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


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 = 5.08 × 10(-7)) 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.
The University of Texas School of Public Health, Brownsville Regional Campus, Brownsville, Texas, USA. huiqi.qu@uth.tmc.edu
Hui-Qi
HQ
Qu
Quan
Q
Li
Yang
Y
Lu
Craig L
CL
Hanis
Susan P
SP
Fisher-Hoch
Joseph B
JB
McCormick
D005260:Female; D005838:Genotype; D006801:Humans; D007333:Insulin Resistance / Q000235:genetics / Q000502:physiology*; D008297:Male; D017058:Mexican Americans / Q000235:genetics / Q000706:statistics & numerical data; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D025341:Principal Component Analysis