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

Abstract

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, E1, 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 stratified by DHEAS levels to adjust for differences in DHEAS levels between sexes. For men and women separately, mean levels of E2, E1, 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 ] £ 100%, in which C m and C f represent the mean concentrations of the steroid in men and women respectively. Results: The relative contributions (%) of the testes to hormone levels per DHEAS stratum (, 2, 2-4, 4 -6 and .6 mmol/l) respectively were, for E2, 72%, 60%, 52% and 44%; for E1, 54%, 47%, 35% and 34%; for androstenedione, 14%, 4%, 12% and 0%; 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.European Journal of Endocrinology 152 261-268

Association of FSH With Metabolic Syndrome in Postmenopausal Women: A Comparison With CRP, Adiponectin and Leptin

“…We found significantly higher values of E2 in obese women in comparison with non-obese women. A positive correlation between E2 and BMI was relatively weak, but comparable to the findings of other authors [24,[27][28]. However, we did not find a statistically significant difference in E2 concentration between women with and without MetS, despite significantly lower values of FSH in women with MetS.…”

“…The absence of difference in E2 concentration between the aforementioned groups may be partially explained by the fact that postmenopausal obesity is more prominently associated with free E2, which is consistent with the dual effect of obesity toward increasing estrogen production and decreasing SHBG in the circulation [23,29]. Additionally, in some studies more prominent correlations between E1 or estrone sulphate and BMI than with E2 have been observed [24,27]. The simple correlation between FSH and E2 was statistically significant but very weak.…”

Human platelets differentially concentrate estradiol, estrone and testosterone

“…Plasma hormone levels were within values previously reported [12][13][14], but within individuals, platelet E2, E1 and T levels did not appear to reflect plasma levels. Relative to plasma concentrations, platelets concentrate E2 more than T or E1.…”

Sildenafil increases serum testosterone levels by a direct action on the testes

“…The adrenal glands are the major site for production of androstenedione, which is converted to oestrone by aromatase (Payne & Hales, 2004; de Ronde et al , 2005). Enzyme 17,20 lyase, which converts 17α-hydroxyprogesterone to androstenedione, is upregulated with sildenafil treatment in rats (Payne & Hales, 2004; Andric et al , 2010).…”