Why do some glucose-lowering agents improve non-alcoholic fatty liver disease whereas others do not? A narrative review in search of a unifying hypothesis

Diabetes Metab Res Rev. 2023 Oct;39(7):e3668. doi: 10.1002/dmrr.3668. Epub 2023 Jun 12.

Abstract

Non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2D) are metabolic disorders connected by common pathophysiological mechanisms. Since insulin resistance (IR) and metabolic alterations are common to both conditions, almost all glucose-lowering agents which improve IR have also been studied in patients with NAFLD. Some have shown great efficacy, others none. Thus, the mechanisms behind the efficacy of these drugs in improving hepatic steatosis, steatohepatitis, and eventually fibrosis remain controversial. Glycaemic control improves T2D, but probably has limited effects on NAFLD, as all glucose-lowering agents ameliorate glucose control but only a few improve NAFLD features. In contrast, drugs that either improve adipose tissue function, reduce lipid ingestion, or increase lipid oxidation are particularly effective in NAFLD. We therefore hypothesise that improved free fatty acid metabolism may be the unifying mechanism behind the efficacy of some glucose-lowering agents on NAFLD and may represent the key to NAFLD treatment.

Keywords: FFA; NAFLD; diabetes; glucose-lowering agents; lipid metabolism.

Publication types

  • Review
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Diabetes Mellitus, Type 2* / drug therapy
  • Diabetes Mellitus, Type 2* / metabolism
  • Glucose / metabolism
  • Humans
  • Insulin Resistance*
  • Lipids
  • Liver
  • Non-alcoholic Fatty Liver Disease* / drug therapy
  • Non-alcoholic Fatty Liver Disease* / metabolism

Substances

  • Glucose
  • Lipids