Association between insulin receptor gene exon 17 rs1799817 variant and risk of nonalcoholic fatty liver disease

Abstract

Background and objectives: Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease characterized by accumulation of triglycerides in hepatocytes without alcohol consumption. Considering the key role of insulin resistance in NAFLD, we investigated whether insulin (INS) and insulin receptor (INSR) gene variants were associated with NAFLD risk. Materials and methods:This study was conducted as a case-control study and 230 subjects, including 128 controls and 102 cases with biopsy-proven NAFLD, were enrolled and genotyped using PCR-RFLP method. Results:We observed no significant difference in genotype or allele frequencies between the cases with NAFLD and controls for INS gene rs689 variant either before or after adjustment for confounding factors including age, BMI, sex, smoking status, systolic blood pressure, and diastolic blood pressure. However, the INSR rs1799817 "TT" genotype compared with the "CC" genotype and "CC+CT" genotypes appears to be a marker of decreased NAFLD susceptibility (P=0.029; OR=0.14, 95%CI=0.03-0.82 and P=0.048; OR=0.20, 95%CI= 0.04-0.98, respectively). Conclusions:To our knowledge, our findings suggested for the first time that the INSR rs1799817 "TT" genotype compared with the "CC" genotype and "CC+CT" genotypes had 86% and 80% decreased risks for NAFLD, respectively. Nevertheless, further studies are needed to confirm these findings.