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

D. Preiss, N. Sattar, L. Harborne, J. Norman, R. Fleming

Research output: Contribution to journalArticle (Academic Journal)


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.
Original languageEnglish
Pages (from-to)1337-1343
Number of pages7
JournalInternational Journal of Clinical Practice
Issue number9
Publication statusPublished - 2008

Bibliographical note

RIS file


  • Adult Alanine Transaminase Analysis of Variance Anti-Obesity Agents Biological Markers Female Humans Metformin Middle Aged Obesity Polycystic Ovary Syndrome Young Adult gamma-Glutamyltransferase

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