Fading of Protective Roots: Severe Hypertension Among Mexican American Immigrants

Purpose: Little if any prior research has examined the risk of hypertension, particularly the risk of severe hypertension, among Mexican immigrants in the United States. The purpose of this study is to examine prevalence and risk of severe hypertension among foreign born Mexican Americans in the United States compared to native born whites, blacks, and Mexican Americans.

Methods: Data consisted of four continuous National Health and Nutrition Examination Surveys (NHANES) spanning 1999-2006 of individuals, 20 years or older (n =14,041). Logistic regressions and odds ratios were computed to determine prevalence and severity of hypertension in Mexican immigrants compared to native populations, controlling for demographic and other risk factors. Hypertension was defined as a systolic blood pressure ≥140 or diastolic blood pressure of ≥90 mm Hg or the use of antihypertensive medication, while severe hypertension as a systolic blood pressure ≥160 or diastolic blood pressure of ≥100 mm Hg.

Results: Overall, foreign born Mexican Americans had lower rates of hypertension than native born whites (OR= 0.7; P=0.002). However the prevalence of hypertension among foreign born Mexican Americans ages 65 and older was not significantly different from that of native born whites, while the prevalence of severe hypertension was significantly greater. Foreign born Mexican American males and females 65 and older were 1.8 (P=0.032) and 1.7 (P=0.039) times greater, respectively, than native whites to have severe hypertension. Elevated risks persisted even after diagnosis by a health care professional. Among the diagnosed, foreign born Mexican Americans, 20 years and older were twice as likely as native born whites to have severe hypertension (OR=2.0; P=0.020). Lower income and no usual source of medical care were particularly significant predictors of severe hypertension. However, disparities in frequency of severe hypertension were not significant after controlling for education, income, health insurance, and a usual source of medical care.

Conclusion: First-generation immigrants are often thought to have an advantage over the native born population with respect to health risk factors. Contrary to this belief, objective data analyzed from 1999-2006 NHANES showed significantly greater rates of severe hypertension among older Mexican American immigrants. This first time finding of increased health risk due to rate of severe hypertension might generalize to other disease processes in older Mexican American immigrants. Consequently, policy directed to improving the accessibility and affordability of health care of older Mexican immigrants is needed to address this disparity in hypertension and possibly other health issues.