Sleep Duration and Chronic Disease Risk in Later Life: Longitudinal Evidence and Mechanism Analysis From China

As population aging accelerates, multimorbidity among older adults poses a growing public health challenge, highlighting the need to identify modifiable behavioral risk factors. Sleep, a core aspect of daily life, remains underexplored in the context of healthy aging. Utilizing five waves (2011-2020) of nationally representative longitudinal data from China (<i>N</i> = 10,065), this study employs individual fixed effects and instrumental variable methods to examine the impact of sleep duration on chronic disease risk. The findings indicate that longer nighttime sleep is associated with a lower likelihood of having chronic diseases, and this pattern remains consistent across multiple robustness checks. Mechanism analyses suggest that sleep promotes health by improving physiological function, psychological well-being, and behavioral vitality. Effects are particularly pronounced among the oldest-old, non-drinkers, and those not living with children. These results offer empirical support for incorporating sleep-focused strategies into interventions aimed at mitigating chronic disease risks in aging populations.