The Roles of Androgens in Humans: Biology, Metabolic Regulation and Health

Abstract

Androgens are an important and diverse group of steroid hormone molecular species. They play varied functional roles, such as the control of metabolic energy fate and partition, the maintenance of skeletal and body protein and integrity and the development of brain capabilities and behavioral setup (including those factors defining maleness). In addition, androgens are the precursors of estrogens, with which they share an extensive control of the reproductive mechanisms (in both sexes). In this review, the types of androgens, their functions and signaling are tabulated and described, including some less-known functions. The close interrelationship between corticosteroids and androgens is also analyzed, centered in the adrenal cortex, together with the main feedback control systems of the hypothalamic–hypophysis–gonads axis, and its modulation by the metabolic environment, sex, age and health. Testosterone (T) is singled out because of its high synthesis rate and turnover, but also because age-related hypogonadism is a key signal for the biologically planned early obsolescence of men, and the delayed onset of a faster rate of functional losses in women after menopause. The close collaboration of T with estradiol (E2) active in the maintenance of body metabolic systems is also presented Their parallel insufficiency has been directly related to the ravages of senescence and the metabolic syndrome constellation of disorders. The clinical use of T to correct hypoandrogenism helps maintain the functionality of core metabolism, limiting excess fat deposition, sarcopenia and cognoscitive frailty (part of these effects are due to the E2 generated from T). The effectiveness of using lipophilic T esters for T replacement treatments is analyzed in depth, and the main problems derived from their application are discussed.

Association between sex hormones and bone age in boys aged 9–18 years from China

“…Testosterone is the main substrate for estrogen synthesis, a process that is irreversible. The metabolic actions of testosterone partly result from its conversion to estradiol 24 . During puberty in boys, estradiol was found to increase simultaneously with testosterone levels and directly correlate with CA and BA, height and weight.…”

Efficacy and mechanism of lipoic acid in the treatment of reproductive injury caused by perfluorooctanoic acid

“…AR mainly exists in the Sertoli cells of the testes and is a necessary intermediate substance for androgen to serve the role of spermatogenic regulation ( 18 , 37 ). T serves a role in male reproduction by affecting the synthesis of E2( 38 ). The levels of FSH were increased, and the levels of T and E2 were decreased in the PFOA-induced rats.…”

A meta-analysis: Effect of androgens on reproduction in sows

“…T plays a regulatory role in female menopause and pregnancy (1,4). T can be converted into estradiol under the catalysis of aromatase (5).…”