Novel antidiabetic medications for non-alcoholic fatty liver disease with type 2 diabetes mellitus

Liver-related diseases are the leading causes of death in patients with type 2 diabetes mellitus (T2DM) in Japan. Type 2 diabetes mellitus is closely associated with non-alcoholic fatty liver disease (NAFLD), which is the most prevalent chronic liver disease worldwide. Non-alcoholic steatohepatitis (NASH), a severe form of NAFLD, can lead to hepatocellular carcinoma and hepatic failure. Non-alcoholic steatohepatitis can be called diabetic hepatopathy. There are no established pharmacotherapies for NAFLD/NASH patients with T2DM. Although metformin is established as the first-line therapy for T2DM, given its relative safety and beneficial effects on glycosylated hemoglobin, weight, and cardiovascular mortality, this agent is not recommended as specific therapy for NASH/NAFLD due to lack of clinical evidence. The effects of pioglitazone on NASH histology with T2DM have been extensively proved, but several concerns exist, such as body weight gain, fluid retention, cancer incidence, and bone fracture. In recent years, novel antidiabetic medications have been approved for T2DM, such as glucagon-like peptide 1 receptor agonists, dipeptidyl peptidase 4 inhibitors, and sodium/glucose cotransporter 2 inhibitors. A key clinical question for hepatologists is what kinds of antidiabetic medications are the most appropriate for the treatment of NAFLD accompanied by T2DM, to prevent progression of hepatic fibrosis resulting in HCC/liver-related mortality without increased risk of cardiovascular events. This review focuses on novel antidiabetic agents and future perspectives on the treatment of NAFLD/NASH with T2DM.