Sleep duration and hypercholesterolaemia: Results from the National Health Interview Survey 2008

BackgroundPrevious studies have shown an inconsistent association between sleep duration and hypercholesterolaemia. This study examined the association between sleep duration and hypercholesterolaemia in a nationally representative sample of US adults.MethodsA cross-sectional study of 16,652 participants in the 2008 National Health Interview Survey (aged ⩾18 years, 52.5% women) was conducted. Sleep duration was categorized as ⩽5, 6, 7, 8, or ⩾9 h. Hypercholesterolaemia (n = 5578) was assessed by questionnaire.ResultsA significant gender difference was found in the association between sleep duration and hypercholesterolaemia (P interaction = 0.003). Among women, sleep duration ⩽5 h was positively associated with hypercholesterolaemia after adjusting for potential confounders and mediators including physical activity, psychological distress, body mass index, diabetes mellitus, and hypertension. Compared with a sleep duration of 7 h (referent), the multivariate odds ratio (OR) of hypercholesterolaemia was 1.27 (95% confidence interval [CI] 1.04–1.54) for sleep duration ⩽5 h. In contrast, among men, sleep duration ⩾8 h was inversely associated with hypercholesterolaemia. Compared with a sleep duration of 7 h (referent), the multivariate OR of hypercholesterolaemia was 0.80 (95% CI 0.69–0.94) and 0.78 (95% CI 0.60–1.00) for sleep durations of 8 and ⩾9 h, respectively. In subgroup analyses, the positive association between sleep duration ⩽5 h and hypercholesterolaemia in women, and the inverse association between sleep duration ⩾8 h and hypercholesterolaemia in men, were more pronounced among those aged <60 years and race/ethnic groups other than non-Hispanic Whites.ConclusionSleep duration ⩽5 h was positively associated with hypercholesterolaemia in women, whereas sleep duration ⩾8 h was inversely associated with hypercholesterolaemia in men.