Metformin Effects on Follistatin and Oxyntomodulin Levels and Its Relationship With Polycystic Ovaries Syndrome and Associated Comorbidities: Secondary Analysis of Randomized Double-blind Clinical Study.

Abstract

Background: An abnormal secretion of incretins, specially Glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and oxyntomodulin (OXM), have been described in subjects with Type 2 diabetes mellitus and PCOS. OXM has important actions in the metabolism including the ability to reduce food intake and improve insulin secretion reducing the liver fat accumulation. Metformin is an insulin-sensitizing hypoglycemic drug and is widely used in the treatment of PCOS. Whether treatment with metformin may affect circulating levels of OXM is not known and is the subject of this study. Design: a secondary analysis, randomized double-blind clinical trial. Methods: Forty-five patients with PCOS were recruited, divided into one group that received metformin (n=21) and one group who received placebo (n=24) to evaluate the levels of follistatin and oxyntomodulin before and after the use of metformin (1500mg/day). Blood levels of oxyntomodulin and follistatin were evaluated by ELISA tests. Results: At the end of the study, 20 patients were evaluated, 5 (25%) from the group using metformin and 15 (75%) from the placebo group. There was no significant difference in the variation in follistatin and oxyntomodulin levels between the metformin and placebo groups. There was a significant difference in follistatin levels among participants with hyperandrogenic and non-hyperandrogenic phenotype. There was no significant difference in oxyntomodulin levels in the different phenotypes. Conclusion: The use of metformin for 60 days did not alter follistatin and oxyntomodulin levels, and there was a significant difference between the follistatin values in hyperandrogenic and non-hyperandrogenic phenotypes. Trial registration: Brazilian Registration Platform for Clinical Studies - REBEC -ID RBR-47tvky / Brazilian Health Ministry- ID 17127713.2.0000.5149.