Sleep loss due to worry and future risk of cardiovascular disease and all-cause mortality: the Scottish Health Survey

BACKGROUND:

The association between specific sleeping disorders and risk of cardiovascular disease (CVD) is unclear. We assessed the association between sleep loss due to worry and future risk of CVD and death in a representative sample of community dwelling adults.

METHODS:

A cohort of 11,905 adults (aged 53.4 ± 12.2 years, 42.2% male) without known history of CVD were drawn from the Scottish Health Surveys. Self-reported sleep disturbance was measured using a single item from the General Health Questionnaire. Incident CVD events (comprising CVD death, nonfatal myocardial infarction, coronary surgical procedures, stroke, and heart failure) over 8-year follow up were ascertained by a linkage to national registers; a total of 1448 CVD events and 1249 all-cause deaths were recorded.

RESULTS:

15.6% of the sample reported 'rather more' or 'much more than usual' sleep loss due to worry over the prior 4 weeks. Sleep loss due to worry (much more than usual) was associated with elevated risk of CVD [age- and sex-adjusted hazard ratio (HR) 1.74, 95% confidence interval (CI) 1.35-2.25] and all-cause mortality (age- and sex-adjusted HR 2.02, 95% CI 1.57-2.61). Adjustment for a range of psychosocial, behavioural, and clinical risk factors partly attenuated the association, and in particular health behaviours (smoking, alcohol, physical inactivity) accounted for approximately 40% of the sleep-CVD relation.

CONCLUSION:

Sleep loss due to worry was associated with a greater risk of CVD and all-cause mortality, but the association can be largely explained by intermediate risk factors such as health behaviours.