Findings by Dr. Meredith Wallace et al. Show that Lower Sleep-Wake Rhythmicity and Lower Sleep Continuity Pose Risk for Mortality in Older Men

Most studies use individual sleep characteristics to predict health outcomes. However, a recent paradigmatic shift in sleep research has led investigators to study sleep through a “sleep health” framework. Within this framework, sleep is viewed as a multidimensional pattern of sleep-wakefulness that promotes physical and mental well-being and is characterized along multiple domains including duration, continuity, timing, satisfaction, sleepiness, regularity, and rhythmicity. Meredith Wallace, PhD; Stephen Smagula, PhD; Martica H. Hall, PhD; Daniel Buysse, MD; and other colleagues used this sleep health framework to examine the relationship between multivariable sleep health and mortality in a large sample of older men from the Osteoporotic Fractures in Men (MrOS) Sleep Study. In total, 2,887 men completed relevant assessments and were followed for up to 11 years. Investigators selected one actigraphy or self-reported sleep characteristic to represent each of the seven proposed sleep health domains and then applied multivariable Cox models, survival trees, and random survival forests to robustly determine which of the selected sleep characteristics are most strongly associated with increased mortality risk. 

Across approaches, lower sleep-wake rhythmicity and lower sleep continuity (both objectively measured via actigraphy) conferred the strongest risk for mortality among older men, ranking sixth and eighth, respectively, among 43 possible sleep and non-sleep predictors. Notably, the importance of multidimensional sleep health for predicting all-cause mortality in older men followed only age, cognition, and cardiovascular disease. Critical next steps will be to conduct studies to elucidate the physiological, psychological, and behavioral mechanisms through which rhythmicity and continuity relate to mortality in older men and to develop new treatments that target the specific sleep profiles that cause morbidity and mortality. Ultimately, studying multidimensional sleep health could improve public health by promoting healthy sleep for the entire population, rather than only those with sleep disorders.  

Which Sleep Health Characteristics Predict All-Cause Mortality in Older Men? An Application of Flexible Multivariate Approaches
Wallace ML, Stone K, Smagula SF, Hall MH, Simsek B, Kado DM, Redline S, Vo TN, Buysse DJ

SLEEP, January 2018,