Associations of physical activity, sleep with functional disability in Chinese older adults: a five-year prospective study

OBJECTIVE: To explore the associations of Physical Activity (PA) and sleep with functional disability among older adults. METHOD: A total of 1927 participants were enrolled from the China Health and Retirement Longitudinal Study (CHARLS) between 2015 and 2020. Activities of Daily Living (ADL) were used to assess functional status. Sleep consisted of nighttime sleep (healthy sleep, or unhealthy sleep) and daytime nap sleeping (extended, moderate, short, or none), and PA was classified as sufficient or insufficient. Effects of sleep and PA on ADL Disability (ADLD) among the elderly were examined using logistic regression analysis, with Odds Ratios (ORs) and 95% Confidence Intervals (95% CIs) calculated. RESULTS: After a follow-up of 5-years, healthy nighttime sleep was linked to a decreased odds of ADLD (OR = 0.77, 95% CI: 0.60‒0.98). In participants with sufficient PA, healthy nighttime sleep was linked to the odds of ADLD (OR = 0.68, 95% CI: 0.52‒0.90). No multiplicative interaction of PA and nighttime sleeping was found. Moreover, the association between healthy nighttime sleep and decreased risk of ADLD was consistent in females (OR = 0.64, 95% CI: 0.45‒0.91) and those with complications (OR = 0.63, 95%CI: 0.46‒0.87). CONCLUSION: Healthy nighttime sleep may be beneficial for preventing ADLD in older people. The benefits of sufficient PA with healthy sleep on reducing the risk of ADLD remain uncertain.