Associations between sleep duration trajectories and physical dysfunction among middle-aged and older Chinese adults.

Background: The relationship between a single time-point measurement of sleep duration and physical dysfunction has been extensively investigated. However, few researches has concentrated on the effects of sleep duration trajectories. This study sought to evaluate the association between sleep duration trajectories and physical dysfunction in a longitudinal cohort of middle-aged and older Chinese individuals.

Methods: This research included a large pool of subjects (n = 7157) between the ages of 45 and 80 from the China Longitudinal Study of Health and Retirement (CHARLS). Utilizing sleep duration data collected periodically between 2011 and 2015, the sleep duration trajectory was plotted using the group-based trajectory modeling (GBTM). Physical dysfunction was evaluated using data from 2015. Multivariable logistic regression model was then used to examine the risk of physical dysfunction with different sleep time trajectories.

Results: Three distinct sleep duration trajectories were identified: class 1, consistently long sleep duration(n = 2504, 34.98%); Class 2: consistently moderate sleep duration(n = 2338, 32.67%); Class 3: consistently short sleep duration( n = 2315, 32.35%). Multivariable logistic regression revealed that compared with consistently moderate sleep duration, consistently short sleep duration was significantly positively correlated with the risk of physical dysfunction in unadjusted model and adjusted model (OR: 1.75, 95% CI: 1.54 ~ 1.99; p < 0.001).

Conclusions: Consistently short sleep duration trajectories are positively correlated with physical dysfunction compared to participants with consistently moderate sleep duration trajectories. The study points out the significant importance of keeping an eye on how sleep duration changes over time.