ETHNIC-DIFFERENCES IN RISK-FACTORS ASSOCIATED WITH THE PREVALENCE OF NON-INSULIN-DEPENDENT DIABETES-MELLITUS - THE SAN-LUIS VALLEY DIABETESSTUDY

Non-insulin-dependent diabetes mellitus is 2-5 times more common in Hi spanics than in non-Hispanic whites in the United States. The authors conducted this case-control study in two Colorado counties from 1984 t o 1986 to determine whether known risk factors for non-insulin-depende nt diabetes mellitus explained the excess incidence in Hispanics. Ther e were 279 subjects with prevalent diabetes and 488 subjects with norm al glucose tolerance who were eligible for this analysis. After adjust ment for age and sex, results showed that Hispanics were 3.5 times mor e likely than non-Hispanic whites to have non-insulin-dependent diabet es mellitus (95% confidence interval 2.4-4.9). The excess risks of dia betes associated with body mass index, subscapular and triceps skinfol d thickness, family history of diabetes, and income were similar in Hi spanics and non-Hispanic whites, after adjustment for age and sex. How ever, 1-unit increases in subscapular/triceps skinfold ratio and waist /hip ratio were associated with greater increases in risk among non-Hi spanic whites than among Hispanics. When risk factors were entered int o logistic regression models simultaneously, higher subscapular skinfo lds, a higher waist/hip ratio, family history of diabetes, older age, male sex, and lower income were independently associated with non-insu lin-dependent diabetes mellitus in both ethnic groups. No association was found with skin reflectance, a marker for Amerindian admixture. Wh ile the excess risk of diabetes in Hispanics was reduced, a significan t 1.9-fold excess risk in Hispanics remained. Further studies are need ed to understand factors contributing to the excess prevalence of diab etes in Hispanic Americans.