OBJECTIVE -The goal of this study was to determine whether depressive symptoms predict type 2 diabetes.
RESEARCH DESIGN AND METHODS-We analyzed data on depressive symptoms (including recent fatigue, sleep disturbance, feelings of hopelessness, loss of libido, and increased irritability) in a longitudinal, biracial cohort study of 11,615 initially nondiabetic adults aged 48 -67 years, who were subsequently followed for 6 years for the development of type 2 diabetes.RESULTS -At baseline, depressive symptoms were positively associated with BMI, fasting insulin, systolic blood pressure, caloric intake, physical inactivity, and current smoking (all P Ͻ 0.05). In prospective analyses, after adjusting for age, race, sex, and education, individuals in the highest quartile of depressive symptoms had a 63% increased risk of developing diabetes compared with those in the lowest quartile (relative hazard [RH] 1.63, 95% CI 1.31-2.02). This relation persisted after adjustment for stress-associated lifestyle factors (smoking, physical activity, caloric intake, and adiposity) (1.28, 1.02-1.60) and metabolic covariates (fasting insulin and glucose, lipids, blood pressure, and adiposity) (1.38, 1.10 -1.73).CONCLUSIONS -In this cohort, depressive symptoms predicted incident type 2 diabetes. This relation is only partially explained by demographic, metabolic, and lifestyle factors. Possible neuroendocrine mediators of the stress-obesity-diabetes relationship require further evaluation in prospective cohort studies that use an established tool to assess depression and incorporate neurohormonal measurements.
Diabetes Care 27:429 -435, 2004T here has been a growing interest in depression as a novel risk factor for the development of type 2 diabetes as several studies have demonstrated that the presence of depressive symptoms is predictive of incident type 2 diabetes (1,2). Possible mechanisms include the influence of depressive symptoms on behaviors, such as physical activity, diet, and adherence to treatment recommendations (3-7), or their influence on the activity of the hypothalamic-pituitaryadrenal (HPA) axis and sympathetic nervous system (8 -13). Similar mechanisms have been proposed for parallel observations regarding depressive symptoms as predictors of coronary heart disease (14). Previous epidemiological studies of psychological risk factors as predictors of diabetes, however, have been limited by small sample sizes, limited physiological data, and reliance on self-report of diabetes measures (1,2).The Atherosclerosis Risk in Communities (ARIC) study is an attractive study in which to evaluate this relationship because data from standardized measurements are available on clinical outcomes, such as type 2 diabetes, and on depressive symptoms (as captured by a Vital Exhaustion Questionnaire) in a large, biracial, community-based cohort of middle-aged adults who were followed over a 6-year period. Therefore, we conducted a prospective analysis of depressive symptoms as predictors of type 2 diabetes in middleaged adults in ARIC....