NAMPT gene rs2058539 variant is a risk factor for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease is a chronic liver disease and a growing global epidemic. The aim of this study was to investigate the association between a visfatin gene (NAMPT) variant and nonalcoholic fatty liver disease, owing to the connection between this disease and insulin resistance, obesity, inflammation, and oxidative stress, and the role of visfatin in these metabolic disorders.

In the present case-control study, we enrolled 312 genetically unrelated individuals, including 154 patients with biopsy-proven nonalcoholic fatty liver disease and 158 controls. The rs2058539 polymorphism of NAMPT gene was genotyped using the PCR-RFLP method.

Genotype and allele distributions of NAMPT gene rs2058539 polymorphism conformed to the Hardy-Weinberg equilibrium both in the case and control groups (p>0.05). The distribution of NAMPT rs2058539 genotypes and alleles differed significantly between the cases with nonalcoholic fatty liver disease and controls. The "CC" genotype of the NAMPT rs2058539 compared with "AA" genotype was associated with a 2.5-fold increased risk of nonalcoholic fatty liver disease after adjustment for confounding factors [p=0.034; odds ratio (OR)=2.52, 95% confidence interval (CI)=1.36-4.37]. Moreover, the NAMPT rs2058539 "C" allele was significantly overrepresented in the nonalcoholic fatty liver disease patients than controls (p=0.022; OR=1.77, 95%CI=1.14-2.31).

Our findings indicated for the first time that the NAMPT rs2058539 "CC" genotype is a marker of increased nonalcoholic fatty liver disease susceptibility; however, it needs to be supported by further investigations in other populations.