Association of rs5742612 Polymorphism in the Promoter Region of IGF1 Gene with Nonalcoholic Fatty Liver Disease: A Case-Control Study.

OBJECTIVE: Nonalcoholic fatty liver disease (NAFLD) is an emerging global chronic liver disease encompassing a wide spectrum of disorders ranging from simple steatosis to nonalcoholic steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Considering the strong association between NAFLD and insulin resistance, and the vital role of insulin-like growth factor 1 (IGF1) in IR, we hypothesized that IGF1 gene polymorphism might be associated with NAFLD. METHODS: A total of 302 subjects, including 149 patients with biopsy-proven NAFLD and 153 controls, were enrolled in this case-control study. All the subjects were genotyped for the rs5742612 polymorphism of the IGF1 gene using the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: The distribution of IGF1 rs5742612 genotypes and alleles differed significantly between the cases with NAFLD and controls. The IGF1 rs5742612 CC genotype compared with the TT genotype or the TT+TC genotype occurred more frequently in the cases than the controls and the differences remained significant after adjustment for confounding factors such as age and body mass index (P = .011, OR = 2.71, 95%CI = 1.16-5.85; and P = .032, OR = 2.29, 95% CI = 1.10-5.24, respectively). CONCLUSION: For the first time, this study uncovered that the IGF1 rs5742612 CC genotype compared with the TT genotype or the TT+TC genotype had a 2.71-fold or 2.29-fold increased risk for NAFLD, respectively.