Diabetes mellitus, coronary heart disease incidence, and death from all causes in African American and European American women The NHANES I Epidemiologic Follow-up Study

Abstract

Few data are available on risk for coronary heart disease in African American women with diabetes mellitus, a well-established coronary risk factor in European American women. This study tests the hypothesis that medical history of diabetes predicts coronary heart disease incidence in African American women in a national cohort. Participants in the NHANES I Epidemiologic Follow-up Study in this analysis were 1035 African American and 5732 European American women aged 25–74 years without a history of coronary heart disease. Average follow-up for survivors was 19 years (maximum 22 years). Risk of incident coronary heart disease by baseline diabetes status was estimated. Proportional hazards analyses for African American women aged 25–74 revealed significant associations of coronary heart disease risk with diabetes after adjusting for age (RR = 2.40; 95% CI, 1.58–3.64, P < 0.01). After adjusting for age, smoking, and low education, there was an elevated risk in diabetics age 25–74 (RR = 2.34; 95% CI, 1.54–3.56, P < 0.01); this association did not differ significantly from that for European American women. Excess coronary incidence in African American compared to European American women aged 25–64 was statistically explained by controlling for diabetes history, age, education, and smoking but only partly explained by age and diabetes history. In African American women aged 25–74, diabetes was also associated with increased coronary heart disease, cardiovascular, and all-cause mortality. The population attributable risk of coronary heart disease incidence associated with a medical history of diabetes was 8.7% in African American women and 6.1% in European American women. Medical history of diabetes was a significant predictor of coronary heart disease incidence and mortality in African American women and explained some of the excess coronary incidence in younger African American compared to European American women.