Discrimination, Smoking, and Cardiovascular Disease Risk: A Moderated Mediation Analysis with the Multi-Ethnic Study of Atherosclerosis

BackgroundRace is a social determinant of cardiovascular (CVD) risk and the American Heart Association has called for increased research to understand how this social determinants of health (SDoH) impacts CVD risk. Carotid intima-media thickness (cIMT) and carotid plaque are reliable indicators of cardiovascular risk. Further, research highlights that disparities exist in these indicators of cardiovascular risk such that racial/ethnic minorities generally exhibit greater characteristics of cardiovascular risk with respect to these indices (e.g., greater cIMT and higher carotid plaque scores) than white individuals due, in part, to exacerbated stress experienced from racial discrimination. At present, the mechanisms driving these racial/ethnic disparities is poorly understood. Methods and ResultsData came from the baseline examination of the Multi-Ethnic Study of Atherosclerosis (MESA). 6,814 participants aged 45-84 free of clinical CVD completed assessments on health behavior, perceived discrimination, CVD-related risk factors, and sociodemographics. Four biological sex-stratified moderated mediation models were used to examine the associations between discrimination, cigarette smoking, and mean cIMT and plaque, modeled separately. We hypothesized that cigarette use would mediate the association between discrimination and carotid artery disease features and that these associations would be moderated by race/ethnicity. While results did not fully support our study hypothesis, racial/ethnic differences were observed across biological sex. Significant indirect effects of discrimination on plaque scores were observed among Hispanic females such that increased discrimination was associated with more cigarette use which, in turn, was associated with higher plaque (b=.04, CI=.01, .08). Similar findings were observed among Hispanic males in relation to mean cIMT (b=.003, CI=.00, .01) and among white (b=.04, CI=.01, .08) and Hispanic males (b=.03, CI=.004, .07) and plaque. No other racial/ethnic differences were observed. ConclusionsResults suggest that cardiovascular risk disparities should be examined within frameworks that consider the importance of the intersection of multiple identities (e.g., race and gender). To better address the American Heart Associations call to examine social determinants of cardiovascular health, researchers must incorporate the complexity of the intersection of various social positions in future work.