Associations of Leisure Activities and Sleep Duration with Cognitive Function: A Nationwide Prospective Cohort Study of Chinese Old Adults.

Abstract

Leisure activities and sleep duration are correlated and have been linked to cognitive function, but most studies have examined only one of these factors. To investigate the independent and joint associations of leisure activities and sleep duration with cognitive function among older adults. We included 7,796 participants aged≥65 years from the Chinese Longitudinal Healthy Longevity Survey during 2008-2018 (waves 5-8). Self-reported leisure activities and sleep duration were assessed at baseline, and cognitive function was measured repeatedly using the Chinese version of the Mini-Mental State Examination (MMSE) at baseline and during follow-up. We used linear mixed models to estimate regression coefficients (β) and 95% confidence intervals (CI). The median follow-up duration was 5.77 years. After adjusting for each other and potential confounders, both lower leisure activity score (each 1-point decrease β= -0.33, 95% CI: -0.36 to -0.30) and longer sleep duration (each 1-hour increase β= -0.17, 95% CI: -0.22 to -0.11) were independently associated with lower MMSE score. Furthermore, we observed an additive interaction between leisure activities and sleep duration (pinteraction < 0.001). A combination of low leisure activity score and long sleep duration was strongly associated with decreased MMSE score (β= -2.51, 95% CI: -2.85 to -2.16) compared with the group with combined high leisure activity score and normal sleep duration. Both leisure activities and sleep duration were independently associated with cognitive function. Moreover, the combination of leisure inactivity and prolonged sleep duration predicted worse cognitive function (a preclinical hallmark of Alzheimer's disease) in an additive manner.