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

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. 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. Using hierarchical clustering on principal components analysis, we identified three distinct profiles of sleep/circadian changes. 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]) had approximately double the risk of all-cause mortality over a median follow-up time of 2.1 years after the second sleep visit. Large increases in daytime napping duration were associated with over double the risk of all-cause (HR = 2.24 [1.25, 4.01]) and cardiovascular (CVD) mortality (HR = 2.93 [1.14, 7.51]), while decreases in nighttime sleep duration were linked to elevated CVD mortality (HR = 2.78 [1.06, 7.31]). These results, independent of comorbidities and covariates, 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.