Sleep duration, mortality and the influence of age

Abstract

Prior work has shown that both short and long sleep predict mortality. However, sleep duration decreases with age and this may affect the relationship of sleep duration with mortality. The purpose of the present study was to assess whether the association between sleep duration and mortality varies with age. Prospective cohort study. 43,863 individuals (64% women), recruited in September 1997 during the Swedish National March and followed through record-linkages for 13 years. Sleep duration was self-reported and measured using the Karolinska Sleep Questionnaire, and grouped into 4 categories: ≤5, 6, 7 (reference) and ≥8 h. Up to 2010 3548 deaths occurred. Multivariable Cox proportional hazards regression models with attained age as time scale were fitted to estimate mortality rate ratios. Among individuals <65 years, short (≤5 h) and long (≥8 h) sleep duration showed a significant relationship with mortality (HR 1.37, 95% CI 1.09–1.71, and HR 1.27, 95% CI 1.08–1.48). Among individuals 65 years or older, no relationships between sleep duration and mortality were observed. The effect of short and long sleep duration on mortality was highest among young individuals and decreased with increasing age. The results suggest that age plays an important role in the relationship between sleep duration and mortality.Electronic supplementary materialThe online version of this article (doi:10.1007/s10654-017-0297-0) contains supplementary material, which is available to authorized users.

Sleep duration and mortality – Does weekend sleep matter?

“…The gradual reduction of weekend sleep duration as subjects become older might be the reason behind the reduction in HR with increasing age found in our previous study on the same cohort (Akerstedt et al., ), and confirmed here. A similar age effect was found for short sleep in relation to hypertension, CVD and obesity in the meta‐analysis by Itani et al.…”

“…In these two meta‐analyses, age‐subgroup analyses, using 65 years as cut‐off, showed an increased mortality in both age groups among individuals with long sleep, but no significant association between short sleep and mortality in any of the age groups. In a recent study (Akerstedt et al., ), we found a U‐shaped relationship between sleep duration and mortality only among subjects below the age of 65 years.…”

“…The latter should be of importance for interpreting data on sleep duration and mortality. In a previous study the association between long or short sleep duration and mortality decreased with increasing age, and was no longer significant in the ≥65 years group (Akerstedt et al., ).…”

Self‐Reported Sleep Duration and Quality and Cardiovascular Disease and Mortality: A Dose‐Response Meta‐Analysis

“…A total of 74 studies met the inclusion criteria; the process of study selection is shown in Figure 1 8, 9, 11, 12, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89,...…”

“…** References 11, 21, 23, 25, 26, 27, 29, 32, 33, 34, 36, 39, 40, 41, 44, 46, 47, 48, 49, 51, 52, 53, 54, 56, 57, 61, 64, 66, 68, 70, 71, 72, 77, 79, 80, 84, 86, 87, 88.…”