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

Abstract Background 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. Methods 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. Results 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]). Conclusions 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.