Stroke is a heterogeneous syndrome, and determining risk factors and treatment depends on the specific pathogenesis of stroke. Risk factors for stroke can be categorized as modifiable and nonmodifiable. Age, sex, and race/ethnicity are nonmodifiable risk factors for both ischemic and hemorrhagic stroke, while hypertension, smoking, diet, and physical inactivity are among some of the more commonly reported modifiable risk factors. More recently described risk factors and triggers of stroke include inflammatory disorders, infection, pollution, and cardiac atrial disorders independent of atrial fibrillation. Single-gene disorders may cause rare, hereditary disorders for which stroke is a primary manifestation. Recent research also suggests that common and rare genetic polymorphisms can influence risk of more common causes of stroke, due to both other risk factors and specific stroke mechanisms, such as atrial fibrillation. Genetic factors, particularly those with environmental interactions, may be more modifiable than previously recognized. Stroke prevention has generally focused on modifiable risk factors. Lifestyle and behavioral modification, such as dietary changes or smoking cessation, not only reduces stroke risk, but also reduces the risk of other cardiovascular diseases. Other prevention strategies include identifying and treating medical conditions, such as hypertension and diabetes, that increase stroke risk. Recent research into risk factors and genetics of stroke has not only identified those at risk for stroke but also identified ways to target at-risk populations for stroke prevention.

BACKGROUND:Stroke is the leading cause of death in China. According to the Chinese Stroke Screening and Prevention Project, 8 main risk factors were assessed and individuals with 3 or more risk factors were identified as high-risk population of stroke. To explore the potential impropriety of counting the risk factors but ignoring the different strength of association of each risk factor, we performed this study. METHODS:Relevant databases were searched for case-control and cohort studies focusing on the risk factors of stroke. We systematically identified studies conducted between 1990 and 2015 that included data on the frequency of risk factors in Chinese Han populations. Pooled relative risks and odds ratios, with their 95% confidence intervals, were calculated for the cohort and case-control studies, respectively. RESULTS:Fifteen cohort studies and 178 case-control studies were identified. Hypertension was the strongest independent risk factor for stroke (pooled odds ratio, 3.50; pooled relative risk, 2.68). Diabetes mellitus, heart disease, family history of stroke, hyperlipidemia, overweight, and smoking were also mildly predictive (pooled odd ratios, 1.82-2.68; pooled relative risks, 1.27-2.47). By contrast, physical exercise was a protective factor against stroke (pooled odd ratio, .49). CONCLUSIONS:There was a measurable difference in the strength of association of the 8 risk factors with stroke; hypertension and diabetes were associated with the highest risks, indicating a need to focus resources on patients with these conditions. Giving risk factors equal weighting may not be an appropriate screening methodology.

OBJECTIVE:To examine whether social isolation and loneliness (1) predict acute myocardial infarction (AMI) and stroke among those with no history of AMI or stroke, (2) are related to mortality risk among those with a history of AMI or stroke, and (3) the extent to which these associations are explained by known risk factors or pre-existing chronic conditions. METHODS:Participants were 479 054 individuals from the UK Biobank. The exposures were self-reported social isolation and loneliness. AMI, stroke and mortality were the outcomes. RESULTS:Over 7.1 years, 5731 had first AMI, and 3471 had first stroke. In model adjusted for demographics, social isolation was associated with higher risk of AMI (HR 1.43, 95% CI 1.3 to -1.55) and stroke (HR 1.39, 95% CI 1.25 to 1.54). When adjusted for all the other risk factors, the HR for AMI was attenuated by 84% to 1.07 (95% CI 0.99 to 1.16) and the HR for stroke was attenuated by 83% to 1.06 (95% CI 0.96 to 1.19). Loneliness was associated with higher risk of AMI before (HR 1.49, 95% CI 1.36 to 1.64) but attenuated considerably with adjustments (HR 1.06, 95% CI 0.96 to 1.17). This was also the case for stroke (HR 1.36, 95% CI 1.20 to 1.55 before and HR 1.04, 95% CI 0.91 to 1.19 after adjustments). Social isolation, but not loneliness, was associated with increased mortality in participants with a history of AMI (HR 1.25, 95% CI 1.03 to 1.51) or stroke (HR 1.32, 95% CI 1.08 to 1.61) in the fully adjusted model. CONCLUSIONS:Isolated and lonely persons are at increased risk of AMI and stroke, and, among those with a history of AMI or stroke, increased risk of death. Most of this risk was explained by conventional risk factors.

Data on the sex-specific differences in risk of stroke among patients with H-type hypertension are limited. We aimed to analyze interactions between sex and other risk factors on stroke, including the sex-methylenetetrahydrofolate reductase (MTHFR) interaction. A retrospective analysis of baseline data from 2040 patients with hypertension and hyperhomocysteinemia (HHcy) included demographic characteristics, biomarkers, history of chronic diseases and lifestyle factors. Polymerase chain reaction-restriction fragment length polymorphism method was used to investigate the C677T polymorphism of MTHFR gene. We examined independent effects and interactions between sex and stratified factors on the risk of stroke by logistic regression model. A total of 1412 patients suffered stroke, and the prevalence of stroke was 70.65% in men and 66.53% in women. Both men and women had independent risk factors for stroke, including diabetes mellitus, atrial fibrillation, smoking, increased level of systolic blood pressure (SBP) and plasma total homocysteine (tHcy), as well as the decreased level of high-density lipoprotein cholesterol. Diastolic blood pressure (DBP) -specific risk of stroke was unique to men. Interactions between sex and other risk factors on stroke risk were statistically significant: age, fasting plasma glucose (FPG), SBP, DBP, triglycerides (TG) and tHcy. Furthermore, tHcy interacted with age, SBP and DBP in men, and age, SBP, DBP, FPG, and TG in women to modulate the risk of stroke. Although TT genotype did not have an independent effect on stroke, it could interact with sex and FPG, TG and SBP to increase stroke. In conclusion, sex-specific differences are useful to stratify the risk of stroke and assist clinicians in the decision to select a reasonable therapeutic option for high-risk patients.

OBJECTIVES:To explore the risk factors for stroke by using National Health and Nutrition Examination Survey (NHANES). METHODS:A total of 19384 cases from the NHANES database during 2005 to 2016 were included in this study, of which 661 were stroke patients, with a weighted prevalence of 2.60%. Univariate and multivariate logistic regression analysis was used to analyze possible risk factors for stroke. RESULTS:The risk of stroke was 1.839 times higher in subjects with diabetes than in those without diabetes, P<0.001. An average increase of 1 ug/dL in blood lead was associated with a 1.082-fold increase in stroke risk, P<0.001. Subjects with mild-, moderate-, and moderately severe or severe depression had a 1.567-fold, 1.836-fold, and 3.279-fold higher risk than those without depression respectively, P<0.001. The risk of stroke in subjects with sleep disorders was 1.622 times higher than those without sleep disorders, P<0.001. CONCLUSIONS:Patients with diabetes, lower household income (<$2000), PHQ-9 depression score (5-27), trouble sleep, older age and higher concentration of blood lead are associated with a higher risk of stroke.

BACKGROUND:The overall global burden of stroke is considerable and increasing. In China, stroke is the leading cause of death and disability. METHODS:For this study, we used data from the National Stroke Screening Survey in 2012 and the 2010 Chinese population from sixth National Census of Populations to calculate a standardized (by age, gender, and education) stroke prevalence. Prevalence, risk factors, and management of stroke were compared by gender, age, and site. FINDINGS:The standardized prevalence rate of survival stroke patients in study population aged 60 and older was 4.94% in total. Hypertension was the most prevalent risk factor for stroke. Compared to men, women were more likely to have diabetes, obesity, elevated low-density lipoprotein cholesterol (LDL-C), and atrial fibrillation (P < 0.05). Men were far more likely to drink and smoke than women (P < 0.05). The rates of diabetes and atrial fibrillation were substantially higher in urban than those in rural stroke survivors (P < 0.05). Rural stroke survivors exhibited higher rates of smoking and alcohol consumption than urban stroke survivors (P < 0.05). INTERPRETATION:The stroke prevalence in China is in line with median worldwide stroke prevalence. Traditional risk factors remain highly prevalent in stroke survivors, among which hypertension was the most common. Stroke prevalence rates and risk factors varied by age, sex, and sociogeological factors.