Differential associations of sleep duration, sleep disturbance and falls among middle-aged and older adults with and without cardiovascular disease status: results from the China Health and Retirement Longitudinal Study (CHARLS)

OBJECTIVE: The aim of this study was to investigate the associations between sleep duration, sleep disturbances and falls in different cardiovascular disease (CVD) states in a Chinese middle-aged and older adult population. METHODS: This study used two waves (2011 wave1 and 2013 wave2) of data from the China Health and Retirement Longitudinal Study (CHARLS) to collect information on social, economic, and health status by tracking Chinese individuals aged 45 and above. The study used a logistic regression model to examine the association between sleep parameters and falls. Restricted cubic spline was used to analyze the association of sleep duration with falls in the overall population, and in the population with or without CVD. RESULTS: The overall incidence of new falls among all subjects was 18.35%. It was 24.54% in the population with CVD and 17.36% in the population without CVD. After adjusting for multiple factors, short sleep duration (less than 6 h) was significantly associated with an elevated risk of falls in total populations and with or without CVD, with OR values (95%CI) of 1.267(1.143,1.405), 1.227(1.095,1.376) and 1.442(1.130,1.841), respectively. Long sleep duration (longer than 9 h) was significantly associated with an increased risk of falls only in the CVD population, with OR values of 2.042(1.175,3.550). Sleep disturbance more than 3 days per week was significantly associated with elevated fall risk in the total population and in the population without CVD, and more than 5 days was significantly associated with elevated fall risk in the CVD population. CONCLUSIONS: This study reveals the association between sleep parameters and falls, particularly among patients with cardiovascular disease, where long sleep duration is associated with falls. This suggests that long sleep may be an important factor in the risk of falls in CVD patients.