. Since previous studies have indicated that shift work is detrimental to health, we minimized the influence of shift work in the studies. We also placed importance on the existence of reference groups since this made the results clearer. Based on these points, we analyzed previous studies to clarify the epidemiological evidence regarding the association between long working hours and health. We established inclusion criteria and carried out a systematic search for articles published in the Medline and PsycINFO databases between 1995-2012. RESULTS:We identified a total of 17 articles and 19 studies (12 prospective cohort and 7 cross-sectional studies). The outcomes were all-cause mortality, circulatory disease, diabetes mellitus, metabolic syndrome, depressive state, anxiety, other psychological disorders, sleep condition, cognitive function, and health-related behavior. Long working hours had significant adverse effects on most health outcomes. CONCLUSIONS:We concluded that working long hours is associated with depressive state, anxiety, sleep condition, and coronary heart disease. However, further studies that appropriately deal with the definition of long working hours and shift work are needed.
Relationship between Job Stress and Hypo-high-density Lipoproteinemia of Chinese Workers in Shanghai: The Rosai Karoshi Study.
Muratsubaki Tomohiko,Hattori Tomomi,Li Jue,Fukudo Shin,Munakata Masanori
Chinese medical journal
BACKGROUND:Karoshi, or death due to overwork, has now become a serious social problem in China. Worsening of cardiovascular risks by stress might initiate karoshi. Many studies have examined the relationship between job stress and obesity, hypertension, and type 2 diabetes mellitus, but less evidence exists for dyslipidemia like hypo-high-density lipoproteinemia (hypo-HDL). The aim of this study was to investigate the relationship between job stress and hypo-HDL of Chinese workers in Shanghai. METHODS:We studied 2219 Chinese workers in Shanghai, who participated in the Japan-China cooperative study for the prevention of karoshi. A questionnaire was administered to examine the lifestyle characteristics, job category, weekly working hours, and job stress. Job demand and job control were quantified using the National Institute for Occupational Safety and Health questionnaire. Modified job strain measure was defined by the combination of low job control and high demand. Hypo-HDL was defined as plasma high-density lipoprotein cholesterol concentration of <1.04 mmol/L (40 mg/dl). Multivariate logistic regression analysis was performed for hypo-HDL as a dependent variable. RESULTS:Modified job strain was not related to hypo-HDL either in men or women. In men, multivariate adjusted odds ratio (OR) for having hypo-HDL was significantly higher in the lowest job control tertile compared with the highest job control tertile (OR = 1.39, 95% confidence interval [CI] 1.03-1.87, P = 0.034). In the same model, a similar trend was observed for women, but it did not reach a statistically significant level (OR = 1.51, 95% CI, 0.88-2.56, P = 0.132). CONCLUSION:A low level of job control but not modified job strain was significantly related to higher prevalence of hypo-HDL of Chinese workers in Shanghai.
Night duty and decreased brain activity of medical residents: a wearable optical topography study.
Nishida Masaki,Kikuchi Senichiro,Miwakeichi Fumikazu,Suda Shiro
Medical education online
BACKGROUND:Overwork, fatigue, and sleep deprivation due to night duty are likely to be detrimental to the performance of medical residents and can consequently affect patient safety. OBJECTIVE:The aim of this study was to determine the possibility of deterioration of cerebral function of sleep-deprived, fatigued residents using neuroimaging techniques. DESIGN:Six medical residents were instructed to draw blood from artificial vessels installed on the arm of a normal cooperator. Blood was drawn at a similar time of the day, before and after night duty. To assess sleep conditions during night duty, the participants wore actigraphy units throughout the period of night duty. Changes in cerebral hemodynamics, during the course of drawing blood, were measured using a wearable optical topography system. RESULTS:The visual analogue scale scores after night duty correlated negatively with sleep efficiency during the night duty (ρ = -0.812, p = 0.050). The right prefrontal cortex activity was significantly decreased in the second trial after night duty compared with the first (p = 0.028). The extent of [oxy-Hb] decrease, indicating decreased activity, in the right dorsolateral prefrontal cortex correlated negatively with the Epworth sleepiness score after night duty (ρ = -0.841, p = 0.036). CONCLUSIONS:Sleep deprivation and fatigue after night duty, caused a decrease in the activity of the right dorsolateral prefrontal cortex of the residents, even with a relatively easy routine. This result implies that the brain activity of medical residents exposed to stress on night duty, although not substantially sleep-deprived, was impaired after the night duty, even though they apparently performed a simple medical technique appropriately. Reconsideration of the shift assignments of medical residents is strongly advised. ABBREVIATIONS:DLPFC: Dorsolateral prefrontal cortex; ESS: Epworth sleepiness scale; PSQI: Pittsburgh sleep quality index; ROI: Regions of interest; VAS: Visual analogue scale; WOT: Wearable optical topography.
Oxidative stress in exercise training: the involvement of inflammation and peripheral signals.
Magherini Francesca,Fiaschi Tania,Marzocchini Riccardo,Mannelli Michele,Gamberi Tania,Modesti Pietro Amedeo,Modesti Alessandra
Free radical research
The evidence about the health benefits of regular physical activity is well established. Exercise intensity is a significant variable and structured high-intensity interval training (HIIT) has been demonstrated to improve both whole-body and skeletal muscle metabolic health in different populations. Conversely, fatigue accumulation, if not resolved, leads to overwork, chronic fatigue syndrome (CFS), overtraining syndrome up to alterations of endocrine function, immune, systemic inflammation, and organic diseases with health threat. In response to temporary increases in stress during training, some athletes are unable to maintain sufficient caloric intake, thus suffering a negative energy balance that causes further stress. The regulation of the energy balance is controlled by the central nervous system through an elaborate interaction of the signalling that involves different tissues such as leptin, adiponectin and ghrelin whose provide important feedback to the hypothalamus to regulate the energy balance. Although exercise-induced reactive oxygen species are required for normal force production in muscle, high levels of ROS appear to promote contractile dysfunction. However, a high level of oxidative stress in may induce a rise in inflammatory markers and a disregulation in expression of adiponectin, leptin and grelin.
Physician-Training Stress and Accelerated Cellular Aging.
Ridout Kathryn K,Ridout Samuel J,Guille Constance,Mata Douglas A,Akil Huda,Sen Srijan
BACKGROUND:Stress is a key precipitant for many common diseases, but established biological markers to track stress and guide investigations into mechanisms linking stress and disease are lacking. Cross-sectional studies have identified correlations between stress and telomere attrition, but no large, longitudinal studies examining the impacts of chronic stress on telomere length exist. Residency training for physicians is a well-established stressful experience and can be used as a prospective stress model. METHODS:In a longitudinal cohort study of 250 interns (first-year residents) at 55 United States hospital systems serving during the 2015-2016 academic year, we examined associations between measures of the residency experience and saliva-measured telomere attrition. RESULTS:Telomere length shortened significantly over the course of internship year, from mean ± SD of 6465.1 ± 876.8 base pairs before internship to 6321.5 ± 630.6 base pairs at the end of internship (t = 2.69; p = .008). Stressful early family environments and neuroticism were significantly associated with shorter preinternship telomere length. Longer work hours were associated with greater telomere intern telomere loss over the year (p = .002). Of note, the mean telomere attrition during internship year was six times greater than the typical annual attrition rate identified in a recent meta-analysis. CONCLUSIONS:This work implicates telomere attrition as a biologically measurable consequence of physician training, with the magnitude of attrition associated with workload. Identification of an objective, biological sequela of residency stress may help to facilitate the development of effective interventions. Further, the findings implicate telomere attrition as an objective biomarker to follow the pathologic effects of stress, in general.
Long-term performance of instrumental activities of daily living in young and middle-aged stroke survivors-Impact of cognitive dysfunction, emotional problems and fatigue.
Blomgren Charlotte,Samuelsson Hans,Blomstrand Christian,Jern Christina,Jood Katarina,Claesson Lisbeth
BACKGROUND:With an upward trend in the number of people who return home to independent living after stroke, the ability to perform more complex activities is becoming an increasingly important long-term outcome after stroke. Although associations between Instrumental Activities of Daily Living (IADL) and cognitive dysfunction, emotional problems, and fatigue have been reported, less is known about the long-term impact of these stroke consequences on the performance of everyday activities in young and middle-aged stroke survivors. OBJECTIVE:To explore the impact of cognitive dysfunction, emotional problems, and fatigue on long-term performance of instrumental activities of daily living in young and middle-aged stroke survivors. METHOD:Data on stroke survivors, aged 18-69 at index stroke, were collected from the Sahlgrenska Academy Study on Ischaemic Stroke. IADL outcome was assessed using the Frenchay Activities Index (FAI), and the impact of chosen variables was assessed using Spearman´s rank-order correlation and logistic regression. RESULTS:Seven years after index stroke, 296 stroke survivors (median age of 64) were included in this study. Cognitive dysfunction showed the strongest correlations with FAI outcome and independently explained worse outcome on FAI summary score and the domain of work/leisure activities. Fatigue was independently explanatory of worse outcome on FAI summary score and domestic chores, while depressive symptoms independently explained worse outcome on work/leisure activities. In a subgroup with only those participants who had no or minimal residual neurological deficits at follow-up (NIHSS score 0), cognitive dysfunction independently explained worse outcome on FAI summary score and work/leisure activities. Depressive symptoms independently explained worse outcome on FAI summary score and domestic chores. CONCLUSION:Our results show that in young and middle-aged stroke survivors, cognitive dysfunction, depressive symptoms, and fatigue negatively impact performance of IADL even at seven years post stroke onset. Further, we have shown that an impact of both cognitive dysfunction and depressive symptoms can be found also among stroke survivors with mild or no remaining neurological deficits.
Inhibition of apoptosis exacerbates fatigue-damage tendon injuries in an in vivo rat model.
Bell R,Robles-Harris M A,Anderson M,Laudier D,Schaffler M B,Flatow E L,Andarawis-Puri N
European cells & materials
Tendinopathy is a common and progressive musculoskeletal disease. Increased apoptosis is an end-stage tendinopathy manifestation, but its contribution to the pathology of the disease is unknown. A previously established in vivo model of fatigue damage accumulation shows that increased apoptosis is correlated with the severity of induced tendon damage, even in early onset of the disease, supporting its implication in the pathogenesis of the disease. Consequently, this study aimed to determine: (1) whether apoptosis could be inhibited after fatigue damage and (2) whether its inhibition could lead to remodeling of the extracellular matrix (ECM) and pericellular matrix (PCM), to ultimately improve the mechanical properties of fatigue-damaged tendons. The working hypothesis was that, despite the low vascular nature of the tendon, apoptosis would be inhibited, prompting increased production of matrix proteins and restoring tendon mechanical properties. Rats received 2 or 5 d of systemic pan-caspase inhibitor (Q-VD-OPh) or dimethyl sulfoxide (DMSO) carrier control injections starting immediately prior to fatigue loading and were sacrificed at days 7 and 14 post-fatigue-loading. Systemic pan-caspase inhibition for 2 d led to a surprising increase in apoptosis, but inhibition for 5 d increased the population of live cells that could repair the fatigue damage. Further analysis of the 5 d group showed that effective inhibition led to an increased population of cells producing ECM and PCM proteins, although typically in conjunction with oxidative stress markers. Ultimately, inhibition of apoptosis led to further deterioration in mechanical properties of fatigue-damaged tendons.
Effect of Long Working Hours on Self-reported Hypertension among Middle-aged and Older Wage Workers.
Yoo Dong Hyun,Kang Mo-Yeol,Paek Domyung,Min Bokki,Cho Sung-Il
Annals of occupational and environmental medicine
OBJECTIVES:Many studies have reported an association between overwork and hypertension. However, research on the health effects of long working hours has yielded inconclusive results. The objective of this study was to identify an association between overtime work and hypertension in wage workers 45 years and over of age using prospective data. METHODS:Wage workers in Korea aged 45 years and over were selected for inclusion in this study from among 10,254 subjects from the Korean Longitudinal Study of Ageing. Workers with baseline hypertension and those with other major diseases were excluded. In the end, a total of 1,079 subjects were included. A Cox proportional hazards model was used to calculate hazard ratios and adjust for baseline characteristics such as sex, age, education, income, occupation, form of employment, body mass index, alcohol habit, smoking habit, regular exercise, and number of working days per week. Additional models were used to calculate hazard ratios after gender stratification. RESULTS:Among the 1,079 subjects, 85 workers were diagnosed with hypertension during 3974.2 person-months. The average number of working hours per week for all subjects was 47.68. The proportion of overtime workers was 61.0% (cutoff, 40 h per week). Compared with those working 40 h and less per week, the hazard ratio of subjects in the final model, which adjusted for all selected variables, working 41-50 h per week was 2.20 (95% confidence interval [CI], 1.19-4.06), that of subjects working 51-60 h per week was 2.40 (95% CI, 1.07-5.39), and that of subjects working 61 h and over per week was 2.87 (95% CI, 1.33-6.20). In gender stratification models, the hazard ratio of the females tended to be higher than that of the males. CONCLUSION:As the number of working hours per week increased, the hazard ratio for diagnosis of hypertension significantly increased. This result suggests a positive association between overtime work and the risk of hypertension.
Expression of Cx43 and Cx45 in Cardiomyocytes of an Overworked Rat Model.
Fa yi xue za zhi
ABSTRACT:Objective To study the effect of overwork stress response on the expression of connexin 43（Cx43） and connexin 45（Cx45） in cardiomyocytes and on cardiac function. Methods The experimental animals were divided into control group, overworked 1-month group and overworked 2-month group. A overworked rat model was established by forcing swimming of overworked group. The expressions of Cx43 and Cx45 in myocardial tissues of experimental animals were detected by Western blotting, while the corresponding myocardial tissues were stained with hematoxylin-eosin （HE） staining and Masson's staining, then histologically observed. Results Western blotting results showed that, compared with the control group, Cx43 expression in myocardial tissues of overworked rats decreased while Cx45 expression increased. HE staining and Masson's staining results showed that hypertrophy, rupture and interstitial fiber tissue hyperplasia were observed in myocardial fibers of overworked rats. Conclusion Overwork stress response may affect cardiac function as an independent factor and may even cause heart failure or arrhythmias and lead to death.
Nonlinear associations between working hours and overwork-related cerebrovascular and cardiovascular diseases (CCVD).
Lin Ro-Ting,Chien Lung-Chang,Kawachi Ichiro
Long working hours are recognized as a risk factor for cerebrovascular and cardiovascular diseases (CCVD). We investigated the relationship between working hours and different CCVD severity outcomes-death, disability, and illness-across industries in Taiwan from 2006 to 2016. We applied a generalized additive mixed model to estimate the association between working hours and the rate of each severity outcome, adjusted for salary, unemployment rate, time, and a random intercept. Industry-average working hours were significantly associated with each outcome level of overwork-related CCVD, especially when monthly working hours increased from 169 (relative risk [RR] = 1.46, 95% confidence interval [CI] 1.002-2.12) to 187 (RR = 5.73, 95% CI 3.61-9.08). Although RR trends declined after monthly working hours exceeded 187, excess risks remained statistically significant. Each 1-hour increase in working hours had a stronger effect on the RR increase in death and disability than on illness. Variations in CCVD risks existed across industries, with the highest risk in transportation and information. Reducing working hours is essential to preventing overwork-related CCVD, especially the more severe outcomes. We recommend further research to address possible underreporting of less severe cases, and to explore actions to narrow the gaps in risk across industries.
Overwork accelerates thrombotic reaction: implications for the pathogenesis of Karoshi.
Otsui Kazunori,Yamamoto Junichiro,Inoue Nobutaka
Journal of thrombosis and thrombolysis
Work-related stressors are potential causes of cardiovascular diseases (CVDs) and stroke; however, the pathophysiological mechanisms by which occupational stress induces and exacerbates CVDs remain unclear. The global thrombosis test (GTT) is a novel in vitro assay for evaluating both thrombotic reactions and subsequent thrombolysis. The time required to form an occlusive thrombus with the GTT, called as the occlusion time (OT), and the time to lyse the thrombus, the lysis time (LT), are markers of thrombotic and thrombolytic reactions, respectively. We investigated the impact of work-related stress on the thrombotic and thrombolytic reactions in 46 healthy medical residents. Off-duty or on-duty blood samples were collected on the mornings of non-work days or after the night duty on the emergent room respectively. The duration of sleep was significantly shorter during night duty than during off-duty nights [2.25 (1.0, 3.0) h vs. 6.0 (5.0, 7.0) h; p < 0.001]. Baseline OT was 310.3 (260.9, 437.7) s. whereas the on-duty OT was significantly shortened [284.2 (230.5, 355.8) s; p < 0.01]. LT was significantly prolonged during overwork conditions compared with off-duty conditions [1547 (1346, 1908) s vs. 1470 (1219, 1692) s; p < 0.05]. Overwork accelerates the thrombotic reactions. These reactions might explain the pathogenesis of overwork-related CVDs. The GTT is a good tool for evaluating of the level of fatigue.
Mortality associated with sleep duration and insomnia.
Kripke Daniel F,Garfinkel Lawrence,Wingard Deborah L,Klauber Melville R,Marler Matthew R
Archives of general psychiatry
BACKGROUND:Patients often complain about insufficient sleep or chronic insomnia in the belief that they need 8 hours of sleep. Treatment strategies may be guided by what sleep durations predict optimal survival and whether insomnia might signal mortality risks. METHODS:In 1982, the Cancer Prevention Study II of the American Cancer Society asked participants about their sleep duration and frequency of insomnia. Cox proportional hazards survival models were computed to determine whether sleep duration or frequency of insomnia was associated with excess mortality up to 1988, controlling simultaneously for demographics, habits, health factors, and use of various medications. RESULTS:Participants were more than 1.1 million men and women from 30 to 102 years of age. The best survival was found among those who slept 7 hours per night. Participants who reported sleeping 8 hours or more experienced significantly increased mortality hazard, as did those who slept 6 hours or less. The increased risk exceeded 15% for those reporting more than 8.5 hours sleep or less than 3.5 or 4.5 hours. In contrast, reports of "insomnia" were not associated with excess mortality hazard. As previously described, prescription sleeping pill use was associated with significantly increased mortality after control for reported sleep durations and insomnia. CONCLUSIONS:Patients can be reassured that short sleep and insomnia seem associated with little risk distinct from comorbidities. Slight risks associated with 8 or more hours of sleep and sleeping pill use need further study. Causality is unproven.
Patterns of performance degradation and restoration during sleep restriction and subsequent recovery: a sleep dose-response study.
Belenky Gregory,Wesensten Nancy J,Thorne David R,Thomas Maria L,Sing Helen C,Redmond Daniel P,Russo Michael B,Balkin Thomas J
Journal of sleep research
Daytime performance changes were examined during chronic sleep restriction or augmentation and following subsequent recovery sleep. Sixty-six normal volunteers spent either 3 (n = 18), 5 (n= 16), 7 (n = 16), or 9 h (n = 16) daily time in bed (TIB) for 7 days (restriction/augmentation) followed by 3 days with 8 h daily TIB (recovery). In the 3-h group, speed (mean and fastest 10% of responses) on the psychomotor vigilance task (PVT) declined, and PVT lapses (reaction times greater than 500 ms) increased steadily across the 7 days of sleep restriction. In the 7- and 5-h groups speed initially declined, then appeared to stabilize at a reduced level; lapses were increased only in the 5-h group. In the 9-h group, speed and lapses remained at baseline levels. During recovery, PVT speed in the 7- and 5-h groups (and lapses in the 5-h group) remained at the stable, but reduced levels seen during the last days of the experimental phase, with no evidence of recovery. Speed and lapses in the 3-h group recovered rapidly following the first night of recovery sleep; however, recovery was incomplete with speed and lapses stabilizing at a level comparable with the 7- and 5-h groups. Performance in the 9-h group remained at baseline levels during the recovery phase. These results suggest that the brain adapts to chronic sleep restriction. In mild to moderate sleep restriction this adaptation is sufficient to stabilize performance, although at a reduced level. These adaptive changes are hypothesized to restrict brain operational capacity and to persist for several days after normal sleep duration is restored, delaying recovery.
Sympathetic and angiotensinergic responses mediated by paradoxical sleep loss in rats.
Perry Juliana C,Bergamaschi Cássia T,Campos Ruy R,Andersen Monica L,Montano Nicola,Casarini Dulce E,Tufik Sergio
Journal of the renin-angiotensin-aldosterone system : JRAAS
INTRODUCTION:Recent investigations over the past decade have linked the development of hypertension to sleep loss, although the mechanisms underlying this association are still under scrutiny. To determine the relationship between sleep deprivation and cardiovascular dysfunction, we examined the effects of paradoxical sleep deprivation on heart rate, blood pressure, sympathetic nerve activity (SNA) and their consequences in the blood renin-angiotensin system. MATERIALS AND METHODS:Wistar-Hannover male rats were randomly assigned to three experimental groups: 1) control, 2) paradoxical sleep deprivation for 24 h and 3) paradoxical sleep deprivation for 96 h. Blood pressure and heart rate were recorded in awake, freely moving rats. RESULTS:Heart rate was higher in the 96 h paradoxical sleep deprivation group compared with the control group. Renal SNA was increased in all deprived groups. However, no significant statistical differences were observed in blood pressure or splanchnic SNA among groups. Paradoxical sleep deprivation (24 and 96 h) reduced plasma angiotensin II (Ang II) concentrations. CONCLUSIONS:The results suggest that selective sleep deprivation produces an increase in SNA, preferentially in the kidney. Thus, alterations in the sympathetic system in response to sleep loss may be an important pathway through which hypertension develops.
Age-related difference in the sleep pressure-lowering effect between an angiotensin II receptor blocker and a calcium channel blocker in Asian hypertensives: the ACS1 Study.
Kario Kazuomi,Hoshide Satoshi
Hypertension (Dallas, Tex. : 1979)
Sleep blood pressure (BP), which is partly determined by salt sensitivity and intake, is an important cardiovascular risk in hypertensives. However, there have been no studies on age-related differences in the sleep BP-lowering effect between angiotensin II receptor blockers and calcium channel blockers in Asians. Azilsartan Circadian and Sleep Pressure-the 1st Study was a multicenter, randomized, open-label, 2-parallel-group study conducted to compare the efficacy of 8-week oral treatment with an angiotensin II receptor blocker (azilsartan 20 mg) or a calcium channel blocker (amlodipine 5 mg) on sleep BP as evaluated by ambulatory BP monitoring. Among the overall population, amlodipine treatment achieved significantly greater reduction in sleep BP, awake BP, and 24-hour BP than azilsartan treatment. BP reduction by amlodipine was particularly pronounced in elderly hypertensive patients aged ≥60 years old. Among patients ≥60 years old, the amlodipine group had numerically, but not significantly, higher control rate of sleep BP compared with the azilsartan group. Similar results were found for awake BP and 24-hour BP. These results suggest a greater BP reduction/control by amlodipine compared with azilsartan and that reduction/control of BP by amlodipine was also more effective in the elderly population. As recommended in the American Society of Hypertension/The international Society of Hypertension and the National Institute for Health and Clinical Excellence guidelines for differentiating treatment according to age, amlodipine should be one of the options for starting treatment in the elderly population. CLINICAL TRIAL URL: http://clinicaltrials.gov/show/NCT01762501 CLINICAL TRIAL ID: NCT01762501.
Effects of mental resilience on neuroendocrine hormones level changes induced by sleep deprivation in servicemen.
Sun Xinyang,Dai Xuyan,Yang Tingshu,Song Hongtao,Yang Jialin,Bai Jing,Zhang Liyi
The aim of this study was to investigate the effects of mental resilience on the changes of serum rennin, angiotensin, and cortisol level induced by sleep deprivation in servicemen. By random cluster sampling, a total of 160 servicemen, aged from 18 to 30, were selected to undergo 24-hour total sleep deprivation and administered the military personnel mental resilience scale after the deprivation procedure. The sleep deprivation procedure started at 8 a.m. on Day 8 and ended at 8 a.m. on Day 9 after 7 days of normal sleep for baseline preparation. Blood samples were drawn from the 160 participants at 8 a.m. respectively on Day 8 and Day 9 for hormonal measurements. All blood samples were analyzed using radioimmunoassay. As hypothesized, serum rennin, angiotensin II, and cortisol level of the participants after sleep deprivation were significantly higher than those before (P < 0.05). The changes of serum rennin and cortisol in the lower mental resilience subgroup were significantly greater (P < 0.05); problem-solving skill and willpower were the leading influence factors for the increases of serum rennin and cortisol respectively induced by sleep deprivation. We conclude that mental resilience plays a significant role in alleviating the changes of neurohormones level induced by sleep deprivation in servicemen.
Neural mechanism of angiotensin-converting enzyme inhibitors in improving heart rate variability and sleep disturbance after myocardial infarction.
Lin Wei-Lun,Chen Yu-Ruey,Lai Chun-Ting,Yamada Shinya,Liu Shin-Huei,Chou Yu-Hui,Fu Yun-Ching,Yang Cheryl C H,Kuo Terry B J,Lo Li-Wei,Chen Shih-Ann
BACKGROUND:Sympathetic hyperactivity and poor sleep quality are reported in myocardial infarction (MI) patients and angiotensin-converting enzyme inhibitors (ACEI) can improve long-term survival in these patients. We aimed to evaluate ACEI effects on cardiac autonomic activity (CAA) and disordered sleep patterns in ambulatory rats after MI. METHODS:Polysomnographic recording was performed in sham (n = 8) and MI (n = 9) male rats during normal daytime sleep before and after captopril treatment. Spectral analyses of the electroencephalogram and electromyogram were evaluated to define active waking (AW), quiet sleep (QS), and paradoxical sleep (PS). Central sleep apnea (CSA) events were measured by analyzing the electromyogram of the diaphragm. CAA was measured by power spectrum analyses of heart rate variability (HRV). RESULTS:In the MI group, there was a higher low frequency/high frequency ratio during sleep, which reduced significantly after captopril treatment, especially at the QS stage compared to that before captopril treatment. The frequency of sleep interruption was higher in the MI group than the sham group. Increased AW and PS, and decreased QS times were noted in the MI group compared to the sham group. These changes were restored to baseline after captopril treatment in the MI group. CSA events were significantly increased in the MI group, and were restored to the normal level after captopril treatment. CONCLUSIONS:Our results demonstrate significant sleep fragmentation with sympathetic hyperactivity after MI, and that captopril restores the autonomic dysfunction and sleep disorder. These findings suggest that ACEI improved sleep-related respiration disorder after MI by restoring autonomic homeostasis, and provide a hypothesis generating for future studies in humans.
Angiotensin II-mediated nondipping during sleep in healthy humans: effects on baroreflex function at subsequent daytime.
Sayk Friedhelm,Twesten Christoph,Adametz Isabel,Franzen Klaas,Vonthein Reinhard,Dodt Christoph,Meusel Moritz
American journal of physiology. Regulatory, integrative and comparative physiology
Blood pressure dipping at night is mediated by sleep-inherent, active downregulation of sympathetic vascular tone. Concomitantly, activity of the renin-angiotensin system is reduced, which might contribute to the beneficial effect of baroreflex downward resetting on daytime blood pressure homeostasis. To evaluate whether experimental nondipping mediated by angiotensin II during sleep would alter blood pressure and baroreflex function the next day in healthy humans, angiotensin-II or placebo (saline) was infused for a 7-h period at night, preventing blood pressure dipping in 11 sleeping normotensive individuals (5 males, balanced, crossover design). Baroreflex function was assessed about 1 h upon awakening and stop of infusion via microneurographic recordings of muscle sympathetic nerve activity (MSNA), showing that resting MSNA was significantly increased following angiotensin II nondipping compared with placebo ( = 0.029), whereas blood pressure and heart rate remained unchanged. Baroreflex sensitivity in response to vasoactive drug challenge was preserved, and neuroendocrine markers of fluid balance and electrolytes did not differ between conditions. Ambulatory blood pressure during subsequent daytime was not altered. Data were compared with analog experiments previously performed within the same subjects during awake daytime (ANCOVA). We conclude that angiotensin-II mediated nocturnal nondipping did not induce blood pressure elevation at subsequent daytime in healthy humans but was linked to increased vasoconstrictive sympathetic activity. This is in contrast to a prolonged increase in blood pressure in corresponding daytime experiments of the same individuals. Evidently, sleep strongly preserves normotensive blood pressure homeostasis in healthy humans.
Receptors for vasoactive intestinal peptide (VIP) on human mononuclear leucocytes are upregulated during prolonged strain and energy deficiency.
Wiik P,Opstad P K,Knardahl S,Bøyum A
VIP receptors on blood mononuclear leucocytes and plasma VIP concentrations were studied during a ranger training course lasting for five days with almost continuous physical activity, and energy deficiency. The maximum binding capacity (Bmax) for the high affinity receptor increased (p less than 0.0005) from 0.71 (SEM = 0.11, N = 10) fmol/million cells to a maximum of 7.33 (SEM = 1.0) fmol/million cells on Day 4. There was no significant change in the dissociation constant (Kd) for the high affinity receptor, and no effect on Kd nor Bmax for the low affinity VIP receptor was detected. Plasma VIP concentration increased (p less than 0.0005) from 8.8 pmol/l (SEM = 0.6) to a maximum of 23.4 (SEM = 1.9) on the second day of the course. However, the highest plasma concentrations were about one order of magnitude lower than the dissociation constant (Kd) for the high affinity VIP receptor on the mononuclear leucocytes. These data indicate that heterologous upregulation of the high affinity VIP receptor on mononuclear blood cells takes place during combined strenuous physical exercise, and calorie deficiency.
Vasoactive intestinal polypeptide (VIP) and cerebrospinal fluid (CSF) of sleep-deprived cats restores REM sleep in insomniac recipients.
Prospéro-Garcia O,Morales M,Arankowsky-Sandoval G,Drucker-Colin R
In the past few years a steadily increasing number of substances have been suggested to qualify as sleep-inducing factors. Most 'sleep factors' appear to exert their effects on slow-wave sleep. Recently, however, it has been shown that the cerebrospinal fluid (CSF) of sleep-deprived cats may contain a rapid eye movement (REM) sleep factor, and that vasoactive intestinal peptide (VIP) may be a specific REM sleep inducer. The purpose of this study is to determine whether the CSF of sleep-deprived cats and VIP can reverse insomnia produced by parachlorophenylalanine (PCPA). Donor cats were sleep-deprived for 24 h and their CSF extracted. Some donor cats were additionally pre-treated with chloramphenicol, and some extracted CSF was heated. Recipient cats were injected with 400 mg/kg i.p. of PCPA on two consecutive days. Twenty-four h after the second injection, the recipient cats were intraventricularly injected with a 100-microliters of the various CSF types or 200 ng of VIP. The results showed that only CSF from sleep-deprived cats and VIP were capable of restoring REM sleep in the otherwise PCPA insomniac cats. Since the return of REM sleep was through an increase in its frequency, it is suggested that the CSF of sleep-deprived cats contains a VIP-like sleep factor possibly involved in triggering REM sleep.
Brain distribution of vasoactive intestinal peptide receptors following REM sleep deprivation.
Jiménez-Anguiano A,García-García F,Mendoza-Ramírez J L,Durán- Vázquez A,Drucker-Colín R
Vasoactive intestinal peptide (VIP) has been shown to increase rapid eye movement (REM) sleep in normal and insomniac animals, while the administration of anti-VIP antibodies or an antagonist of VIP receptors decreases REM sleep. In addition, recently, it has been suggested that a VIP-like substance accumulates in the CSF during waking and that it may be involved in the production of the REM rebound normally seen following REM sleep deprivation. This evidence suggests that VIP may be important in modulating REM sleep in normal conditions and during REM sleep rebound. To determine whether VIP is involved in REM sleep homeostasis, VIP receptors of discrete brain areas was determined by autoradiography after 24 and 72 h of REM sleep deprivation (REM SD) by the water tank technique. Since this procedure has been suggested to produce some stress, an additional group adapted for 7 days to the sleep deprivation situation was tested. The results showed that REM SD produces an increase in the density of VIP receptors in several brainstem and forebrain structures at 24 h of REM SD and more so at 72 h of REM SD. Interestingly, results showed that habituation to the REM SD procedure decreases the density of VIP receptors in some areas of the brain of the REM sleep-deprived rats. The results are discussed in terms of the possibility that waking induces an increase of VIP receptors in several structures, which in turn are responsible for modulating REM sleep, but that stress contributes in part to VIP receptor changes.
Decreased REM sleep and altered circadian sleep regulation in mice lacking vasoactive intestinal polypeptide.
Hu Wang-Ping,Li Jia-Da,Colwell Christopher S,Zhou Qun-Yong
OBJECTIVES:Vasoactive intestinal polypeptide (VIP) has been implicated in sleep regulation as a promoter of rapid eye movement (REM) sleep. Previous work has shown that the amount of time spent in REM sleep is increased by intracerebroventricular administration of VIP, and reduced by treatment with VIP antagonists or antibodies against VIP. A variety of evidence suggests that VIP is critical for normal expression of circadian rhythmicity of diverse physiological and behavioral parameters. In the present study, we investigated the role of this peptide in sleep regulation using VIP-deficient (VIP-/-) mice. METHODS:EEG/EMG sleep-wake patterns were recorded in VIP-/- mice and their wild-type littermate controls under normal light-dark (LD), constant darkness (DD) and sleep deprivation conditions. RESULTS:VIP-/- mice exhibited reduced REM sleep time over the 24-h cycle while total daily amounts of NREM sleep and wakefulness were not altered significantly. The reduced REM sleep time in VIP-/- mice occurred entirely during the day due to a reduction in the duration, but not the frequency, of REM sleep bouts. In response to sleep deprivation, compensatory rebounds in NREM sleep and REM sleep were also attenuated in VIP-/- mice. Finally, the loss of VIP altered the temporal distribution of sleep in that the VIP -/- mice exhibited smaller amplitude rhythms in total sleep, NREM sleep, and REM sleep under both LD and DD. CONCLUSIONS:These results indicate that VIP regulates the duration of REM sleep, sleep homeostatic mechanisms as well as the temporal patterning of sleep.
Sleep debt: the impact of weekday sleep deprivation on cardiovascular health in older women.
Cabeza de Baca Tomás,Chayama Koharu Loulou,Redline Susan,Slopen Natalie,Matsushita Fumika,Prather Aric A,Williams David R,Buring Julie E,Zaslavsky Alan M,Albert Michelle A
STUDY OBJECTIVES:Short sleep duration is associated with increased cardiovascular disease (CVD) risk. However, it is uncertain whether sleep debt, a measure of sleep deficiency during the week compared to the weekend, confers increased cardiovascular risk. Because sleep disturbances increase with age particularly in women, we examined the relationship between sleep debt and ideal cardiovascular health (ICH) in older women. METHODS:Sleep debt is defined as the difference between self-reported total weekday and weekend sleep hours of at least 2 hours among women without apparent CVD and cancer participating in the Women's Health Stress Study follow-up cohort of female health professionals (N = 22 082). The ICH consisted of seven health factors and behaviors as defined by the American Heart Association Strategic 2020 goals including body mass index, smoking, physical activity, diet, blood pressure, total cholesterol, and glucose. RESULTS:Mean age was 72.1 ± 6.0 years. Compared to women with no sleep debt, women with sleep debt were more likely to be obese and have hypertension (pall < .05). Linear regression models adjusted for age and race/ethnicity revealed that sleep debt was significantly associated with poorer ICH (B = -0.13 [95% CI = -0.18 to -0.08]). The relationship was attenuated but remained significant after adjustment for education, income, depression/anxiety, cumulative stress, and snoring. CONCLUSION:Sleep debt was associated with poorer ICH, despite taking into account socioeconomic status and psychosocial factors. These results suggest that weekly sleep duration variation, possibly leading to circadian misalignment, may be associated with cardiovascular risk in older women.
A laboratory approach for characterizing chronic fatigue: what does metabolomics tell us?
Erasmus Elardus,Mason Shayne,van Reenen Mari,Steffens Francois E,Vorster B Chris,Reinecke Carolus J
Metabolomics : Official journal of the Metabolomic Society
INTRODUCTION:Manifestations of fatigue range from chronic fatigue up to a severe syndrome and myalgic encephalomyelitis. Fatigue grossly affects the functional status and quality of life of affected individuals, prompting the World Health Organization to recognize it as a chronic non-communicable condition. OBJECTIVES:Here, we explore the potential of urinary metabolite information to complement clinical criteria of fatigue, providing an avenue towards an objective measure of fatigue in patients presenting with the full spectrum of fatigue levels. METHODS:The experimental group consisted of 578 chronic fatigue female patients. The measurement design was composed of (1) existing clinical fatigue scales, (2) a hepatic detoxification challenge test, and (3) untargeted proton nuclear magnetic resonance (H-NMR) procedure to generate metabolomics data. Data analysed via an in-house Matlab script that combines functions from a Statistics and a PLS Toolbox. RESULTS:Multivariate analysis of the original 459 profiled H-NMR bins for the low (control) and high (patient) fatigue groups indicated complete separation following the detoxification experimental challenge. Important bins identified from the H-NMR spectra provided quantitative metabolite information on the detoxification challenge for the fatigue groups. CONCLUSIONS:Untargeted H-NMR metabolomics proved its applicability as a global profiling tool to reveal the impact of toxicological interventions in chronic fatigue patients. No clear potential biomarker emerged from this study, but the quantitative profile of the phase II biotransformation products provide a practical visible effect directing to up-regulation of crucial phase II enzyme systems in the high fatigue group in response to a high xenobiotic-load.
REM sleep vs exploratory wakefulness: Alternatives within adult 'sleep debt'?
Sleep medicine reviews
Our declining sleep duration over early human infant development is largely through REM sleep (REM), loss, not of nonREM. It coincides with the infant's increasing locomotion providing for multisensory inputs ('exploratory wakefulness' - EW), together facilitating neural restructuring and behavioural adaptations ('neuroplasticity'). EW also involves curiosity, novelty, navigation, spatial memory, associated emotions, and feeding; all having brain processes particularly active in REM. It is proposed that: 1) REM is a proxy for EW in facilitating neuroplasticity; 2) necessitating REM having a locomotor output, actively inhibited (the atonia); 3) human adults retain many (neotenous) infant characteristics including large amounts of REM towards the end of usual sleep, where REM's qualitative changes indicate reduced sleep pressure, 4) as in infancy, some of our adult REM remains replaceable by EW (without REM rebounds), mostly in this final REM episode whenever EW need prevails. Accordingly, our adult sleep duration is adaptable to habitual shortening via this REM episode substituted by purposeful EW, which could provide extra (day) light exposure for circadian synchrony. Such processes may underlie seasonally shorter (6 h) sleep, eg in hunter-gather people. This flexibility of REM questions the extent of our western 'chronic sleep debt'. Evidence is provided to counter claims that this absent REM would cause obesity and related disorders. 200w.
Postulated vasoactive neuropeptide autoimmunity in fatigue-related conditions: a brief review and hypothesis.
Staines Donald R
Clinical & developmental immunology
Disorders such as chronic fatigue syndrome (CFS) and gulf war syndrome (GWS) are characterised by prolonged fatigue and a range of debilitating symptoms of pain, intellectual and emotional impairment, chemical sensitivities and immunological dysfunction. Sudden infant death syndrome (SIDS) surprisingly may have certain features in common with these conditions. Post-infection sequelae may be possible contributing factors although ongoing infection is unproven. Immunological aberration may prove to be associated with certain vasoactive neuropeptides (VN) in the context of molecular mimicry, inappropriate immunological memory and autoimmunity. Adenylate cyclase-activating VNs including pituitary adenylate cyclase-activating polypeptide (PACAP), vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) act as hormones, neurotransmitters, neuroregulators, immune modulators and neurotrophic substances. They and their receptors are potentially immunogenic. VNs are widely distributed in the body particularly in the central and peripheral nervous systems and have been identified in the gut, adrenal gland, blood cells, reproductive system, lung, heart and other tissues. They have a vital role in maintaining cardio-respiratory function, thermoregulation, memory, concentration and executive functions such as emotional responses including social cues and appropriate behaviour. They are co-transmitters for a number of neurotransmitters including acetylcholine and gaseous transmitters, are potent immune regulators with primarily anti-inflammatory activity, and have a significant role in protection of the nervous system against toxic assault as well as being important in the maintenance of homeostasis. This paper describes a biologically plausible mechanism for the development of certain fatigue-related syndromes based on loss of immunological tolerance to these VNs or their receptors following infection, other events or de novo resulting in significant pathophysiology possibly mediated via CpG fragments and heat shock (stress) proteins. These conditions extend the public health context of autoimmunity and VN dysregulation and have implications for military medicine where radiological, biological and chemical agents may have a role in pathogenesis. Possible treatment and prevention options are considered.
Do cytosine guanine dinucleotide (CpG) fragments induce vasoactive neuropeptide mediated fatigue-related autoimmune disorders?
Staines Donald R
Autoimmune dysfunction of certain vasoactive neuropeptides (e.g., vasoactive intestinal peptide, pituitary adenylate cyclase activating polypeptide) may be implicated in a range of disorders associated with fatigue-like states (chronic fatigue syndrome, Gulf War syndrome) and even sudden infant death syndrome (SIDS). The important roles of these vasoactive neuropeptides make them a vulnerable target for autoimmune dysfunction. They are known to be associated with heat shock proteins for intracellular functioning with which they may form immunostimulating complexes. Cytosine guanine dinucleotide (CpG) fragments are potently immunogenic DNA fragments which serve as friend or foe recognition systems between bacterial (hypomethylated) and mammalian (methylated) DNA and are being assessed for suitability for use in human vaccines as adjuvants. Interactions between CpG fragments, heat shock proteins and vasoactive neuropeptides may be associated with fatigue-related autoimmune conditions.
Do vasoactive neuropeptides and heat shock proteins mediate fatigue-related autoimmune disorders?
Staines Donald R
Autoimmune dysfunction of certain vasoactive neuropeptides may be implicated in a range of disorders associated with fatigue like states (chronic fatigue syndrome, Gulf War syndrome) and even sudden infant death syndrome. These substances have neurotrophic, neuroregulatory, and neurotransmission functions, as well as that of immune modulators and hormones. They exert significant control over carbohydrate and lipid metabolism. The hypothesis is that because these substances have vital and indispensable roles in cellular processes, loss or compromise of these roles would lead to predictable and severe cellular and systemic effects. The important roles of certain VNs make them a vulnerable target for autoimmune dysfunction. They are known to be associated with heat shock proteins for intracellular functioning with which they may form immunostimulating complexes. While peptide-HSP complexes are a relatively new area for research, this paper asserts that attention could be focused on these substances and complexes in an effort to elucidate a number of perplexing fatigue-associated disorders.
Infant stress and sleep deprivation as an aetiological basis for the sudden infant death syndrome.
Simpson J M
Early human development
SIDS is almost invariably sleep-related. Viable syndrome aetiology must be compatible with its many epidemiologically diverse risk factors, each of which directly or indirectly associates with the creation of psychological and/or physiological infant stress, and the subsequent disruption of normal, contented sleep. During essential deep 'rebound' recovery sleep, arousal ability and upper airway muscle tone decrease further to that in normal sleep, with subsequent upper airway obstruction. When stress impact causes sufficient sleep disruption and physiological fatigue, a failure to arouse and so restore sufficient tone to overcome such obstruction results in sudden, unexpected death. SIDS has therefore many causes which share a final lethal mechanical pathway. Evidence is presented for obstructive apnoea during sleep as being the primary syndrome death mode, for sleep disruption, reduced arousal ability, and infant stress in SIDS, and for risk factor association with the creation of this stress. Specific infant vulnerability in the first 6 months of life to stress predominantly related to total dependency on a carer for gratification of need, and to obstructive sleep apnoea due to normal anatomical, physical, and respiratory immaturity, including rapid physiological fatigue, and peaks in sleep and thermal stress vulnerability, are discussed. Further reasons for the limited age period of SIDS, and for reduced neonatal risk, are given. Prone sleeping risk can relate to positional airway obstruction during normal sleep without prior infant stress. Much of SIDS aetiology appears to concern factors related to socio-economic deprivation and subsequent sub-optimal infant care.
Persistent fatigue induced by interferon-alpha: a novel, inflammation-based, proxy model of chronic fatigue syndrome.
Russell Alice,Hepgul Nilay,Nikkheslat Naghmeh,Borsini Alessandra,Zajkowska Zuzanna,Moll Natalie,Forton Daniel,Agarwal Kosh,Chalder Trudie,Mondelli Valeria,Hotopf Matthew,Cleare Anthony,Murphy Gabrielle,Foster Graham,Wong Terry,Schütze Gregor A,Schwarz Markus J,Harrison Neil,Zunszain Patricia A,Pariante Carmine M
The role of immune or infective triggers in the pathogenesis of Chronic Fatigue Syndrome (CFS) is not yet fully understood. Barriers to obtaining immune measures at baseline (i.e., before the trigger) in CFS and post-infective fatigue model cohorts have prevented the study of pre-existing immune dysfunction and subsequent immune changes in response to the trigger. This study presents interferon-alpha (IFN-α)-induced persistent fatigue as a model of CFS. IFN-α, which is used in the treatment of chronic Hepatitis C Virus (HCV) infection, induces a persistent fatigue in some individuals, which does not abate post-treatment, that is, once there is no longer immune activation. This model allows for the assessment of patients before and during exposure to the immune trigger, and afterwards when the original trigger is no longer present. Fifty-five patients undergoing IFN-α treatment for chronic HCV were assessed at baseline, during the 6-12 months of IFN-α treatment, and at six-months post-treatment. Measures of fatigue, cytokines and kynurenine pathway metabolites were obtained. Fifty-four CFS patients and 57 healthy volunteers completed the same measures at a one-off assessment, which were compared with post-treatment follow-up measures from the HCV patients. Eighteen patients undergoing IFN-α treatment (33%) were subsequently defined as having 'persistent fatigue' (the proposed model for CFS), if their levels of fatigue were higher six-months post-treatment than at baseline; the other 67% were considered 'resolved fatigue'. Patients who went on to develop persistent fatigue experienced a greater increase in fatigue symptoms over the first four weeks of IFN-α, compared with patients who did not (Δ Treatment Week (TW)-0 vs. TW4; PF: 7.1 ± 1.5 vs. RF: 4.0 ± 0.8, p = 0.046). Moreover, there was a trend towards increased baseline interleukin (IL)-6, and significantly higher baseline IL-10 levels, as well as higher levels of these cytokines in response to IFN-α treatment, alongside concurrent increases in fatigue. Levels increased to more than double those of the other patients by Treatment Week (TW)4 (p = 0.011 for IL-6 and p = 0.001 for IL-10). There was no evidence of an association between persistent fatigue and peripheral inflammation six-months post-treatment, nor did we observe peripheral inflammation in the CFS cohort. While there were changes in kynurenine metabolites in response to IFN-α, there was no association with persistent fatigue. CFS patients had lower levels of the ratio of kynurenine to tryptophan and 3-hydroxykynurenine than controls. Future studies are needed to elucidate the mechanisms behind the initial exaggerated response of the immune system in those who go on to experience persistent fatigue even if the immune trigger is no longer present, and the change from acute to chronic fatigue in the absence of continued peripheral immune activation.
Altered neuroendocrine control and association to clinical symptoms in adolescent chronic fatigue syndrome: a cross-sectional study.
Wyller Vegard Bruun,Vitelli Valieria,Sulheim Dag,Fagermoen Even,Winger Anette,Godang Kristin,Bollerslev Jens
Journal of translational medicine
BACKGROUND:Chronic fatigue syndrome (CFS) is a common and disabling disorder, and a major threat against adolescent health. The pathophysiology is unknown, but alteration of neuroendocrine control systems might be a central element, resulting in attenuation of the hypothalamus-pituitary-adrenalin (HPA) axis and enhancement of the sympathetic/adrenal medulla (SAM) system. This study explored differences in neuroendocrine control mechanisms between adolescent CFS patients and healthy controls, and whether characteristics of the control mechanisms are associated with important clinical variables within the CFS group. METHODS:CFS patients 12-18 years of age were recruited nation-wide to a single referral center as part of the NorCAPITAL project. A broad case definition of CFS was applied. A comparable group of healthy controls were recruited from local schools. A total of nine hormones were assayed and subjected to network analyses using the ARACNE algorithm. Symptoms were charted by a questionnaire, and daily physical activity was recorded by an accelerometer. RESULTS:A total of 120 CFS patients and 68 healthy controls were included. CFS patients had significantly higher levels of plasma norepinephrine, plasma epinephrine and plasma FT4, and significantly lower levels of urine cortisol/creatinine ratio. Subgrouping according to other case definitions as well as adjusting for confounding factors did not alter the results. Multivariate linear regression models as well as network analyses revealed different interrelations between hormones of the HPA axis, the SAM system, and the thyroid system in CFS patients and healthy controls. Also, single hormone degree centrality was associated with clinical markers within the CFS group. CONCLUSION:This study reveals different interrelation between hormones of the HPA axis, the SAM system, and the thyroid system in CFS patients and healthy controls, and an association between hormone control characteristics and important clinical variables in the CFS group. These results add to the growing insight of CFS disease mechanisms. Trial registration Clinical Trials NCT01040429.
Chronically restricted sleep leads to depression-like changes in neurotransmitter receptor sensitivity and neuroendocrine stress reactivity in rats.
Novati Arianna,Roman Viktor,Cetin Timur,Hagewoud Roelina,den Boer Johan A,Luiten Paul G M,Meerlo Peter
STUDY OBJECTIVES:Frequently disrupted and restricted sleep is a common problem for many people in our Western society. In the long run, insufficient sleep may have repercussions for health and may sensitize individuals to psychiatric diseases. In this context, we applied an animal model of chronic sleep restriction to study effects of sleep loss on neurobiological and neuroendocrine systems that have been implied in the pathophysiology of depression, particularly the serotonergic system and the hypothalamic-pituitary-adrenal (HPA) axis. DESIGN:Adult rats were exposed to a schedule of chronic partial sleep deprivation allowing them only 4 h of sleep per day. Sleep restriction was achieved by placing the animals in slowly rotating drums. To examine the regulation and reactivity of the HPA axis, blood samples were collected to measure adrenocorticotropin (ACTH) and corticosterone (CORT) responses. MEASUREMENTS AND RESULTS:While one day of restricted sleep had no significant effect on HPA axis stress reactivity, sleep restriction for a week caused a blunted pituitary ACTH response in a conditioned fear paradigm. Despite this lower ACTH response, adrenal CORT release was normal. The blunted pituitary response may be related to reduced sensitivity of serotonin-1A receptors and/or receptors for corticotropin-releasing hormone (CRH), since sleep restricted rats showed similar reductions in ACTH release to direct pharmacological stimulation with a serotonin-1A agonist or CRH. CONCLUSIONS:Chronic sleep restriction may lead to changes in neurotransmitter receptor systems and neuroendocrine reactivity in a manner similar to that seen in depression. This experimental study thus supports the hypothesis that disrupted and restricted sleep may contribute to the symptomatology of psychiatric disorders.
Too little sleep gradually desensitizes the serotonin 1A receptor system.
Roman Viktor,Walstra Irene,Luiten Paul G M,Meerlo Peter
STUDY OBJECTIVES:In our 24-hour society, frequently disrupted and restricted sleep is a rapidly increasing problem that may contribute to the development of diseases such as depression. One of the proposed neurobiological mechanisms underlying depression is a disturbance in the brain's serotonergic neurotransmission, particularly a desensitization of the serotonin (5-HT)1A receptor system. However, a relationship between chronic sleep loss and changes in (5-HT)1A receptors has not been established yet. Therefore, in the present study, we experimentally tested the hypothesis that chronic sleep restriction leads to desensitization of the (5-HT)1A receptor system. DESIGN:Rats were subjected to a schedule of restricted sleep allowing them 4 hours of sleep per day. Sleep restriction was achieved by placing the animals in slowly rotating wheels. The sensitivity of the (5-HT)1A receptor system was examined by measuring the hypothermic response to a standard injection of a 1A agonist. RESULTS:After 2 days of restricted sleep, the sensitivity of the (5-HT)1A receptor system was not yet affected; however, after 8 days of sleep restriction, it was desensitized. Control experiments indicated that the effect of sleep restriction was not due to forced activity or stress. Importantly, the desensitization of the (5-HT)1A system persisted for many days even with unlimited recovery sleep. Normalization occurred gradually but required at least 7 days. CONCLUSIONS:Chronic sleep restriction causes a gradual and persistent desensitization of the (5-HT)1A receptor system. This finding provides a link between chronic sleep loss and sensitivity for disorders that are associated with altered serotonergic neurotransmission.
A comparison of the recognition of overwork-related cardiovascular disease in Japan, Korea, and Taiwan.
Park Jungsun,Kim Yangho,Cheng Yawen,Horie Seichi
In Japan, Korea, and Taiwan, cerebrovascular and cardiovascular diseases (CVDs) caused by overwork are recognized by government as work-related. These three countries are the only countries in the world that officially recognize CVDs caused by psychosocial factors (e.g., overwork) as work-related cerebrovascular and cardiovascular diseases (WR-CVDs), and compensate employees accordingly. The present study compared the similarities and differences among the recognition of overwork-related CVDs in Japan, Korea, and Taiwan. The criteria by which WR-CVDs are identified are very similar in the three countries. However, in the interval surveyed (1996-2009), Korea had a remarkably larger number of recognized WR-CVD patients than did Japan or Taiwan. Recognition of occupational diseases is influenced by various factors, including socio-cultural values, the nature of occupational health care schemes, the extent of the social security umbrella, national health insurance policy, and scientific evidence. Our results show that social factors may be very different among the three countries studied, although the recognition criteria for WR-CVDs are quite similar.
Compensation for work-related cerebrocardiovascular diseases.
Won Jong-Uk,Kim Inah
Journal of Korean medical science
The purpose of this study was to discuss the history of, and concerns regarding, the newly amended criteria of occupational cerebrovascular or cardiovascular diseases (CCVDs). Since the early 1990s, CCVDs have been the second most common occupational disease, despite fluctuations in their criteria. The first issue was the deletion of cerebral hemorrhage on duty as a recognized occupational disease in 2008. The second issue was the obscurity regarding definitions of an acute stressful event (within 24 hr before disease occurrence), short-term overwork (within 1 week), and chronic overwork (for 3 or more months). In this amendment, chronic overwork was defined as work exceeding 60 hr per week. If the average number of weekly working hours does not exceed 60 hr, night work, physical or psychological workload, or other risk factors should be considered for the recognition of occupational CCVDs. However, these newly amended criteria still have a few limitations, considering that there is research evidence for the occurrence of disease in those working fewer than 60 hr per week, and other risk factors, particularly night work, are underestimated in these criteria. Thus, we suggest that these concerns be actively considered during future amendment and approval processes.
Napping and weekend catchup sleep do not fully compensate for high rates of sleep debt and short sleep at a population level (in a representative nationwide sample of 12,637 adults).
Leger Damien,Richard Jean-Baptiste,Collin Olivier,Sauvet Fabien,Faraut Brice
INTRODUCTION:Short total sleep time (TST < 6 h) is a strong major health determinant that correlates with numerous metabolic, cardiovascular and mental comorbidities, as well as accidents. Our aim was to better understand, at a population level, how adults adapt their TST during the week, and how short sleepers and those with sleep debt and sleep restriction use napping or catching up on sleep during weekends (ie, sleep debt compensation by sleeping longer), which may prevent these comorbidities. METHODS:A large representative sample of 12,367 subjects (18-75 years old) responded by phone to questions about sleep on a national recurrent health poll (Health Barometer, Santé Publique France 2017) assessing sleep schedules (TST) at night, when napping, and over the course of a 24-h period while using a sleep log on workdays and weekends. Retained items were: (1) short sleep (TST ≤ 6 h/24 h); (2) chronic insomnia (international classification of sleep disorders third edition, ICSD-3 criteria); (3) sleep debt (self-reported ideal TST - TST > 60 min, severe > 90 min); and (4) sleep restriction (weekend TST - workday TST = 1-2 h, severe > 2 h). RESULTS:Average TST/24 h was 6h42 (± 3 min) on weekdays and 7h26 (± 3 min) during weekends. In addition, 35.9% (± 1.0%) of the subjects were short sleepers, 27.7% (± 1.0%) had sleep debt (18.8% (± 0.9%) severe), and 17.4% (± 0.9%) showed sleep restriction (14.4% (± 0.8%) severe). Moreover, 27.4% (± 0.9%) napped at least once per week on weekdays (average: 8.3 min (± 0.5 min)) and 32.2% (± 1.0%) on weekend days (13.7 min (± 0.7 min)). Of the 24.2% (± 0.9%) of subjects with severe sleep debt (> 90 min), only 18.2% (± 1.6%) balanced their sleep debt by catching up on sleep on weekends (14.9% (± 0.8%) of men and 21.5% (± 0.9%) of women), and 7.4% (± 1.2%) of these subjects balanced their sleep debt by napping (7.8% (± 0.5%) of men and 6.6% (± 0.4%) of women). The remaining 75.8% (± 5.4%) did not do anything to balance their severe sleep debt during the week. DISCUSSION AND CONCLUSIONS:Short sleep, sleep debt, and sleep restriction during weekdays affected about one third of adults in our study group. Napping and weekend catch-up sleep only compensated for severe sleep debt in one in four subjects.
Sleep debt elicits negative emotional reaction through diminished amygdala-anterior cingulate functional connectivity.
Motomura Yuki,Kitamura Shingo,Oba Kentaro,Terasawa Yuri,Enomoto Minori,Katayose Yasuko,Hida Akiko,Moriguchi Yoshiya,Higuchi Shigekazu,Mishima Kazuo
OBJECTIVES:Sleep debt reportedly increases emotional instability, such as anxiety and confusion, in addition to sleepiness and psychomotor impairment. However, the neural basis of emotional instability due to sleep debt has yet to be elucidated. This study investigated changes in emotional responses that are elicited by the simulation of short-term sleep loss and the brain regions responsible for these changes. SUBJECTS AND METHODS:Fourteen healthy adult men aged 24.1±3.3 years (range, 20-32 years) participated in a within-subject crossover study consisting of 5-day sessions of both sleep debt (4 h for time in bed) and sleep control (8 h for time in bed). On the last day of each session, participants underwent polysomnography and completed the State-Trait Anxiety Inventory and Profile of Mood States questionnaires. In addition, functional magnetic resonance imaging was conducted while performing an emotional face viewing task. RESULTS:Restricted sleep over the 5-day period increased the activity of the left amygdala in response to the facial expression of fear, whereas a happy facial expression did not change the activity. Restricted sleep also resulted in a significant decrease in the functional connectivity between the amygdala and the ventral anterior cingulate cortex (vACC) in proportion to the degree of sleep debt (as indicated by the percentage of slow wave sleep and δ wave power). This decrease was significantly correlated with activation of the left amygdala and deterioration of subjective mood state. CONCLUSION:The results of this study suggest that continuous and accumulating sleep debt that can be experienced in everyday life can downregulate the functional suppression of the amygdala by the vACC and consequently enhance the response of the amygdala to negative emotional stimuli. Such functional alteration in emotional control may, in part, be attributed to the neural basis of emotional instability during sleep debt.
Local modulation of human brain responses by circadian rhythmicity and sleep debt.
Muto Vincenzo,Jaspar Mathieu,Meyer Christelle,Kussé Caroline,Chellappa Sarah L,Degueldre Christian,Balteau Evelyne,Shaffii-Le Bourdiec Anahita,Luxen André,Middleton Benita,Archer Simon N,Phillips Christophe,Collette Fabienne,Vandewalle Gilles,Dijk Derk-Jan,Maquet Pierre
Science (New York, N.Y.)
Human performance is modulated by circadian rhythmicity and homeostatic sleep pressure. Whether and how this interaction is represented at the regional brain level has not been established. We quantified changes in brain responses to a sustained-attention task during 13 functional magnetic resonance imaging sessions scheduled across the circadian cycle, during 42 hours of wakefulness and after recovery sleep, in 33 healthy participants. Cortical responses showed significant circadian rhythmicity, the phase of which varied across brain regions. Cortical responses also significantly decreased with accrued sleep debt. Subcortical areas exhibited primarily a circadian modulation that closely followed the melatonin profile. These findings expand our understanding of the mechanisms involved in maintaining cognition during the day and its deterioration during sleep deprivation and circadian misalignment.
Unrecognized Sleep Loss Accumulated in Daily Life Can Promote Brain Hyperreactivity to Food Cue.
Katsunuma Ruri,Oba Kentaro,Kitamura Shingo,Motomura Yuki,Terasawa Yuri,Nakazaki Kyoko,Hida Akiko,Moriguchi Yoshiya,Mishima Kazuo
Epidemiological studies have shown that sleep debt increases the risk of obesity. Experimental total sleep deprivation (TSD) has been reported to activate the reward system in response to food stimuli, but food-related responses in everyday sleep habits, which could lead to obesity, have not been addressed. Here, we report that habitual sleep time at home among volunteers without any sleep concerns was shorter than their optimal sleep time estimated by the 9-day extended sleep intervention, which indicates that participants had already been in sleep debt in their usual sleep habits. The amygdala and anterior insula, which are responsible for both affective responses and reward prediction, were found to exhibit significantly lowered activity in the optimal sleep condition. Additionally, a subsequent one-night period of TSD reactivated the right anterior insula in response to food images; however, the activity level of amygdala remained lowered. These findings indicate that (1) our brain is at risk of hyperactivation to food triggers in everyday life, which could be a risk factor for obesity and lifestyle diseases, and (2) optimal sleep appears to reduce this hypersensitivity to food stimuli.
Fatigue in childhood chronic disease.
Nap-van der Vlist Merel M,Dalmeijer Geertje W,Grootenhuis Martha A,van der Ent Cornelis K,van den Heuvel-Eibrink Marry M,Wulffraat Nico M,Swart Joost F,van Litsenburg Raphaële R L,van de Putte Elise M,Nijhof Sanne L
Archives of disease in childhood
BACKGROUND AND OBJECTIVES:Recently, in adults, the incidence and severity of fatigue was found to exist rather independently from the somatic diagnosis. Since fatigue is distressing when growing up with a chronic disease, we aim to investigate: (1) the prevalence and extent of fatigue among various paediatric chronic diseases and (2) the effect of fatigue on health-related quality of life (HRQoL). DESIGN AND SETTING:Cross-sectional study in two children's hospitals. PATIENTS:Children and adolescents 2-18 years of age with cystic fibrosis, an autoimmune disease or postcancer treatment visiting the outpatient clinic. OUTCOME MEASURES:Fatigue and HRQoL were assessed using the Pediatric Quality of Life Inventory (PedsQL) multidimensional fatigue scale (with lower scores indicating more fatigue) and PedsQL generic core scales, respectively. Linear regression analysis and analysis of covariance were used to compare fatigue scores across disease groups and against two control groups. The effect of fatigue on HRQoL was calculated. Data were adjusted for age, sex and reporting method. RESULTS:481 children and adolescents were assessed (60% participation rate, mean age 10.7±4.9, 42% men). Children and adolescents with chronic disease reported more fatigue than the general population (mean difference -6.6, 95% CI -8.9 to -4.3 (range 0-100)), with a prevalence of severe fatigue of 21.2%. Fatigue scores did not differ significantly between disease groups on any fatigue domain. Fatigue was associated with lower HRQoL on all domains. CONCLUSIONS:Fatigue in childhood chronic disease is a common symptom that presents across disease, age and sex groups. Fatigue affects HRQoL. Our findings underscore the need to systematically assess fatigue. Future studies should determine possible biological and psychosocial treatment targets.
The Role of Sleep Quality and Fatigue on the Benefits of an Interdisciplinary Treatment for Adults With Chronic Pain.
de la Vega Rocío,Racine Melanie,Castarlenas Elena,Solé Ester,Roy Rubén,Jensen Mark P,Miró Jordi,Cane Douglas
Pain practice : the official journal of World Institute of Pain
BACKGROUND:Interdisciplinary chronic pain treatment is effective for reducing pain intensity and pain-related disability, and for improving psychological function. However, the mechanisms that underlie these treatment-related benefits are not yet well understood. Sleep problems and fatigue are modifiable factors often comorbid with chronic pain. The goal of this study was to evaluate the role that changes in sleep quality and fatigue might have on the benefits of an interdisciplinary chronic pain treatment. METHODS:A total of 125 adults with chronic pain participated in a 4-week interdisciplinary pain management program. Measures of depression, sleep disturbance, fatigue, pain intensity, and physical function were administered at pre- and post-treatment. Three regression analyses were conducted to evaluate the contribution of pre- to post-treatment improvements in fatigue and sleep disturbance to the pre- to post-treatment improvements in pain intensity, disability, and depression, while controlling for demographic characteristics (age and sex) and pain intensity. RESULTS:Changes in fatigue and sleep disturbance made independent and significant contributions to the prediction of treatment-related benefits in pain intensity; improvements in depressive symptoms were predicted by improvements in fatigue, and improvements in disability were only predicted by pre-treatment and pre- to post-treatment decreases in pain intensity (one of the control variables). CONCLUSIONS:In addition to sleep, fatigue emerged as a key potential mechanism of multidisciplinary chronic pain treatment-related improvements, suggesting that interventions including elements that effectively target sleep and fatigue may enhance the efficacy of interdisciplinary chronic pain programs. This possibility should be evaluated in future research.
Chronic stress exposure, diurnal cortisol slope, and implications for mood and fatigue: Moderation by multilocus HPA-Axis genetic variation.
Starr Lisa R,Dienes Kimberly,Li Y Irina,Shaw Zoey A
Chronic stress exposure has been shown to alter hypothalamic-pituitary-adrenal (HPA) axis functioning, which may mediate its effects on psychopathology and negative health outcomes. The nature of the chronic stress-HPA axis dysregulation is unclear and individuals likely vary in the extent to and manner in which indices of HPA axis regulation, such as diurnal cortisol slope, are influenced by chronic stress. We examined whether HPA-axis-linked genetic variation moderates the association between chronic stress and diurnal cortisol slope, and potential implications for mood and fatigue (possible manifestations of negative clinical outcomes). 211 adolescents (M age 15.89, 54.5% female) completed chronic stress interviews and provided DNA samples. Participants then provided saliva samples at waking and 12 h post-waking for two consecutive weekdays. HPA-axis genetic variation was calculated using a multilocus genetic profile score (MGPS) approach, using ten SNPs from CRHR1, NR3C1, NR3C2, and FKBP5 to generate an additive score of HPA-axis-linked genetic risk. Neither chronic stress nor MGPS directly predicted diurnal slope, but MGPS moderated the association between chronic stress and diurnal slope, with stress predicting a high waking cortisol followed by steep slope among youth with low but not high MGPS scores. MGPS also interacted with chronic stress to predict both negative affect and fatigue, and moderated the indirect effect of chronic stress on mood and fatigue via diurnal slope. Results suggest that diurnal cortisol regulation may be one mechanism by which genetic risk intensifies the association between chronic stress and negative outcomes.
Identifying and validating blood mRNA biomarkers for acute and chronic insufficient sleep in humans: a machine learning approach.
Laing Emma E,Möller-Levet Carla S,Dijk Derk-Jan,Archer Simon N
Acute and chronic insufficient sleep are associated with adverse health outcomes and risk of accidents. There is therefore a need for biomarkers to monitor sleep debt status. None are currently available. We applied elastic net and ridge regression to transcriptome samples collected in 36 healthy young adults during acute total sleep deprivation and following 1 week of either chronic insufficient (<6 hr) or sufficient sleep (~8.6 hr) to identify panels of mRNA biomarkers of sleep debt status. The size of identified panels ranged from 9 to 74 biomarkers. Panel performance, assessed by leave-one-subject-out cross-validation and independent validation, varied between sleep debt conditions. Using between-subject assessments based on one blood sample, the accuracy of classifying "acute sleep loss" was 92%, but only 57% for classifying "chronic sleep insufficiency." A reasonable accuracy for classifying "chronic sleep insufficiency" could only be achieved by a within-subject comparison of blood samples. Biomarkers for sleep debt status showed little overlap with previously identified biomarkers for circadian phase. Biomarkers for acute and chronic sleep loss also showed little overlap but were associated with common functions related to the cellular stress response, such as heat shock protein activity, the unfolded protein response, protein ubiquitination and endoplasmic reticulum-associated protein degradation, and apoptosis. This characteristic response of whole blood to sleep loss can further aid our understanding of how sleep insufficiencies negatively affect health. Further development of these novel biomarkers for research and clinical practice requires validation in other protocols and age groups.
Sleep debt at the community level: impact of age, sex, race/ethnicity and health.
Fox Elliott C,Wang Kairuo,Aquino Melissa,Grandner Michael A,Xie Dawei,Branas Charles C,Gooneratne Nalaka S
OBJECTIVES:Insufficient sleep has become recognized as a pervasive problem in modern society. Sleep debt is a novel measure of sleep adequacy that may be useful in describing those at risk for inadequate sleep. Our objective was to investigate factors that may be associated with sleep debt at the population level, as well as build upon previous data that showed that minority groups may be more likely to have sleep debt. DESIGN:A cross-sectional population phone survey included questions regarding amount of sleep required and amount of sleep achieved. Sleep debt was calculated by subtracting sleep achieved from sleep required. SETTING:This study was designed by the Philadelphia Health Management Corporation and conducted over landlines and cell phones. PARTICIPANTS:The Random Digit Dialing method was used to randomly choose 8,752 adults older than 18 years from several counties in and around Philadelphia to answer questions about sleep. MEASUREMENTS:Logistic regression was performed to test associations between sleep debt and various sociodemographic factors in different population subgroups to identify those at risk for sub-optimal sleep duration. RESULTS:Sleep debt was seen to decrease with age, a novel finding that is in contrast with literature suggesting that older adults have poor sleep. Greater sleep debt was also associated with female gender, Hispanic/Latino ethnicity, <40 years of age, self-reported poor health, and increased stress. CONCLUSIONS:Although older adults may sleep less as they age, they may also require less sleep to feel rested, resulting in less sleep debt. This and other demographic factors, such as female gender and Hispanic/Latino ethnicity, can be used to identify those at higher risk of inadequate sleep and potentially manage their sleep debt.
Three Cases of Karoshi Without the Typical Pathomorphological Features of Cardiovascular/Cerebrovascular Disease.
Miao Qi,Li Jing,Pan Yu-Peng,Yu Yan-Geng,Zhang Fu,Xiao Ning,Li Dong-Ri
The American journal of forensic medicine and pathology
Karoshi is a term used to describe unexplained sudden death associated with overwork and has become a serious public health issue in China. Cases have occurred in physicians, university professors, engineers in high-tech companies, and blue-collar workers. The mechanisms associated with death by overwork are very complex. According to most researchers, karoshi is considered to be caused by an excessive workload that induces deterioration of underlying hypertension or atherosclerosis. These conditions inevitably lead to death from cardiovascular or cerebrovascular diseases. However, in our own experience, we have found that in some cases, the victims of karoshi were in a chronic state of overwork but without a history of cardiovascular or cerebrovascular diseases. In support of this, we have found that even autopsies have revealed few positive findings except for cardiac hypertrophy. In this article, we report 3 typical cases of karoshi but without the typical pathomorphological features of cardiovascular or cerebrovascular disease.
The Concept, Status Quo and Forensic Pathology of Karoshi.
Fa yi xue za zhi
ABSTRACT:"Karoshi" originates from Japan's economic take-off period in the 1960s and 1970s. It is generally believed that overwork lead to the accumulation of fatigue, which triggers the outbreak of potential diseases, and results in sudden death. Karoshi causes great harm to both the community and families because it occurs primarily in 30 to 60 year old young adults. Japan put Karoshi into the category of industrial injury for the first time in 2001 and started to undertake a series of studies in the sociological and pathological fields. However, there is a tremendous gap in the forensic pathological diagnosis domain. In China, research on Karoshi started from the 1990s and is closely related to the reform and opening up policy as well as economic development. According to the incomplete statistics, 600 thousand people die from overwork each year in China, the highest in the world. Karoshi has become one of the most serious social problems in China at the present stage, thus a systematic study in the sociology and forensic pathology fields is urgently required. This paper summarizes the past and present status of Karoshi, and puts forward the problems that need attention during the judicial expertise of Karoshi from forensic pathology perspective.
Karoshi May Be a Consequence of Overwork-Related Malignant Arrhythmia.
Xiao Ning,Yang Bo-Fan,Shi Jing-Zhuo,Yu Yan-Geng,Zhang Fu,Miao Qi,Li Dong-Ri
Medical science monitor : international medical journal of experimental and clinical research
BACKGROUND Karoshi, which is sudden death associated with overwork, has become a serious problem in China. Many studies have examined the relationship between cardiovascular risks and karoshi, but there is little evidence that explains the exact mechanism by which overwork induces sudden death. In these cases, there are few obvious positive findings from forensic autopsies except for histories of overwork prior to death. Therefore, we assume that abnormalities, such as cardiac arrhythmia, rather than organic changes are the cause of karoshi. MATERIAL AND METHODS In the present study, the forced swim test (FST) was used to establish models of overwork. The myocardial tissues of SD rats taking FST (1 h per day, for 30 consecutive days) were collected. The arrhythmia-related molecule CX43 as well as its upstream regulation molecule Cav-1 and cSrc were tested by Western blot (WB) and immunohistochemistry (IHC). HE staining and Masson's staining were performed in the myocardium tissue section. RESULTS We observed downregulation of caveolin-1 (Cav1) followed by cSrc activation, resulting in the decrease of connexin43 (Cx43) levels in overwork models. Myocardial interstitial fibrosis, which is associated with electrophysiological aberrances that result in arrhythmia, was also found in the overwork models. CONCLUSIONS These data provide a mechanistic explanation for the speculated link between karoshi and cardiac arrhythmias.
Overwork and cerebrocardiovascular disease in Korean adult workers.
Jang Tae-Won,Kim Hyoung-Ryoul,Lee Hye-Eun,Myong Jun-Pyo,Koo Jung-Wan,Ye Byeong-Jin,Won Jong-Uk
Journal of occupational health
OBJECTIVES:Long work hours and overwork may increase the cardiovascular load of workers. But long work hours and overwork are not the same. Cardiovascular overload from working is dependent on the physical demand of the work and the worker's physical fitness, as well as the working hours. This cross-sectional study was designed to identify the association between overwork and cerebrocardiovascular disease, taking into account the physical demand of work, physical fitness, and work hours. METHODS:Study data were obtained from surveillance of occupational cerebrocardiovascular disease. Questionnaire surveys including general and work-related characteristics were conducted. Maximum acceptable work time was estimated using the physical work demand and physical fitness of the subjects. The overwork index, which was the ratio of maximum acceptable work time and actual work hours of the subjects, was calculated. RESULTS:In the workers with a moderate or high physical demand of work, the adjusted odds ratios for overwork indexes of 1.01-1.20, 1.21-1.50, and >1.50 were 2.679 (95% confidence interval (CI) 1.025-6.999), 3.124 (95% CI 1.111-8.783), and 4.331 (95% CI 1.719-10.908), respectively. CONCLUSIONS:The results indicate that the risk of cerebrocardiovascular disease might be high in the workers with long working hours, high physical demand of work, and poor physical fitness engaged in work with a moderate to high physical work demand. Work hours should be accommodated according to the worker's physical fitness and the physical demand of work, and this could lower the risk of cerebrocardiovascular disease.
Overwork, stroke, and karoshi-death from overwork.
Acta neurologica Taiwanica
Karoshi, death from over-work, is usually the extreme result of acute cardiovascular events including stroke. Among 203 karoshi cases received worker compensation in Japan, sixty percent died of stroke. Karoshi is a term for social medicine originated form Japan. Literature reviews on karoshi found that long overtime at work, on duty in holidays, attending a new job with no family members around, and working at night shift are risk factors. Work stress increases secretion of catecholamines (epinephrine and norepinephrine) and cortisol which is associated with progression of atherosclerosis and increased risk of cardiovascular diseases and stroke. To avoid long working hours, stress management and treatment of hypertension, diabetes, and hyperlipidemia are key issues in preventing karoshi caused by stroke.
Oxalic acid and diacylglycerol 36:3 are cross-species markers of sleep debt.
Weljie Aalim M,Meerlo Peter,Goel Namni,Sengupta Arjun,Kayser Matthew S,Abel Ted,Birnbaum Morris J,Dinges David F,Sehgal Amita
Proceedings of the National Academy of Sciences of the United States of America
Sleep is an essential biological process that is thought to have a critical role in metabolic regulation. In humans, reduced sleep duration has been associated with risk for metabolic disorders, including weight gain, diabetes, obesity, and cardiovascular disease. However, our understanding of the molecular mechanisms underlying effects of sleep loss is only in its nascent stages. In this study we used rat and human models to simulate modern-day conditions of restricted sleep and addressed cross-species consequences via comprehensive metabolite profiling. Serum from sleep-restricted rats was analyzed using polar and nonpolar methods in two independent datasets (n = 10 per study, 3,380 measured features, 407 identified). A total of 38 features were changed across independent experiments, with the majority classified as lipids (18 from 28 identified). In a parallel human study, 92 metabolites were identified as potentially significant, with the majority also classified as lipids (32 of 37 identified). Intriguingly, two metabolites, oxalic acid and diacylglycerol 36:3, were robustly and quantitatively reduced in both species following sleep restriction, and recovered to near baseline levels after sleep restriction (P < 0.05, false-discovery rate < 0.2). Elevated phospholipids were also noted after sleep restriction in both species, as well as metabolites associated with an oxidizing environment. In addition, polar metabolites reflective of neurotransmitters, vitamin B3, and gut metabolism were elevated in sleep-restricted humans. These results are consistent with induction of peroxisome proliferator-activated receptors and disruptions of the circadian clock. The findings provide a potential link between known pathologies of reduced sleep duration and metabolic dysfunction, and potential biomarkers for sleep loss.
Normative variation in self-reported sleep quality and sleep debt is associated with stimulated pro-inflammatory cytokine production.
Prather Aric A,Marsland Anna L,Hall Martica,Neumann Serina A,Muldoon Matthew F,Manuck Stephen B
Activation of innate inflammatory pathways, marked by increased production of pro-inflammatory cytokines, has been proposed as a potential mechanism linking poor sleep and inflammatory disease risk. In the present study, we examined associations of self-reported sleep quality and duration, and a calculated measure of sleep debt with the production of pro-inflammatory cytokines, interleukin (IL)-6, IL-1beta, and tumor necrosis factor (TNF)-alpha among a community sample of 156 healthy adults. Bivariate correlations revealed an inverse association between sleep quality and production of all the three pro-inflammatory cytokines that was retained for IL-1beta after controlling for demographic and health characteristics. Hierarchical linear regressions also revealed that higher sleep debt scores predicted greater production of IL-1beta and IL-6 after adjusting for covariates. Secondary analyses showed an interaction between sleep debt and body mass index (BMI) in the prediction IL-1beta, suggesting that the impact of sleep debt on cytokine production is greater among participants with lower BMI scores. Further exploration of this potential psychophysiological pathway linking sleep difficulty and inflammatory disease susceptibility is warranted.
Rapid eye movement sleep debt accrues in mice exposed to volatile anesthetics.
Pick Jeremy,Chen Yihan,Moore Jason T,Sun Yi,Wyner Abraham J,Friedman Eliot B,Kelz Max B
BACKGROUND:General anesthesia has been likened to a state in which anesthetized subjects are locked out of access to both rapid eye movement (REM) sleep and wakefulness. Were this true for all anesthetics, a significant REM rebound after anesthetic exposure might be expected. However, for the intravenous anesthetic propofol, studies demonstrate that no sleep debt accrues. Moreover, preexisting sleep debts dissipate during propofol anesthesia. To determine whether these effects are specific to propofol or are typical of volatile anesthetics, the authors tested the hypothesis that REM sleep debt would accrue in rodents anesthetized with volatile anesthetics. METHODS:Electroencephalographic and electromyographic electrodes were implanted in 10 mice. After 9-11 days of recovery and habituation to a 12 h:12 h light-dark cycle, baseline states of wakefulness, nonrapid eye movement sleep, and REM sleep were recorded in mice exposed to 6 h of an oxygen control and on separate days to 6 h of isoflurane, sevoflurane, or halothane in oxygen. All exposures were conducted at the onset of light. RESULTS:Mice in all three anesthetized groups exhibited a significant doubling of REM sleep during the first 6 h of the dark phase of the circadian schedule, whereas only mice exposed to halothane displayed a significant increase in nonrapid eye movement sleep that peaked at 152% of baseline. CONCLUSION:REM sleep rebound after exposure to volatile anesthetics suggests that these volatile anesthetics do not fully substitute for natural sleep. This result contrasts with the published actions of propofol for which no REM sleep rebound occurred.
Does our sleep debt affect patients' safety?
Tewari Anurag,Soliz Jose,Billota Federico,Garg Shuchita,Singh Harsimran
Indian journal of anaesthesia
The provision of anaesthesia requires a high level of knowledge, sound judgement, fast and accurate responses to clinical situations, and the capacity for extended periods of vigilance. With changing expectations and arising medico-legal issues, anaesthesiologists are working round the clock to provide efficient and timely health care services, but little is thought whether the "sleep provider" is having adequate sleep. Decreased performance of motor and cognitive functions in a fatigued anaesthesiologist may result in impaired judgement, late and inadequate responses to clinical changes, poor communication and inadequate record keeping, all of which affect the patient safety, showing without doubt the association of sleep debt to the adverse events and critical incidents. Perhaps it is time that these issues be promptly addressed to prevent the silent perpetuation of a problem that is pertinent to our health and our profession. We endeavour to focus on the evidence that links patient safety to fatigue and sleepiness of health care workers and specifically on anaesthesiologists. The implications of sleep debt are deep on patient safety and strategies to prevent this are the need of the hour.
Sleep Restriction Enhances the Daily Rhythm of Circulating Levels of Endocannabinoid 2-Arachidonoylglycerol.
Hanlon Erin C,Tasali Esra,Leproult Rachel,Stuhr Kara L,Doncheck Elizabeth,de Wit Harriet,Hillard Cecilia J,Van Cauter Eve
STUDY OBJECTIVES:Increasing evidence from laboratory and epidemiologic studies indicates that insufficient sleep may be a risk factor for obesity. Sleep curtailment results in stimulation of hunger and food intake that exceeds the energy cost of extended wakefulness, suggesting the involvement of reward mechanisms. The current study tested the hypothesis that sleep restriction is associated with activation of the endocannabinoid (eCB) system, a key component of hedonic pathways involved in modulating appetite and food intake. METHODS:In a randomized crossover study comparing 4 nights of normal (8.5 h) versus restricted sleep (4.5 h) in healthy young adults, we examined the 24-h profiles of circulating concentrations of the endocannabinoid 2-arachidonoylglycerol (2-AG) and its structural analog 2-oleoylglycerol (2-OG). We concomitantly assessed hunger, appetite, and food intake under controlled conditions. RESULTS:A robust daily variation of 2-AG concentrations with a nadir around the middle of the sleep/overnight fast, followed by a continuous increase culminating in the early afternoon, was evident under both sleep conditions but sleep restriction resulted in an amplification of this rhythm with delayed and extended maximum values. Concentrations of 2-OG followed a similar pattern, but with a lesser amplitude. When sleep deprived, participants reported increases in hunger and appetite concomitant with the afternoon elevation of 2-AG concentrations, and were less able to inhibit intake of palatable snacks. CONCLUSIONS:Our findings suggest that activation of the eCB system may be involved in excessive food intake in a state of sleep debt and contribute to the increased risk of obesity associated with insufficient sleep. COMMENTARY:A commentary on this article appears in this issue on page 495.
Human brain patterns underlying vigilant attention: impact of sleep debt, circadian phase and attentional engagement.
Maire Micheline,Reichert Carolin F,Gabel Virginie,Viola Antoine U,Phillips Christophe,Berthomier Christian,Borgwardt Stefan,Cajochen Christian,Schmidt Christina
Sleepiness and cognitive function vary over the 24-h day due to circadian and sleep-wake-dependent mechanisms. However, the underlying cerebral hallmarks associated with these variations remain to be fully established. Using functional magnetic resonance imaging (fMRI), we investigated brain responses associated with circadian and homeostatic sleep-wake-driven dynamics of subjective sleepiness throughout day and night. Healthy volunteers regularly performed a psychomotor vigilance task (PVT) in the MR-scanner during a 40-h sleep deprivation (high sleep pressure) and a 40-h multiple nap protocol (low sleep pressure). When sleep deprived, arousal-promoting thalamic activation during optimal PVT performance paralleled the time course of subjective sleepiness with peaks at night and troughs on the subsequent day. Conversely, task-related cortical activation decreased when sleepiness increased as a consequence of higher sleep debt. Under low sleep pressure, we did not observe any significant temporal association between PVT-related brain activation and subjective sleepiness. Thus, a circadian modulation in brain correlates of vigilant attention was only detectable under high sleep pressure conditions. Our data indicate that circadian and sleep homeostatic processes impact on vigilant attention via specific mechanisms; mirrored in a decline of cortical resources under high sleep pressure, opposed by a subcortical "rescuing" at adverse circadian times.
Mouse Gambling Task reveals differential effects of acute sleep debt on decision-making and associated neurochemical changes.
Pittaras Elsa,Callebert Jacques,Dorey Rodolphe,Chennaoui Mounir,Granon Sylvie,Rabat Arnaud
Sleep loss is associated with sleepiness, sustained attention, and memory deficits. However, vulnerability of higher cognitive processes (i.e. decision making) to sleep debt is less understood. Therefore, a major challenge is to understand why and how higher cognitive processes are affected by sleep debt. We had established in mice correlations between individual decision-making strategies, prefrontal activity, and regional monoaminergic levels. Now, we show that acute sleep debt (ASD) disturbs decision-making processes and provokes brain regional modifications of serotonin and dopamine that could explain why ASD promotes inflexible and more risk-prone behaviors. Finally, we highlight, for the first time, that in a large group of healthy inbred mice some of them are more sensitive to ASD by showing inflexible behavior and decision-making deficits. We were also able to predict mice that would be the most vulnerable to ASD depending of their behavior before ASD exposure.
Importance of fatigue and its measurement in chronic liver disease.
Gerber Lynn H,Weinstein Ali A,Mehta Rohini,Younossi Zobair M
World journal of gastroenterology
The mechanisms of fatigue in the group of people with non-alcoholic fatty liver disease and non-alcoholic steatohepatitis are protean. The liver is central in the pathogenesis of fatigue because it uniquely regulates much of the storage, release and production of substrate for energy generation. It is exquisitely sensitive to the feedback controlling the uptake and release of these energy generation substrates. Metabolic contributors to fatigue, beginning with the uptake of substrate from the gut, the passage through the portal system to hepatic storage and release of energy to target organs (muscle and brain) are central to understanding fatigue in patients with chronic liver disease. Inflammation either causing or resulting from chronic liver disease contributes to fatigue, although inflammation has not been demonstrated to be causal. It is this unique combination of factors, the nexus of metabolic abnormality and the inflammatory burden of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis that creates pathways to different types of fatigue. Many use the terms central and peripheral fatigue. Central fatigue is characterized by a lack of self-motivation and can manifest both in physical and mental activities. Peripheral fatigue is classically manifested by neuromuscular dysfunction and muscle weakness. Therefore, the distinction is often seen as a difference between intention (central fatigue) ability (peripheral fatigue). New approaches to measuring fatigue include the use of objective measures as well as patient reported outcomes. These measures have improved the precision with which we are able to describe fatigue. The measures of fatigue severity and its impact on usual daily routines in this population have also been improved, and they are more generally accepted as reliable and sensitive. Several approaches to evaluating fatigue and developing endpoints for treatment have relied of biosignatures associated with fatigue. These have been used singly or in combination and include: physical performance measures, cognitive performance measures, mood/behavioral measures, brain imaging and serological measures. Treatment with non-pharmacological agents have been shown to be effective in symptom reduction, whereas pharmacological agents have not been shown effective.
Fatigue in chronic liver disease: New insights and therapeutic approaches.
Swain Mark G,Jones David E J
Liver international : official journal of the International Association for the Study of the Liver
The management of fatigue associated with chronic liver disease is a complex and major clinical challenge. Although fatigue can complicate many chronic diseases, it is particularly common in diseases with an inflammatory component. Fatigue can have both peripheral (i.e., neuromuscular) and central (i.e., resulting from changes in neurotransmission within the brain) causes. However, fatigue in chronic liver disease has strong social/contextual components and is often associated with behavioural alterations including depression and anxiety. Given the increasing awareness of patient-reported outcomes as important components of treatment outcomes and clinical research, there is a growing need to better understand and manage this poorly understood yet debilitating symptom. Although several pathophysiological mechanisms for explaining the development of fatigue have been generated, our understanding of fatigue in patients with chronic liver disease remains incomplete. A better understanding of the pathways and neurotransmitter systems involved may provide specific directed therapies. Currently, the management of fatigue in chronic liver disease can involve a combined use of methods to beneficially alter behavioural components and pharmacological interventions, of which several treatments have potential for the improved management of fatigue in chronic liver disease. However, evidence and consensus are lacking on the best approach and the most appropriate biochemical target(s) whilst clinical trials to address this issue have been few and limited by small sample size. In this review, we outline current understanding of the impact of fatigue and related symptoms in chronic liver disease, discuss theories of pathogenesis, and examine current and emerging approaches to its treatment.
A Systematic Review of Biological Mechanisms of Fatigue in Chronic Illness.
Matura Lea Ann,Malone Susan,Jaime-Lara Rosario,Riegel Barbara
Biological research for nursing
Fatigue, a commonly reported symptom, is defined as an overwhelming, debilitating, and sustained sense of exhaustion that decreases the ability to function and carry out daily activities. To date, cancer researchers have been in the forefront in investigating the possible biological mechanisms of fatigue, identifying inflammation, dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, and activation of the autonomic nervous system. The purpose of this systematic review is to describe fatigue and what is known about the biological mechanisms described in cancer in five chronic, noninfectious illnesses: heart failure, multiple sclerosis, chronic kidney disease, rheumatoid arthritis, and chronic obstructive pulmonary disease. We searched PubMed and EMBASE using fatigue as a major Medical subject headings (MeSH) heading with each individual disease added as a search term followed by each biological mechanism. We included only primary research articles published in English between 1996 and 2016 describing studies conducted in adult humans. We identified 26 relevant articles. While there is some evidence that the biological mechanisms causing fatigue in cancer are also associated with fatigue in other chronic illnesses, more research is needed to explore inflammation, the HPA axis, and the autonomic nervous system, and other mechanisms in relation to fatigue in a variety of chronic illnesses.
Fatigue interventions in long term, physical health conditions: A scoping review of systematic reviews.
Hulme Katrin,Safari Reza,Thomas Sarah,Mercer Tom,White Claire,Van der Linden Marietta,Moss-Morris Rona
OBJECTIVE:Fatigue is prominent across many long term physical health conditions. This scoping review aimed to map the fatigue intervention literature, to ascertain if certain interventions may be effective across conditions, and if novel interventions tested in specific long term conditions may be promising for other conditions. METHODS:Scoping review methodological frameworks were used. Electronic bibliographic databases were searched (inception to November 2016) for systematic reviews of fatigue interventions in long term conditions. Inclusion criteria were: long term physical health condition; review focus on fatigue management; objective and systematic review process; primary review outcome is fatigue. Articles focussing on surgical interventions or treatments thought to trigger fatigue were excluded. A narrative synthesis was performed. RESULTS:Of 115 full texts screened, 52 reviews were included. Interventions were categorised as pharmacological and non-pharmacological (exercise, psychological/behavioural and complementary medicine). Pharmacological interventions did not consistently demonstrate benefit, except for anti-TNFs and methylphenidate which may be effective at reducing fatigue. Non-pharmacological interventions such as graded exercise and fatigue-specific psychological interventions may be effective, but heterogeneous intervention components limit conclusions. 'Complementary medicine' interventions (e.g. Chinese herbal medicines) showed promise, but the possibility of publication bias must be considered. CONCLUSIONS:Further research is necessary to inform clinical practice. The reported effectiveness of some interventions across inflammatory health conditions, such as anti-TNFs, aerobic exercise, and psychologically based approaches such as CBT, highlights a potential transdiagnostic avenue for fatigue management. More novel strategies that may be worth exploring include expressive writing and mindfulness, although the mechanisms for these in relation to fatigue are unclear. More work is needed to identify transdiagnostic mechanisms of fatigue and to design interventions based on these.