Prospective Associations Between Depressive Symptoms and the Metabolic Syndrome: the Spirited Life Study of Methodist Pastors in North Carolina

BACKGROUND: Metabolic syndrome (Met-S) has a robust concurrent association with depression. A small, methodologically limited literature suggests that Met-S and depression are reciprocally related over time, an association that could contribute to their overlapping influences on morbidity and mortality in cardiovascular disease, diabetes, and cancer. PURPOSE: Using a refined approach to the measurement of Met-S as a continuous latent variable comprising continuous components, this study tested the prospective associations between Met-S and depression. METHODS: This study of 1114 clergy included four annual assessments of depressive symptoms and Met-S components. Standard methods were used to measure Met-S risk factors, and the Patient Health Questionnaire-8 was used to assess depressive symptoms. We used confirmatory factor analysis to verify the structure of Met-S and depression and structural equation modeling to quantify the prospective relationships. RESULTS: The statistical models confirmed the validity of quantifying Met-S as a continuous latent variable, replicated previous evidence of a concurrent association, and indicated a significant prospective association of initial depressive symptoms with subsequent Met-S. Initial Met-S was at most only weakly associated with subsequent depressive symptoms, and the former prospective effect was significantly larger. Associations of depressive symptoms and Met-S were significant for both men and women, but somewhat stronger among men. CONCLUSIONS: Results support representation of Met-S as a continuous latent variable. The association of initial depressive symptoms with later Met-S suggests that interventions addressing these correlated risk factors may prove useful in preventive efforts.