SOCIAL INEQUALITIES AND ATHEROSCLEROSIS - THE ATHEROSCLEROSIS RISK INCOMMUNITIES STUDY

The cross-sectional associations of social class indicators with coron ary heart disease prevalence and subclinical atherosclerosis were inve stigated among 15,800 persons from four US communities between 1987 an d 1989. Among persons without clinical atherosclerotic disease, ultras ound-determined intimal-medial wall thickening of the carotid arteries was used as an indicator of subclinical atherosclerosis. Odds ratios for coronary heart disease prevalence and mean differences in carotid wall thickness were investigated before and after adjustment for cardi ovascular risk factors. After adjustment for age and gender, the lowes t income category was associated with a threefold increase in coronary heart disease odds compared with the highest category (for whites, od ds ratio (OR) = 3.4, 95% confidence interval (CI) 1.8-6.6; for blacks, OR = 3.2, 95% CI 2.2-4.8). Odds ratios increased linearly with decrea sing income (p < 0.0001). Low education was also associated with incre ased odds of coronary heart disease after adjustment for age and gende r, but the association was stronger in whites than in blacks (lowest c ategory vs. highest: for whites, OR = 3.8, 95% CI 2.5-5.9; for blacks, OR = 1.7, 95% CI 0.9-3.1). Similar patterns were found for subclinica l atherosclerosis: Carotid wall thickness increased with decreasing in come and education, but trends by education were clearer in whites tha n in blacks. Lower occupational categories were also associated with i ncreased coronary heart disease prevalence odds and increased carotid wall thickness. After adjustment for risk factors, associations with c linical coronary heart disease persisted but associations with carotid wall thickness disappeared, suggesting that factors related to the cl inical expression of lesions may vary by social class. The process of atherogenesis and its clinical expression are patterned by social clas s, emphasizing the need to address social inequalities in the preventi on of cardiovascular disease.