Association of adiponectin gene polymorphisms with type 2 diabetes in an African American population enriched for nephropathy

Abstract

Objective: Polymorphisms in the adiponectin gene (ADIPOQ) have been associated with type 2 diabetes and diabetic nephropathy in type 1 diabetes, in mostly European-derived populations.

Research Design and Methods: A comprehensive association analysis of 24 SNPs in the adiponectin gene was performed for type 2 diabetes and diabetic nephropathy in African Americans.

Results: The minor allele (A) in a single SNP in intron 1, rs182052, was associated with diabetic nephropathy (P=0.0015, OR=1.37, CI=1.13-1.67, dominant model) in an African American sample of 851 cases with diabetic nephropathy and 871 non-diabetic controls in analyses incorporating adjustment for varying levels of racial admixture. This association remained significant after adjustment of the data for BMI, age, and gender (P=0.0013 – 0.0004). We further tested this SNP for association with longstanding type 2 diabetes without nephropathy (n=317), and evidence of association was also significant (P=0.0054, OR=1.46, CI=1.12-1.91, dominant model) when compared to the same set of 871 non-diabetic controls. Combining the type 2 diabetes and diabetic nephropathy samples into a single group of cases (n=1168) resulted in the most significant evidence of association (P=0.0003, OR=1.40, CI=1.17-1.67, dominant model). Association tests between age at onset of type 2 diabetes and the rs182052 genotypes also revealed significant association between the presence of the minor allele (A/A or A/G) and earlier onset of type 2 diabetes.

Conclusions: The SNP rs182052 in intron 1 of the adiponectin gene is associated with type 2 diabetes in African Americans.