The effect of metformin on glucose metabolism in patients receiving glucocorticoids.

Glucocorticoids have powerful anti-inflammatory and immunomodulatory effects, but chronic use of these drugs can cause hyperglycemia, type 2 diabetes mellitus, hepatic steatosis, obesity, and other complications due to their metabolic actions. Metformin is a widely used drug for the treatment of type 2 diabetes mellitus with a known ability to lower blood glucose levels. This review focuses on metformin's actions on glucose metabolism and its potential use as a drug to limit the metabolic side effects of glucocorticoid treatment. Available data suggest that metformin inhibits complex I of the mitochondrial electron transport chain, crucial gluconeogenic enzymes, and fatty acid synthesis that leads to a significant improvement in glucose tolerance and maintenance of insulin sensitivity during glucocorticoid treatment. Three small randomized control trials have demonstrated that metformin can limit changes in glucose metabolism during treatment with prednisone. These studies reveal a promising potential for metformin use as a therapeutic agent to reduce glucocorticoid-induced hyperglycemia and improve patient outcomes.