Oxidative Stress in Fatty Liver Disease with Metabolic and Non-metabolic Etiologies

Background: Fatty liver disease (FLD) is classified into metabolic dysfunction-associated fatty liver disease (MAFLD) and non-MAFLD based on the presence of metabolic abnormalities. The pathophysiology of FLD is complex; however, oxidative stress (OS) seems to play a significant role in its progression. Objectives: This study examined oxidative stress markers linked to FLD. Methods: A total of 64 patients with FLD, including 38 MAFLD and 26 non-MAFLD patients, respectively, were evaluated and compared with 22 healthy individuals. To assess oxidative stress, in addition to the activities of catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) enzymes, total oxidant status (TOS), malondialdehyde (MDA), and total antioxidant capacity (TAC) were measured in the serum of the participants. Results: It was found that TOS, MDA, and TAC levels in the serum were significantly higher in the FLD group compared to the healthy individuals. Notably, these increases were more pronounced in the MAFLD group compared to the non-MAFLD group. Additionally, CAT and GPx enzyme activities were significantly elevated in patients with FLD than in the control group. The MAFLD group exhibited the highest CAT enzyme activity, while the non-MAFLD group demonstrated the highest GPx enzyme activity. Conversely, serum SOD enzyme activity was decreased across all studied groups, with no significant differences observed between them. Conclusion: Patients with MAFLD and non-MAFLD exhibit an imbalance in their oxidative stress systems. It appears that CAT and GPx enzymes probably play crucial roles in the antioxidant defense mechanisms in these patients, respectively.