title: Luteinizing hormone secretion is not influenced by insulin infusion in women with polycystic ovary syndrome despite improved insulin sensitivity during pioglitazone treatment.
abstract: It has been reported in women with polycystic ovary syndrome (PCOS) that LH secretion is not altered by insulin infusion. To determine whether insulin resistance may have precluded an effect of insulin, pulsatile LH secretion and gonadotropin responses to GnRH were examined in PCOS women (n = 9) before and after pioglitazone treatment (45 mg/d) for 20 wk in the presence and absence of a hyperinsulinemic euglycemic clamp (80 mU/m2.min). Frequent blood samples were obtained for 12 h (every 10 min) as well as during sequential administration of GnRH at doses of 2, 10, and 20 microg over 12 h. A significant (P < 0.05) improvement in insulin sensitivity was seen in the subjects after treatment. Mean LH levels, LH pulse frequency and amplitude, as well as gonadotropin responses to GnRH were not influenced by pioglitazone, either with or without insulin infusion. We conclude that in PCOS women, inappropriate gonadotropin release does not appear to be a consequence of hyperinsulinemia.
authors.affiliation: Department of Reproductive Medicine, University of California-San Diego, School of Medicine, 9500 Gilman Drive, La Jolla, California 92093-0633, USA.
authors.forename: Rinku V
authors.initials: RV
authors.lastname: Mehta
authors.forename: Ketan S
authors.initials: KS
authors.lastname: Patel
authors.forename: Mickey S
authors.initials: MS
authors.lastname: Coffler
authors.forename: Michael H
authors.initials: MH
authors.lastname: Dahan
authors.forename: Richard Y
authors.initials: RY
authors.lastname: Yoo
authors.forename: Johanna S
authors.initials: JS
authors.lastname: Archer
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Malcom
authors.forename: R Jeffrey
authors.initials: RJ
authors.lastname: Chang
mesh_terms: D000328:Adult; D000735:Androstenedione / Q000097:blood; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000378:metabolism*; D000077205:Pioglitazone; D011085:Polycystic Ovary Syndrome / Q000188:drug therapy* / Q000378:metabolism; D013739:Testosterone / Q000097:blood; D045162:Thiazolidinediones / Q000627:therapeutic use*
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin; D045162:Thiazolidinediones; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D000735:Androstenedione; D007986:Luteinizing Hormone; D000077205:Pioglitazone