Do socioeconomic gradients in subclinical atherosclerosis vary according to acculturation level? Analyses of Mexican-Americans in the multi-ethnic study of atherosclerosis.

OBJECTIVE: To examine whether the association between socioeconomic position (SEP) and subclinical atherosclerosis in Mexican-Americans would be moderated by acculturation. Although SEP shows a consistent, inverse relationship with cardiovascular disease (CVD) risk in westernized non-Hispanic white populations, the relationship in ethnic minorities, including Hispanics, is often weak or even reversed (i.e., worse health with higher SEP). METHODS: Participants were 801 Hispanics of Mexican origin (49.6% = female; average age = 60.47 years) from the Multi-Ethnic Study of Atherosclerosis cohort who underwent computed tomography of the chest for coronary artery calcium (CAC) and thoracic aortic calcium (TAC). SEP was represented by a composite of self-reported education and income. Acculturation was a composite score, including language spoken at home, generation, and years of "exposure" to U.S. culture. RESULTS: Small but statistically significant SEP by acculturation interaction effects were identified in relation to prevalent CAC, prevalent TAC, and extent of TAC (all p < .05). Follow-up analyses revealed that the direction of the SEP gradient on detectable CAC changed as individuals progressed from low to high acculturation. Specifically, the association between SEP and calcification was positive at low levels of acculturation (i.e., a "reversed" gradient), and negative in circumstances of high acculturation (i.e., the expected, protective effect of higher SEP). CONCLUSIONS: The findings support the utility of examining SEP and acculturation simultaneously, and of disaggregating large ethnic groupings (e.g., "Hispanic") into meaningful subgroups to better understand health risks.