title: Metformin induces a prompt decrease in LH-stimulated testosterone response in women with PCOS independent of its insulin-sensitizing effects.
abstract: BACKGROUND
  The use of insulin-sensitizing drugs has been shown to improve both the reproductive and the metabolic aspects of PCOS. However, the mechanisms by which metformin exerts its effects in PCOS are still not completely understood. There is growing evidence of a direct effect of metformin on ovarian steroidogenesis, independent of its effects on insulin sensitivity.
  
  
  METHODS
  We evaluated the short-term effects of metformin compared to placebo on basal and LH- stimulated androgen secretion as well as on hormonal and metabolic parameters in 19 women with PCOS during a four-day randomized, double-blinded placebo-controlled clinical trial. In a three month follow-up evaluation, we investigated the longer-term therapeutic effects of metformin on ovulation, metabolic and endocrine parameters.
  
  
  RESULTS
  Compared to placebo, 2 days of metformin was associated with a borderline significant reduction in the free androgen index (FAI) (p = 0.05) and with a reduction in the serum concentration of LH-stimulated testosterone (T) (p = 0.03). Following three months of use, a decline in serum T was observed, independent of changes in weight, metabolic parameters, or insulin sensitivity.
  
  
  CONCLUSIONS
  In women with PCOS, Metformin induces a prompt decrease in LH-stimulated T secretion after only several days of use. This action precedes the medication's effects on insulin sensitivity or weight loss.
authors.forename: Dorothea
authors.initials: D
authors.lastname: Kurzthaler
authors.forename: Dijana
authors.initials: D
authors.lastname: Hadziomerovic-Pekic
authors.forename: Ludwig
authors.initials: L
authors.lastname: Wildt
authors.affiliation: Department of Gynecologic Endocrinology and Reproductive Medicine, Medical University of Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria. beata.seeber@uki.at.
authors.forename: Beata E
authors.initials: BE
authors.lastname: Seeber
mesh_terms: D000302:Adrenal Cortex / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D000328:Adult; D015992:Body Mass Index; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017588:Hyperandrogenism / Q000209:etiology / Q000517:prevention & control; D006946:Hyperinsulinism / Q000209:etiology / Q000517:prevention & control; D007004:Hypoglycemic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D007333:Insulin Resistance; D007986:Luteinizing Hormone / Q000037:antagonists & inhibitors* / Q000235:genetics; D008687:Metformin / Q000009:adverse effects / Q000627:therapeutic use*; D050177:Overweight / Q000150:complications; D010060:Ovulation / Q000187:drug effects; D011085:Polycystic Ovary Syndrome / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D013739:Testosterone / Q000097:blood / Q000378:metabolism*; D015430:Weight Gain / Q000187:drug effects; D055815:Young Adult
chemical_list: D007004:Hypoglycemic Agents; D011994:Recombinant Proteins; D013739:Testosterone; D007986:Luteinizing Hormone; D008687:Metformin