A higher urinary albumin-to-creatinine ratio (ACR) is more strongly related to incident—but not recurrent—coronary heart disease (CHD) in black versus white Americans, reports a study in the Journal of the American Medical Association.
The analysis included data on black and white adults in the United States enrolled in the prospective Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. Urinary ACR was evaluated for association with CHD outcomes, including possible differences between racial groups. Incident CHD was evaluated in about 23,000 participants initially free of this condition, and recurrent CHD in nearly 5000 individuals with CHD at baseline. The mean follow-up time was 4.4 years.
Higher ACR had a greater impact on incident CHD in black participants. At an ACR above 300 mg/g, the age-adjusted and sex-adjusted incidence of CHF was 20.59 per 1000 person-years in black participants versus 13.60 per 1000 person-years in white participants. After adjustment for cardiovascular risk factors and medications, the risk of incident CHD was threefold higher (hazard ratio 3.21) in black adults with ACR greater than 300 mg/g (versus less than 10 mg/g). The association was no longer significant in white participants.
By contrast, the risk of recurrent CHD events associated with high ACR did not differ by race. At an ACR above 300 mg/g, adjusted hazard ratios for first recurrent CHD event were 2.21 for black and 2.48 for white participants.
High urinary ACR is more frequent in black than in white adults. Previous REGARDS data have shown that albuminuria is a stronger risk factor for stroke in black than in white individuals.
The new results suggest that the association extends to CHD. The relative risk of incident CHD associated with high ACR appears two times greater in black than in white individuals. No such difference is apparent for recurrent CHD risk. The investigators conclude, “Future studies should examine whether addition of ACR can improve the diagnosis and management of CHD in black individuals” [Gutierrez OM, et al. Association between urinary albumin excretion and coronary heart disease in black vs white adults. JAMA 2013; 310:706–714].
