INCREASED INSULIN-SECRETION IN PATIENTS WITH MULTIFOLLICULAR AND POLYCYSTIC OVARIES AND ITS IMPACT ON OVULATION INDUCTION

Objective: to assess the oral glucose tolerance test (OGTT)-stimulated insulin secretion and its relation to pulsatile GnRH ovulation induct ion outcome in patients with multifollicular or polycystic ovaries (PC Os). Design: Prospective study. Setting: Reproductive Endocrinology Ce nter, University of Bologna, Bologna, Italy. Patients: Eight normal an d 29 anovulatory women (8 with multifollicular ovaries and 21 with PCO s). Intervention: A stnadard OGTT was performed in all subjects. In al l anovulatory patients, ovulation was induced with pulsatile GnRH (5 m u g IV every 60 minutes). In multifollicular ovary patients, pulsatile GnRH was administered alone, whereas in PCOs it was preceded by GnRh agonist (GnRH-a) suppression. Main Outcome Measures: Glucose, insulin, and C-peptide response to the OGTT, expressed as area under the curve (AUC). Ovulatory rates in response to pulsatile GnRH. Results: Insuli n and C-peptide AUC were greater than controls in both multifollicular ovary and PCO patients. Insulin AUC was positively correlated to ovar ian volume. Ovulation was achieved in 88% and 57% of multifollicular o vary and PCO patients, respectively. Body mass index and glucose AUC b ut not insulin and C-peptide AUC were significantly greater in the ano vulatory PCO. Conclusions: [1] insulin AUC was increased in both multi follicular ovary and PCO patients; [2] derangements of insulin secreti on may be present in a greater variety of anovulatory patients than pr eviously thought; [3] insulin levels during the OGTT did not predict a response to pulsatile GnRH in PCOs, suggesting complex insulin intera ctions of the ovarian level; [4] given the in vitro stimulatory proper ties of insulin of granulosa cells synergistic with FSH, we propose th at excessive insulin levels may may contribute to the ovarian enlargem ent often bound in multifollicular ovary and PCO patients.