JMIR Publications

ABSTRACT

Background:

Little is known about the associations between sleep duration and ADL disability among middle-aged and elderly in China.

Objective:

This study aims to explore the associations between sleep duration and ADL disability among middle-aged and elderly in China.

Methods:

Data of 17,607 participants from the 2018 China Health and Retirement Longitudinal Study (CHARLS), an ongoing national longitudinal survey of Chinese adults aged 45 years and above. Self-reported sleep duration per night obtained from face-to-face interviews. The ADL was measured using a 6-item summary assessed with an ADL scale that includes eating, dressing, transferring, bathing, using the toilet, and continence. Multivariable generalized linear model (GLM) with binomial family and log link were adopted to assess the associations between sleep duration and ADL disability.

Results:

Data were analyzed form 17,607 participants, 8375(47.6%) were men. The mean (SD) age was 62.7 (10.0) years old. Individuals with 4 hour or less (odds ratio [OR]=1.91, 95% confidence interval [CI], 1.60-2.27), 5 hours (OR=1.33, 95% CI, 1.09-1.62), 9 hours (OR=1.48, 95% CI, 1.13-1.93), and 10 hours or more (OR=1.88, 95% CI, 1.47-2.14) of sleep per night had a higher risk of ADL disability than in the reference group (7 hours per night) after adjusting for a number of covariates. Restricted cubic splines analysis suggested a U-shaped association between sleep duration and ADL disability.

Conclusions:

In this study, a U-shaped association between sleep duration and ADL disability was found, indicating that ADL disability should be monitored in individuals with insufficient (≤4, 5 hours per night) or excessive (9, ≥10 hours per night) sleep duration. Future studies are needed to focus on examining the mechanism between sleep duration and ADL disability.