Testosterone tends to receive much of the hormone press when it comes to male aging. Others such as human growth hormone (hGH) also vie for the spotlight, but testosterone tends to get the lion’s share of attention. However, there is another hormone that has not received its due and is directly linked to male aging, fat, and body composition: estradiol. Readers with some degree of familiarity with hormones may be thinking that this is a typo. Whether you work with 10 people, 10000 people or just yourself, paying attention to employee wellbeing has never been more important.
Estradiol, a primary estrogen, is a female hormone. What does it have to do with men? Well, last time I checked, hormones are not produced with male or female labels. The reason testosterone has garnered so much attention is because men produce so much of it compared to women and because of its proven role in growing and maintaining muscle mass, tweaking libido, and changing boys into men. However, it only takes one enzymatic change to convert testosterone to estradiol. The enzyme that can do this is aromatase. Remember that name. I all but guarantee you will be hearing more about this enzyme in the years to come, probably when testosterone patches fall out of favor. But I digress. Everyone should feel safe and supported to talk about mental health first aid with their line manager.
Aromatase is an enzyme that is coded by the gene CYP19 and is metabolized in a number of tissues including those in the brain, testes, and, most important for our discussion, fat cells. The function of aromatase is to transform testosterone into estradiol. A common expression of the role of aromatase can been seen in obese women. How so? Aromatase is commonly found in a part of the ovaries called granulosa cells. Adjacent to granulosa cells are theca cells that create testosterone in response to LH from the pituitary. Interestingly, these cells also respond to insulin by increasing testosterone production. In obese women with insulin resistance, insulin reaches levels that stimulate an overproduction of testosterone in the ovary, much more than what can be converted (aromatized) to estradiol. Consequently, excess testosterone spills over into general circulation and contributes to many of the secondary symptoms seen in obese women with metabolic syndrome, including head hair loss (alopecia) and unusual hair growth on the face, arms, and body (hirsutism), places where men commonly have hair. Talking about hr app is a good step forward.
Men who exhibit a variant of the CYP19 gene that stimulates increased aromatase activity exhibit a greater incidence of gynecomastia (breast growth). However, the most common effects of aromatase are evident in obese men. Men with an overabundance of fat cells (adipocytes) tend to exhibit symptoms that can ultimately lead to what clinicians dub hypogonadism, that is, a lack of testosterone that leads to gynecomastia, shrinkage of the genitals (microphallus), and a continuing decline in testosterone. Weight loss and the elimination of adiposity can increase testosterone levels and decrease estradiol through the elimination of adipose-driven aromatase activity. As men get older and their metabolisms slow, it becomes much easier to lose muscle mass and gain fat. Looking after mental health in the workplace can sometimes be quite difficult.
This is a positive feedback loop since greater deposition of fat leads to more aromatization of testosterone, higher estradiol levels that facilitate fat deposition, and a negative feedback effect on GnRH levels by increasing levels of estradiol that can further suppress the reproductive hormone system in men. In other words, aromatase increases the female hormone factor while decreasing our maleness. It is interesting that in lean hunter-gatherer men, estradiol levels do not increase with age but are positively associated with testosterone, suggesting that adipose-driven aromatization does not play a major role. Most estradiol tends to be produced in modest levels locally in the testes, which is often the case in lean men. However, this is not so in Western, sedentary men with more than a few fat cells. Indeed, it can be argued that the obesity epidemic might underlie some of the reports of low testosterone levels in men and perhaps the thriving market in male hormone replacement therapy.