17‐Hydroxyprogesterone response to buserelin testing in the polycystic ovary syndrome

OBJECTIVE: We determined the 17-hydroxyprogesterone (17-OH P) response to buserelin, a GnRH agonist, and its relation to ovarian volume in the patients with polycystic ovary syndrome (PCOS). DESIGN: We compared 17-OH P response to buserelin in a large group of patients with that in a control group of healthy women. We also investigated whether there is any relation between LH-induced 17-OH P production in response to buserelin and ovarian volume. PATIENTS: Ten normal women and 31 women with PCOS were included in the study. MEASUREMENT: Pelvic ultrasound examination by abdominal or vaginal transducer was performed. Serum basal levels of LH, FSH, free testosterone and 17-OH P were measured by radioimmunoassay. 17-OH P responses to both ACTH and buserelin were detected. Cortisol levels were measured before and after dexamethasone suppression. RESULTS: The subcutaneous administration of 1 mg buserelin produced an increase in serum 17-OH P, which peaked within 24 hours in all groups. The mean +/- SEM level of 17-OH P, 24 hours after buserelin stimulation in the women with PCOS (15.94 +/- 1.31 nmol/l) was significantly higher (P < 0.001) than in the control group (6.75 +/- 0.69 nmol/l). The women with PCOS had increases in 17-OH P levels exceeding 10.15 nmol/l 24 hours after buserelin testing. The increased 17-OH P responses to buserelin were unchanged by pretreatment with dexamethasone to suppress adrenal function. The 17-OH P response was significantly related to ovarian volume (r = 0.53, P < 0.01). CONCLUSIONS: Our findings suggest that the serum 17-OH P response to a 1-mg subcutaneous test dose of buserelin may be a diagnostic and practical test for PCOS. increased ovarian volume in PCOS may be responsible for the elevated 17-OH P response to buserelin, a GnRH agonist, at least in some patients.