Meta-analysis of associations between the peroxisome proliferator-activated receptor-γ Pro12Ala polymorphism and susceptibility to nonalcoholic fatty liver disease, rheumatoid arthritis, and psoriatic arthritis.
BACKGROUND
The purpose of this study was to examine whether a Proline (Pro)-to-Alanine (Ala) exchange at codon 12 (Pro12Ala) polymorphism of the peroxisome proliferator-activated receptor-gamma (PPARγ) is associated with susceptibility to nonalcoholic fatty liver disease (NAFLD), rheumatoid arthritis (RA), and psoriatic arthritis (PsA).


METHODS
A meta-analysis was conducted on the association between the PPARγ Pro12Ala polymorphism and NAFLD, RA, and PsA.


RESULTS
Nine studies, including five on NAFLD, two on RA, and two on PsA, were available for the meta-analysis consisting of 8082 cases and 3790 controls. The meta-analysis revealed no association between the Ala allele of the PPARγ Pro12Ala polymorphism and NAFLD (odds ratios [OR]=0.936, 95% confidence interval [CI]=0.672-1.302, p=0.693). However, stratification by ethnicity indicated an association between the Ala allele and NAFLD in East Asians (OR=0.700, 95% CI=0.496-0.987, p=0.042), but not in Europeans (OR=1.128, 95% CI=0.863-1.475, p=0.378). Analysis using the dominant model showed the same Ala allele pattern in East Asians and Europeans (OR=0.688, 95% CI=0.484-0.978, p=0.037; OR=1.051, 95% CI=0.782-1.413, p=0.742), demonstrating a significant association between the Ala allele and NAFLD in East Asians. The meta-analysis revealed no association between the Ala allele and RA in East Asians (OR=0.467, 95% CI=0.188-1.161, p=0.101), and no association was found between the Ala allele and PsA in Europeans (OR=0.869, 95% CI=0.465-1.627, p=0.662).


CONCLUSIONS
Our meta-analysis demonstrates that the PPARγ Pro12Ala polymorphism is associated with susceptibility to NAFLD in East Asians, but not in European populations.
1 Division of Rheumatology, Department of Internal Medicine, Korea University Anam Hospital, Korea University College of Medicine , Seoul, Korea.
Young Ho
YH
Lee
Sang-Cheol
SC
Bae
Gwan Gyu
GG
Song
D000409:Alanine / Q000235:genetics; D015535:Arthritis, Psoriatic / Q000235:genetics*; D001172:Arthritis, Rheumatoid / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D065626:Non-alcoholic Fatty Liver Disease / Q000235:genetics*; D047495:PPAR gamma / Q000235:genetics*; D011110:Polymorphism, Genetic; D011392:Proline / Q000235:genetics
D047495:PPAR gamma; D011392:Proline; D000409:Alanine