Androgen metabolism and the menopause.

The concentration of androgens in the blood peaks in early adulthood. While the concentrations of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) decline steadily, the concentrations of androstenedione (A) and testosterone (T) decline just before or at the menopause. DHEAS is bound strongly to albumin, resulting in a very low metabolic clearance rate (MCR) of about 12 L/day. DHEA and A are bound weakly to albumin and their MCRs are 1800 to 2000 L/day. T is bound strongly to sex hormone-binding globulin (SHBG), and the MCR of T is about 500 L/day. There are no significant changes in the MCRs at the menopause or with age. The pathways of metabolism are not altered at the menopause but aromatization of DHEA, A, and T to estrone and estradiol all increase with age. Thus, androgen metabolism in general is affected more by age than by the menopause itself.