Changes in nocturnal sleep and daytime nap durations predict all-cause mortality among older adults: the Panel on Health and Ageing of Singaporean Elderly. Issue 7 (2nd May 2018)

• Record Type: Journal Article
• Authors: Cheng, Grand H -L; Malhotra, Rahul; Østbye, Truls; Chan, Angelique; Ma, Stefan; Lo, June C
• Is Part Of: Sleep. Volume 41:Issue 7(2018)
• Publication Date: 2018-05-02
• Subjects: nocturnal sleep duration -- daytime nap duration -- all-cause mortality -- older adults; Sleep -- Physiological aspects -- Periodicals; Sleep disorders -- Periodicals; Sommeil -- Aspect physiologique -- Périodiques; Sommeil, Troubles du -- Périodiques; Sleep disorders; Sleep -- Physiological aspects; Sleep -- physiological aspects; Sleep Wake Disorders; Psychophysiology; Electronic journals; Periodicals; 616.8498
• DOI: 10.1093/sleep/zsy087
• Languages: English
• ISSNs: 0161-8105

Abstract

Abstract: Study Objectives: To determine the effects of changes in nocturnal sleep and daytime nap durations on all-cause mortality among older adults. Methods: Two-thousand four-hundred forty-eight community-dwelling older Singaporeans (≥60 years) reported their nocturnal sleep and daytime nap durations at baseline (2009) and the 2-year follow-up. At each phase, they were grouped into the recommended (7–8 hours), short (≤6 hours), and long (≥9 hours) sleep duration categories, and the none (0 hour), short (≤1 hour), and long (>1 hour) nap duration categories. Cox regression analysis was conducted to quantify the associations of changes in sleep and nap durations over 2 years with all-cause mortality risk in the subsequent 4 years (till end of 2015). Multivariable fractional polynomial regression, which treated sleep and nap durations as continuous variables was conducted as a supplementary analysis. Results: Relative to individuals who had the recommended sleep durations at both baseline and follow-up, the risks of all-cause mortality were higher among older adults who reported considerable changes in sleep duration (from short to long sleep and vice versa, hazard ratio [HR] = 2.14–2.56). Furthermore, compared to those who did not nap at both time points, significantly higher mortality risks were found in individuals who showed any increase in nap duration (HR = 1.86–2.16), or reduced their nap from long to short duration (HR = 1.86). Supplementary analysis revealed similar findings. Conclusions: In addition to the change in nocturnal sleep duration, change in daytime nap duration can also predict risks of all-cause mortality among older adults. It is crucial to track older adults' sleep and nap durations longitudinally.