A direct approach to the estimation of the origin of oestrogens and androgens in elderly men by comparison with hormone levels in postmenopausal women

Objective: The origin of oestrogens in men is only partly understood. From infusion studies with radioactively labelled hormones, we know that oestradiol (E2) and oestrone (E1) are either directly secreted by the testes and adrenal glands or peripherally produced from testicular or adrenal androgens. Design and methods: We determined E2, El, androstenedione, testosterone and dehydroepiandrosterone sulphate (DHEAS) in 292 elderly men and 367 postmenopausal women. We considered postmenopausal women as men without testes, assuming that the postmenopausal ovary is not endocrinologically active and that the testes do not contribute to circulating levels of DHEAS. Subjects were stratitied by DHEAS levels to adjust for differences in DHEAS levels between sexes. For men and women separately, mean levels of E2, El, androstenedione and testosterone were calculated per DHEAS stratum. The relative direct and indirect contributions of the testes to steroid levels in men were calculated by the formula [(C-m-C-f)/C-m] X 100%, in which C-m and C-f represent the mean concentrations of the steroid in men and women respectively. Results: The relative contribution S (%) of the testes to hormone levels per DHEAS stratum (< 2, 2-4, 4-6 and > 6 mumol/l) respectively were, for E2, 72%, 60%, 52% and 44%; for E1, 54%, 47%, 35% and 34%; for androstenedione, 14%, 4%, 12% and 01%; and, for testosterone, 88%, 88%, 87% and 83%. Conclusions: We conclude that in elderly men dependent on DHEAS levels, 44-72% of E2 and 34-54% of E1 originate directly or indirectly from the testes.