Gonadotropines, Ovarian hormones and hot flushes during the menopausal transition. the role of inhibin A and B

In this study, the relationship between inhibin A and B, FSH, E2 and vasomotor complaints during the menopausal transition were studied in a small sample of 59 women without hormone replacement therapy. The mean levels of Inhibin A and B fall substantially before the final menses. Current interpretations of the sources of inhibin A and B are in accordance with the concept that inhibin A is primarily a secretory product of the dominant follicle and the corpus luteum and inhibin B is a product of the small antral follicle in the recruited cohort ( Burger et al., 1999). At the time of menopause there will only be a very small number of dominant follicles left, but still some antral follicles. The shift from inhibin A to inhibin B being the dominant inhibin support this theory, i.e. there is no ovulation post menopause. In contrast to other authors we were able to detect both inhibin A and B post menopause. (Ala-Fossi 1998)To our surprise the levels of inhibin B was higher than inhibin A, suggesting follicular function post menopause and secretion of inhibin A from stromal cells post menopause. It was possible to identify three different patterns among the hormonal changes in relation to hot flushes. Premenopause, a relationship between hot flushes and high levels of FSH and low levels of E2 were found. Immediately after menopause, a correlation between TSH and vasomotor complaints was found. Finally, the second year post menopause a negative correlation between androgens and vasomotor complaints was found among women who recovered from hot flushes. In this study we also found that inhibin A and B were correlated to hot flushes before menopause.