Zhongguo quanke yixue (Oct 2023)
Relationship between Sleep Duration and All-cause Mortality in Middle-aged and Older Adults
Abstract
Background The scale and follow-up time of studies related to the association between sleep duration and all-cause mortality in middle-aged and older adults vary widely, and the results of studies such as correlations and recommended sleep duration remain controversial. Objective To explore the association between sleep duration and the risk of all-cause mortality in middle-aged and older adults. Methods From January to December 2022, the longitudinal study cohort was created based on the case ID numbers of coding manual combined with baseline and follow-up data of the China Health and Retirement Longitudinal Study (CHARLS) and Chinese Longitudinal Healthy Longevity Study (CLHLS) databases from January to December in 2022, which ultimately included 43 922 respondents. Social demographics, health status and health-related behaviors, sleep duration and death related information were extracted from CHARLS and CLHLS databases, recoding and variable transformations were performed according to the measurement and evaluation criteria of relevant indicators. The Kaplan-Meier method of Log-Rank test was used to plot survival curves, and the Cox proportional hazard regression model was used to explore the relationship between sleep duration and mortality risk in the middle-aged and older adults, followed by unrestricted cubic spline to observe the effect of the continuous-type variable of sleep duration on mortality risk. Results Among 43 922 middle-aged and older adults with a median follow-up of 6 years and an average sleep duration of 7.32 h, 9 369 cases (21.33%) had sleep duration of≤5 h, 7 779 cases (17.71%) had sleep duration of >5-6 h, 295 cases (0.67%) had sleep duration of >6-7 h, 15 611 cases (35.54%) had sleep duration of >7-8 h, 2 567 cases (5.84%) had sleep duration of >8-9 h, 5 011 cases (11.41%) had sleep duration of >9-10 h and 3 290 cases had sleep duration >10 h (7.49%) . Kaplan-Meier survival analysis showed that middle-aged and older adults with moderate sleep duration (>6-7 h) had the highest probability of survival, and those with extra-long sleep duration (>10 h) had the lowest probability of survival. Cox regression model results showed that compared with middle-aged and older adults with sleep duration >10 h, middle-aged and elderly adults with sleep duration of ≤5 h〔HR (95%CI) =1.19 (1.09, 1.29) , P<0.05〕, >7-8 h〔HR (95%CI) =1.16 (1.08, 1.25) , P<0.05〕, >8-9 h〔HR (95%CI) =1.32 (1.19, 1.46) , P<0.05〕, and >9-10 h〔HR (95%CI) =1.12 (1.04, 1.22) , P<0.05〕 had increased risk of death. Restricted cubic spline showed an S-shaped non-linear association between sleep duration and risk of all-cause death (P=0.023) , with no significant association of sleep duration of 4.62-7.97 h with the risk of death, significant association of sleep duration <4.62 h and >7.97-10.00 h with all-cause mortality risk. Conclusion Middle-aged and older adults with moderate sleep duration had the highest probability of survival, so the recommended sleep duration for middle-aged and older adults is 5-7 h.
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