PITUITARY-FUNCTION IS ALTERED DURING THE SAME CYCLE IN WOMEN WITH POLYCYSTIC-OVARY-SYNDROME TREATED WITH CONTINUOUS OR CYCLIC ORAL-CONTRACEPTIVES OR A GONADOTROPIN-RELEASING-HORMONE AGONIST

Objective: To determine if continuous oral contraceptive (OC) therapy was superior to a cyclic regimen in achieving persistent pituitary sup pression of LH in patients with polycystic ovary syndrome (PCOS). Desi gn: Fourteen women (ages 16 to 41 years) with PCOS received one of thr ee treatment groups: continuous OC therapy (30 mu g ethinyl E(2) plus 150 mu g desogestrel), cyclic OC therapy, or monthly injections of a G nRH agonist (GnRH-a, leuprolide acetate depot 3.75 mg) for 3 months. B asal hormone levels were obtained before initiating therapy, on days 1 5 to 17 of the 3rd month of treatment (study 1) and again on days 26 t o 28 of the 3rd month (study 2). A GnRH stimulation test was also perf ormed during study 1 and study 2. Results: After 3 months of treatment , LH levels were decreased significantly in all groups with less effec tive suppression observed in the cyclic OC group compared with the con tinuous OC or GnRH-a groups. A significant rise in LH was found only i n the cyclic OC group after 5 to 7 days of placebo treatment (study 1 versus study 2). An increase in T was also observed in the cyclic OC g roup during study 2, whereas the continuous OC and GnRH-a groups showe d continued inhibition of T levels. Although there was no significant difference in LII area under the curve (AUG) measurements after GnRH s timulation in study 1 versus study 2, the LH AUC was significantly gre ater in both studies in the cyclic OC group compared with the continuo us OC or GnRH-a groups. Conclusions: Increased LH secretion during the week of placebo in the cyclic OC group was associated with a concomit ant increase in T. The striking rise in LH secretion after GnRH stimul ation in the cyclic OC group may represent increased pituitary sensiti vity in patients receiving cyclic OCs regardless of the phase of the t reatment cycle, perhaps secondary to increased pituitary stores of LH in these women.