Objective To test whether depression modifies the association between treatable cardiovascular risk factors and incident cardiac events (angina pectoris or myocardial infarction) in a population-based cohort of middle-aged workers.

Method 10,541 Gazel working men and women free of cardiovascular disease at baseline (1993) were followed-up over 20 years for carefully validated incident cardiac events. Depression was measured at baseline and every three years with the Center for Epidemiological Studies-Depression (CES-D). We used time-dependent Cox regressions to calculate hazard ratios (HR) of cardiac events associated with depression, main treatable cardiovascular risk factors (hypertension, diabetes, and dyslipidemia), and their interactions, adjusting for demographic, lifestyle and clinical characteristics.

Results Over 20 years of follow-up, 592 incident cases of cardiac events were identified. Depression was significantly associated with incident cardiac events (HR 1.55, P = 0.002), as was hypertension (HR 1.49, P = 0.02), diabetes (HR 2.54, P = 0.001), and dyslipidemia (HR 1.55, P = 0.003). No statistically significant interaction was observed between depression and hypertension, diabetes or dyslipidemia in relation to incident cardiac events (all P ≥ 0.16).

Conclusion The association between depression and cardiac events is unlikely to be explained by a heightened impact of hypertension, diabetes or dyslipidemia. Therefore, other pathways should be searched for to explain this association.