Low levels of serum inhibin A and inhibin B in women with hypergonadotropic amenorrhea and evidence of high levels of activin A in women with hypothalamic amenorrhea

Objective: To examine serum levels of inhibin A, inhibin B, and activin A in women with secondary hypergonadotropic or hypothalamic amenorrhea. Design: Retrospective study. Setting: Universities of Udine, Pisa, and Modena in Italy, and of Wien in Austria. Patient(s): Forty women with idiopathic premature ovarian failure (POF), 23 women with hypogonadotropic hypothalamic amenorrhea, 40 healthy postmenopausal women, and 40 age-matched women with normal ovarian function (controls). Intervention(s): Blood samples were collected between 8 and 9 am. Main Outcome Measure(s): Serum levels of inhibin A, inhibin B, and activin A. Result(s): Women with POF had lower concentrations of serum inhibin A and inhibin B than women with hypothalamic amenorrhea and fertile controls, and the difference between these concentrations was statistically significant. Levels of inhibin A and inhibin B were low in postmenopausal women and were no different than in women with POF. Serum levels of activin A were not significantly different among women with POF, fertile controls, and postmenopausal women. Women with hypogonadotropic hypothalamic amenorrhea had higher activin A values than did controls. No significant correlation was found between the level of inhibin A or inhibin B and the length of amenorrhea or the level of FSH. Conclusion(s): Low levels of circulating inhibins A and B, but not activin A, reflect ovarian failure in women with POF, whereas women with hypogonadotropic hypothalamic amenorrhea have normal levels of inhibins A and B and high levels of activin A.