Accelerometer-Derived Sleep Onset Timing and Cardiovascular Disease Incidence: A UK Biobank Cohort Study

Abstract

Background: Growing evidence suggests that various aspects of sleep are associated with cardiovascular risk. However, studies in this area are often based on recollection-dependent questionnaires or diaries. Accelerometers can be used to derive sleep parameters and measure sleep patterns objectively. This study examined the associations between objectively measured sleep onset timing and cardiovascular diseases (CVD). Methods: Data from 103,413 UK Biobank participants that wore an accelerometer on their wrist for seven days were used in this study. We derived sleep onset and waking up time from the raw data, allowing for analysis of sleep timing, sleep duration, and sleep irregularity over this period. From this, we examined the association between sleep onset timing and CVD incidence using a series of Cox proportional hazards models. Findings: 3172 cases of CVD were reported during a mean follow-up period of 5.7 (±0.49) 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 1.24 (95% CI, 1.10–1.39; p <0.005), 1.12 (1.01–1.25; p = 0.04), and 1.25 (1.02–1.52; p = 0.03) for sleep onset <10pm, 11:00pm-11:59pm, and ≥12am, respectively, compared to 10:00pm-10:59pm. Importantly, sensitivity analyses revealed this association was largely confined to, and accentuated in, females, with only sleep onset <10pm significant for males. Interpretation: Our 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. Funding: Huma Therapeutics. Declaration of Interest: SN, ABR, ACC, BDO, MA, DM and DP are employees of Huma Therapeutics. Ethical Approval: Participants provided informed consent, and the UKB study received ethical approval from the North West Multi-Centre Research Ethics Committee (REC reference: 16/NW/0382) and was conducted in accordance with the principles of the Declaration of Helsinki. The current analyses were conducted under UKB application number 55668.