Using a large state sample of Hispanics over several years, our study has several important findings on the association of acculturation and chronic disease prevalence. First, self-reported prevalence of hypertension and diabetes varied by country of origin. Second, stratifying by nativity status demonstrated significant differences in disease reporting by country of origin. Third, among all foreign-born subgroups, only Mexicans reported lower odds of hypertension after adjustment for socioeconomic and acculturation factors. Fourth, acculturation, as measured by years of residence in the U.S. and citizenship status, was an important predictor of hypertension and diabetes. This suggests that acculturation may differentially impact Hispanic subgroups. Our findings highlight the importance of disaggregation of Hispanics by country of origin and acculturation factors whenever possible.
Nativity had important differential effects. Compared with NHW, we found that U.S.-born Mexicans, Central Americans South Americans and foreign-born Mexicans had lower odds of reporting hypertension. The rate of hypertension increased after adjustment for socioeconomic status and acculturation factors in all groups except for South Americans. There was no difference in the reported odds of hypertension compared to NHWs in fully adjusted models for the other Hispanic subgroups. As people spend more time in the U.S., lifestyle changes and a consequent increase in BMI may significantly lead to a poorer cardiovascular profile [19–21]. Our study also found that U.S.-born Hispanics had higher BMIs compared to foreign-born Hispanics, regardless of country of origin. However, changes in clinical risk factors might differ in each Hispanic subgroup. Prior studies have shown that despite similar cardiac risk factors, Hispanic subgroups have varying degrees of subclinical CVD, including higher coronary artery calcium (CAC) scores and inflammation as measured by C-reactive protein [12, 22–24]. This may be attributed to the genetic diversity in Hispanic subgroups . The low prevalence of hypertension among Mexicans, despite acculturation, might be explained by the geographic proximity to their native land, which may play a stronger role in preservation of family ties and traditions despite length of residency in the U.S. and English language acquisition .
The “Hispanic Paradox” refers to the epidemiological finding that foreign-born Hispanics – largely Mexican – often fare better than their white counterparts on morbidity and mortality outcomes, despite lower levels of income, education, and worse health care access [27–29]. This difference has been attributed to a healthy migrant effect, healthier behaviors, and/or cultural traditions. The healthy migrant effect posits that healthier persons are more likely to migrate thus producing increased longevity and health in the emigrant population. The acculturation hypothesis states that Hispanic cultural orientation results in healthier behaviors that result in better health outcomes and is thus protective against the effects of lower socioeconomic status in the U.S. . Prior studies of the healthy migrant effect have focused primarily on Mexicans with few studies focusing on Hispanic subgroups .
Similar to prior studies, we also found lower odds of reported hypertension among foreign-born Mexicans even after adjustment for acculturation . However, we found no significant difference in the odds of reported hypertension compared with NHWs after adjustment for socioeconomic and acculturation factors among all other foreign-born Hispanic subgroups. Our findings suggest that acculturation may differentially impact Hispanic subgroups and highlights the importance of disaggregation of Hispanics by country of origin and acculturation factors.
In agreement with existing literature, we found that reported diabetes rates varied with country of origin [6, 7, 32]. In our study, Mexicans, regardless of nativity status, have higher odds of reporting diabetes compared to NHWs, even after adjusting for BMI. In contrast, U.S.-born Central and South Americans had lower odds of reporting diabetes compared to NHWs. In addition, U.S.-born Other Hispanic and foreign-born Central Americans had higher odds of reporting diabetes. These findings might be attributed to genetic and behavioral differences, which make different subgroups more susceptible to diabetes and the metabolic syndrome and not hypertension. We found an increasing trend in the odd ratios for reporting diabetes as the years of residence in the U.S. increased (Table 4). This is consistent with prior studies that have shown an inverse relationship between increasing acculturation and a less healthy diet and increased rates of obesity [5, 8, 21, 30, 33]. Our findings show a complex relationship between greater acculturation and diabetes, likely because of the distinct Hispanic subgroups and numerous acculturation metrics available in our study.
We found higher odds of reporting hypertension among foreign-born Other Hispanics and higher rates of diabetes among U.S.-born Other Hispanics compared with NHWs. These differences may be due to a higher socioeconomic and acculturation status for this subgroup. Compared to other Hispanic subgroups, the Other Hispanics had high rates of college education, higher incomes, private insurance, and higher unadjusted rates of hypertension and diabetes. Among the foreign-born Hispanics, Other Hispanics were the most acculturated with 82% living in the U.S. greater than fifteen years and most speaking English well. The self-identification as “Other Hispanic” may reflect people who do not fit a particular pre-established Hispanic subgroup (i.e., European Hispanics or Brazilian) or people who identify as biracial or bi-ethnic (i.e., participant with only one Hispanic parent). The self-identity of Hispanics is complex and is influenced by the country of origin and nativity status . Future studies should include bi-racial or bi-ethnic Hispanics as they constitute a poorly studied subgroup.
Strengths and limitations
A major strength of our study is its large sample size of Hispanics over a seven-year period that used the same sampling and data collection methodology in a state with one of the largest Hispanic populations. The survey questions allowed for a more detailed analysis of self-identified Hispanics by country of origin and acculturation factors than has been available in previous studies. We were able to assess acculturation in four dimensions (i.e., English language ability, years of residence in the U.S., citizenship, and nativity status). In addition, California’s Hispanic demographic patterns allowed for a larger and more representative sample of Hispanics from Central and South America, groups traditionally underrepresented in other datasets. Importantly, our data allowed for statistical analyses that controlled for important confounders such as intensity of clinical services utilization.
Our study had several limitations. First, our data are cross-sectional and thus associations found are not proof of causality. Second, the self-reported nature of hypertension and diabetes may cause underestimation of disease rates, particularly because many Hispanics are uninsured and have less access to regular sources of healthcare. However, self-reported data for hypertension and diabetes have been shown to be highly correlated with physicians’ records [34–36]. Similarly, self-reported English language ability, one of the metrics of acculturation, was self-reported, consistent with current U.S. census definitions. We lacked significant data on Caribbean Hispanics and Black Hispanics, which may represent a large segment of the Hispanic population in other parts of the U.S. Finally, Hispanics who self-identified as “2+ Hispanic” and “Other Hispanic” represent a heterogeneous group from multiple countries of origin. However, these groups represent primarily U.S.-born Hispanics. Inclusion of these categories is important since it is reflective of the complex demographic self-identity of Hispanics that should be included in analyses of Hispanics.