Polymorphisms in peroxisome proliferator-activated receptor-γ pro12Ala (PPAR-γ Pro12Ala) have been associated with Non-alcoholic Fatty Liver Disease (NAFLD) in several studies. However, the results of these studies are not entirely consistent. Thus, we performed a meta-analysis to investigate the association between the PPAR-γ Pro12Ala polymorphisms and NAFLD.

Studies were identified by searching PubMed database and manual assessment of the cited references in the retrieved articles. Study-specific relative risks (RRs) and 95 % confidence intervals (CIs) were estimated using a random-effect model. Study quality was assessed using the Newcastle–Ottawa scale.

Relevant medical researches show that 11 studies have been conducted on the analysis of NAFLD for meta-analysis, with a total of 2404 cases and 3959 participating controls. Meta-analysis results show that PPAR-γ Pro12Ala polymorphism and NALAD Ala alleles[no association between dominance model (OR = 0.968, 95%CI: 0.734–1.276, P = 0.815); Pro/Ala vs. Pro/Pro (OR = 0.930, 95 % CI: 0.701–1.233, P = 0.612); Ala/Ala vs. Pro/Pro (OR = 1.220, 95 % CI: 0.668–2.230, P = 0.518); recessive model (OR = 0.907, 95 % CI: 0.516–1.596, P = 0.736)]. Moreover, stratification by ethnicity also revealed that no matter it is in Caucasian populations or in Asian populations, NAFLD has no association with the PPAR-γ Pro12Ala polymorphism.

According to the meta-analysis, both in Asians and Caucasian populations, the PPAR-γ Pro12Ala polymorphism can't be demonstrated to have any link with susceptibility to NAFLD.