Assessing the Association of Self-Reported Sleep Duration and Metabolic Syndrome Among Middle-Aged and Older Adults in China from the China Health and Retirement Longitudinal Survey.

Objectives: We aim to investigate the correlation between sleep and metabolic syndrome (MS) among a community population 45 years of age and older in China. Methods: A cross-sectional analysis of 9096 participants from China health and longitudinal study was carried out. MS was defined by consensus criteria. Sleep durations were assessed by self-reported questionnaire. Odds ratio (OR) and 95% confidence intervals (CIs) for MS were obtained using multivariable-adjusted regression analysis. Results: Long habitual daytime sleep had a positive influence on MS (OR = 1.50, 95% CI = 1.10-2.06). For elderly, short daytime sleep significantly increased risk of MS (OR = 2.14, 95% CI = 1.25-3.67). Females with long daytime sleep was associated with increased risk of MS (OR = 1.54, 95% CI = 1.04-2.29). Conclusions: Daytime sleep significantly increased risk of MS for middle-aged and elderly Chinese. The hazard role of daytime sleep on MS was various between age and sex groups. Results of this study needed to be verified by future longitudinal studies.