Decreased inhibin B responses following recombinant human chorionic gonadotropin administration in normal women and women with polycystic ovary syndrome.

OBJECTIVE: To determine whether granulosa cells contribute to excess androgen production, by assessing inhibin B (Inh B) responses to hCG in women with polycystic ovary syndrome (PCOS) and in normal women. DESIGN: Prospective study. SETTING: Academic medical center. PATIENT(S): Twenty women with PCOS and 16 normal women. INTERVENTION(S): Blood samples obtained before and 24 hours after injection of 25 µg recombinant hCG (r-hCG). MAIN OUTCOME MEASURE(S): Basal and stimulated Inh B, E2, androstenedione (A), and T responses after r-hCG administration. RESULT(S): In normal and PCOS women, r-hCG induced a significant reduction of Inh B levels. Lowered Inh B responses were not related to body mass index, PCOS status, or age by multivariate regression. Recombinant hCG significantly increased serum A and E2 in both normal and PCOS women. CONCLUSION(S): In normal and PCOS women, Inh B production was decreased following r-hCG administration. These findings strongly suggest that in PCOS women androgen excess is not enhanced by LH-stimulated Inh B production. CLINICAL TRIAL REGISTRATION NUMBER: NCT00747617.