Associations of acculturation and socioeconomic status with subclinical cardiovascular disease in the multi-ethnic study of atherosclerosis

Objectives. We assessed whether markers of acculturation (birthplace and number of US generations) and socioeconomic status (SES) are associated with markers of subclinical cardiovascular disease—carotid artery plaque, internal carotid intima-media thickness, and albuminuria—in 4 racial/ethnic groups.Methods. With data from the Multi-Ethnic Study of Atherosclerosis (n = 6716 participants aged 45–84 years) and race-specific binomial regression models, we computed prevalence ratios adjusted for demographics and traditional cardiovascular risk factors.Results. The adjusted US- to foreign-born prevalence ratio for carotid plaque was 1.20 (99% confidence interval CI] = 0.97, 1.39) among Whites, 1.91 (99% CI = 0.94, 2.94) among Chinese, 1.62 (99% CI = 1.28, 2.06) among Blacks, and 1.23 (99% CI = 1.15, 1.31) among Hispanics. Greater carotid plaque prevalence was found among Whites, Blacks, and Hispanics with a greater number of generations with US residence (P < .001) and among Whites with less education and among Blacks with lower incomes. Similar associations were observed with intima-media thickness. There was also evidence of an inverse association between albuminuria and SES among Whites and Hispanics.Conclusions. Greater US acculturation and lower SES were associated with a higher prevalence of carotid plaque and greater intima-media thickness but not with albuminuria. Maintenance of healthful habits among recent immigrants should be encouraged.Beginning with the Ni-Hon-San study,^1,2 which was initiated in the 1960s, research has associated increased acculturation to Western lifestyles with more-adverse cardiovascular disease (CVD) risk factor profiles and with increased CVD morbidity and mortality. Specifically, greater Western acculturation has frequently been linked to increased body mass index (BMI; weight in kilograms divided by height in meters squared),^3–5 waist circumference and abdominal obesity,^6,7 hypertension,^7–9 type II diabetes,^10,11 and CVD morbidity and mortality.^1,12,13 However, little research has explored associations between acculturation and subclinical CVD.^14,15Abundant research also exists that links low socioeconomic status (SES) to increased levels of CVD risk factors, morbidity, and mortality.^14,16–18 In general, SES has been found to be inversely related to subclinical measures of CVD, including coronary artery calcification (CAC),^14,19–22 carotid artery plaque, and intima-media thickness^20,23–26 and albuminuria.²⁷ Relations with peripheral artery disease have been inconsistent.^28–30 The extent to which these associations vary by race/ethnicity has been examined infrequently. There is, however, some evidence that the relation between SES and disease may differ across racial/ethnic groups.^14,31,32 Specifically, in the Multi-Ethnic Study of Atherosclerosis (MESA) there was a higher prevalence of CAC among Whites with low education than among those with more education, whereas the reverse was true for Hispanics.¹⁴We investigated whether acculturation and SES were associated with other measures of subclinical disease, specifically with carotid plaque and albuminuria. The relation of acculturation and SES to CAC has been described in MESA.¹⁴ Although CAC, carotid plaque, and albuminuria are all subclinical measures of CVD and are related to adverse clinical outcomes, these measures represent different aspects of the disease process and have relatively weak intercorrelations.³³ Thus, they may be differentially related to our exposures of interest.The investigation of these patterns is important from a public health perspective and may yield clues regarding the etiology of atherosclerosis. On the basis of previous work,¹⁴ we hypothesized that increased Western acculturation, as assessed by place of birth, migration history, and duration of US residence, is associated with increased carotid plaque, intima-media thickness, and albuminuria. Additionally, we expected there to be an interaction between race/ethnicity and SES with respect to their associations with subclinical CVD. Specifically, we expected Whites and Blacks at lower SES to have more-adverse subclinical CVD profiles than those at higher SES, whereas for Hispanics and Chinese, we expected the reverse to be true.