Non-alcoholic fatty liver disease (NAFLD) is a common liver disease and it represents the hepatic manifestation of metabolic syndrome, which includes type 2 diabetes mellitus (T2DM), dyslipidemia, central obesity and hypertension. Glucagon-like peptide-1 (GLP-1) analogues and dipeptidyl peptidase-4 (DPP-4) inhibitors were widely used to treat T2DM. These agents improve glycemic control, promote weight loss and improve lipid metabolism. Recent studies have demonstrated that the GLP-1 receptor (GLP-1R) is present and functional in human and rat hepatocytes. In this review, we present data from animal researches and human clinical studies that showed GLP-1 analogues and DPP-4 inhibitors can decrease hepatic triglyceride (TG) content and improve hepatic steatosis, although some effects could be a result of improvements in metabolic parameters. Multiple hepatocyte signal transduction pathways and mRNA from key enzymes in fatty acid metabolism appear to be activated by GLP-1 and its analogues. Thus, the data support the need for more rigorous prospective clinical trials to further investigate the potential of incretin therapies to treat patients with NAFLD.
Animals ; Clinical Trials as Topic ; Dipeptidyl-Peptidase IV Inhibitors ; pharmacology ; therapeutic use ; Glucagon-Like Peptide 1 ; agonists ; Humans ; Hypoglycemic Agents ; pharmacology ; therapeutic use ; Lipid Metabolism ; drug effects ; Non-alcoholic Fatty Liver Disease ; drug therapy ; metabolism ; Triglycerides ; metabolism

The vascular endothelial function is impaired in the very early stage of atherosclerosis in diabetic patients. The goal of this study was to identify the mechanism underlying the improvement in vascular endothelial function by sitagliptin in type 2 diabetes mellitus patients. This study was an open-labeled prospective observational single arm trial. Forty patients were treated with 50 mg of sitagliptin once daily for 12-weeks. The flow-mediated dilation (FMD) and plasma adiponectin were measured at baseline and 12 weeks after initiating treatment. The %FMD was significantly increased after treatment (4.13 +/- 1.59 vs 5.12 +/- 1.55, P < 0.001), whereas the nitroglycerin-mediated dilation (NMD) did not change. The plasma adiponectin levels significantly increased (13.0 +/- 11.3 vs 14.3 +/- 12.8, P < 0.001). The changes in the FMD were significantly correlated with those of the plasma adiponectin (r = 0.322, P < 0.05). A multivariate linear regression analysis demonstrated that the improvement in the FMD is associated with the plasma adiponectin (P < 0.05). The treatment of type 2 diabetes mellitus patients with sitagliptin reverses vascular endothelial dysfunction, as evidenced by increase in the FMD, and improvement of the adiponectin levels (UMIN Clinical Trials Registry System as trial ID UMIN000004236).
Adiponectin/blood ; Aged ; Aged, 80 and over ; Atherosclerosis/complications/drug therapy ; Diabetes Mellitus, Type 2/complications/*drug therapy ; Dipeptidyl-Peptidase IV Inhibitors/pharmacology/*therapeutic use ; Drug Administration Schedule ; Endothelium, Vascular/*drug effects/physiopathology ; Female ; Humans ; Male ; Middle Aged ; Nitroglycerin/therapeutic use ; Prospective Studies ; Pyrazines/pharmacology/*therapeutic use ; Regression Analysis ; Triazoles/pharmacology/*therapeutic use ; Vasodilation/drug effects ; Vasodilator Agents/therapeutic use

The vascular endothelial function is impaired in the very early stage of atherosclerosis in diabetic patients. The goal of this study was to identify the mechanism underlying the improvement in vascular endothelial function by sitagliptin in type 2 diabetes mellitus patients. This study was an open-labeled prospective observational single arm trial. Forty patients were treated with 50 mg of sitagliptin once daily for 12-weeks. The flow-mediated dilation (FMD) and plasma adiponectin were measured at baseline and 12 weeks after initiating treatment. The %FMD was significantly increased after treatment (4.13 +/- 1.59 vs 5.12 +/- 1.55, P < 0.001), whereas the nitroglycerin-mediated dilation (NMD) did not change. The plasma adiponectin levels significantly increased (13.0 +/- 11.3 vs 14.3 +/- 12.8, P < 0.001). The changes in the FMD were significantly correlated with those of the plasma adiponectin (r = 0.322, P < 0.05). A multivariate linear regression analysis demonstrated that the improvement in the FMD is associated with the plasma adiponectin (P < 0.05). The treatment of type 2 diabetes mellitus patients with sitagliptin reverses vascular endothelial dysfunction, as evidenced by increase in the FMD, and improvement of the adiponectin levels (UMIN Clinical Trials Registry System as trial ID UMIN000004236).
Adiponectin/blood ; Aged ; Aged, 80 and over ; Atherosclerosis/complications/drug therapy ; Diabetes Mellitus, Type 2/complications/*drug therapy ; Dipeptidyl-Peptidase IV Inhibitors/pharmacology/*therapeutic use ; Drug Administration Schedule ; Endothelium, Vascular/*drug effects/physiopathology ; Female ; Humans ; Male ; Middle Aged ; Nitroglycerin/therapeutic use ; Prospective Studies ; Pyrazines/pharmacology/*therapeutic use ; Regression Analysis ; Triazoles/pharmacology/*therapeutic use ; Vasodilation/drug effects ; Vasodilator Agents/therapeutic use