Associations between metabolic syndrome and depression in women: Findings from the National Health and Nutrition Examination Survey, 2005-2008

Background and Significance: Although depression is associated with diabetes and heart disease, it is not known why. The literature on associations between depression and metabolic syndrome, a precursor to diabetes and heart disease, are inconsistent. Objective: To investigate the association between metabolic syndrome and depression in a large nationally representative sample of adults. Methods: Logistic regression was used to assess associations between metabolic syndrome as an entity, using the updated National Cholesterol Education Program criteria and depression as measured by the Patient Health Questionnaire in men and women with 2005-2008 data from the National Health and Nutrition Examination Survey. Results: Analyses of a fasting subsample of adults without pregnancy, heart disease or stroke (1,460 women and 1,598 men) revealed that depression and metabolic syndrome are associated in women (odds ratio (OR) = 2.41, 95% confidence interval (CI): 1.43, 4.04), but not in men. The association remained after excluding diabetics (OR = 2.37, 95% CI: 1.38, 4.06), and after controlling for age, education, physical activity and number of chronic conditions in the nondiabetic subsample (OR = 1.60, 95% CI: 1.01, 2.55). As the number of components of metabolic syndrome increased, so did the prevalence of depression among women (p < 0.0001). Waist circumference >= 88 cm and fasting glucose >= 100 mg/dl were each associated with higher prevalence of depression. Conclusion: This study has important implications for women's health, considering both the higher rates of depression in women compared to men, and established risks associated with metabolic syndrome.