Abstract
BACKGROUND: The aim of this study is to assess the longitudinal association of the insomnia with short sleep duration phenotype with cardiovascular disease (CVD) and cerebrovascular disease (CBVD) in the UK biobank using self-reported insomnia and accelerometer-measured habitual sleep duration.
METHODS: The sample sizes for incident CVD and CBVD were 6959 and 7690 participants, respectively, with an average follow-up time of 3.6 years for CVD and 3.4 years for CBVD. Short sleep duration was defined as a nightly sleep duration below the sample median (<7.3 hours) and insomnia as a self-report of difficulty falling or staying asleep “Usually” versus Never/Rarely/Sometimes. Participants were classified into 4 mutually exclusive sleep groups based on the presence or absence of short sleep duration (Yes/No) and insomnia symptoms (Yes/No). Multivariable Cox proportional hazards models were used adjusting for major confounders.
RESULTS: Compared with normal sleepers with normal sleep duration, participants with insomnia with short sleep duration (hazard ratio [HR]=1.39, 95% CI=1.11-1.74), but not those with insomnia with normal sleep duration (HR=1.13, 95% CI=0.89-1.43) or normal sleepers with short sleep duration (HR=1.03, 95% CI=0.86-1.23) were significantly associated with incident CVD. Similarly, participants with insomnia with short sleep duration (HR=1.76, 95% CI=1.29-2.39), but not those with insomnia with normal sleep duration (HR=1.04, 95% CI=0.72-1.49) or short sleep duration (HR=1.13, 95% CI=0.87-1.48) were significantly associated with incident CBVD.
CONCLUSIONS: These results from the UK biobank database using accelerometer to assess habitual objective sleep duration, extend previous findings that the insomnia with short sleep duration phenotype is associated with significantly increased risk of incident CVD and CBVD.