A prospective study on the association of sleep duration with grip strength among middle-aged and older Chinese

Abstract

BackgroundLongitudinal studies on sleep duration and grip strength decline are limited. This study aimed to evaluate the associations of baseline sleep duration with follow-up grip strength and grip strength changeover time among a large sample of middle-aged and older Chinese. MethodsData from China Health and Retirement Longitudinal Study, CHARLS (2011–2015), were analyzed. Hand grip strength was measured by dynamometers twice with 4 years interval. Baseline self-reported nighttime sleep duration was collected by questionnaire. Basic demographics, life habits and health status were considered as potential confounders. Multivariate linear regression models with quadratic function and mixed-effects regression models were fitted. ResultsInverted U-shaped associations occurred between baseline sleep duration and follow-up grip strength for both males (βlinear = 1.011, plinear = 0.002; βquadratic = −0.061, pquadratic = 0.014) and females (βlinear = 0.605, plinear = 0.005, βquadratic = −0.041, pquadratic = 0.019). Compared to the sleep duration of 7 h, significant interactions of <5 hours-by-time (γ= − 0.966 with SEE = 0.442, p = .029) in males as well as 5–7 hours-by-time (γ= − 0.717 with SEE = 0.294, p = .015), 7–9 hours-by-time (γ= − 0.632 with SEE = 0.311, p = .042) and >9 hours-by-time (γ= − 1.567 with SEE = 0.560, p = .005) in females were found. ConclusionFor both males and females, compared to the intermediate sleep duration, shorter or longer sleep may predict the weaker follow-up grip strength and the faster rate of hand grip strength decline over time.