Relationship between Sleep Duration and All-Cause Mortality in the Elderly: An Updated and Dose-Response Meta-Analysis. (Preprint)

BACKGROUND Short or long sleep duration is recognized as a potential risk factor for all-cause mortality in the elderly, yet the results are not often reproducible. OBJECTIVE We aimed to investigate whether sleep duration was associated with an increased risk of all-cause mortality in the elderly through a comprehensive meta-analysis. METHODS Literature retrieval, research selection and data extraction were done independently and in duplicate. Effect-size estimates are expressed as odds ratio (OR) and 95% confidence interval (CI). RESULTS Summary data from 35 articles, involving 11746 elderly people, were meta-analyzed. Overall analyses revealed a significant association between long sleep duration and all-cause mortality in the elderly (OR=1.27, 95% CI: 1.19-1.35, P <.001), and short sleep duration was marginally related to the all-cause mortality in the elderly (OR=1.05; 95% CI: 1.00-1.09; P =.045). The Egger’s test indicated no publication bias between sleep duration and all-cause mortality in the elderly. In subgroup analyses, the association with all-cause mortality was reinforced in elderly women with long sleep duration (OR=1.48, 95% CI: 1.18-1.85, P =.002) relative to elderly men with long sleep duration (OR=1.3, 95% CI: 1.10-1.50, P =.001). Further dose-response analyses showed a J-shaped relationship between sleep duration and all-cause mortality in the elderly. CONCLUSIONS Our meta-analytical findings demonstrated a J-shaped relationship between sleep duration and all-cause mortality in the elderly. For long sleep duration, elderly women had a higher mortality rate than elderly men.