Adiposity-related risks among the middle-aged and elderly Chinese: the role of siesta and nocturnal sleep duration.

Background: increasingly, research suggests that lack of sleep is linked to adiposity worldwide, but few studies have been conducted in middle-aged and elderly Chinese subjects. The purpose of the present study was to analyze the association of siesta and nocturnal sleep duration with the prevalence of adiposity in middle-aged and elderly Chinese individuals. Methods: a total of 7,891 community dwelling Chinese subjects who had participated in the 2015 China Health and Retirement Longitudinal Study were included. A four-stage random sampling method was used to select participants. Siesta and nocturnal sleep duration was self-reported. Adiposity, including general obesity and abdominal obesity, was assessed. Multiple logistic analyses were conducted to explore the association between siesta, nocturnal sleep duration, and adiposity. Results: people with long siesta durations (≥ 1 hour/day) were significantly associated with an increased risk for abdominal obesity, independently and in all subgroup analyses, when compared to those without regular siesta. ORs after adjustment of confounding factors included: all subjects, OR = 1.45, 95 % CI, 1.23 to 1.70; middle-aged subjects, OR = 1.46, 95 % CI, 1.15 to 1.86; elderly, OR = 1.43, 95 % CI, 1.14 to 1.78. Conclusions: our data show that siesta duration plays a role in the prevalence of age-specific abdominal obesity. Individuals with long siesta durations are more likely to have abdominal obesity among the middle-aged and elderly population when compared to those without regular siesta. The results of this study need to be confirmed by further studies.