Abstract
This study aims to investigate the independent and joint associations of sleep duration and physical activity on the risk of functional limitations in older adults, providing scientific evidence for prevention and intervention strategies. This cross-sectional study utilized data from the 2020 China Health and Retirement Longitudinal Study. Sleep duration, physical activity, and functional limitations status were collected through structured questionnaires. Multivariable logistic regression models with progressive adjustments were conducted to evaluate the independent and joint associations of sleep duration and physical activity on functional limitations risk in older adults. The final model adjusted for sociodemographic characteristics (age, gender, place of residence, marital status, education level, and personal income), health behaviors (smoking status, alcohol consumption, and social participation), and health outcomes (depressive symptoms and number of chronic diseases). Additionally, sensitivity analyses were performed to assess the robustness of the results. A total of 11,941 eligible older adults was included in this study, with 47.80% male and 52.20% female. The prevalence of functional limitations was 16.02%. Multivariable logistic regression analysis indicated that, compared to adequate sleep duration (6-8 hours), both short sleep (OR = 1.523, 95% CI: 1.352-1.716, P <.001) and long sleep (OR = 1.160, 95% CI: 1.004-1.339, P = .043) were associated with an increased risk of functional limitations (P <.05). Compared to the high physical activity group, the no physical activity group (OR = 2.533, 95% CI: 2.202-2.915, P <.001) and the low physical activity group (OR = 2.187, 95% CI: 1.819-2.629, P <.001) had a significantly higher risk of functional limitations (P <.001). The joint analysis demonstrated that combining adequate sleep duration with high physical activity was strongly associated with reduced functional limitations risk in older adults. The sensitivity analysis results were consistent with the main findings, further confirming the robustness of the results. The findings suggest that maintaining adequate sleep duration combined with a high level of physical activity is associated with a significant reduction in the risk of functional limitations among older adults. These findings provide important evidence for developing strategies to address functional limitations in older adults and highlight the potential value of comprehensive lifestyle interventions in geriatric health management.