Associations between sleep duration and abnormal serum lipid levels: data from the Korean National Health and Nutrition Examination Survey (KNHANES).

BACKGROUND

Shorter or longer sleep duration has been reported to be associated with abnormal serum lipid levels, but the findings have been inconsistent. This study examined associations between sleep duration and abnormal serum lipid levels in a Korean adult population.

METHODS

This study used the data of 13,609 people aged ≥20 years from the Korean National Health and Nutrition Examination Survey (KNHANES) in 2010-2012. Sleep duration was classified into five groups: ≤5, 6, 7 (reference category), 8, and ≥9 hours. The serum concentrations of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride were measured and defined in terms of abnormal serum lipid levels. Multiple logistic regressions were performed to determine the associations between sleep duration and abnormal serum lipid levels. The covariates included age, sex, education, marital status, current smoking, alcohol consumption, physical activity, body mass index, hypertension, diabetes, depressive symptoms, and stress level.

RESULTS

Self-reported sleep duration of ≤5 hours was significantly associated with high TC and high LDL-C levels in unadjusted models, but after adjusting for age and sex, the statistical significance disappeared. On the other hand, after adjusting for covariates, self-reported sleep duration of ≥9 h was significantly associated with low HDL-C levels (odds ratio = 1.30; 95% confidence interval = 1.09-1.54).

CONCLUSIONS

These findings suggest that longer sleep duration is associated with low HDL-C levels among Korean adults.