Dyslipidemia and insulin resistance in relation to genetic admixture among Hispanics and non-Hispanic blacks of Caribbean origin.

The tendency to develop insulin resistance and dyslipidemia varies between black Africans, white Europeans, and Amerindian racial groups. Genetic admixture of these three racial groups has resulted in hybrid populations of Hispanics and non-Hispanic blacks. The current study was undertaken to examine the relationship of white European admixture to insulin resistance and dyslipidemia among Hispanics and non-Hispanic blacks of Caribbean origin. The study population included 224 Hispanics and 684 non-Hispanic blacks without a history of diabetes who were recruited between 1995 and 1999 on the island of St. Croix in the U.S. Virgin Islands. For each participant, anthropometric measurements were performed, and a fasting blood sample was analyzed for glucose, insulin, and serum lipids (triglycerides, HDL cholesterol). Genetic admixture was determined from grandparent race data. Hispanics were more likely than non-Hispanic blacks to have dyslipidemia and insulin resistance (measured by HOMA-IR method). White European admixture was significantly and inversely associated with insulin resistance among Hispanics. There was no significant relationship between white European admixture and insulin resistance or dyslipidemia among non-Hispanic blacks. Individuals who classified themselves as Hispanic blacks appeared to have a greater risk for cardiovascular disease than Hispanic whites or non-Hispanic blacks.