Association of coexisting diabetes and depression with mortality after myocardial infarction

Abstract

Objective: Diabetes and depression are both linked to an increased mortality risk after myocardial infarction (MI). Population-based studies suggest that having both diabetes and depression results in an increased mortality risk, beyond that of having diabetes or depression alone. The purpose of this study was to examine the joint association of diabetes and depression with mortality in MI patients.

Research design and methods: Data were derived from two multicenter cohort studies in the Netherlands, comprising 2,704 patients who were hospitalized for MI. Depression, defined as a Beck Depression Inventory score ≥10, and diabetes were assessed during hospitalization. Mortality data were retrieved for 2,525 patients (93%).

Results: During an average follow-up of 6.2 years, 439 patients died. The mortality rate was 14% (226 of 1,673) in patients without diabetes and depression, 23% (49 of 210) in patients with diabetes only, 22% (118 of 544) in patients with depression only, and 47% (46 of 98) in patients with both diabetes and depression. After adjustment for age, sex, smoking, hypertension, left ventricular ejection fraction, prior MI, and Killip class, hazard ratios for all-cause mortality were 1.38 (95% CI 1.00-1.90) for patients with diabetes only, 1.39 (1.10-1.76) for patients with depression only, and as much as 2.90 (2.07-4.07) for patients with both diabetes and depression.

Conclusions: We observed an increased mortality risk in post-MI patients with both diabetes and depression, beyond the association with mortality of diabetes and depression alone.

Figure 1

Kaplan-Meier curves for all-cause mortality for each diabetes and depression category (unadjusted analysis).

Figure 2

Kaplan-Meier curves for cardiac mortality for each diabetes and depression category (unadjusted analysis).