Metformin Lowers Blood Glucose by Reducing Fat in the Liver

Researchers report that when mice with mutated acetyl-CoA carboxylase—which regulates fat production as well as the ability to burn fat—are given the diabetes drug metformin, the drug does not lower the animals’ blood sugar levels. It appears that inhibitory phosphorylation of acetyl-CoA carboxylase is essential for the control of lipid metabolism and for metformin-induced improvements in insulin action. The Nature Medicine findings indicate that metformin does not directly reduce sugar metabolism but instead reduces fat in the liver, which then allows insulin to work better.