#Marked decrease of the male hormone testosterone free#
Conditions that increase (e.g., pregnancy, exogenous estrogen therapy, liver cirrhosis, hyperthyroidism) or decrease (i.e., obesity, exogenous androgen therapy, insulin, glucocorticoids) SHBG inversely affect circulating levels of free (active) testosterone. Testing of total testosterone levels also measures inactive testosterone, which is bound to sex hormone-binding globulin (SHBG), a liver-synthesized protein with a high affinity for sex steroids. In circulation, active testosterone is free or bound to albumin. 4 Ten years after the onset of menopause, circulating testosterone and androstenedione levels are half of perimenopausal levels. 4,5 Consequently, women who have undergone bilateral oophorectomy have a marked decrease in circulating testosterone levels, though serum concentrations of DHEA and androstenedione remain stable due to adrenal compensation. 3 Menopause is not associated with a rapid decline in androgen production the postmenopausal ovary is hormonally active and accounts for 40% to 50% of postmenopausal testosterone production. In target tissues, circulating testosterone is converted to dihydrotestosterone by 5-alpha-reductase and aromatized to estradiol.Īndrogen levels decline with age throughout a woman’s life, starting in her mid-30s. DHEA-S is almost exclusively produced in the adrenal glands, whereas DHEA, androstenedione and testosterone are produced in the adrenal glands and ovaries and by peripheral conversion. 2 DHEA-S, DHEA and androstenedione are the main prohormones that are peripherally converted to the active androgens testosterone and dihydrotestosterone. In women, roughly 25% of androgen production occurs in the adrenal glands, 25% occurs in the ovaries, and the rest occurs peripherally. The biologically active androgens in women are dehydroepiandrosterone sulfate (DHEA-S), dehydroepiandrosterone (DHEA), androstenedione, testosterone and dihydrotestosterone. Androgen synthesis, production and measurement in women Here we will discuss the physiologic roles of androgens as well as the indications and best-practice recommendations for androgen therapy in women. Several randomized controlled trials have established the short-term safety and efficacy of prescribed testosterone in women when doses approximate physiologic levels. 1Ĭurrently, the only evidenced-based indication for testosterone therapy in women is for treating hypoactive sexual desire disorder in postmenopausal women. 1 The physiologic effects of androgens are in part due to their role as precursors for estrogen synthesis, but these hormones also have independent effects on female reproductive tissues, mood, cognition, breasts, bones, muscles, vasculature and other systems. However, androgens are also important for female sexual health and well-being. To read it in its entirety, including a complete set of references, please visit: Įstrogens are the principal sex hormones responsible for female reproductive maturation and sexual characteristics. Please note: This is an abridged version of an article recently published in the Cleveland Clinic Journal of Medicine. We do not endorse non-Cleveland Clinic products or services Policy Advertising on our site helps support our mission. Cleveland Clinic is a non-profit academic medical center.
0 kommentar(er)
