Abstract
STUDY OBJECTIVES: The aim of this research was to investigate the relationships between objectively measured sleep duration and physical function in older adults. METHODS: We recruited community-dwelling older adults aged ≥ 60 years old in Taipei City, Taiwan. Sleep duration was measured with accelerometers and recorded as the total hours of sleep per night for each participant. The following physical functions were assessed: 1) grip strength (measured by handgrip dynamometer), 2) balance (1-leg standing test), 3) lower body strength (5-timed chair stand), 4) basic mobility (timed up and go test), 5) gait speed (5-m walk test). The relationships between sleep duration and physical function outcomes were analyzed using generalized additive models, controlling for objectively measured sedentary behavior and moderate-to-vigorous physical activity, and other sociodemographic variables. RESULTS: A total of 121 older adults (men = 28.9%; mean age = 70.0 ± 5.0 years) was included in this study. A positive association of sleep duration with grip strength was found after adjusting for covariates (P = .005). No significant associations were observed between sleep duration and the other physical function outcomes. CONCLUSIONS: For older adults, lengthening their sleep duration may be helpful to enhance the grip strength. This result has implications for improving their health by targeting better performance in specific physical functions. Further studies of sleep duration and physical function among older adults should investigate the underlying mechanisms.