PPARγ Pro12Ala and His447His polymorphisms and susceptibility to Alzheimer's disease: a meta-analysis.

We investigated whether Pro12Ala (C→G) and His447His (C→T) polymorphisms of the peroxisome proliferator- activated receptor gamma (PPARg) gene are associated with susceptibility to Alzheimer's disease (AD). We conducted a meta- analysis of the associations between the PPARg Pro12Ala and His447His polymorphisms and AD in subjects. The meta-analysis was performed according to the apolipoprotein E (APOE) ɛ4 allele status. A total of eight studies were considered in our meta-analysis, comprising 2948 patients with AD and 3753 controls. Meta-analysis showed no association between AD and the PPARg Pro12Ala G allele in any of the study subjects (odds ratio (OR) = 1.013, 95% confidence interval (95%CI) = 0.906-1.132, P = 0.821) or in the European and Asian populations (OR = 0.997, 95%CI = 0.890-1.118, P = 0.965; OR = 1.409, 95%CI = 0.832-2.387, P = 0.202, respectively). We tested whether the APOE ɛ4 allele affects the association between the PPARg Pro12Ala polymorphism and AD. Meta-analysis showed no association between AD and the PPARg G allele in any of the study subjects with or without the APOE ɛ4 allele. Meta-analysis showed no association between AD and the PPARg His447His T allele in the European population (OR for