Association of Long Sleep and Physical Inactivity With Incident Disability in Community-Dwelling Older Adults: A 5-year Longitudinal Study

ObjectivesThis study examined whether sleep duration and physical inactivity were associated with incident disability among community-dwelling older adults.MethodsA total of 4,372 adults aged ≥70 years participated in a baseline assessment. We assessed self-reported sleep duration and physical activity using the International Physical Activity Questionnaire - Short Form. We measured monthly incident disability over 5 years.ResultsThe Cox proportional hazards regression analysis showed long sleep duration (≥9 h, HR 1.32, 95% CI 1.05-1.67) and physical inactivity (HR 1.33, 95% CI 1.13-1.57) were associated with incident disability in multivariate analyses. Coexistence of long sleep duration and physical inactivity had higher risk of incident disability than each factor individually (HR 1.69, 95% CI 1.11-2.58), even though the synergistic interaction was mildly effective.DiscussionThis study demonstrated that long sleep duration and physical inactivity were independently associated with the risk of incident disability among older adults.