The association between sleep duration, napping, and stroke stratified by self-health status among Chinese people over 65 years old from the China health and retirement longitudinal study

Abstract
Purpose Stroke is a major cause of death in China. This study aimed to investigate the association between sleep duration (nighttime sleep and daytime napping) and stroke in elderly Chinese individuals with self-reported health status. Methods A total of 4785 Chinese adults over 65 years from the 2011 China Health and Retirement Longitudinal Study (CHARLS) were included. Binary logistic regression was used to estimate odds ratios and 95% confidence intervals of the association between sleep duration and stroke stratified by self-reported health status. Results A significant association between short sleep duration (< 7 h per day) and the risk of stroke (aOR = 2.05; 95% CI 1.31–3.19), after controlling for sociodemographic characteristics, lifestyle factors, health status, and comorbidities. There was no significant association between short and long sleep duration and stroke in the individuals who reported good general health status. However, in individuals who reported poor health status, short sleep duration (aOR = 2.11; 95% CI 1.30–3.44) and long sleep duration (aOR = 1.86; 95% CI 1.08–3.21) were significantly associated with increased risk of stroke, compared with normal sleep duration (7–8 h per day). Disability was significantly associated with stroke in both self-reported good and poor health groups. Rural residence was significantly associated with a lower risk of stroke among individuals who reported poor health status. Conclusions Both short and long sleep duration were significantly associated with stroke among individuals who reported poor health. Stroke prevention should be focused on elderly individuals who believe that they have health problems.