DPP-4 Inhibitors Improve Liver Dysfunction in Type 2 Diabetes Mellitus

BACKGROUND: Dipeptidyl peptidase-4 (DPP-4) inhibitors might have pleiotropic effects because receptors for incretin exist in various tissues, including liver. We examined whether DPP-4 inhibitors affect liver function in patients with type 2 diabetes. MATERIAL/METHODS: A retrospective review of 459 patients with type 2 diabetes who were prescribed DPP-4 inhibitors was performed. After exclusion of patients with hepatitis B or C, steroid use, and other diseases that might affect liver function and diabetes status, 224 patients were included in the analysis. RESULTS: Forty-four patients (19.6%) with liver injury defined by aspartate transaminase (AST) or alanine transaminase (ALT) over the normal level of 40 U/L. In the patients with liver injury, AST and ALT were significantly decreased after 6 months from the first date of DPP-4 prescription, with mean changes of −6.2 U/L [95% confidence interval (CI) −10.9 to −1.4, p=0.012] and of −11.9 U/L (95%CI −19.5 to −4.2, p=0.003), respectively. Percent changes in AST were significantly and negatively correlated with baseline AST and ALT (r=−0.27, p<0.001 and r=−0.23, p=0.002, respectively), and percent changes in ALT were also negatively correlated with them (r=−0.23, p=0.001 and r=−0.27, p<0.001, respectively). CONCLUSIONS: DPP-4 inhibitors improved liver dysfunction in patients with type 2 diabetes.