PROBLEM: Regulation of ovarian folliculogenesis involves bidirectional communication between the immune and endocrine systems. Somatostatin analogues have been reported to acutely suppress elevated androgens in polycystic ovary syndrome (PCOS). The aim of our study was to analyze the morphologic and hormonal-metabolic response to octreotide therapy for one month in insulin-resistant PCOS patients in whom luteinizing hormone (LH) effect had formerly been separated by a six-month GnRH-agonist (GnRH-a) course.
METHOD: Fifteen PCOS patients were studied two months after completing a six-month GnRH-a (decapeptyl 3.75 mg monthly injection) course. Seven of the patients (group A), who were insulin-resistant and gave hyperinsulinemic response to a glucose challenge, received a 50-μg subcutaneous injection of octreotide twice a day for one month. The nonhyperinsulinemic patients (group B) received placebo injections. Hormonal measurements, oral glucose tolerance test (OGTT), and transvaginal ovarian ultrasound were performed before and toward the end of the treatment period.
RESULTS: After octreotide ovarian volume dropped significantly in group A (× ± SD) (19.2 + 5.1 versus 14.7 ± 5.5 cc, P = .02). LH levels increased (3.25 ± 1.22 versus 5.95 ± 4.34 mu/ml, P = .05) as did E2 levels (38.0 ± 11.4 versus 55.1 ± 12.7 pg/ml, P = .005). There was no change in follicle-stimulating hormone, 17-hydroxy-progesterone, free testosterone, or androstenedione levels. Insulin secretion during OGTT dropped significantly (555 ± 294 versus 68 ± 29 μu/ml/hr, P = .002). Glucose tolerance was not affected. In contrast, the placebo-treated group B patients showed an increase in ovarian volume (10.9 ± 3.5 versus 14.8 ± 3.3 cc, P = .001) while their gonadotropin and steroid profile relapsed, similarly to our patients receiving octreotide.
CONCLUSIONS: Octreotide has an adjunctive beneficial effect to GnRH-a on ovarian morphology although, at the dose used, there was no suppression of gonadotropin or ovarian steroid levels. The changes in ovarian morphology are probably mediated through suppression of insulin levels and/or other ovarian growth factors.