Smoking, Screen-Based Sedentary Behavior, and Diet Associated with Habitual Sleep Duration and Chronotype: Data from the UK Biobank.

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.