Association Between the PPARG Gene Polymorphism and the Risk of Diabetic Nephropathy: A Meta-Analysis

Background: The Pro12Ala polymorphism in the peroxisome proliferator-activated receptor gamma (PPARG) gene is suggested to associate with diabetic nephropathy. Aim: A meta-analysis was conducted to investigate the potential association of PPARG gene polymorphisms with susceptibility to diabetic nephropathy. Methods: A comprehensive search of MEDLINE (1966 to June 2011) was conducted to identify published epidemiologic studies related to polymorphisms of the PPARG gene and diabetic nephropathy. A database search yielded 5 studies involving 2758 patients. Odds ratios (ORs) along with their 95% confidence intervals (CIs) were computed to compare the distribution of alleles and genotypes between cases and controls. Results: The combined results based on all studies showed no significant difference in genotype distribution (Pro/Pro: OR. 1.42, 95% CI, 0.96-2.09); Pro/Ala: OR, 0.74, 95% CI, 0.50-1.10; Ala/Ala: OR, 0.85, 95% CI, 0.52-1.38) between cases and controls. After stratification for race, results were similar except that patients with diabetic nephropathy had a significantly higher frequency of Pro/Pro (OR, 1.82; 95% CI, 1.17-2.85) than controls among Asians. Conclusion: This meta-analysis suggests that the Pro12Ala polymorphism of the PPARG gene may be associated with diabetic nephropathy among Asians.