Objective: To examine the contribution of depressed mood in obese subjects on the prediction of a future coronary heart disease event (CHD).
Design: A prospective population-based cohort study of three independent cross-sectional surveys with 6239 subjects, 45-74 years of age and free of diagnosed CHD, stroke and cancer. During a mean follow-up of 7 years, 179 CHD events occurred among men and 50 events among women.
Subjects: A total of 737 (23%) male and 773 (26%) female subjects suffering from obesity (BMI >or=30 kg/m2).
Measurements: Body weight determined by trained medical staff following a standardized protocol; standardized questionnaires to assess subsyndromal depressive mood and other psychosocial features.
Results: The main effect of obesity to predict a future CHD (hazard ratio, HR=1.38, 95% CI 1.03-1.84; P=0.031) and the interaction term of obesity by depression (HR=1.73, 95% CI 0.98-3.05; P=0.060) were borderline significant, both covariate adjusted for multiple risk factors. Relative to the male subgroup with normal body weight and no depression, the male obese group with no depression was not at significantly increased risk for CHD events (HR=1.17, 95% CI 0.76-1.80; P=0.473) whereas CHD risk in males with both obesity and depressed mood was substantially increased (HR=2.32, 95% CI 1.45-3.72, P>0.0001). The findings for women were similar, however, not significant probably owing to lack of power associated with low event rates. Combining obesity and depressed mood resulted in a relative risk to suffer from a future CHD event of HR 1.84 (95% CI 0.79-4.26; P=0.158).
Conclusions: Depressed mood substantially amplifies the CHD risk of middle-aged obese, but otherwise apparently healthy men. The impact of depression on the obesity risk in women is less pronounced.