Phosphatidylethanolamine N-methyltransferase gene rs7946 polymorphism plays a role in risk of nonalcoholic fatty liver disease: evidence from meta-analysis.

ABSTRACT

BACKGROUND: Phosphatidylethanolamine N-methyltransferase (PEMT) governs the secretion of hepatic triglycerides in the form of very low-density lipoprotein and has been implicated in nonalcoholic fatty liver disease (NAFLD). Studies on the role of the PEMT rs7946 polymorphism as a genetic modifier of NAFLD have reported inconsistent results. This meta-analysis was carried out to evaluate and summarize the association of PEMT rs7946 with susceptibility to NAFLD. METHODS: A comprehensive literature search in Scopus, PubMed, Embase, Science Direct and Google Scholar was performed up to 31 August 2015, followed by data extraction and examination of summary estimates. RESULTS: Six independent studies with a total of 792 NAFLD cases and 2722 controls fulfilled the inclusion criteria. Pooled results indicated that the rs7946 A-allele was associated significantly with an increased risk of NAFLD [odds ratio (OR) 1.55, 95% confidence interval (CI) 1.14-2.11, P=0.005]. A significant association was also found in alternative genetic models of inheritance dominant, recessive and homozygote (OR 1.62, 95% CI 1.10-2.39, P=0.01; OR 1.42, 95% CI 1.12-1.81, P=0.003; and OR 1.64, 95% CI 1.18-2.29, P=0.004, respectively). Subgroup analysis by ethnicity indicated a significant association only in the East-Asians in the additive (OR=2.08, 95% CI 1.12-3.86, P=0.02), recessive (OR=2.94, 95% CI 1.60-5.37, P=0.0005) and homozygote (OR=1.86, 95% CI 1.15-3.01, P=0.01) models. CONCLUSION: This study provides evidence of a significant association between the PEMT rs7946 A-allele and a risk of NAFLD, with the effect being more prominent in East-Asians, but not in non-Asians.