Decreased prevalence of hypertension in Mexican-Americans.

Relatively few studies of hypertension have been carried out in Mexican-Americans, a population characterized by high rates of obesity and non-insulin-dependent diabetes mellitus. We therefore compared the prevalence of hypertension according to four different definitions in 3,297 Mexican-Americans and in 1,873 non-Hispanic whites from the San Antonio Heart Study, a population-based study of cardiovascular disease and diabetes. By all four definitions, the crude prevalence of hypertension in both sexes was lower in Mexican-Americans than in non-Hispanic whites, although only two of the eight pairwise comparisons were statistically significant. However, after adjusting for the potentially confounding effects of age, body mass index, and non-insulin-dependent diabetes mellitus, Mexican-Americans did have a statistically significant lower prevalence of both systolic and diastolic hypertension than did non-Hispanic whites in both sexes (odds ratios ranging from 0.66 to 0.71 depending on the definition of hypertension). The cause of this lower prevalence is unknown, but study of this ethnic group with elevated levels of risk factors for hypertension (obesity, hyperinsulinemia, and diabetes) may provide additional insights into the etiology of hypertension.