Background Sleep duration has been implicated in the etiology of obesity but less is known about the association between sleep and other behavioral risk factors for cardiovascular disease. Purpose The aim of this study was to examine the associations among sleep duration, chronotype, and physical activity, screen-based sedentary behavior, tobacco use, and dietary intake. Methods Regression models were used to examine sleep duration and chronotype as the predictors and cardiovascular risk factors as outcomes of interest in a cross-sectional sample of 439,933 adults enrolled in the UK Biobank project. Results Short sleepers were 45 % more likely to smoke tobacco than adequate sleepers (9.8 vs. 6.9 %, respectively). Late chronotypes were more than twice as likely to smoke tobacco than intermediate types (14.9 vs. 7.4 %, respectively). Long sleepers reported 0.61 more hours of television per day than adequate sleepers. Early chronotypes reported 0.20 fewer daily hours of computer use per day than intermediate chronotypes. Early chronotypes had 0.25 more servings of fruit and 0.13 more servings of vegetables per day than late chronotypes. Conclusions Short and long sleep duration and late chronotype are associated with greater likelihood of cardiovascular risk behaviors. Further work is needed to determine whether these findings are maintained in the context of objective sleep and circadian estimates, and in more diverse samples. The extent to which promoting adequate sleep duration and earlier sleep timing improves heart health should also be examined prospectively.

Graphical abstract

Background/Objectives Obstructive sleep apnea (OSA) has been linked to an increased risk for Alzheimer's disease (AD), but little prospective evidence exists on the effects of OSA treatment in preclinical AD. The objective was to determine if continuous positive airway pressure (CPAP) treatment adherence, controlling for baseline differences, predicts cognitive and everyday function after 1 year in older adults with mild cognitive impairment (MCI) and to determine effect sizes for a larger trial. Design Quasi‐experimental pilot clinical trial with CPAP adherence defined as CPAP use 4 hours or more per night over 1 year. Setting Sleep and geriatric clinics and community. Participants Older adults, aged 55 to 89 years, with an apnea‐hypopnea index of 10 or higher participated: (1) MCI, OSA, and CPAP adherent (MCI +CPAP), n = 29; and (2) MCI, OSA, CPAP nonadherent (MCI −CPAP), n = 25. Intervention CPAP. Measurements The primary cognitive outcome was memory (Hopkins Verbal Learning Test‐Revised), and the secondary cognitive outcome was psychomotor/cognitive processing speed (Digit Symbol subtest from the Wechsler Adult Intelligence Scale Substitution Test). Secondary function and progression measures were the Everyday Cognition, Alzheimer's Disease Cooperative Study‐Clinical Global Impression of Change Scale, and Clinical Dementia Rating. Results Statistically significant improvements in psychomotor/cognitive processing speed in the MCI +CPAP group vs the MCI −CPAP group were observed at 1 year after adjustment for age, race, and marital status (parameter estimate = 1.68; standard error = 0.47; 95% confidence interval = 0.73‐2.62), with a 6‐month effect size (ES) of 0.46 and a 1‐year ES of 1.25. There were small to moderate ESs for memory (ES 0.20, 6 mo), attention (ES 0.25, 1 y), daytime sleepiness (ES 0.33, 6 mo and ES 0.22, 1 y), and everyday function (ES 0.50, 6 mo) favoring the MCI +CPAP group vs the MCI −CPAP group. Conclusion Controlling for baseline differences, 1 year of CPAP adherence in MCI +OSA significantly improved cognition, compared with a nonadherent control group, and may slow the trajectory of cognitive decline. Trial Registration Number Memories; NCT01482351; https://clinicaltrials.gov/ct2/show/NCT01482351?cond=MCI+and+OSA&rank=1 J Am Geriatr Soc 67:558–564, 2019.

Long sleepers with evening preference may be a sleep phenotype at high cardiovascular risk. Further work is needed to examine these relationships longitudinally and to assess the effects of chronotherapeutic interventions on cardiovascular risk behaviours.