Acculturation and socioeconomic position as predictors of coronary calcification in a multiethnic sample

Background - Coronary calcium has recently emerged as a marker of subclinical coronary heart disease. Although there has been much interest in race differences in calcification, heterogeneity within race or ethnic groups has not been investigated. Methods and Results - Data from the Multi-Ethnic Study of Atherosclerosis (MESA), a population-based study of coronary calcification, were used to investigate acculturation and socioeconomic position as predictors of coronary calcification within 2553 non-Hispanic whites, 1734 non-Hispanic blacks, 1457 Hispanics, and 797 Chinese residing in the United States. Coronary calcium was assessed by chest CT. Relative risk regression and linear regression were used to estimate adjusted associations of sociodemographic variables with the presence and amount of calcium. Not being born in the United States was associated with a lower prevalence of calcification in blacks (relative prevalence [RP], 0.75; 95% confidence limit [CL], 0.61 to 0.94) and Hispanics (RP, 0.89; 95% CL, 0.81 to 0.98) after adjustment for age, sex, income, and education. Years in the United States was positively associated with prevalence of calcification in non-US-born Chinese (adjusted RP per 10 years in United States, 1.06; 95% CL, 1.01 to 1.11) and non-US-born blacks (RP, 1.59; 95% CL, 1.22 to 2.06). Low education was associated with a higher prevalence of calcification in whites (adjusted RP for no high school versus complete college, 1.17; 95% CL, 1.05 to 1.32) but with lower prevalence of calcification in Hispanics (RP, 0.91; 95% CL, 0.77 to 1.09) (P for interaction=0.02). US birth and time in the United States were also positively associated with the extent of calcification in persons with detectable calcium. These differences did not appear to be accounted for by smoking, body mass index, LDL and HDL cholesterol, hypertension, and diabetes. Conclusions - Acculturation and socioeconomic factors are associated with differences in the prevalence and amount of coronary calcification within whites, Chinese, blacks, and Hispanics. The presence of this heterogeneity needs to be acknowledged in the quantification and investigation of race/ethnic differences.