Many of us know that men with low testosterone are prone to low libido and struggle to maintain muscle mass.
However, having low levels of the hormone can do much more damage than just trouble in the bedroom or at the gym.
Now, experts are raising awareness about low testosterone, sometimes dubbed ‘male menopause,’ and its debilitating effects on men’s health.
Testosterone is a male sex hormone primarily produced in the testicles. However, testosterone receptors are spread throughout the body.
It helps to maintain bone density, fat distribution, muscle mass, facial and body hair, sex drive, and sperm production, according to the Mayo Clinic.
Estimates from the University of Wisconsin show that low testosterone affects roughly 12 percent of men in their 50s, 19 percent in their 60s, 28 percent in their 70s, and 49 percent in their 80s
Male testosterone levels tend to be highest around age 20 and decline naturally with age.
At their highest, testosterone levels should be anywhere between 300 and 1,200 ng/dL.
Once men hit their mid-thirties, testosterone declines by at least one percent per year.
However, men can become deficient at any age.
Experts have revealed to DailyMail.com the 10 crucial warning signs below:
Testosterone levels peak in young adulthood, around age 20, but decline by about 1 percent annually after age 30
Experts told DailyMail.com that symptoms of low testosterone include low sex drive, fatigue, decreased muscle mass, depression, and weak bones, among others
Low sex drive
‘Testosterone is the primary driver of someone’s libido, or sex drive,’ Dr Helen L Bernie, director of male sexual and reproductive health at Indiana University, told DailyMail.com.
This leads to men having no interest in sex or masturbation.
Low sex drive is one of the most common symptoms of testosterone deficiency, and it’s one of the top concerns Dr Bernie’s patients have.
This is due the presence of androgen receptors, where testosterone binds, in areas of the brain that process desire. Without testosterone, there is nothing to signal arousal.
‘You do need testosterone in order for a man to have an erection,’ Dr Bernie said. ‘If you have very low testosterone levels, it’s very hard to get an erection.’
While there has to be increased blood flow to the penis to maintain an erection, testosterone is also necessary since there are receptors within erectile tissue, also known as the corpus cavernosum, inside the penis.
‘Erectile tissue in someone who has low testosterone can atrophy or become less healthy,’ Dr Bobby Najari, urologist at NYU Langone, told DailyMail.com.
This leads blood flow in the penis to become less responsive to sexual stimulation, he said. Lack of testosterone can also make medications like Viagra less effective.
Low testosterone’s lack of libido can also cause erectile dysfunction.
Low testosterone could tank your mood, Dr Najari said.
Similar to with sex drive, androgen receptors are found in several areas of the brain, including the amygdala, which processes fear.
However, more research is needed to understand this relationship.
‘We know that there are androgen receptors centrally located in the brain,’ Dr Najari said. ‘But the exact mechanism of the symptoms is less well understood.’
Other factors on top of low testosterone could lead to depression, he mentioned, such as poor sleep or thyroid dysfunction.
Dr Helen L. Bernie, director of male sexual and reproductive health at Indiana University (left), and Dr Bobby Najari, urologist at NYU Langone (right), pointed to several lasting health consequences of low testosterone, including memory issues, diabetes, fatigue, and depression
Similar to depression, androgen receptors could lead to poor memory. These receptors can be found in the hippocampus, the part of the brain responsible for learning and memory, as well as the cerebrum, which controls thinking and reasoning.
When there isn’t enough of the hormone to bind to those receptors, it could lead to forgetfulness, Dr Bernie said.
When there isn’t enough of the hormone to bind to those receptors, it could lead to forgetfulness.
‘Testosterone is our primary driver of motivation and energy levels,’ Dr Bernie said.
Testosterone is a diurnal hormone, meaning that it’s highest in the morning and gradually decreases throughout the day.
It’s also a type of androgen hormone, a steroid, meaning that it keeps us energized.
Since it decreases, men with low levels are going to be more tired throughout the day than those with normal levels.
‘Men with chronically low testosterone will have decreased energy levels. They’ll have fatigue,’ Dr Bernie said.
Decreased muscle mass
Testosterone promotes muscle growth and has been shown to suppress fat gain. When levels are low, muscle mass begins to dwindle, Dr Bernie said.
In one study from Japan, men with low levels of free testosterone- the amount of the hormone not bound to receptors- were two to three times more likely to have muscle loss with aging as those with normal levels.
This is because lean muscle mass is replaced with fatty adipose tissue, also known as body fat.
Strength training can help rebuild that lost muscle.
Increased belly fat
Having more fat tissue, especially around the abdomen, can be a sign of low testosterone, Dr Najari said.
This is due to that fatty adipose tissue that replaces lean muscle mass.
One review in obese men found that low testosterone specifically increases fat deposits in the abdomen.
‘One of the most common reasons for lower testosterone, as men get older, is just increasing amounts of fat tissue that that break down the testosterone,’ Dr Najari said.
Fat cells produce aromatase, an enzyme that converts testosterone to estrogen. Estrogen then causes more fat to be deposited in the abdomen, as well as the chest, hips, and thighs.
‘In men, testosterone is converted into estrogen,’ Dr Najari said. ‘And we know, in both sexes, that estrogen is involved in the maintenance of bone health. So for men who have lower testosterone levels, they’ll have lower estrogen levels.’
This causes the bones to thin or break down. It can also lead to osteoporosis, a condition causes by weak or brittle bones.
At first, the condition may have no symptoms, but as it progresses, it can cause back pain, stooped posture, fractures, and loss of height, according to the Mayo Clinic.
Testosterone is intertwined with insulin, the hormone made by the pancreas that helps the body store sugar for energy.
‘Insulin is testosterone dependent, so you have to have some testosterone in your body in order for insulin to function well,’ Dr Bernie said.
When insulin function is impaired, it leads to poor control of glucose, leading to high blood sugar and diabetes.
A 2016 study in the journal Diabetes Care found that testosterone therapy could reduce insulin resistance in diabetic men with low testosterone.
Some studies have suggested that low testosterone can lead to greater chance of heart disease, cardiac arrest, and stroke.
Research published in the American Heart Association’s journal, Circulation, found that men with low testosterone had a greater risk of dying from heart disease than those with normal levels.
This may be due to testosterone opening up blood vessels to the heart, allowing blood to flow more freely.
The link between testosterone and heart disease has been controversial among experts, Dr Bernie said.
While some studies have suggested that testosterone therapy could increase the risk of heart attack and stroke, she pointed toward research published last week in the New England Journal of Medicine. This study found that testosterone therapy in men with low levels did not raise the risk of adverse cardiac events.