Superoxide dismutase 2 genetic variation as a susceptibility risk factor for alcoholic cirrhosis

Abstract

Aims: Superoxide dismutase 2 (SOD2) is an important antioxidant phase 2 enzyme. The associations of SOD2 genetic variation and the risk of advanced alcoholic liver diseases are still debatable. We aimed to investigate the association of the main SOD2 genetic variant (47T>C) and the susceptibility to alcoholic cirrhosis. Methods: A total of 80 patients with alcoholic cirrhosis (AC), 80 patients with alcoholic non-cirrhosis (ANC), 80 with viral hepatitis B-related cirrhosis (VC), and 165 healthy controls (HC) were enrolled into this study. A polymerase chain reaction was used to genotype their SOD2 47T>C (rs4880). Results: There was no statistical difference in the frequency distribution of the three SOD2 47T>C genotypes among groups. However, if individuals with C variant were grouped together, the AC group had higher frequency of SOD2 C/C or C/T genotype than ANC, VC and HC groups had (38.7% vs. 21.3%, 26.3% and 21.8%, respectively, P = 0.010). After adjustment for confounders, the SOD2 C/C and C/T genotypes remained associated with the risk of AC (adjusted OR: 2.79 and 3.50, respectively, P < 0.03, compared with ANC and HC groups). In contrast, there was no significant difference of SOD2 genetic variation between VC and HC groups. Conclusions: Anti-oxidative enzyme SOD2 47T>C genetic variant may increase the susceptibility to AC. This suggests that oxidative stress plays a role in the development of AC.