Discrimination, Smoking, and Cardiovascular Disease Risk: A Moderated Mediation Analysis With MESA

BACKGROUND: Carotid intima-media thickness (cIMT) and carotid plaque are reliable indicators of cardiovascular disease risk, and research highlights that racial and ethnic minority individuals generally exhibit higher cIMT and carotid plaque than White individuals. At present, the mechanisms driving these disparities among different racial and ethnic and biological sex groups are poorly understood. METHODS AND RESULTS: Data came from the baseline examination of MESA (Multi-Ethnic Study of Atherosclerosis). A total of 6814 participants aged 45 to 84 years free of clinical cardiovascular disease completed assessments on health behavior and perceived discrimination. Four sex-stratified moderated mediation models examined associations between discrimination, cigarette smoking, and mean cIMT and plaque. We hypothesized that cigarette use would mediate the association between discrimination and carotid artery disease features, and that these would differ by race and ethnicity. Indirect effects of discrimination on plaque were observed among Hispanic women such that discrimination was associated with cigarette use and, in turn, higher plaque (β=0.04 [95% CI, 0.01–0.08]). Indirect effects of discrimination on mean cIMT were found among Hispanic (β=0.003 [95% CI, 0.0001–0.007]) and White men (β=0.04 [95% CI, 0.01–0.08]) such that discrimination was associated with cigarette use and, in turn, higher cIMT. Finally, a positive indirect effect of discrimination on plaque was observed among Hispanic men (β=0.03 [95% CI, 0.004–0.07]). No other racial and ethnic differences were observed. CONCLUSIONS: To understand and address social determinants of cardiovascular disease, researchers must incorporate an intersectional framework that will allow us to understand the complex nature of discrimination and cardiovascular disease risk for individuals of varying intersecting identities and social positions.