Serum Low-Density Lipoprotein Cholesterol Levels and Depressive Mood in Korean Adults: A Nationwide Population-Based Study

BACKGROUND: The association between serum cholesterol levels and depression has been studied extensively; however, results are inconsistent. This study aimed to investigate the association between low-density lipoprotein cholesterol (LDL-C) levels and depressive symptoms among Korean adults. METHODS: This cross-sectional study used data obtained from the 2007–2015 Korea National Health and Nutrition Examination Survey. In total, 40,904 adults were included in the final analysis. Participants were categorized into five groups according to their LDL-C levels, using the Korean guidelines for dyslipidemia. Symptoms of depression were evaluated using a self-reported questionnaire. Weighted logistic regression was used to examine the relationship between LDL-C levels and self-reported depressive symptoms. RESULTS: Compared with the intermediate category, the lowest (<70 mg/dL) and highest (≥160 mg/dL) LDL-C categories were associated with depressive symptoms, after adjusting for potential confounding factors (odds ratio [OR], 1.191; 95% confidence interval [CI], 1.008–1.409; OR, 1.241; 95% CI, 1.073–1.435, respectively). The highest LDL-C category was positively associated with depressive symptoms in those who were middle-aged, female, had a low body mass index, and taking or not taking dyslipidemia medications. CONCLUSION: A U-shaped association was identified between LDL-C categories and self-reported depressive symptoms. Our findings suggest that LDL-C levels that are too low or too high are associated with self-reported depressive symptoms. Further prospective studies are needed to determine the causal relationship of this association.