Adiponectin polymorphisms and non-alcoholic fatty liver disease risk: A meta-analysis

Background and Aim The adiponectin polymorphism has been implicated in susceptibility to non-alcoholic fatty liver disease (NAFLD), but the results remain inconclusive. The aim of this meta-analysis is to investigate the association between adiponectin polymorphisms and NAFLD risk. Methods All eligible case–control studies published up to September 2013 were identified by searching PubMed, Web of Science, and CNKI. Effect sizes of odds ratio (OR) and 95% confidence interval (95% CI) were calculated by using a fixed- or random-effect model. Results A total of 10 case–control studies were included; of those, there were nine studies (1223 cases and 1580 controls) for +45T>G polymorphism, seven studies (876 cases and 989 controls) for +276G>T polymorphism, and three studies (299 cases and 383 controls) for −11337C>G polymorphism. Overall, a significantly increased risk was found for +45T>G and −11377C>G polymorphism (+45T>G: OR = 1.45, 95% CI: 1.06–2.00 for recessive model, OR = 1.48, 95% CI: 1.07–2.06 for GG vs TT; −11377C>G: OR = 1.52, 95% CI: 1.10–2.09 for dominant model, OR = 3.88, 95% CI: 1.29–11.68 for GG vs CC), while for +276G>T polymorphism, we found a significantly decreased risk between them (OR = 0.65, 95% CI: 0.45–0.94 for recessive model, OR = 0.58, 95% CI: 0.40–0.84 for TT vs GG). In subgroup analysis by ethnicity, significant association was detected among Asians for +276G>T polymorphism, but not for +45T>G polymorphism. Besides, none of the three adiponectin polymorphisms was associated with the serum adiponectin levels. Conclusion This meta-analysis suggests that adiponectin +45T>G and −11377C>G polymorphisms might be a risk factor for NAFLD, while +276G>T polymorphism may be a protective factor for NAFLD among Asians.