Depressive symptoms and cardiovascular mortality in older black and white adults: evidence for a differential association by race.

BACKGROUND

An emerging body of research suggests that depressive symptoms may confer an "accelerated risk" for cardiovascular disease (CVD) in blacks compared with whites. Research in this area has been limited to cardiovascular risk factors and early markers; less is known about black-white differences in associations with important clinical end points.

METHODS AND RESULTS

The authors examined the association between depressive symptoms and overall CVD mortality, ischemic heart disease (IHD) mortality, and stroke mortality in a sample of 6158 (62% black; 61% female) community-dwelling older adults. Cox proportional hazards models were used to model time-to-CVD, IHD, and stroke death over a 9- to 12-year follow-up. In race-stratified models adjusted for age and sex, elevated depressive symptoms were associated with CVD mortality in blacks (hazard ratio [HR], 1.95; 95% confidence interval [CI], 1.61 to 2.36; P<0.001) but were not significantly associated with CVD mortality in whites (HR, 1.26; 95% CI, 0.95 to 1.68; P=0.11; race by depressive symptoms interaction, P=0.03). Similar findings were observed for IHD mortality (black: HR, 1.99; 95% CI, 1.49 to 2.64; P<0.001; white: HR, 1.28; 95% CI, 0.86 to 1.89; P=0.23) and stroke mortality (black: HR, 2.08; 95% CI, 1.32 to 3.27; P=0.002; white: HR, 1.32; 95% CI, 0.69 to 2.52; P=0.40). Findings for total CVD mortality and IHD mortality were attenuated but remained significant after adjusting for standard risk factors. Findings for stroke were reduced to marginal significance.

CONCLUSIONS

Elevated depressive symptoms were associated with multiple indicators of CVD mortality in older blacks but not in whites. Findings were not completely explained by standard risk factors. Efforts aimed at reducing depressive symptoms in blacks may ultimately prove beneficial for their cardiovascular health.