Influence of adiponectin gene polymorphisms in Japanese patients with non-alcoholic fatty liver disease

Single nucleotide polymorphisms (SNPs) of the adiponectin gene have been reported to be associated with insulin resistance and the prevalence of type-2 diabetes. We investigated the SNPs of adiponectin in non-alcoholic fatty liver disease (NAFLD) patients. One hundred nineteen patients histologically diagnosed as having NAFLD and 115 control subjects were examined. Adiponectin SNP sites were investigated at +45 of exon 2 and at +276 of intron 2; these sites have been thought to be associated with diabetes or insulin resistance. Regarding the +276 SNP, the frequency of G/G tended to be higher in NAFLD patients than in controls, but not significantly. Among females only, however, the G/G frequency was significantly higher in NAFLD patients. As for the +45 SNP, in the severe fibrosis group, the frequency of G/G homozygotes was significantly higher than that in the mild fibrosis group, and G/G homozygotes of the +45 SNP proved by multivariate analysis to be an independent factor in severe fibrosis. In NAFLD patients with adiponectin +45 G/G, homeostasis model assessment-insulin resistance was significantly higher than in NAFLD patients without adiponectin +45 G/G. Adiponectin SNPs were found to be associated with the progression of liver fibrosis and insulin resistance, suggesting that adiponectin SNPs might play roles in the occurrence and progression of NAFLD.