Ethnic differences in cardiovascular risk factor burden among middle-aged women: Study of Women's Health Across the Nation (SWAN)

Background: We evaluated ethnic differences in the 10-year risk of myocardial infarction or coronary death derived from Framingham risk equation and in a composite measure of emerging cardiovascular disease risk factors in women and whether statistical adjustments for educational attainment, geographic location, and lifestyle attenuated the magnitude of the ethnic differences in risk. Methods: Two thousand eight hundred thirty-four premenopausal women free of stroke, heart disease, or diabetes and aged of 42 to 52 years (1400 whites, 729 African American, 226 Hispanic, 231 Chinese, and 248 Japanese) had measurements of blood pressure, lipids and lipoproteins, waist circumference, glucose, insulin, lipoprotein(a), fibrinogen, factor VII, plasminogen activator inhibitor, tissue-type plasminogen activator antigen, and high-sensitivity C-reactive protein. Framingham risk score and number of risk factors in the top quartile of the distribution of risk factors not included in the Framingham score (called composite burden) were calculated. Results: The unadjusted mean values for the two summary scores were higher among African Americans and Hispanics than other groups. Statistical adjustments for education and geographical site accounted for a majority of the ethnic differences, with an additional small effect of lifestyle for the composite burden score. Largest ethnic differences were apparent for waist circumference, lipoprotein(a), high-sensitivity C-reactive protein, and untreated blood pressure. Conclusions: A substantial part of the risk associated with ethnicity can be attributed to socioeconomic status and geographical location. As the ethnic composition of the United States population becomes more diverse, it is important to appreciate the cardiovascular disease risk factor burden present in some minority groups.