Ancestral effect on HOMA-IR levels quantitated in an american population of Mexican origin

Abstract

OBJECTIVE - An elevated insulin resistance index (homeostasis model assessment of insulin resistance [HOMA-IR]) is more commonly seen in the Mexican American population than in European populations. We report quantitative ancestral effects within a Mexican American population, and we correlate ancestral components with HOMA-IR. RESEARCH DESIGN AND METHODS - We performed ancestral analysis in 1,551 participants of the Cameron County Hispanic Cohort by genotyping 103 ancestry-informative markers (AIMs). These AIMs allow determination of the percentage (0-100%) ancestry from three major continental populations, i.e., European, African, and Amerindian. RESULTS - We observed that predominantly Amerindian ancestral components were associated with increased HOMA-IR (β = 0.124, P = 1.64 × 10-7). The correlation was more significant in males (Amerindian β = 0.165, P = 5.0831027) than in females (Amerindian β = 0.079, P = 0.019). CONCLUSIONS - This unique study design demonstrates how genomic markers for quantitative ancestral information can be used in admixed populations to predict phenotypic traits such as insulin resistance. © 2012 by the American Diabetes Association.