Association of a polymorphic variant of the adiponectin gene with Insulin resistance in African Americans

Abstract

Hypertension, type 2 diabetes, and obesity are common complex disorders that contribute to cardiovascular (CV) disease. Insulin resistance increases CV risk and is present in these disorders. Adiponectin, a protein secreted by adipocytes with metabolic and vascular protective effects, is lower in obesity and insulin resistance. Several single nucleotide polymorphisms (SNP) have been identified in the adiponectin (ADIPOQ) gene. Associations of ADIPOQ polymorphisms with diabetes and obesity have been described in Caucasians and Asians. The purpose of this study was to determine if genetic variants of ADIPOQ are associated with insulin resistance and CV risk in African Americans. Metabolic traits (lipids, glucose, insulin, and insulin sensitivity) and blood pressure were measured in 273 African Americans. DNA was examined by DNA sequence analysis and SNPs of candidate genes including ADIPOQ were studied. Statistica analyses were performed by regression of the quantitative trait phenotypes on the groups defined by the SNP genotypes, adjusting for age, sex, and body mass index (BMI). SNP 712 (rs3774261) of the ADIPOQ gene showed significant association with insulin resistance (p = 0.001). Despite the relatively small sample, our results indicate that genes that regulate adipocyte function may have a regulatory role in the expression of metabolic traits in obesity-associated chronic disease. © 2008 Wiley Periodicals, Inc.