Longitudinal Association Between Sleep Duration and Depressive Symptoms in Chinese Elderly

Abstract

Aim

This study aimed to evaluate the longitudinal association between sleep duration and depressive symptoms among the elderly in China.

Methods

A data set from China Health and Retirement Longitudinal Study (CHARLS) in 2011, 2013 and 2015 was adopted with a total of 22,847 respondents aged ≥60-years-old. A linear regression analysis with generalized estimating equations was employed to examine the longitudinal associations between duration of total sleep, nighttime sleep and daytime nap, and depressive symptoms.

Results

An extra hour of total sleep including nighttime sleep and daytime nap was associated with lower incidence of depressive symptoms among the elderly after adjusting all confounders (OR=0.83, 95% CI: 0.82–0.84). In addition, an extra hour of nighttime sleep (OR=0.82, 95% CI: 0.80–0.83) or daytime nap (OR=0.93, 95% CI: 0.89–0.97) was also negatively associated with depressive symptoms among the elderly. After controlling the total sleep time, an extra hour of nighttime sleep was negatively associated with depressive symptoms (OR=0.88, 95% CI: 0.84 to 0.92), while an extra hour of daytime nap displayed a positive association with depressive symptoms (OR=0.88, 95% CI: 0.84 to 0.92). Compared with the moderate nappers, only extended nappers had significantly higher incidence of depressive symptoms (OR=1.32, 95% CI: 1.19 to 1.45).

Conclusion

For the elderly in China, increasing their total sleep, nighttime sleep, and/or daytime nap duration would reduce the incidence of depressive symptoms. Moreover, after fixing the total sleep time, increasing nighttime sleep was more beneficial to the decrease of the incidence of depressive symptoms than daytime nap.

Keywords:

• sleep duration
• daytime nap
• depressive symptoms
• China
• the elderly

Ethics Approval

The data collection in CHARLS was ethically approved by the Biomedical Ethics Review Committee of Peking University (approval number: IRB00001052–11015). Ethics approval for the use of CHARLS data was obtained from the University of Newcastle Human Research Ethics Committee (H-2015-0290).

Acknowledgments

The authors would like to thank the China Center for Economic Research and the National School of Development of Peking University for providing the data of China Health and Retirement Longitudinal Study (CHARLS).

Author Contributions

All authors made substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; took part in drafting the article or revising it critically for important intellectual content; gave final approval of the version to be published; and agree to be accountable for all aspects of the work.

Disclosure

The authors declare that they have no competing interests for this work.

Additional information

Funding

This study was supported by grants from National Natural Science Foundation of China (71774006) and China Postdoctoral Science Foundation (2019M650392). The funders had no role in the design, analysis, or writing of the manuscript.