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 induction outcome in patients with multifollicular or polycystic ovaries (PCOs).


METHODS
Prospective study.


METHODS
Reproductive Endocrinology Center, University of Bologna, Bologna, Italy.


METHODS
Eight normal and 29 anovulatory women (8 with multifollicular ovaries and 21 with PCOs).


METHODS
A standard OGTT was performed in all subjects. In all anovulatory patients, ovulation was induced with pulsatile GnRH (5 micrograms i.v. every 60 minutes). In multifollicular ovary patients, pulsatile GnRH was administered alone, whereas in PCOs it was preceded by GnRH agonist (GnRH-a) suppression.


METHODS
Glucose, insulin, and C-peptide response to the OGTT, expressed as area under the curve (AUC). Ovulatory rates in response to pulsatile GnRH.


RESULTS
Insulin and C-peptide AUC were greater than controls in both multifollicular ovary and PCO patients. Insulin AUC was positively correlated to ovarian volume. Ovulation was achieved in 88% and 57% of multifollicular ovary and PCO patients, respectively. Body mass index and glucose AUC but not insulin and C-peptide AUC were significantly greater in the anovulatory PCO.


CONCLUSIONS
[1] Insulin AUC was increased in both multifollicular ovary and PCO patients; [2] derangements of insulin secretion may be present in a greater variety of anovulatory patients than previously thought; [3] insulin levels during the OGTT did not predict a response to pulsatile GnRH in PCOs, suggesting complex insulin interactions at the ovarian level; [4] given the in vitro stimulatory properties of insulin on granulosa cells synergistic with FSH, we propose that excessive insulin levels may contribute to the ovarian enlargement often found in multifollicular ovary and PCO patients.
Filicori
M
M
Reproductive Endocrinology Center, Bologna, Italy.
Flamigni
C
C
Cognigni
G
G
Dellai
P
P
Michelacci
L
L
Arnone
R
R
D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D002096:C-Peptide / Q000097:blood; D005260:Female; D005951:Glucose Tolerance Test; D007987:Gonadotropin-Releasing Hormone / Q000627:therapeutic use; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D000078790:Insulin Secretion; D010049:Ovarian Diseases / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism*; D006080:Ovarian Follicle / Q000000981:diagnostic imaging; D010053:Ovary / Q000000981:diagnostic imaging; D010062:Ovulation Induction; D011085:Polycystic Ovary Syndrome / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000378:metabolism*; D011446:Prospective Studies; D014463:Ultrasonography
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D007987:Gonadotropin-Releasing Hormone