The effect of metformin on serum FABP4 and PPARγ levels in patients with type 2 diabetes + nonalcoholic fatty liver disease

This prospective observational study, conducted at the Affiliated Hospital of Inner Mongolia Medical University, aimed to investigate the effects of metformin on serum Fatty acid-binding protein 4 (FABP4) and Peroxisome Proliferator-activated receptor γ (PPARγ) levels in patients with Type 2 Diabetes Mellitus (T2DM) complicated by Nonalcoholic Fatty Liver Disease (NAFLD). From June 2022 to January 2023, we enrolled patients with T2DM + NAFLD (Group A, n = 31), patients with T2DM treated with metformin monotherapy (Group B, n = 30), and healthy controls (NGT group, n = 37). Serum FABP4 and PPARγ levels were quantified using enzyme-linked immunosorbent assay (ELISA). After one month of metformin treatment in the T2DM + NAFLD group, changes in these biomarkers were compared to baseline levels and between groups. The results revealed that both the T2DM and T2DM + NAFLD groups had higher Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) and FABP4 levels, and lower PPARγ levels compared to the NGT group. Notably, these differences were more pronounced in the T2DM + NAFLD group compared to the T2DM group. Following metformin treatment, HOMA-IR and FABP4 levels decreased, while PPARγ levels increased in the T2DM + NAFLD group. These findings suggest that metformin may improve insulin resistance by reducing serum FABP4 and increasing PPARγ levels, thereby leading to improved glucose and lipid metabolism in T2DM + NAFLD patients. Thus, FABP4 and PPARγ may serve as potential predictors of T2DM + NAFLD.