Socioeconomic status and progression of carotid atherosclerosis. Prospective evidence from the Kuopio Ischemic Heart Disease Risk Factor Study

Abstract

Socioeconomic status (SES) is importantly associated with cardiovascular morbidity and mortality, but no information exists on the relationship between SES and progression of atherosclerotic vascular disease. We investigated the association between education and income and the 4-year progression of carotid atherosclerosis in a population-based sample of Finnish men. Data from the Kuopio Ischemic Heart Disease Risk Factor Study were used to estimate changes in maximum and mean intima-media thickness (IMT) and maximum plaque height across levels of SES in 1022 men. Associations between SES and atherosclerotic progression were examined in relation to risk factors and stratified by baseline levels of atherosclerosis and prevalent ischemic heart disease (IHD). There were significant, inverse, graded relationships between levels of education and income for all three progression measures, which were largely unaffected by risk factor adjustment. For education, the age- and baseline IMT-adjusted maximum progression for those with primary schooling or less was 0.28 mm and for those who graduated from high school, 0.24 mm (P = .05). Compared with the lowest SES group, men with the highest SES had 14% to 29% less atherosclerotic progression, depending on the measure used. Associations of the same magnitude were evident in subgroups without advanced baseline IMT and in men who were free of IHD. These results show that men with poor education and low income have significantly greater progression of carotid atherosclerosis than men with more advantages. The findings strengthen the contention that SES plays a significant role early in the atherosclerotic disease process and that reducing the burden of atherosclerotic vascular disease associated with lower SES will require approaches that focus on all stages of the life course.