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

Background: Previous 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. Methods: A 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. Results: A 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. Conclusion: Sleep duration <= 5 h was positively associated with hypercholesterolaemia in women, whereas sleep duration >= 8 h was inversely associated with hypercholesterolaemia in men. (C) 2011 Elsevier B.V. All rights reserved.