Leptin and altitude in the cardiovascular diseases.
Cabrera de León Antonio,González Delia Almeida,Méndez Lina I Pérez,Aguirre-Jaime Armando,del Cristo Rodríguez Pérez Ma,Coello Santiago Domínguez,Trujillo Irma Carballo
Obesity research
OBJECTIVE:The lower mortality from coronary ischemic disease in populations living at high altitude has been related to an increase of high-density lipoprotein (HDL)-cholesterol at altitude. Leptin has been proposed as a cardiovascular risk factor. We investigated whether leptin varies according to the altitude at which people live. RESEARCH METHODS AND PROCEDURES:This was a cross-sectional study of the first 889 people enrolled in a cohort study in the Canary Islands, Spain. The relationship among serum leptin, altitude, obesity, and other cardiovascular risk factors was analyzed by bivariate and multivariate tests. RESULTS:Leptin levels showed an inverse correlation to altitude expressed in meters (r = -0.10). Obese subjects had this leptin-altitude association (r = -0.19), but they also had a direct correlation of leptin to HDL-cholesterol (r = 0.27) and an inverse correlation of leptin to the total cholesterol-to-HDL-cholesterol ratio (r = -0.34), triglycerides (r = -0.29), apolipoprotein B (r = -0.21), and glycemia (r = -0.19). Nonobese subjects had only the leptin-altitude association (r = -0.11). The final regression model included altitude as predictor. Other associated variables were gender, physical activity, BMI, age, smoking (reducing leptin independently of BMI), alcohol, heart rate, and income. DISCUSSION:Serum leptin level decreases when altitude increases, and this association could help to explain the lower cardiovascular mortality rate at high altitude. However, because in obese subjects there is a direct association of leptin with HDL-cholesterol and an inverse association with the lipid atherogenic fractions, we suggest the hypothesis of different roles for bound and free leptin, with free leptin being a cardiovascular protective factor in obese people.
10.1038/oby.2004.186
Inverse association between diabetes and altitude: a cross-sectional study in the adult population of the United States.
Obesity (Silver Spring, Md.)
OBJECTIVE:To determine whether geographical elevation is inversely associated with diabetes, while adjusting for multiple risk factors. METHODS:This is a cross-sectional analysis of publicly available online data from the Behavioral Risk Factor Surveillance System, 2009. Final dataset included 285,196 US adult subjects. Odds ratios were obtained from multilevel mixed-effects logistic regression analysis. RESULTS:Among US adults (≥20 years old), the odds ratio for diabetes was 1.00 between 0 and 499 m of altitude (reference), 0.95 (95% confidence interval, 0.90-1.01) between 500 and 1,499 m, and 0.88 (0.81-0.96) between 1,500 and 3,500 m, adjusting for age, sex, body mass index, ethnicity, self-reported fruit and vegetable consumption, self-reported physical activity, current smoking status, level of education, income, health status, employment status, and county-level information on migration rate, urbanization, and latitude. The inverse association between altitude and diabetes in the US was found among men [0.84 (0.76-0.94)], but not women [1.09 (0.97-1.22)]. CONCLUSIONS:Among US adults, living at high altitude (1,500-3,500 m) is associated with lower odds of having diabetes than living between 0 and 499 m, while adjusting for multiple risk factors. Our findings suggest that geographical elevation may be an important factor linked to diabetes.
10.1002/oby.20800
Vitamin D deficiency in relation to general and abdominal obesity among high educated adults.
Mansouri Masoume,Miri Ali,Varmaghani Mehdi,Abbasi Rowshanak,Taha Parisa,Ramezani Shadi,Rahmani Elnaz,Armaghan Rohangyz,Sadeghi Omid
Eating and weight disorders : EWD
PURPOSE:To assess the association of vitamin D deficiency with general and abdominal obesity among high educated Iranian adults. METHODS:Current cross-sectional study was done on 500 Iranian professors aged 35 years or more. Complete data on general and abdominal obesity as well as serum 25(OH)D concentrations were available for 352 persons. Obesity was considered as body mass index ≥ 30, and abdominal obesity as waist circumference ≥ 80 cm for women and ≥ 94 cm for men. Furthermore, vitamin D deficiency was defined as serum 25(OH)D < 30 ng/ml. RESULTS:Mean age of study population was 53.03 ± 7.15 years. Compared with those in the first quartile of serum 25(OH)D, participants in the fourth quartile were less likely to be generally obese (OR 0.46, 65% CI 0.22-0.99). Such finding was also seen even after taking potential confounders into account. Furthermore, we found an inverse association between serum 25(OH)D and abdominal obesity in fully adjusted model (OR 0.44, 95% CI 0.22-0.86). In addition, a significant positive association was found between vitamin D deficiency and obesity; such that after controlling for potential confounders, participants with vitamin D deficiency had 2.16 and 2.04 times greater odds for having general (OR 2.16, 95% CI 1.05-4.45) and abdominal obesity (OR 2.04, 95% CI 1.16-3.60), respectively, than those with normal levels of vitamin D. CONCLUSION:Serum 25(OH)D concentrations were inversely associated with general and abdominal obesity. In addition, vitamin D deficiency was positively associated with both general and abdominal obesity. LEVEL OF EVIDENCE:Level V, cross-sectional descriptive study.
10.1007/s40519-018-0511-4
Associations between the built environment and body mass index in the Mexican American Mano A Mano Cohort.
Zhang Xueying,Zhao Hua,Chow Wong-Ho,Durand Casey,Markham Christine,Zhang Kai
The Science of the total environment
BACKGROUND:Obesity is highly prevalent in Mexican American adults. Studies on the role of the built environment in relation to obesity among this population are scarce. OBJECTIVES:To investigate cross-sectional associations between multiple components of the built environment, and Body Mass Index (BMI) as well as obesity status among Mexican American adults enrolled in the Mano a Mano Cohort (MAC) study in Houston, Texas. METHODS:We calculated BMI from measured height and weight among 9534 Mexican American adults (aged 20-60) who participated in the baseline survey during 2008-2013. Several metrics of exposure to the built environment (physical activity environment, land use, and food environment) were generated using Geographic Information System and Google Maps based on participants' residential address. Generalized linear regression and logistic regression models were used to estimate associations between exposure to the built environment, a continuous BMI variable and categorical BMI variables (<30, ≥30 and ≥35), respectively. RESULTS:Among all built environment exposure variables investigated, road density (total road length per km) [0.21 (0.06, 0.36) as coefficient (95% CI)], intersection density (intersection links per km) [0.74 (0.21, 1.28)], networked distance (km) [-0.29 (-0.47, -0.10)], and walking time (mins) [-0.02 (-0.04, -0.01)] to the nearest parks had statistically significantly linear associations with BMI. Those variables were found to have statistically significant associations with BMI ≥ 35 in logistic regression models, the odds ratio was 1.08 (1.02, 1.14) for road density, 1.31 (1.07, 1.60) for intersection density, 0.91 (0.85, 0.98) for networked distance, and 0.99 (0.99, 1.00) for walking time. None of the built environment exposure variables were found to be associated with BMI ≥ 30. CONCLUSIONS:Living in areas with high density of roads exhibited significant associations with increased BMI, in particular BMI ≥ 35, among enrolled Mexican American adults in the MAC study.
10.1016/j.scitotenv.2018.11.122
Ambient Temperature and Prevalence of Obesity: A Nationwide Population-Based Study in Korea.
Yang Hae Kyung,Han Kyungdo,Cho Jae-Hyoung,Yoon Kun-Ho,Cha Bong-Yun,Lee Seung-Hwan
PloS one
BACKGROUND:Recent studies have suggested a possible association between outdoor or indoor temperature and obesity. We aimed to examine whether ambient temperature is associated with the prevalence of obesity or abdominal obesity in the Korean population. METHODS:Data on anthropometric, socio-demographic, laboratory and lifestyle factors were retrieved from National Health Insurance System data obtained in 2009-2010. Thirty years (1981 to 2010) of meteorological parameters for 71 observation areas were acquired from the Korea Meteorological Administration. Included in this analysis were 124,354 individuals. A body mass index (BMI) ≥ 25 kg/m2 and a waist circumference (WC) ≥ 90 cm (men) or 85 cm (women) were considered to represent obesity and abdominal obesity, respectively. RESULTS:The mean annual temperature (MAT) ranged from 6.6°C to 16.6°C, and BMI was positively correlated with MAT (r = 0.0078, P = 0.0065). WC was positively correlated with MAT (r = 0.0165, P < 0.0001) and negatively correlated with the number of days with mean temperature < 0°C (DMT0; r = -0.0129, P = 0.0002). After adjusting for age, sex, smoking status, alcohol consumption, exercise, income, residential area and altitude, the odds ratios (95% CI) for obesity and abdominal obesity in the highest quintile MAT group were 1.045 (1.010, 1.081) and 1.082 (1.042, 1.124), respectively, compared with the lower four quintiles of the MAT group. Similarly, subjects in the area of the lowest quintile of DMT0 had significantly higher odds of abdominal obesity compared with the higher four quintile groups of DMT0. CONCLUSION:This study finds an association between ambient temperature and prevalence of obesity in the Korean population when controlling for several confounding factors. Adaptive thermogenesis might be a possible explanation for this phenomenon.
10.1371/journal.pone.0141724
Ultraviolet radiation, vitamin D and the development of obesity, metabolic syndrome and type-2 diabetes.
Gorman Shelley,Lucas Robyn M,Allen-Hall Aidan,Fleury Naomi,Feelisch Martin
Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology
Obesity is increasing in prevalence in many countries around the world. Its causes have been traditionally ascribed to a model where energy intake exceeds energy consumption. Reduced energy output in the form of exercise is associated with less sun exposure as many of these activities occur outdoors. This review explores the potential for ultraviolet radiation (UVR), derived from sun exposure, to affect the development of obesity and two of its metabolic co-morbidities, type-2 diabetes and metabolic syndrome. We here discuss the potential benefits (or otherwise) of exposure to UVR based on evidence from pre-clinical, human epidemiological and clinical studies and explore and compare the potential role of UVR-induced mediators, including vitamin D and nitric oxide. Overall, emerging findings suggest a protective role for UVR and sun exposure in reducing the development of obesity and cardiometabolic dysfunction, but more epidemiological and clinical research is required that focuses on measuring the direct associations and effects of exposure to UVR in humans.
10.1039/c6pp00274a
Ultraviolet radiation suppresses obesity and symptoms of metabolic syndrome independently of vitamin D in mice fed a high-fat diet.
Geldenhuys Sian,Hart Prue H,Endersby Raelene,Jacoby Peter,Feelisch Martin,Weller Richard B,Matthews Vance,Gorman Shelley
Diabetes
The role of vitamin D in curtailing the development of obesity and comorbidities such as the metabolic syndrome (MetS) and type 2 diabetes has received much attention recently. However, clinical trials have failed to conclusively demonstrate the benefits of vitamin D supplementation. In most studies, serum 25-hydroxyvitamin D [25(OH)D] decreases with increasing BMI above normal weight. These low 25(OH)D levels may also be a proxy for reduced exposure to sunlight-derived ultraviolet radiation (UVR). Here we investigate whether UVR and/or vitamin D supplementation modifies the development of obesity and type 2 diabetes in a murine model of obesity. Long-term suberythemal and erythemal UVR significantly suppressed weight gain, glucose intolerance, insulin resistance, nonalcoholic fatty liver disease measures; and serum levels of fasting insulin, glucose, and cholesterol in C57BL/6 male mice fed a high-fat diet. However, many of the benefits of UVR were not reproduced by vitamin D supplementation. In further mechanistic studies, skin induction of the UVR-induced mediator nitric oxide (NO) reproduced many of the effects of UVR. These studies suggest that UVR (sunlight exposure) may be an effective means of suppressing the development of obesity and MetS, through mechanisms that are independent of vitamin D but dependent on other UVR-induced mediators such as NO.
10.2337/db13-1675
Road Traffic and Railway Noise Exposures and Adiposity in Adults: A Cross-Sectional Analysis of the Danish Diet, Cancer, and Health Cohort.
Christensen Jeppe Schultz,Raaschou-Nielsen Ole,Tjønneland Anne,Overvad Kim,Nordsborg Rikke B,Ketzel Matthias,Sørensen Thorkild Ia,Sørensen Mette
Environmental health perspectives
BACKGROUND:Traffic noise has been associated with cardiovascular and metabolic disorders. Potential modes of action are through stress and sleep disturbance, which may lead to endocrine dysregulation and overweight. OBJECTIVES:We aimed to investigate the relationship between residential traffic and railway noise and adiposity. METHODS:In this cross-sectional study of 57,053 middle-aged people, height, weight, waist circumference, and bioelectrical impedance were measured at enrollment (1993-1997). Body mass index (BMI), body fat mass index (BFMI), and lean body mass index (LBMI) were calculated. Residential exposure to road and railway traffic noise exposure was calculated using the Nordic prediction method. Associations between traffic noise and anthropometric measures at enrollment were analyzed using general linear models and logistic regression adjusted for demographic and lifestyle factors. RESULTS:Linear regression models adjusted for age, sex, and socioeconomic factors showed that 5-year mean road traffic noise exposure preceding enrollment was associated with a 0.35-cm wider waist circumference (95% CI: 0.21, 0.50) and a 0.18-point higher BMI (95% CI: 0.12, 0.23) per 10 dB. Small, significant increases were also found for BFMI and LBMI. All associations followed linear exposure-response relationships. Exposure to railway noise was not linearly associated with adiposity measures. However, exposure > 60 dB was associated with a 0.71-cm wider waist circumference (95% CI: 0.23, 1.19) and a 0.19-point higher BMI (95% CI: 0.0072, 0.37) compared with unexposed participants (0-20 dB). CONCLUSIONS:The present study finds positive associations between residential exposure to road traffic and railway noise and adiposity.
10.1289/ehp.1409052
Green spaces, excess weight and obesity in Spain.
O'Callaghan-Gordo Cristina,Espinosa Ana,Valentin Antonia,Tonne Cathryn,Pérez-Gómez Beatriz,Castaño-Vinyals Gemma,Dierssen-Sotos Trinidad,Moreno-Iribas Conchi,de Sanjose Silvia,Fernandez-Tardón Guillermo,Vanaclocha-Espi Mercedes,Chirlaque María Dolores,Cirach Marta,Aragonés Nuria,Gómez-Acebo Inés,Ardanaz Eva,Moreno Víctor,Pollan Marina,Bustamante Mariona,Nieuwenhuijsen Mark J,Kogevinas Manolis
International journal of hygiene and environmental health
BACKGROUND:The epidemiological evidence on green spaces and obesity is inconsistent. OBJECTIVES:To study the association of access to green spaces and surrounding greenness with obesity in Spain. METHODS:We enrolled 2354 individuals 20-85 years from urban areas of seven provinces of Spain between 2008-13. Subjects were randomly selected population controls of the MCC-Spain case-control study. We geocoded current residences and defined exposures in a buffer of 300 m around them: i) access to green space, identified using Urban Atlas, and ii) levels of surrounding greenness, measured by the Normalized Difference Vegetation Index. We examined excess weight/obesity as binary outcomes based on body mass index and waist-hip ratio. We examined effect modification by genetic factors, sex and individual socio-economic status and mediation by physical activity and concentrations of PM and NO. To assess potential effect modification by genetic factors, we used a polygenic risk score based on obesity polymorphisms detected in genome-wide association studies. We used logistic mixed-effects models with a random effect for catchment area adjusted for potential confounders. RESULTS:Access to green space was associated with a reduced risk of excess weight/obesity after adjusting for confounders [excess weight: OR (95%CI) = 0.82 (0.63, 1.07), p-value = 0.143; abdominal obesity: OR (95%CI) = 0.68 (0.45, 1.01), p-value = 0.057]. In the stratified analysis, this association was only observed in women. Associations between surrounding greenness and excess weight/obesity were null or modest based on a 1 IQR increase in NDVI [excess weight: OR (95%CI) = 0.99 (0.88, 1.11), p-value = 0.875; abdominal obesity: OR (95%CI) = 0.91 (0.79, 1.05), p-value = 0.186]. The observed associations were not mediated by physical activity or air pollution. DISCUSSION:Access to green space may be associated with decreased risk of excess weight/obesity among women in Spain. Mechanisms explaining this association remain unclear.
10.1016/j.ijheh.2019.10.007
Ambient air pollution and overweight and obesity in school-aged children in Barcelona, Spain.
de Bont Jeroen,Casas Maribel,Barrera-Gómez Jose,Cirach Marta,Rivas Ioar,Valvi Damaskini,Álvarez Mar,Dadvand Payam,Sunyer Jordi,Vrijheid Martine
Environment international
BACKGROUND:Ambient air pollution may increase the risk of overweight and obesity in children. However, available evidence is still scarce and has mainly focused on ambient air pollution exposure occurring at home without considering the school environment. The aim of this study is to assess whether exposure to ambient air pollution at home and school is associated with overweight and obesity in primary school children. METHODS:We studied 2660 children aged 7-10 years during 2012 in Barcelona. Child weight and height were measured and age- and sex-specific z-scores for body mass index (zBMI) were calculated using the WHO growth reference 2007. Overweight and obesity were defined using the same reference. Land use regression models were used to estimate levels of nitrogen dioxide (NO), particulate matter <2.5 μm (PM), <10 μm (PM) and coarse (PM) at home. Outdoor levels of NO, PM, elemental carbon (EC), and ultrafine particles (UFP) were measured in the schoolyard. Multilevel mixed linear and ordered logistic models were used to assess the association between ambient air pollution (continuous per interquartile range (IQR) increase and categorical with tertile cutoffs) and zBMI (continuous and ordinal: normal, overweight, obese), after adjusting for socio-demographic characteristics. RESULTS:An IQR increase in PM-home (5.6 μg/m) was associated with a 10% increase in the odds of being overweight or obese (odds ratio (OR) = 1.10; 95% CI = 1.00, 1.22). Children exposed to the highest tertile of UFP-school (>27,346 particles/cm) had a 30% higher odds of being overweight or obese (OR = 1.30; 95%CI = 1.03, 1.64) compared to the lowest tertile of UFP exposure. We also observed that exposure to NO, PM or EC at schools was associated with higher odds of overweight or obese at medium compared to low levels of exposure. Home and school exposures did not show any significant associations with zBMI (except PM-school comparing tertile 2 vs tertile 1) but were similar in direction. CONCLUSIONS:This study suggests that exposure to ambient air pollution, especially at school, is associated with childhood risk for overweight and obesity. A cautious interpretation is warranted because associations were not always linear and because school and home air pollution measurements were not directly comparable.
10.1016/j.envint.2019.01.048
Ambient Air Pollutants Have Adverse Effects on Insulin and Glucose Homeostasis in Mexican Americans.
Chen Zhanghua,Salam Muhammad T,Toledo-Corral Claudia,Watanabe Richard M,Xiang Anny H,Buchanan Thomas A,Habre Rima,Bastain Theresa M,Lurmann Fred,Wilson John P,Trigo Enrique,Gilliland Frank D
Diabetes care
OBJECTIVE:Recent studies suggest that air pollution plays a role in type 2 diabetes (T2D) incidence and mortality. The underlying physiological mechanisms have yet to be established. We hypothesized that air pollution adversely affects insulin sensitivity and secretion and serum lipid levels. RESEARCH DESIGN AND METHODS:Participants were selected from BetaGene (n = 1,023), a study of insulin resistance and pancreatic β-cell function in Mexican Americans. All participants underwent DXA and oral and intravenous glucose tolerance tests and completed dietary and physical activity questionnaires. Ambient air pollutant concentrations (NO2, O3, and PM2.5) for short- and long-term periods were assigned by spatial interpolation (maximum interpolation radius of 50 km) of data from air quality monitors. Traffic-related air pollution from freeways (TRAP) was estimated using the dispersion model as NOx. Variance component models were used to analyze individual and multiple air pollutant associations with metabolic traits. RESULTS:Short-term (up to 58 days cumulative lagged averages) exposure to PM2.5 was associated with lower insulin sensitivity and HDL-to-LDL cholesterol ratio and higher fasting glucose and insulin, HOMA-IR, total cholesterol, and LDL cholesterol (LDL-C) (all P ≤ 0.036). Annual average PM2.5 was associated with higher fasting glucose, HOMA-IR, and LDL-C (P ≤ 0.043). The effects of short-term PM2.5 exposure on insulin sensitivity were largest among obese participants. No statistically significant associations were found between TRAP and metabolic outcomes. CONCLUSIONS:Exposure to ambient air pollutants adversely affects glucose tolerance, insulin sensitivity, and blood lipid concentrations. Our findings suggest that ambient air pollutants may contribute to the pathophysiology in the development of T2D and related sequelae.
10.2337/dc15-1795
Urban residential greenness and adiposity: A cohort study in Stockholm County.
Persson Å,Pyko A,Lind T,Bellander T,Östenson C-G,Pershagen G,Eriksson C,Lõhmus M
Environment international
BACKGROUND:Increasing evidence suggests that exposure to residential greenness is associated with positive health outcomes among urban populations. However, few studies have considered effects on adiposity development in a longitudinal setting. OBJECTIVES:This study aimed to explore the association between long-term exposure to urban residential greenness and markers of adiposity. METHODS:A cohort of 5126 adults from five municipalities in Stockholm County was examined clinically at baseline (1992-1998) and follow-up (2002-2006) after on average nine years. Time-weighted average exposure to urban greenness was estimated by Normalized Difference Vegetation Index (NDVI) within 100 m, 250 m, and 500 m buffers around the residential addresses of each participant. Multiple linear and Poisson regression models were used to estimate associations between greenness and change in weight and waist circumference as well as risk of overweight, obesity and central obesity. Co-exposures to air pollution, traffic noise and distance to water were also examined. RESULTS:In women, higher levels of residential greenness were associated with a reduced increase in waist circumference during follow-up (β = -0.11 cm/year, 95% CI -0.14; -0.08 per one interquartile range increase in NDVI) and decreased risk for central obesity (IRR = 0.88: 95% CI 0.79; 0.99) in the 500 m buffer. No associations were observed for men or with regard to weight development or the risk of developing overweight or obesity. Exposure to low NDVI levels in combination with high NO from road traffic and transportation noise as well as long distance to water rendered statistically significant increases in waist circumference in both sexes. CONCLUSION:Higher long-term exposure to greenness was associated with a reduced increase in waist circumference and lower risk of central adiposity in women but not in men. In both sexes, low NDVI exposure in combination with other environmental risk factors appeared particularly harmful.
10.1016/j.envint.2018.10.009
Adverse Cardiovascular Effects of Traffic Noise with a Focus on Nighttime Noise and the New WHO Noise Guidelines.
Münzel Thomas,Kröller-Schön Swenja,Oelze Matthias,Gori Tommaso,Schmidt Frank P,Steven Sebastian,Hahad Omar,Röösli Martin,Wunderli Jean-Marc,Daiber Andreas,Sørensen Mette
Annual review of public health
Exposure to traffic noise is associated with stress and sleep disturbances. The World Health Organization (WHO) recently concluded that road traffic noise increases the risk for ischemic heart disease and potentially other cardiometabolic diseases, including stroke, obesity, and diabetes. The WHO report focused on whole-day noise exposure, but new epidemiological and translational field noise studies indicate that nighttime noise, in particular,is an important risk factor for cardiovascular disease (CVD) through increased levels of stress hormones and vascular oxidative stress, leading to endothelial dysfunction and subsequent development of various CVDs. Novel experimental studies found noise to be associated with oxidative stress-induced vascular and brain damage, mediated by activation of the NADPH oxidase, uncoupling of endothelial and neuronal nitric oxide synthase, and vascular/brain infiltration with inflammatory cells. Noise-induced pathophysiology was more pronounced in response to nighttime as compared with daytime noise. This review focuses on the consequences of nighttime noise.
10.1146/annurev-publhealth-081519-062400
Long-term exposure to transportation noise and its association with adiposity markers and development of obesity.
Foraster Maria,Eze Ikenna C,Vienneau Danielle,Schaffner Emmanuel,Jeong Ayoung,Héritier Harris,Rudzik Franziska,Thiesse Laurie,Pieren Reto,Brink Mark,Cajochen Christian,Wunderli Jean-Marc,Röösli Martin,Probst-Hensch Nicole
Environment international
The contribution of different transportation noise sources to metabolic disorders such as obesity remains understudied. We evaluated the associations of long-term exposure to road, railway and aircraft noise with measures of obesity and its subphenotypes using cross-sectional and longitudinal designs. We assessed 3796 participants from the population-based Swiss Cohort Study on Air Pollution and Lung and Heart Diseases (SAPALDIA), who attended the visits in 2001 (SAP2) and 2010/2011 (SAP3) and who were aged 29-72 at SAP2. At SAP2 we measured body mass index (BMI, kg/m). At SAP3 we measured BMI, waist circumference (centimetres) and Kyle body Fat Index (%) and derived overweight, central and general obesity. Longitudinally for BMI, we derived change in BMI, incidence of overweight and obesity and a 3-category outcome combining the latter two. We assigned source-specific 5-year mean noise levels before visits and during follow-up at the most exposed dwelling façade (Lden, dB), using Swiss noise models for 2001 and 2011 and participants' residential history. Models were adjusted for relevant confounders, including traffic-related air pollution. Exposure to road traffic noise was significantly associated with all adiposity subphenotypes, cross-sectionally (at SAP3) [e.g. beta (95% CI) per 10 dB, BMI: 0.39 (0.18; 0.59); waist circumference: 0.93 (0.37; 1.50)], and with increased risk of obesity, longitudinally (e.g. RR = 1.25, 95% CI: 1.04; 1.51, per 10 dB in 5-year mean). Railway noise was significantly related to increased risk of overweight. In cross-sectional analyses, we further identified a stronger association between road traffic noise and BMI among participants with cardiovascular disease and an association between railway noise and BMI among participants reporting bad sleep. Associations were independent of the other noise sources, air pollution and robust to all adjustment sets. No associations were observed for aircraft noise. Long-term exposure to transportation noise, particularly road traffic noise, may increase the risk of obesity and could constitute a pathway towards cardiometabolic and other diseases.
10.1016/j.envint.2018.09.057
Long-Term Exposure to Transportation Noise in Relation to Development of Obesity—a Cohort Study.
Pyko Andrei,Eriksson Charlotta,Lind Tomas,Mitkovskaya Natalya,Wallas Alva,Ögren Mikael,Östenson Claes-Göran,Pershagen Göran
Environmental health perspectives
BACKGROUND:Exposure to transportation noise is widespread and has been associated with obesity in some studies. However, the evidence from longitudinal studies is limited and little is known about effects of combined exposure to different noise sources. OBJECTIVES:The aim of this longitudinal study was to estimate the association between exposure to noise from road traffic, railways, or aircraft and the development of obesity markers. METHODS:We assessed individual long-term exposure to road traffic, railway, and aircraft noise based on residential histories in a cohort of 5,184 men and women from Stockholm County. Noise levels were estimated at the most exposed façade of each dwelling. Waist circumference, weight, and height were measured at recruitment and after an average of 8.9 y of follow-up. Extensive information on potential confounders was available from repeated questionnaires and registers. RESULTS:Waist circumference increased 0.04 cm/y (95% CI: 0.02, 0.06) and 0.16 cm/y (95% CI: 0.14, 0.17) per 10 dB L in relation to road traffic and aircraft noise, respectively. No corresponding association was seen for railway noise. Weight gain was only related to aircraft noise exposure. A similar pattern occurred for incidence rate ratios (IRRs) of central obesity and overweight. The IRR of central obesity increased from 1.22 (95% CI: 1.08, 1.39) in those exposed to only one source of transportation noise to 2.26 (95% CI: 1.55, 3.29) among those exposed to all three sources. CONCLUSION:Our results link transportation noise exposure to development of obesity and suggest that combined exposure from different sources may be particularly harmful. https://doi.org/10.1289/EHP1910.
10.1289/EHP1910
Effects of climatic variables on weight loss: a global analysis.
Ustulin Morena,Keum Changwon,Woo Junghoon,Woo Jeong-Taek,Rhee Sang Youl
Scientific reports
Several studies have analyzed the effects of weather on factors associated with weight loss. In this study, we directly analyzed the effect of weather on intentional weight loss using global-scale data provided by smartphone applications. Through Weather Underground API and the Noom Coach application, we extracted information on weather and body weight for each user located in each of several geographic areas on all login days. We identified meteorological information (pressure, precipitation, wind speed, dew point, and temperature) and self-monitored body weight data simultaneously. A linear mixed-effects model was performed analyzing 3274 subjects. Subjects in North America had higher initial BMIs than those of subjects in Eastern Asia. During the study period, most subjects who used the smartphone application experienced weight loss in a significant way (80.39%, p-value < 0.001). Subjects who infrequently recorded information about dinner had smaller variations than those of other subjects (β = 0.007, p-value < 0.001). Colder temperature, lower dew point, and higher values for wind speed and precipitation were significantly associated with weight loss. In conclusion, we found a direct and independent impact of meteorological conditions on intentional weight loss efforts on a global scale (not only on a local level).
10.1038/srep40708
Contribution of daily and seasonal biorhythms to obesity in humans.
Kanikowska Dominika,Sato Maki,Witowski Janusz
International journal of biometeorology
While the significance of obesity as a serious health problem is well recognized, little is known about whether and how biometerological factors and biorhythms causally contribute to obesity. Obesity is often associated with altered seasonal and daily rhythmicity in food intake, metabolism and adipose tissue function. Environmental stimuli affect both seasonal and daily rhythms, and the latter are under additional control of internal molecular oscillators, or body clocks. Modifications of clock genes in animals and changes to normal daily rhythms in humans (as in shift work and sleep deprivation) result in metabolic dysregulation that favours weight gain. Here, we briefly review the potential links between biorhythms and obesity in humans.
10.1007/s00484-014-0871-z
Near-roadway air pollution exposure and altered fatty acid oxidation among adolescents and young adults - The interplay with obesity.
Environment international
BACKGROUND:Air pollution exposure has been shown to increase the risk of obesity and metabolic dysfunction in animal models and human studies. However, the metabolic pathways altered by air pollution exposure are unclear, especially in adolescents and young adults who are at a critical period in the development of cardio-metabolic diseases. OBJECTIVES:The aim of this study was to examine the associations between air pollution exposure and indices of fatty acid and amino acid metabolism. METHODS:A total of 173 young adults (18-23 years) from eight Children's Health Study (CHS) Southern California communities were examined from 2014 to 2018. Near-roadway air pollution (NRAP) exposure (freeway and non-freeway) and regional air pollution exposure (nitrogen dioxide, ozone and particulate matter) during one year before the study visit were estimated based on participants' residential addresses. Serum concentrations of 64 targeted metabolites including amino acids, acylcarnitines, non-esterified fatty acid (NEFA) and glycerol were measured in fasting serum samples. Principal component analysis of metabolites was performed to identify metabolite clusters that represent key metabolic pathways. Mixed effects models were used to analyze the associations of air pollution exposure with metabolomic principal component (PC) scores and individual metabolite concentrations adjusting for potential confounders. RESULTS:Higher lagged one-year averaged non-freeway NRAP exposure was associated with higher concentrations of NEFA oxidation byproducts and higher NEFA-related PC score (all p's ≤ 0.038). The effect sizes were larger among obese individuals (interaction p = 0.047). Among females, higher freeway NRAP exposure was also associated with a higher NEFA-related PC score (p = 0.042). Among all participants, higher freeway NRAP exposure was associated with a lower PC score for lower concentrations of short- and median-chain acylcarnitines (p = 0.044). CONCLUSIONS:Results of this study indicate that NRAP exposure is associated with altered fatty acid metabolism, which could contribute to the metabolic perturbation in obese youth.
10.1016/j.envint.2019.104935
Hypobaric hypoxia causes body weight reduction in obese subjects.
Lippl Florian J,Neubauer Sonja,Schipfer Susanne,Lichter Nicole,Tufman Amanda,Otto Bärbel,Fischer Rainald
Obesity (Silver Spring, Md.)
The reason for weight loss at high altitudes is largely unknown. To date, studies have been unable to differentiate between weight loss due to hypobaric hypoxia and that related to increased physical exercise. The aim of our study was to examine the effect of hypobaric hypoxia on body weight at high altitude in obese subjects. We investigated 20 male obese subjects (age 55.7 +/- 4.1 years, BMI 33.7 +/- 1.0 kg/m(2)). Body weight, waist circumference, basal metabolic rate (BMR), nutrition protocols, and objective activity parameters as well as metabolic and cardiovascular parameters, blood gas analysis, leptin, and ghrelin were determined at low altitude (LA) (Munich 530 m, D1), at the beginning and at the end of a 1-week stay at high altitude (2,650 m, D7 and D14) and 4 weeks after returning to LA (D42). Although daily pace counting remained stable at high altitude, at D14 and D42, participants weighed significantly less and had higher BMRs than at D1. Food intake was decreased at D7. Basal leptin levels increased significantly at high altitude despite the reduction in body weight. Diastolic blood pressure was significantly lower at D7, D14, and D42 compared to D1. This study shows that obese subjects lose weight at high altitudes. This may be due to a higher metabolic rate and reduced food intake. Interestingly, leptin levels rise in high altitude despite reduced body weight. Hypobaric hypoxia seems to play a major role, although the physiological mechanisms remain unclear. Weight loss at high altitudes was associated with clinically relevant improvements in diastolic blood pressure.
10.1038/oby.2009.509
Inverse association between altitude and obesity: A prevalence study among andean and low-altitude adult individuals of Peru.
Woolcott Orison O,Gutierrez Cesar,Castillo Oscar A,Elashoff Robert M,Stefanovski Darko,Bergman Richard N
Obesity (Silver Spring, Md.)
OBJECTIVE:To determine the association between altitude and obesity in a nationally representative sample of the Peruvian adult population. METHODS:This is a cross-sectional analysis of publicly available data from the Food and Nutrition National Center (CENAN, Peru), period 2009-2010. The Prevalence ratio of obesity and abdominal obesity was determined as a measure of association. Obesity and abdominal obesity were diagnosed based on direct anthropometric measurements. RESULTS:The final data set consisted of 31,549 individuals ≥20 years old. The prevalence ratio of obesity was as follows: 1.00 between 0 and 499 m (reference category), 1.00 (95% confidence interval 0.87-1.16) between 500-1,499 m, 0.74 (0.63-0.86) between 1,500-2,999 m, and 0.54 (0.45-0.64) at ≥3,000 m, adjusting for age, sex, self-reported physical activity, out-migration rate, urbanization, poverty, education, and geographical latitude and longitude. In the same order, the adjusted prevalence ratio of abdominal obesity was 1.00, 1.01 (0.94-1.07), 0.93 (0.87-0.99), and 0.89 (0.82-0.95), respectively. We found an interaction between altitude and sex and between altitude and age (P < 0.001, for both interactions) on the association with obesity and abdominal obesity. CONCLUSIONS:Among Peruvian adult individuals, we found an inverse association between altitude and obesity, adjusting for multiple covariates. This adjusted association varied by sex and age.
10.1002/oby.21401
Air Pollution as a Cause of Obesity: Micro-Level Evidence from Chinese Cities.
Yang Zhiming,Song Qianhao,Li Jing,Zhang Yunquan
International journal of environmental research and public health
Chinese air pollution is obviously increasing, and the government makes efforts to strengthen air pollution treatment. Although adverse health effects gradually emerge, research determining individual vulnerability is limited. This study estimated the relationship between air pollution and obesity. Individual information of 13,414 respondents from 125 cities is used in the analysis. This study employs ordinary least squares (OLS) and multinomial logit model (m-logit) to estimate the impact of air pollution on obesity. We choose different air pollution and Body Mass Index (BMI) indicators for estimation. Empirical results show Air Quality Index (AQI) is significantly positively associated with the BMI score. As AQI adds one unit, the BMI score increases 0.031 (SE = 0.002; < 0.001). The influence coefficients of particle size smaller than 2.5 μm (PM), particle size smaller than 10 μm (PM), carbon monoxide (CO), nitrogen dioxide (NO), ozone (O), and sulfur dioxide (SO) to the BMI score are 0.034 (SE = 0.002; < 0.001), 0.023 (SE = 0.001; < 0.001), 0.52 (SE = 0.095; < 0.001), 0.045 (SE = 0.004; < 0.001), 0.021 (SE = 0.002; < 0.001), 0.008 (SE = 0.003; = 0.015), respectively. Generally, air pollution has an adverse effect on body weight. CO is the most influential pollutant, and female, middle-aged, and low-education populations are more severely affected. The results confirm that the adverse health effects of air pollution should be considered when making the air pollution policies. Findings also provide justification for health interventions, especially for people with obesity.
10.3390/ijerph16214296
Association between light at night, melatonin secretion, sleep deprivation, and the internal clock: Health impacts and mechanisms of circadian disruption.
Touitou Yvan,Reinberg Alain,Touitou David
Life sciences
Exposure to Artificial Light At Night (ALAN) results in a disruption of the circadian system, which is deleterious to health. In industrialized countries, 75% of the total workforce is estimated to have been involved in shift work and night work. Epidemiologic studies, mainly of nurses, have revealed an association between sustained night work and a 50-100% higher incidence of breast cancer. The potential and multifactorial mechanisms of the effects include the suppression of melatonin secretion by ALAN, sleep deprivation, and circadian disruption. Shift and/or night work generally decreases the time spent sleeping, and it disrupts the circadian time structure. In the long run, this desynchronization is detrimental to health, as underscored by a large number of epidemiological studies that have uncovered elevated rates of several diseases, including cancer, diabetes, cardiovascular risks, obesity, mood disorders and age-related macular degeneration. It amounts to a public health issue in the light of the very substantial number of individuals involved. The IARC has classified shift work in group 2A of "probable carcinogens to humans" since "they involve a circadian disorganization". Countermeasures to the effects of ALAN, such as melatonin, bright light, or psychotropic drugs, have been proposed as a means to combat circadian clock disruption and improve adaptation to shift and night work. We review the evidence for the ALAN impacts on health. Furthermore, we highlight the importance of an in-depth mechanistic understanding to combat the detrimental properties of exposure to ALAN and develop strategies of prevention.
10.1016/j.lfs.2017.02.008
Invited commentary: nighttime light exposure as a risk factor for obesity through disruption of circadian and circannual rhythms.
Gangwisch James E
American journal of epidemiology
In this issue of the American Journal of Epidemiology, McFadden et al. (Am J Epidemiol. 2014;180(3):245-250) report findings on the relationship between light exposure at night and obesity from a cross-sectional study of United Kingdom women. Their research extends findings from a previous study with elderly participants by including a larger sample size of over 100,000 women and a broader age range of 16 years or older. The findings are consistent with animal studies showing that prolonged light exposure leads to weight gain. Humans' circadian, circannual, and metabolic regulatory systems evolved to be adaptive in environments that were quite different from those faced in modern industrial society. Technology has allowed exposures to levels and timing of light, nutrient intake, and physical activity never before possible. This commentary discusses how nighttime light exposure can increase the risk of obesity and the metabolic syndrome by disrupting circadian and circannual rhythms.
10.1093/aje/kwu119
Sun Exposure and Its Effects on Human Health: Mechanisms through Which Sun Exposure Could Reduce the Risk of Developing Obesity and Cardiometabolic Dysfunction.
International journal of environmental research and public health
Obesity is a significant burden on global healthcare due to its high prevalence and associations with chronic health conditions. In our animal studies, ongoing exposure to low dose ultraviolet radiation (UVR, found in sunlight) reduced weight gain and the development of signs of cardiometabolic dysfunction in mice fed a high fat diet. These observations suggest that regular exposure to safe levels of sunlight could be an effective means of reducing the burden of obesity. However, there is limited knowledge around the nature of associations between sun exposure and the development of obesity and cardiometabolic dysfunction, and we do not know if sun exposure (independent of outdoor activity) affects the metabolic processes that determine obesity in humans. In addition, excessive sun exposure has strong associations with a number of negative health consequences such as skin cancer. This means it is very important to "get the balance right" to ensure that we receive benefits without increasing harm. In this review, we detail the evidence around the cardiometabolic protective effects of UVR and suggest mechanistic pathways through which UVR could be beneficial.
10.3390/ijerph13100999
Global warming and obesity: a systematic review.
An R,Ji M,Zhang S
Obesity reviews : an official journal of the International Association for the Study of Obesity
Global warming and the obesity epidemic are two unprecedented challenges mankind faces today. A literature search was conducted in the PubMed, Web of Science, EBSCO and Scopus for articles published until July 2017 that reported findings on the relationship between global warming and the obesity epidemic. Fifty studies were identified. Topic-wise, articles were classified into four relationships - global warming and the obesity epidemic are correlated because of common drivers (n = 21); global warming influences the obesity epidemic (n = 13); the obesity epidemic influences global warming (n = 13); and global warming and the obesity epidemic influence each other (n = 3). We constructed a conceptual model linking global warming and the obesity epidemic - the fossil fuel economy, population growth and industrialization impact land use and urbanization, motorized transportation and agricultural productivity and consequently influences global warming by excess greenhouse gas emission and the obesity epidemic by nutrition transition and physical inactivity; global warming also directly impacts obesity by food supply/price shock and adaptive thermogenesis, and the obesity epidemic impacts global warming by the elevated energy consumption. Policies that endorse deployment of clean and sustainable energy sources, and urban designs that promote active lifestyles, are likely to alleviate the societal burden of global warming and obesity.
10.1111/obr.12624
Impact of ambient air pollution on obesity: a systematic review.
An Ruopeng,Ji Mengmeng,Yan Hai,Guan Chenghua
International journal of obesity (2005)
BACKGROUND/OBJECTIVES:Over 80% of the global populations living in urban areas are exposed to air quality levels that exceed the World Health Organization limits. Air pollution may lead to unhealthy body weight through metabolic dysfunction, chronic disease onset, and disruption of regular physical activity. SUBJECTS/METHODS:A literature search was conducted in the PubMed and Web of Science for peer-reviewed articles published until September 2017 that assessed the relationship between air pollution and body weight status. A standardized data extraction form was used to collect methodological and outcome variables from each eligible study. RESULTS:Sixteen studies met the selection criteria and were included in the review. They were conducted in seven countries, including the US (n = 9), China (n = 2), Canada (n = 1), Italy (n = 1), The Netherlands (n = 1), Serbia (n = 1), and South Korea (n = 1). Half of them adopted a longitudinal study design, and the rest adopted a cross-sectional study design. Commonly examined air pollutants included PM, NO, SO, O, and overall air quality index. Among a total of 66 reported associations between air pollution and body weight status, 29 (44%) found air pollution to be positively associated with body weight, 29 (44%) reported a null finding, and the remaining eight (12%) found air pollution to be negatively associated with body weight. The reported associations between air pollution and body weight status varied by sex, age group, and type of air pollutant. Three pathways hypothesized in the selected studies were through increased oxidative stress and adipose tissue inflammation, elevated risk for chronic comorbidities, and insufficient physical activity. CONCLUSIONS:Concurrent evidence regarding the impact of air pollution on body weight status remains mixed. Future studies should assess the impact of severe air pollution on obesity in developing countries, focus on a homogenous population subgroup, and elucidate the biomedical and psychosocial pathways linking air pollution to body weight.
10.1038/s41366-018-0089-y
The bright-nights and dim-days of the urban photoperiod: implications for circadian rhythmicity, metabolism and obesity.
Wyse Cathy A,Biello Stephany M,Gill Jason M R
Annals of medicine
Artificial light decreases the amplitude of daily rhythms in human lifestyle principally by permitting activity and food intake to occur during hours of darkness, and allowing day-time activity to occur in dim light, indoors. Endogenous circadian timing mechanisms that oscillate with a period of 24 h have evolved to ensure physiology is synchronized with the daily variations in light, food, and social cues of the environment. Artificial light affects the synchronization between these oscillators, and metabolic disruption may be one consequence of this. By dampening the amplitude of environmental timing cues and disrupting circadian rhythmicity, artificial lighting might initiate metabolic disruption and contribute to the association between global urbanization and obesity. The aim of this review is to explore the historical, physiological, and epidemiological relationships between artificial light and circadian and metabolic dysfunction.
10.3109/07853890.2014.913422
Ambient Light Exposure and Changes in Obesity Parameters: A Longitudinal Study of the HEIJO-KYO Cohort.
Obayashi Kenji,Saeki Keigo,Kurumatani Norio
The Journal of clinical endocrinology and metabolism
CONTEXT:Previous epidemiological studies have suggested an association between nighttime light levels and the prevalence of obesity, although evidence is limited to cross-sectional studies. OBJECTIVE:To evaluate the longitudinal association between ambient light exposure and the subsequent changes in obesity parameters. DESIGN AND PARTICIPANTS:Data from 1110 elderly participants at baseline (mean age, 71.9 years) and data from 766 at follow-up (median, 21 months) were included in this prospective population-based study. MEASURES:Time-dependent ambient light exposure based on objective measurements and changes in the waist-to-height ratio (WHtR) and body mass index (BMI) were measured. RESULTS:Multivariable mixed-effect linear regression models showed a significant association between light exposure and the %WHtR gain; this was independent of potential confounders (eg, caloric intake, physical activity, and sleep/wake parameters). Nighttime or evening exposure to higher light intensity was significantly associated with subsequent %WHtR gain. Morning exposure to a longer time ≥500 lux or nighttime exposure to a longer time <3 lux was significantly associated with subsequent %WHtR loss. These association trends were nearly consistent when the BMI was used as an obesity parameter. Increased nighttime light exposure (mean ≥3 vs <3 lux) was estimated to correspond to a 10.2% WHtR gain and a 10.0% increase in BMI over 10 years. CONCLUSIONS:Ambient light exposure, such as increased nighttime or evening light exposure and decreased morning light exposure, was independently associated with subsequent increases in obesity parameters. Further interventional studies are warranted to establish an optimal controlled lighting environment as a preventive option against obesity.
10.1210/jc.2015-4123
The relationship between obesity and exposure to light at night: cross-sectional analyses of over 100,000 women in the Breakthrough Generations Study.
McFadden Emily,Jones Michael E,Schoemaker Minouk J,Ashworth Alan,Swerdlow Anthony J
American journal of epidemiology
There has been a worldwide epidemic of obesity in recent decades. In animal studies, there is convincing evidence that light exposure causes weight gain, even when calorie intake and physical activity are held constant. Disruption of sleep and circadian rhythms by exposure to light at night (LAN) might be one mechanism contributing to the rise in obesity, but it has not been well-investigated in humans. Using multinomial logistic regression, we examined the association between exposure to LAN and obesity in questionnaire data from over 100,000 women in the Breakthrough Generations Study, a cohort study of women aged 16 years or older who were living in the United Kingdom and recruited during 2003-2012. The odds of obesity, measured using body mass index, waist:hip ratio, waist:height ratio, and waist circumference, increased with increasing levels of LAN exposure (P < 0.001), even after adjustment for potential confounders such as sleep duration, alcohol intake, physical activity, and current smoking. We found a significant association between LAN exposure and obesity which was not explained by potential confounders we could measure. While the possibility of residual confounding cannot be excluded, the pattern is intriguing, accords with the results of animal experiments, and warrants further investigation.
10.1093/aje/kwu117
Alterations of circadian rhythms and their impact on obesity, metabolic syndrome and cardiovascular diseases.
Hernández-García Javier,Navas-Carrillo Diana,Orenes-Piñero Esteban
Critical reviews in food science and nutrition
Circadian system is comprised by central circadian pacemaker and several peripheral clocks that receive information from the external environment, synchronizing the circadian clocks. It is widely known that physiology is rhythmic and that the rupture of this rhythmicity can generate serious consequences. Circadian clocks, led by suprachiasmatic nucleus (SCN) in the central nervous system, are the responsible for generating this biological rhythmicity. These clocks are affected by external signals such as light (changes between day and night) and feeding rhythms. In this review, the basic principles of the circadian system and current knowledge of biological clocks are addressed, analyzing the relationship between circadian system, food intake, nutrition, and associated metabolic processes. In addition, the consequences occurring when these systems are not well coordinated with each other, such as the development of cardiovascular and metabolic pathologies, will be thoroughly discussed.
10.1080/10408398.2018.1556579
Trends in adult body-mass index in 200 countries from 1975 to 2014: a pooled analysis of 1698 population-based measurement studies with 19·2 million participants.
Lancet (London, England)
BACKGROUND:Underweight and severe and morbid obesity are associated with highly elevated risks of adverse health outcomes. We estimated trends in mean body-mass index (BMI), which characterises its population distribution, and in the prevalences of a complete set of BMI categories for adults in all countries. METHODS:We analysed, with use of a consistent protocol, population-based studies that had measured height and weight in adults aged 18 years and older. We applied a Bayesian hierarchical model to these data to estimate trends from 1975 to 2014 in mean BMI and in the prevalences of BMI categories (<18·5 kg/m(2) [underweight], 18·5 kg/m(2) to <20 kg/m(2), 20 kg/m(2) to <25 kg/m(2), 25 kg/m(2) to <30 kg/m(2), 30 kg/m(2) to <35 kg/m(2), 35 kg/m(2) to <40 kg/m(2), ≥40 kg/m(2) [morbid obesity]), by sex in 200 countries and territories, organised in 21 regions. We calculated the posterior probability of meeting the target of halting by 2025 the rise in obesity at its 2010 levels, if post-2000 trends continue. FINDINGS:We used 1698 population-based data sources, with more than 19·2 million adult participants (9·9 million men and 9·3 million women) in 186 of 200 countries for which estimates were made. Global age-standardised mean BMI increased from 21·7 kg/m(2) (95% credible interval 21·3-22·1) in 1975 to 24·2 kg/m(2) (24·0-24·4) in 2014 in men, and from 22·1 kg/m(2) (21·7-22·5) in 1975 to 24·4 kg/m(2) (24·2-24·6) in 2014 in women. Regional mean BMIs in 2014 for men ranged from 21·4 kg/m(2) in central Africa and south Asia to 29·2 kg/m(2) (28·6-29·8) in Polynesia and Micronesia; for women the range was from 21·8 kg/m(2) (21·4-22·3) in south Asia to 32·2 kg/m(2) (31·5-32·8) in Polynesia and Micronesia. Over these four decades, age-standardised global prevalence of underweight decreased from 13·8% (10·5-17·4) to 8·8% (7·4-10·3) in men and from 14·6% (11·6-17·9) to 9·7% (8·3-11·1) in women. South Asia had the highest prevalence of underweight in 2014, 23·4% (17·8-29·2) in men and 24·0% (18·9-29·3) in women. Age-standardised prevalence of obesity increased from 3·2% (2·4-4·1) in 1975 to 10·8% (9·7-12·0) in 2014 in men, and from 6·4% (5·1-7·8) to 14·9% (13·6-16·1) in women. 2·3% (2·0-2·7) of the world's men and 5·0% (4·4-5·6) of women were severely obese (ie, have BMI ≥35 kg/m(2)). Globally, prevalence of morbid obesity was 0·64% (0·46-0·86) in men and 1·6% (1·3-1·9) in women. INTERPRETATION:If post-2000 trends continue, the probability of meeting the global obesity target is virtually zero. Rather, if these trends continue, by 2025, global obesity prevalence will reach 18% in men and surpass 21% in women; severe obesity will surpass 6% in men and 9% in women. Nonetheless, underweight remains prevalent in the world's poorest regions, especially in south Asia. FUNDING:Wellcome Trust, Grand Challenges Canada.
10.1016/S0140-6736(16)30054-X
Environmental Determinants of Cardiovascular Disease.
Circulation research
Many features of the environment have been found to exert an important influence on cardiovascular disease (CVD) risk, progression, and severity. Changes in the environment because of migration to different geographic locations, modifications in lifestyle choices, and shifts in social policies and cultural practices alter CVD risk, even in the absence of genetic changes. Nevertheless, the cumulative impact of the environment on CVD risk has been difficult to assess and the mechanisms by which some environment factors influence CVD remain obscure. Human environments are complex, and their natural, social, and personal domains are highly variable because of diversity in human ecosystems, evolutionary histories, social structures, and individual choices. Accumulating evidence supports the notion that ecological features such as the diurnal cycles of light and day, sunlight exposure, seasons, and geographic characteristics of the natural environment such as altitude, latitude, and greenspaces are important determinants of cardiovascular health and CVD risk. In highly developed societies, the influence of the natural environment is moderated by the physical characteristics of the social environments such as the built environment and pollution, as well as by socioeconomic status and social networks. These attributes of the social environment shape lifestyle choices that significantly modify CVD risk. An understanding of how different domains of the environment, individually and collectively, affect CVD risk could lead to a better appraisal of CVD and aid in the development of new preventive and therapeutic strategies to limit the increasingly high global burden of heart disease and stroke.
10.1161/CIRCRESAHA.117.306458
Greenness around schools associated with lower risk of hypertension among children: Findings from the Seven Northeastern Cities Study in China.
Xiao Xiang,Yang Bo-Yi,Hu Li-Wen,Markevych Iana,Bloom Michael S,Dharmage Shyamali C,Jalaludin Bin,Knibbs Luke D,Heinrich Joachim,Morawska Lidia,Lin Shao,Roponen Marjut,Guo Yuming,Lam Yim Steve Hung,Leskinen Ari,Komppula Mika,Jalava Pasi,Yu Hong-Yao,Zeeshan Mohammed,Zeng Xiao-Wen,Dong Guang-Hui
Environmental pollution (Barking, Essex : 1987)
Evidence suggests that residential greenness may be protective of high blood pressure, but there is scarcity of evidence on the associations between greenness around schools and blood pressure among children. We aimed to investigate this association in China. Our study included 9354 children from 62 schools in the Seven Northeastern Cities Study. Greenness around each child's school was measured by NDVI (Normalized Difference Vegetation Index) and SAVI (Soil-Adjusted Vegetation Index). Particulate matter ≤ 1 μm (PM) concentrations were estimated by spatiotemporal models and nitrogen dioxide (NO) concentrations were collected from air monitoring stations. Associations between greenness and blood pressure were determined by generalized linear and logistic mixed-effect models. Mediation by air pollution was assessed using mediation analysis. Higher greenness was consistently associated with lower blood pressure. An increase of 0.1 in NDVI corresponded to a reduction in SBP of 1.39 mmHg (95% CI: 1.86, -0.93) and lower odds of hypertension (OR = 0.76, 95% CI: 0.69, 0.82). Stronger associations were observed in children with higher BMI. Ambient PM and NO mediated 33.0% and 10.9% of the association between greenness and SBP, respectively. In summary, greater greenness near schools had a beneficial effect on blood pressure, particularly in overweight or obese children in China. The associations might be partially mediated by air pollution. These results might have implications for policy makers to incorporate more green space for both aesthetic and health benefits.
10.1016/j.envpol.2019.113422
Association between community greenness and obesity in urban-dwelling Chinese adults.
Huang Wen-Zhong,Yang Bo-Yi,Yu Hong-Yao,Bloom Michael S,Markevych Iana,Heinrich Joachim,Knibbs Luke D,Leskinen Ari,Dharmage Shyamali C,Jalaludin Bin,Morawska Lidia,Jalava Pasi,Guo Yuming,Lin Shao,Zhou Yang,Liu Ru-Qing,Feng Dan,Hu Li-Wen,Zeng Xiao-Wen,Hu Qiang,Yu Yunjing,Dong Guang-Hui
The Science of the total environment
Living in greener places may protect against obesity, but epidemiological evidence is inconsistent and mainly comes from developed nations. We aimed to investigate the association between greenness and obesity in Chinese adults and to assess air pollution and physical activity as mediators of the association. We recruited 24,845 adults from the 33 Communities Chinese Health Study in 2009. Central and peripheral obesity were defined by waist circumference (WC) and body mass index (BMI), respectively, based on international obesity standards. The Normalized Difference Vegetation Index (NDVI) was used to quantify community greenness. Two-level logistic and generalized linear mixed regression models were used to evaluate the association between NDVI and obesity, and a conditional mediation analysis was used also performed. In the adjusted models, an interquartile range increase in NDVI was significantly associated with lower odds of peripheral 0.80 (95% confidence interval [CI]: 0.74-0.87) and central obesity 0.88 (95% CI: 0.83-0.93). Higher NDVI values were also significantly associated with lower BMI. Age, gender, and household income significantly modified associations between greenness and obesity, with stronger associations among women, older participants, and participants with lower household incomes. Air pollution mediated 2.1-20.8% of the greenness-obesity associations, but no mediating effects were observed for physical activity. In summary, higher community greenness level was associated with lower odds of central and peripheral obesity, especially among women, older participants, and those with lower household incomes. These associations were partially mediated by air pollutants. Future well-designed longitudinal studies are needed to confirm our findings.
10.1016/j.scitotenv.2019.135040
Evaluating causal relationships between urban built environment characteristics and obesity: a methodological review of observational studies.
Martin Adam,Ogilvie David,Suhrcke Marc
The international journal of behavioral nutrition and physical activity
BACKGROUND:Existing reviews identify numerous studies of the relationship between urban built environment characteristics and obesity. These reviews do not generally distinguish between cross-sectional observational studies using single equation analytical techniques and other studies that may support more robust causal inferences. More advanced analytical techniques, including the use of instrumental variables and regression discontinuity designs, can help mitigate biases that arise from differences in observable and unobservable characteristics between intervention and control groups, and may represent a realistic alternative to scarcely-used randomised experiments. This review sought first to identify, and second to compare the results of analyses from, studies using more advanced analytical techniques or study designs. METHODS:In March 2013, studies of the relationship between urban built environment characteristics and obesity were identified that incorporated (i) more advanced analytical techniques specified in recent UK Medical Research Council guidance on evaluating natural experiments, or (ii) other relevant methodological approaches including randomised experiments, structural equation modelling or fixed effects panel data analysis. RESULTS:Two randomised experimental studies and twelve observational studies were identified. Within-study comparisons of results, where authors had undertaken at least two analyses using different techniques, indicated that effect sizes were often critically affected by the method employed, and did not support the commonly held view that cross-sectional, single equation analyses systematically overestimate the strength of association. CONCLUSIONS:Overall, the use of more advanced methods of analysis does not appear necessarily to undermine the observed strength of association between urban built environment characteristics and obesity when compared to more commonly-used cross-sectional, single equation analyses. Given observed differences in the results of studies using different techniques, further consideration should be given to how evidence gathered from studies using different analytical approaches is appraised, compared and aggregated in evidence synthesis.
10.1186/s12966-014-0142-8
Environment and obesity in the National Children's Study.
Trasande Leonardo,Cronk Chris,Durkin Maureen,Weiss Marianne,Schoeller Dale A,Gall Elizabeth A,Hewitt Jeanne B,Carrel Aaron L,Landrigan Philip J,Gillman Matthew W
Environmental health perspectives
OBJECTIVE:In this review we describe the approach taken by the National Children's Study (NCS), a 21-year prospective study of 100,000 American children, to understanding the role of environmental factors in the development of obesity. DATA SOURCES AND EXTRACTION:We review the literature with regard to the two core hypotheses in the NCS that relate to environmental origins of obesity and describe strategies that will be used to test each hypothesis. DATA SYNTHESIS:Although it is clear that obesity in an individual results from an imbalance between energy intake and expenditure, control of the obesity epidemic will require understanding of factors in the modern built environment and chemical exposures that may have the capacity to disrupt the link between energy intake and expenditure. The NCS is the largest prospective birth cohort study ever undertaken in the United States that is explicitly designed to seek information on the environmental causes of pediatric disease. CONCLUSIONS:Through its embrace of the life-course approach to epidemiology, the NCS will be able to study the origins of obesity from preconception through late adolescence, including factors ranging from genetic inheritance to individual behaviors to the social, built, and natural environment and chemical exposures. It will have sufficient statistical power to examine interactions among these multiple influences, including gene-environment and gene-obesity interactions. A major secondary benefit will derive from the banking of specimens for future analysis.
10.1289/ehp.11839
Obesity and the natural environment across US counties.
von Hippel Paul,Benson Rebecca
American journal of public health
OBJECTIVES:We estimated the association between obesity and features of the natural environment. We asked whether the association is mediated by diet or by physical activity. METHODS:Using county-level data from the contiguous United States, we regressed adult obesity prevalence on 9 measures of the natural environment. Our regression model accounted for spatial correlation, and controlled for county demographics and the built environment. We included physical activity and diet (proxied by food purchases) as potential mediators. RESULTS:Obesity was more prevalent in counties that are hot in July or cold in January. To a lesser degree, obesity was more prevalent in counties that are dark in January or rainy (but not snowy) year-round. Other aspects of the natural environment-including wind, trees, waterfront, and hills and mountains-had little or no association with obesity. Nearly all of the association between obesity and the natural environment was mediated by physical activity; none was mediated by diet. CONCLUSIONS:Hot summers and cold winters appear to promote obesity by discouraging physical activity. Attempts to encourage physical activity should compensate for the effects of extreme temperatures.
10.2105/AJPH.2013.301838
Impact of the Social and Natural Environment on Preschool-Age Children Weight.
Petraviciene Inga,Grazuleviciene Regina,Andrusaityte Sandra,Dedele Audrius,Nieuwenhuijsen Mark J
International journal of environmental research and public health
The complex impact of environmental and social factors on preschool children being overweight/obese is unclear. We examined the associations between the levels of green space exposure and the risk of being overweight/obese for 4-6 year-old children and assessed the impact of maternal education on these associations. This cross-sectional study included 1489 mother-child pairs living in Kaunas, Lithuania, in 2012-2013. We assessed children overweight/obesity by standardized questionnaires using international body mass index cut-off points, and the level of greenness exposures by satellite-derived normalized difference vegetation index (NDVI) of each child's home and by the distance to a nearest city park. The maternal education was used as the SES indicator. We used logistic regression models to investigate the strength of the associations. Children from families with poorer maternal education, pathological mother-child relations and smoking mothers, and living in areas with less greenness exposure (NDVI-100 m), had significantly higher odds ratios of being overweight/obese. Lower maternal education and distance to a city park modified the effect of greenness cover level exposure on the risk of children being overweight/obese. Higher greenness exposure in the residential settings has beneficial effects on children's physical development. The green spaces exposures for psychosocial stress management is recommended as a measure to prevent overweight/obesity among children.
10.3390/ijerph15030449