Longitudinal association between sleep and 5-year incident metabolic syndrome in older Chinese adults: a community-based cohort study

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.

The dilution effects of healthy lifestyles on the risk of depressive symptoms attributed to life-course disadvantages among Chinese middle-aged and older adults

BACKGROUND

Life-course disadvantages and unhealthy lifestyles are well-known to independently induce depressive symptoms, but whether adopting healthy lifestyles can dilute the depressive risks attributed to life-course disadvantages remain unknown in China.

METHODS

This population-based cross-sectional study included 5724 middle-aged and older people from the China Health and Retirement Longitudinal Study (CHARLS). Depressive symptoms and healthy lifestyles (including regular exercise, reasonable sleep, never smoking, and no heavy alcohol consumption) were collected in 2018 while life-course disadvantages were collected in 2014.

RESULTS

Multiple healthy lifestyles were associated with decreased depressive risks more significantly as the life-course disadvantages increased, with odds ratios (ORs) and 95 % confidence intervals (CIs) of 0.44 (0.25-0.80) and 0.33 (0.21-0.53) for 4 healthy lifestyles in participants with mild and severe life-course disadvantages, respectively. Life-course disadvantages and unhealthy lifestyles had enormous joint effects on depressive symptoms. Finally, adopting multiple healthy lifestyles can dilute the depressive risks attributed to life-course disadvantages and even mask some risks attributed to childhood disadvantages.

LIMITATIONS

Given that dietary data were not gathered by the CHARLS, diet was not included in the lifestyles used in this study. In addition, information on life-course disadvantages was primarily self-reported, which may lead to potential recall bias. Finally, the cross-sectional design of this study cannot capture causal associations well.

CONCLUSIONS

Adopting multiple healthy lifestyles can well-dilute the depressive risks attributed to life-course disadvantages in middle-aged and older Chinese, which is of great importance for reducing the depressive burden and the construction of healthy aging in China.