Depressive Symptoms and Risk of Type 2 Diabetes in a National Sample of Middle-Aged and Older Adults

OBJECTIVE To examine the association between baseline elevated depressive symptoms and incident type 2 diabetes in a national sample of people aged > or =50 years. RESEARCH DESIGN AND METHODS The sample consisted of 6,111 individuals free from self-reported doctor-diagnosed diabetes at baseline in 2002-2003. The eight-item Center for Epidemiological Studies-Depression (CES-D) scale was the measurement of depressive symptoms. Cox proportional hazards regression models were used to assess whether baseline elevated (> or =4) depressive symptoms were associated with a higher risk of type 2 diabetes over 45.8 months of follow-up. RESULTS The hazard ratio (HR) for diabetes was 1.62 (95% CI 1.15-2.29) in a model adjusted for age, sex, marital status, education, total net household wealth, cardiovascular and psychiatric and other noncardiovascular comorbidities, BMI, and health behaviors for participants with elevated CES-D symptoms compared with those without. Complementary analysis performed for a subsample (n = 5,090) showed that additional adjustment of this model for use of antidepressants did not explain the association (HR 1.58, 95% CI 1.09-2.29). CONCLUSIONS Elevated depressive symptoms were associated with a higher risk of developing type 2 diabetes after accounting for sociodemographic, lifestyle, and clinical factors in a national sample of people aged > or =50 years.