Observational studies show that long-term therapy with testosterone prevents progression from prediabetes to diabetes and improves HbA1c. Testosterone enhances insulin sensitivity in obese men with hypogonadism by decreasing fat mass, increasing lean mass, decreasing free fatty acids and suppressing inflammation. This narrative review is focused on detailing the mechanisms that underlie the metabolic aspects of testosterone therapy in humans. Effect of testosterone on I-related metabolic pathways. Effect of testosterone on Glut4 mRNA expression. T-related effects were shown to be androgen receptor dependent. Moreover, if our data are confirmed we could also state that athletes often acutely abuse with T also because of the rapid effects on T metabolic I-related pathways, in addition to possible rapid effects of T on neuromuscular system . Effect of testosterone on I-related… Glut1, Glut3 and Glut4 mRNA expression… This article does not contain any studies with human participants or animals performed by any of the authors. This "non-classical" mechanism has been shown to increase the phosphorylation/activation of the PI3K/AKT and RAS/ERK pathways in mouse skeletal and rat cardiac muscle fibers 1–3, 43, 44. Notably, PI3K/AKT signaling is also involved in the regulation of GLUT4 protein expression by increased biosynthesis, decreased degradation or both . An endocrinologist can diagnose endocrine (hormone) conditions, develop treatment and management plans for them and prescribe medication. For most hormones, having too much or too little of them causes symptoms and issues with your health. The placenta produces the hormones estrogen and progesterone to maintain the pregnancy. The testes are part of the male reproductive system and produce sperm and the hormone testosterone. This review discusses recent evidence that the androgen receptor (AR) is present in male and female β cells. One month postoperatively, ITT and glucose clamp revealed deterioration of insulin sensitivity despite unchanged body composition, suggesting a direct effect of testosterone. Because of the dual action of testosterone on glucose metabolism, it is also possible that in different conditions the effect of testosterone on insulin sensitivity is neutral, which could explain the variable results of previous studies (12–16,21). Serum concentrations of androgens and other sexual steroids, body composition, and insulin sensitivity as assessed with OGTT, ITT, and hyperinsulinemic-euglycemic clamp in a 64-year-old Hispanic woman with Leydig cell tumor of the ovary before surgery and 1 month and 9 months after curative surgery Thus, it is conceivable that testosterone might indirectly influence insulin sensitivity via its effects on body composition. Finally, there is a robust relationship between β-cell dysfunction and testosterone concentrations in these women (Goodarzi et al., 2005, Zhang et al., 2018). As discussed in the previous section for males, the development of hyperglycemia in women with PCOS, suggests that androgen excess promotes β-cell dysfunction in women. During severe androgen deficiency such as androgen depletion therapy (ADT), the additional β cell dysfunction predisposes to diabetes. Taken together, the studies described above demonstrate that testosterone action via AR is necessary for β-cell health and normal GSIS in male mice, and probably also in men. The AR-dependent gene network was investigated in β-cells following a high throughput whole transcriptome sequencing (RNA-Seq) in islets from male βARKO and control mice (Xu et al., 2017). Thus, pulsatile testosterone secretion could constitute another layer of regulation that affects β cell function (Wortham and Sander, 2016). Several glands, organs and tissues make and release hormones, many of which make up your endocrine system. Hormones are chemical messengers that coordinate different functions in your body. Find everything and everyone you need to reach your metabolic health goals, in one place.
