Objective short sleep duration increases the risk of all-cause mortality associated with possible vascular cognitive impairment

Objectives: Cognitive impairment is a leading cause of disability worldwide, and cardiometabolic conditions are key contributors to its development. Short sleep is also a potential contributor to brain health; however, its role in predicting mortality remains poorly understood. We investigated whether objective short sleep duration increases the risk of all-cause mortality associated with coexisting cognitive impairment and cardiometabolic conditions, i.e., possible vascular cognitive impairment (VCI). Design: This is a longitudinal study. Setting: This is a population-based, in-lab study. Participants: A total of 1,524 adults (aged 48.9±13.4 years, 53.4% women) from the Penn State Adult Cohort were included in the study. Measurements: All-cause mortality was estimated after 19.1±5.1 years of follow-up. Neuropsychological testing was performed to ascertain cognitive impairment. Clinical history and physical examination were performed to ascertain stage 2 hypertension, type 2 diabetes, heart disease, and stroke. Possible VCI was defined as the presence of any of these cardiometabolic conditions and cognitive impairment. In-lab, 8-hour polysomnography (PSG) was performed to ascertain short sleep duration (i.e., <6 hours). Results: Multivariable-adjusted Cox proportional-hazard models showed that the risk of all-cause mortality associated with cardiometabolic conditions (n=864) and possible VCI (n=122) was significantly increased in those who slept <6 hours at baseline (hazards ratio [HR] = 1.79, 95% confidence interval [CI] = 1.28-2.51 and HR = 4.01, 95% CI = 2.66-6.05, respectively), while it was negligible in those who slept ≥6 hours (HR = 1.44, 95% CI = 0.99-2.09 and HR = 1.41, 95% CI = 0.70-2.83, respectively). Conclusions: Objective short sleep duration predicts the mortality prognosis of adults with possible VCI. Sleep duration and cognition should be objectively evaluated in patients presenting with a cluster of cardiometabolic conditions and sleep and cognitive complaints. Short sleep is a useful risk factor in the prediction of adverse cardiometabolic and brain health outcomes.