Serum inhibins A and B fall differentially as FSH rises in perimenopausal women

Abstract

BACKGROUND: Serum FSH levels rise with increasing age in normal women, particularly as they enter the menopausal transition and progress to the postmenopausal state. The contributions of decreasing levels of inhibin-A (INH-A) and inhibin-B (INH-B) to this rise are presently unclear, as there are no reports of dimeric INH levels in relation to menopausal status. The present study was undertaken in order to provide preliminary data on relationships amongst the dimeric inhibins, oestradiol (E2) and FSH in normal subjects of defined menopausal status. METHODS: Single serum samples were obtained between cycle days 3 and 8 in regularly cycling women, or at random in those with irregular cycles or ..