Multidimensional sleep-wake changes and risk of all-cause and cardiovascular disease mortality in oldest-old women

Abstract

Sleep-wake patterns often worsen with age and are fundamental to health, yet little is known about their long-term changes in the oldest old and links to mortality risk. We aimed to characterize five-year changes in 24-hour sleep-wake patterns and examine associations with all-cause and cardiovascular disease mortality among community-dwelling women in their 80s and 90s. Among 704 community-dwelling older women (mean age 82.9 years at baseline), we objectively measured 24-hour sleep-wake parameters—including nighttime sleep, daytime napping, and circadian rest–activity rhythms—using 4-night/5-day actigraphy at baseline and again five years later. We used hierarchical clustering on principal components analysis to identify profiles of sleep-wake changes and used Cox proportional hazards models to assess associations with mortality. Here we show that compared to those with stable patterns, women experiencing declining nighttime sleep (hazard ratio [HR] = 2.16 [95% CI: 1.26, 3.72]) or increasing 24-hour sleepiness (HR = 2.09 [1.12, 3.92]) have approximately double the risk of subsequent all-cause mortality over a median follow-up time of 2.1 years, independent of comorbidities and covariates. We also find that increases in daytime napping duration are associated with over double the risk of all-cause (HR = 2.24 [1.25, 4.01]) and cardiovascular disease mortality (HR = 2.93 [1.14, 7.51]), while decreases in nighttime sleep duration are linked to elevated cardiovascular disease mortality (HR = 2.78 [1.06, 7.31]). Our findings suggest that changes in 24-hour sleep/circadian patterns among the oldest old are not simply normal aging but may serve as an important marker of increased mortality risk.