Ethnic and sex differences in disease burden in patients undergoing coronary angiography: the confounding influence of obesity

Abstract

Background: Data from cohort studies, predominantly in Caucasians, have identified obesity as a major risk factor for coronary artery disease (CAD), irrespective of sex. In contrast, reports examining the effects of obesity on mortality in African Americans suggest a weak relationship between body mass index (BMI) and mortality, particularly among women. Data correlating body weight with angiographic severity of CAD is sparse in minority populations. We sought to investigate ethnic-sex differences in the influence of obesity on the extent and severity of CAD.

Methods: We studied 640 patients (66.9% African American) who underwent coronary angiography at a tertiary care center. Cardiovascular risk factor profiles and CAD burden, quantified by the Duke Myocardial Jeopardy scoring system, a validated prognostication tool, were compared across ethnic and sex groups.

Results: Clustering of major cardiovascular risk factors, a higher prevalence of obesity classes II and III, and a statistically significant inverse correlation between BMI and Duke scores were observed among the cohort of African American women. General linear model analysis and stepwise multiple linear regression analysis revealed Duke score to be negatively associated with BMI and higher classes of obesity after adjustment for age and other cardiovascular risk factors in African American women but not in other subgroups.

Conclusions: The observed inverse relationship between BMI and angiographic severity of CAD in African American women is novel and appears to support prior data on the weak association between BMI and cardiovascular mortality in this subgroup.