Accelerometer-derived sleep onset timing and cardiovascular disease incidence: a UK Biobank cohort study

AimsGrowing evidence suggests that sleep quality is associated with cardiovascular risk. However, research in this area often relies upon recollection dependant questionnaires or diaries. Accelerometers provide an alternative tool for deriving sleep parameters measuring sleep patterns objectively. This study examines the associations between accelerometer derived sleep onset timing and cardiovascular disease (CVD). Methods and ResultsWe derived sleep onset and waking up time from accelerometer data collected from 103,712 UK Biobank participants over a period of seven days. From this, we examined the association between sleep onset timing and CVD incidence using a series of Cox proportional hazards models. 3172 cases of CVD were reported during a mean follow-up period of 5{middle dot}7 ({+/-}0{middle dot}49) years. An age- and sex-controlled base analysis found that sleep onset time of 10:00pm-10:59pm was associated with the lowest CVD incidence. A fully adjusted model, additionally controlling for sleep duration, sleep irregularity, and established CVD risk factors, was unable to eliminate this association, producing hazard ratios of 1{middle dot}24 (95% CI, 1{middle dot}10-1{middle dot}39; p<0{middle dot}005), 1{middle dot}12 (1{middle dot}01-1{middle dot}25; p=0{middle dot}04), and 1{middle dot}25 (1{middle dot}02-1{middle dot}52; p=0{middle dot}03) for sleep onset <10:00pm, 11:00pm-11:59pm, and [≥]12:00am, respectively, compared to 10:00pm-10:59pm. Importantly, sensitivity analyses revealed this association was stronger in females, with only sleep onset <10:00pm significant for males. ConclusionsOur findings suggest an independent relationship between sleep onset timing and risk of developing CVD, particularly for women. We also demonstrate the potential utility of collecting information about sleep parameters via accelerometry-capable wearable devices, which may serve as novel cardiovascular risk indicators. Translational PerspectiveAbnormal sleep timing is a feature of poor-quality sleep and is likely to be associated with cardiovascular diseases. Accelerometer-derived measures of sleep quality, particularly sleep timing, may be associated with greater vulnerability to cardiovascular disease, particularly in women. Onset of sleep timing may constitute a novel cardiovascular risk factor and target for preventative intervention. Wearable devices equipped with accelerometers may be useful in assessing sleep related cardiovascular disease risk factors as they would allow passive measurement of sleep parameters, such as sleep timing.