Racial differences in the predictive role of high depressive symptoms on incident heart disease over 18 years: Results from the health and retirement study

Abstract

Background: Studies have investigated racial differences in the relationship between depression and CVD mortality. Objectives: This study tested the hypothesis that race moderates the effect of baseline depressive symptoms on subsequent heart disease among a nationally representative sample of Black and White older Americans. Patients and Methods: Data came from ten waves of the health and retirement study (HRS), a nationally representative longitudi- nal study of US adults over age 50. The present study followed 7,444 Black and White individuals without a diagnosis of heart disease at baseline for up to 18 years for incident heart disease. Elevated depressive symptoms at baseline was the independent variable, time to incident heart disease was the dependent variable, while baseline sociodemographics, health risk behaviors, obesity, and chronic medical conditions were controls. We used Cox proportional hazards models in the pooled sample and stratified by race to test the effect of elevated depressive symptoms on the outcome net of other risk factors. Results: In the pooled sample, a significant positive interaction was found between the effect of elevated depressive symptoms and Black race (hazard ratio, 1.29; 95% CI = 1.01 -1.65), suggesting a stronger effect for Blacks compared to Whites. In fully adjusted race- stratified models, elevated depressive symptoms increased the risk of developing heart disease for Blacks (hazard ratio, 1.47; 95% CI = 1.04 - 2.07) but not Whites (hazard ratio, 1.13; 95% CI = 0.97 -1.32). Conclusions: Black and White older adults differ in the effect of depressive symptoms on subsequent heart disease over a long period of follow up. Elevated depressive symptoms are associated with a larger risk of incident heart disease among Black but not White older individuals.