Sleep Patterns Modify the Association between Vitamin D Status and Coronary Heart Disease: Results from NHANES 2005-2008

Background: Although an increased risk of coronary heart disease (CHD) has been reported in individuals with low vitamin D status, this remains controversial. Growing evidence suggests that sleep behaviors may influence vitamin D endocrine functions. Objectives: We explored the association between serum 25-hydroxyvitamin D [[25(OH)D] concentrations and CHD and whether sleep behaviors modify this relationship. Methods: A cross-sectional analysis of 7511 adults aged >= 20 yin 2005-2008 National Health and Nutrition Examination Survey (NHANES) that included serum 25(OH)D concentrations and provided information on sleep behaviors and history of CHD was performed. Logistic regression models were used to assess the association between serum 25(OH)D concentrations and CHD, whereas stratified analyses and multiplicative interaction tests were used to evaluate the modification effect of overall sleep patterns and each sleep factor on this rela-tionship. The overall sleep patterns integrated 4 sleep behaviors (sleep duration, snoring, insomnia, and daytime sleepiness) in the form of healthy sleep score. Results: Serum 25(OH)D concentrations were inversely associated with risk of CHD (P < 0.01). Hypovitaminosis D [serum 25(OH)D <50nmol/L] was associated with a 71% increased risk of CHD (OR: 1.71; 95% CI: 1.28, 2.28; P < 0.01) compared with that in participants with sufficient vitamin D [serum 25(OH)D >75nmol/L], and the association was more evident and stable among participants with poor sleep patterns (P-interaction < 0.01). Among the individual sleep behaviors, sleep duration had the strongest interaction with 25(OH)D (P -interaction < 0.05). The association between serum 25(OH)D concentrations and risk of CHD was more pronounced in participants with sleep duration <7 h/d or >8 h/d compared with those with sleep duration 7-8 h/d. Conclusions: These findings suggest that the influence of lifestyle-related behavioral risk factors, such as sleep behaviors (especially sleep duration), need to be considered when evaluating the association between serum 25(OH)D concentrations and CHD as well as the clinical benefits of vitamin D supplementation.