Inhibitory effect of sandostatin on secretion of luteinising hormone and ovarian steroids in polycystic ovary syndrome.

Hyperinsulinism accompanies the raised luteinising hormone (LH) concentrations in women with the polycystic ovary syndrome (PCOS). Somatostatin inhibits insulin and LH secretion in healthy adults, so the effect of treatment with a long-acting somatostatin analogue ('Sandostatin') on gonadotropin and androgen secretion in PCOS was investigated. LH pulsatility, androgen concentrations, and hormonal responses to an oral glucose load and to administration of a GnRH agonist (buserelin) were measured before and after 7 days' treatment with sandostatin 100 micrograms subcutaneously twice a day in 10 amenorrhoeic women with classic features of PCOS. Sandostatin significantly reduced integrated LH concentrations and LH pulse amplitudes, oestradiol, testosterone, and androstenedione concentrations, and LH responses to buserelin; it also suppressed insulin and C-peptide responses to an oral glucose load. Thus sandostatin inhibits pituitary and ovarian hormonal responses in part by a direct influence on pituitary activity, and the possibility of an indirect effect mediated by changes in insulin concentrations requires investigation. These findings have implications for the treatment of infertility in women with PCOS.