Serum levels of insulin-like growth factor binding protein-1 and ovulatory responses to clomiphene citrate in women with polycystic ovarian disease.
OBJECTIVE
To study the serum levels of insulin, insulin-like growth factor I (IGF-I), and insulin-like growth factor binding protein-1 (IGFBP-1) in relation to clomiphene citrate (CC) responsiveness in women with polycystic ovarian disease (PCOD).


METHODS
Prospective. PATIENTS, SETTING: Twenty-three women with PCOD admitted consecutively to the University Infertility Clinic, a tertiary referral center.


METHODS
Blood samples were taken at fasting state and during oral glucose tolerance test (OGTT) for the determination of insulin, IGF-I, and IGFBP-1. A dose of 50 to 200 mg/d CC was given for ovulation induction.


RESULTS
With CC treatment, ovulation was achieved in 13 of 23 PCOD patients. The IGFBP-1 concentration was lower in CC nonresponders than in CC responders (20.5 +/- 4.0 ng/mL versus 41.0 +/- 8.5 ng/mL) (P < 0.05). This difference was accentuated in 13 lean PCOD patients. Lean CC nonresponders (n = 7) had almost threefold lower serum IGFBP-1 levels than lean CC responders (n = 6) (24.0 +/- 3.1 ng/mL versus 61.8 +/- 8.6 ng/mL) (P < 0.01). By contrast, among 10 obese PCOD patients, the IGFBP-1 levels were low irrespective of CC responsiveness (14.8 +/- 8.0 ng/mL versus 16.7 +/- 7.2 ng/mL). The differences remained during OGTT. The concentrations of IGF-I, insulin, sex hormone-binding globulin, LH, FSH, and androgens showed no significant differences between CC responders and nonresponders. There was an inverse correlation between serum insulin and IGFBP-1 levels in obese PCOD patients, whereas this was not seen in lean patients.


CONCLUSIONS
In lean PCOD patients, low serum IGFBP-1 concentration is related to CC unresponsiveness by a mechanism unrelated to insulin.
Tiitinen
A E
AE
Department I of Obstetrics and Gynecology, University of Helsinki, Finland.
Laatikainen
T J
TJ
Seppälä
M T
MT
D000328:Adult; D002352:Carrier Proteins / Q000097:blood*; D002996:Clomiphene / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D009765:Obesity / Q000097:blood*; D010062:Ovulation Induction; D011085:Polycystic Ovary Syndrome / Q000097:blood* / Q000188:drug therapy; D011446:Prospective Studies
D002352:Carrier Proteins; D018970:Insulin-Like Growth Factor Binding Protein 1; D002996:Clomiphene; D007334:Insulin-Like Growth Factor I