The effects of 8 months of metformin on circulating GGT and ALT levels in obese women with polycystic ovarian syndrome

Preiss, D. , Sattar, N. , Harborne, L., Norman, J.E. and Fleming, R. (2008) The effects of 8 months of metformin on circulating GGT and ALT levels in obese women with polycystic ovarian syndrome. International Journal of Clinical Practice, 62(9), pp. 1337-1343. (doi: 10.1111/j.1742-1241.2008.01825.x)

Abstract

Context: The prevalence of non-alcoholic fatty liver disease (NAFLD) in polycystic ovarian syndrome (PCOS) is high. Small studies have shown reductions in serum alanine aminotransaminase (ALT) and gamma-glutamyltransaminase (GGT) concentrations, both surrogate liver fat markers, and sometimes improvements in liver histology in individuals with NAFLD treated with metformin. Aims: We investigated whether metformin reduces serum ALT and GGT concentrations in obese women with PCOS. Methods: We performed post hoc data analysis from a trial, involving 82 obese women aged 22-46 years with PCOS, conducted at an academic institution. Participants were treated with metformin 1500 or 2550 mg/day for 8 months. Anthropometric measurements and blood samples (serum ALT, GGT, lipids, leptin, C-reactive protein, insulin, glucose analyses) were taken at baseline, 4 and 8 months. Results: Sixty-six participants completed the study. Mean weight, serum ALT and GGT decreased from 100.3 to 96.6 kg (p < 0.0001), 29.7 to 25.8 U/l (p = 0.012) and 21.4 to 16.9 U/l (p < 0.0001) respectively. Associations between weight reduction and decreases in serum ALT and GGT were highly significant and independent of change in Homeostasis Model Assessment of Insulin Resistance. In women with baseline ALT > 29.7 U/l (median), ALT reduction was highly significant (p = 0.005); however in those with baseline ALT < 29.7 U/l, ALT did not change despite similar weight reduction. There was no difference in reductions in ALT and GGT when the two metformin doses were compared. Intention-to-treat analyses gave comparable results. Conclusions: Metformin therapy is associated with reductions in surrogate liver fat markers in obese women with PCOS. This adds indirect support for a benefit of metformin in attenuating/reversing liver fat accumulation in PCOS and more generally.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Norman, Professor Jane and Preiss, Dr David and Fleming, Professor Richard and Sattar, Professor Naveed
• Authors: Preiss, D., Sattar, N., Harborne, L., Norman, J.E., and Fleming, R.
• College/School: College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health
• Journal Name: International Journal of Clinical Practice
• ISSN: 13685031