Cardiovascular risk factors in Mexican Americans in Laredo, Texas. I. Prevalence of overweight and diabetes and distributions of serum lipids.

An epidemiologic survey of cardiovascular risk factors was carried out on a random sample of Mexican Americans living in two low income census tracts in Laredo, Texas. The prevalence of overweight was found to be intermediate between US national estimates and the rates recorded for Pima Indians. Similarly, the prevalence of fasting hyperglycemia was intermediate between the rates observed in a sample or predominantly Caucasian individuals and those observed in Pima Indians. Excess hyperglycemia in the Laredo Mexican American population compared to predominantly Caucasian populations does not appear to be due to a lower level of medical control of diabetes in the former. Rather, it probably reflects a true excess in the prevalence of diabetes. Serum cholesterol and triglyceride concentrations were also higher in Laredo Mexican Americans than in a Caucasian comparison population. Mexican Americans are of mixed European and native American ancestry. Native Americans have high rates of diabetes which could be on a genetic basis. The intermediate rates of hyperglycemia in Mexican Americans could thus have a genetic explanation. On the other hand, sociocultural determinants could be important since these are known to influence obesity which is a major precursor of diabetes.