Metformin administration improves endothelial function in women with polycystic ovary syndrome

Eur J Endocrinol. 2005 May;152(5):749-56. doi: 10.1530/eje.1.01910.

Abstract

Objective: The aim of this study was to investigate the endothelial status in young women with polycystic ovary syndrome (PCOS), using a simple and easily reproducible hemodynamic method combined with a biological marker and to evaluate the effect of metformin treatment on these parameters.

Design: Descriptive clinical trial.

Methods: Forty young women, 20 with PCOS and 20 normal women of similar age and body mass index were studied. Metformin (1700 mg daily) was administered for 6 months to the PCOS group. The endothelium status and the metabolic and hormonal profile were studied in both groups, as well as after metformin, by flow-mediated dilatation (FMD) on the brachial artery and by measurements of plasma endothelin-1 (ET-1) levels.

Results: FMD was impaired in the PCOS group when compared with controls (3.24+/-0.71% vs 8.81+/-1.07% respectively, P<0.0001), but this difference normalized after metformin treatment (PCOS(post-metformin) vs controls: 8.17+/-1.26 vs 8.81+/-1.07%, P = 0.70) since the values significantly improved after metformin treatment (PCOS(pre-metformin) vs PCOS(post-metformin): 3.24+/-0.71 vs 8.17+/-1.26%, P=0.003). ET-1 levels were significantly higher in the PCOS women compared with the control group (7.23+/-0.50 vs 4.99+/-0.69 fmol/l, P=0.01), they improved significantly after metformin treatment (PCOS(pre-metformin) vs PCOS(post-metformin): 7.23+/-0.50 vs 3.57+/-0.60 fmol/l, P<0.0001) and their difference compared with the control group was reversed (PCOS(post-metformin) vs controls: 3.57+/-0.60 vs 4.99+/-0.69 fmol/l, P=0.13). Metformin administration improved hyperandrogenemia. However, in this study, mathematical methods used to assess insulin resistance failed to show any detected alteration after treatment with metformin.

Conclusions: PCOS women were found to exhibit endothelial dysfunction compared with controls, which was reversed 6 months after metformin administration.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Adult
  • Brachial Artery / physiology
  • Endothelin-1 / blood
  • Endothelium, Vascular / drug effects*
  • Endothelium, Vascular / physiology
  • Female
  • Glucose Intolerance / drug therapy
  • Glucose Intolerance / physiopathology
  • Humans
  • Hypoglycemic Agents / administration & dosage*
  • Insulin Resistance
  • Metformin / administration & dosage*
  • Polycystic Ovary Syndrome / drug therapy*
  • Polycystic Ovary Syndrome / physiopathology
  • Testosterone / blood
  • Vasodilation / drug effects*
  • Vasodilation / physiology

Substances

  • Endothelin-1
  • Hypoglycemic Agents
  • Testosterone
  • Metformin