PREVALENCE OF TYPE 2 DIABETES BY ETHNICITY AND BODY WEIGHT

OBESITY IS A MAJOR RISK FACTOR FOR TYPE 2 DIABETES AND HISPANICS ARE MORE LIKELY THAN NON-HISPANICS WHITES TO BE OVERWEIGHT.

THE PREVALENCE OF OBESITY IS HIGHER IN MEXICAN-AMERICANS AND THEY ARE TWO TO FOUR TIMES MORE LIKELY TO HAVE TYPE 2 DIABETES THAN NON-HISPANIC WHITES AMERICANS OF SIMILAR WEIGHT.

CENTRAL, OR UPPER BODY, OBESITY IS A GREATER RISK FACTOR FOR TYPE 2 DIABETES, COMPARED TO EXCESS WEIGHT CARRIED BELOW THE WAIST.

MEXICAN-AMERICANS WITH CENTRAL BODY OBESITY HAVE AN INCREASED RISK OF TYPE 2 DIABETES.

An interesting study assessed 17 genetic markers in the Mexican-American sub-sample of the San Antonio Heart Study and found an association between Type 2 DM and Rh blood group, and Type 2 DM and haptoglobin phenotype. In a subsequent study, an association was found between Type 2 DM and an insulin-receptor gene in Mexican-Americans, although it was not statistically significant. This insulin-receptor gene had been reported in the Pima population of Native-Americans; hence, the investigators proposed an association between the insulin-receptor gene and Type 2 DM, substantiating the argument for Amerindian admixture in Mexican-Americans.

In a subsequent study, however, the relationship between excess obesity and prevalence of Type 2 DM were assessed in the San Antonio sample. The study uncovered a higher rate of Type 2 DM among Mexican-Americans than among Non-Hispanic Whites, albeit there was a positive association between Type 2 DM and obesity in both groups.

The investigators suggested that obesity is a sign of "westernization" among Mexican-American residents and asserted that since obesity does not explain all the excess prevalence of Type 2 DM in these residents, there must be susceptible genes involved. A number of other studies assessed the issues of social class, ethnic differences, and percentages of Native-American admixture in Mexican-Americans living in the San Antonio area.