Lack of genetic associations between PPAR-γ gene rs1801282 polymorphism and Alzheimer's disease in general population: a meta-analysis.

Published studies have evaluated the association between PPAR-γ rs1801282 polymorphism and Alzheimer's disease (AD) susceptibility. However, a definitive conclusion remains elusive. The aim of this study was to derive a more precise estimation of this association. We searched PubMed, Embase, Alzgene database, Chinese National Knowledge Infrastructure (CNKI), China Biological Medicine Database and Wanfang Databases for related studies. Twelve case-control studies with a total of 4874 cases and 5439 controls were finally identified to be eligible studies in this meta-analysis. The association was assessed by summarizing the odds ratios (ORs) with the corresponding 95% confidence intervals (CIs). Overall, there was no significant association between PPAR-γ rs1801282 polymorphism and Alzheimer's disease risk in all genetic models (the allele model G vs. C: OR=1.09, 95% CI 0.99-1.19, p=0.07; the homozygous model GG vs. CC: OR=1.04, 95% CI 0.75-1.44, p=0.80; heterozygote model GC vs. CC: OR=1.11, 95% CI 1,00-1.22, p=0.05; the dominant model GG+GC vs. CC: OR=1.10, 95% CI 1.00-1.22, p=0.05; the recessive model GG vs. GC+CC: OR=1.02, 95% CI 0.74-1.41, p=0.90). In subgroup analysis by ethnicity, no significant difference was found in both Asians and Caucasians. In summary, the present meta-analysis suggests that the PPAR-γ rs1801282 polymorphism may not be associated with genetic susceptibility of AD in general population.