The impact of body mass index on the link between depressive symptoms and health outcome in patients with heart failure

Background: Depressive symptoms are predictors of shorter cardiac event-free survival, whereas increased body mass index (BMI) is associated with longer cardiac event-free survival in patients with heart failure (HF). However, the impact of BMI on the link between depressive symptoms and cardiac event-free survival is unexplored. The purpose of this study was to determine whether the relationship between depressive symptoms and cardiac event-free survival differs among HF patients stratified by BMI tertiles. Methods: A total of 297 outpatients with HF completed the Patient Health Questionnaire-9 to assess depressive symptoms. Bodymass index was calculated as weight in kilograms divided by height in meters squared. Patients were followed for 1 year to determine cardiac event-free survival. Cox proportional hazard regression with survival curves was used to determine the relationships among depressive symptoms, BMI, and cardiac event-free survival. Results: Both depressive symptoms (P G .001) and lower BMI (P = .002) are independent predictors of shorter cardiac event-free survival after controlling for age, gender, etiology, total comorbidity scores, ejection fraction, New York Heart Association functional class, and prescribed medications. Patients with depressive symptoms had shorter cardiac event-free survival compared with patients without depressive symptoms in the lowest (P = .001) and middle (P = .036) BMI tertiles. There was no difference in cardiac event-free survival between patients with and without depressive symptoms in the highest tertile (P = .894). Conclusions: Higher BMI has a protective role in the adverse effect of depressive symptoms on health outcomes in patients with HF.