Low testosterone, also known as hypogonadism, can have various and very bothersome symptoms. The symptoms are nonspecific and can include decreased energy, loss of libido or sex drive, increased mental fogginess, and difficulty with weight loss and muscle building.
The diagnosis of hypogonadism requires both symptoms of low testosterone as well as laboratory findings of low testosterone (total testosterone level less than 300 ng/dl on morning blood draw). About 3 – 8 % of men under 45 years old and 39% of men over 45 years old have laboratory testing consistent with low testosterone. About 6% of men in the general population have symptoms of low testosterone and laboratory testing to confirm the diagnosis.
Know Your Score
Causes and Risk Factors
Various causes of low testosterone may include stress, obesity, poor sleep, and aging. Total testosterone levels decline by about 1% per year after age 40 and symptoms are further exacerbated as the testosterone binding protein levels rise with age to limit available testosterone. Additional causes are disorders affecting the brain or testicles including various genetic problems, certain chronic illnesses or medications, surgeries, tumors or traumas. The clinical and laboratory evaluation is designed to uncover if there is a specific concerning underlying problem. The investigation only reveals a specific medical cause in about 10% of hypogonadal men.
When to Speak with a Urologist about Low Testosterone
You should speak to a Urologist about low testosterone if you are experiencing decreased energy, loss of libido or sex drive, difficulty with erections, increased mental fogginess, or difficulty with weight loss and muscle building.
What to Expect when Seeking Treatment
In addition to a history and physical examination, initial assessment includes laboratory testing to investigate possible hormonal imbalances leading to hypogonadal symptoms. Testing will include total testosterone, calculated free testosterone, sex-hormone binding globulin (SHBG), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, prolactin and thyroid stimulating hormone. Testing must be obtained before 11 am and a single finding of a low testosterone level must be repeated with one additional morning blood draw to confirm the finding. Testosterone levels in young men can be 50% lower in the afternoon relative to the morning, and the levels for older men can be 10% lower later in the day. Other testing including lipid panel, prostate specific antigen (PSA) and hemoglobin levels will be obtained to help monitor treatment effects.
The laboratory diagnosis is somewhat complicated because no agreed-upon laboratory threshold exists for low total or free testosterone. However, many endocrine societies accept levels below the relatively arbitrary threshold of 300 ng/dl total testosterone and 6.5 ng/dl calculated free testosterone as “low”. Other complicating factors include different normal reference ranges between different laboratories and different methods of performing the testing.
Increasing testosterone has multiple possible benefits that may include increased energy, heightened libido or sex drive, improved mood, better concentration, favorable body composition changes with increased muscle mass and bone strength, and improvement in anemia.
Various lifestyle modifications have been shown to increase the body’s own production of testosterone without medications including weight loss, sleep improvement, and stress reduction. A 14% decrease in body weight has been shown to result in a sustained 80 ng/dl increase in total testosterone.
Several different forms of testosterone medications are available to supplement low levels. The Food and Drug Administration (FDA) has approved the use of testosterone supplementation for certain specific medical conditions, but testosterone supplementation for low testosterone due to aging or without clear cause is an off-label use.
Direct testosterone supplementation may be administered as a morning topical gel, nasal application three times daily, weekly home injections, in-office injections every 10 weeks, or in-office implantable pellets every 16 weeks. Each route has its own unique advantages and drawbacks. For example, there is a small risk of skin-to-skin transference after applying a topical treatment. Injectable testosterone is dissolved in oil and, if the medication is accidentally injected into a blood vessel, there is a small chance of oil traveling to the lungs and causing respiratory symptoms. Your Urologist will help identify the appropriate approach for you, though you may need to try several different options first.
There are some risks of testosterone supplementation and known side effects that require careful monitoring. Possible risks may include worse (lower) HDL cholesterol levels, increased red blood cell formation requiring regular therapeutic phlebotomy, increased estrogen levels resulting in water retention, breast tissue changes, hair loss and acne requiring routine use of anti-estrogen medication, as well as decreases in testicular size and sperm count potentially impeding pregnancy.
The use of testosterone alone results in sperm counts close to zero in 99.9% of men after 6 months. Nearly all (99.7%) men recover enough sperm production after stopping testosterone for natural pregnancy though that may take 2 years, and 50% of men do not return to their pre-testosterone sperm counts. Consequently, young men who are interested in preserving fertility and have not yet completed their families should avoid testosterone medications.
Alternatives to testosterone in these men include lifestyle modifications in conjunction with medical therapy using Clomid (clomiphene citrate) to reset the brain-testicle connection. Clomid works by causing the brain to send more signal to the testicles to cause the testicles to produce more testosterone themselves. Clomid does not risk fertility and has been shown to increase testosterone by about 200 ng/dl with 50% of men describing improvements in symptoms. Few side effects are reported though about 1% of men complain about visual or emotional disturbances and there is a theoretical increased risk of blood clot formation. Clomid cannot be taken for years however because it begins to have a counterproductive effect.
Other medication options to increase testosterone without direct supplementation include hCG injections that directly stimulate more testicular production (primarily used for men previously on direct testosterone supplementation) and Arimidex (anastrozole) pills that prevent the breakdown of testosterone in the body (primary used for obese men). These medications may be added to Clomid for increased effect.
The FDA has warning labels on testosterone products including the possibility of increased cardiovascular risk and dependency. In terms of cardiovascular risk, the controversy started after the publication of several articles demonstrating increased cardiovascular risk. The statistical validity of those studies has been extensively questioned. Other literature supports a protective effect of testosterone supplementation by reducing the risk of obesity, insulin resistance, heart attacks and overall mortality. In terms of dependency, men typically return to within 10% of their baseline testosterone level by 6 months following cessation of testosterone supplementation. Various treatment patterns can be used to reduce the risk of dependency and to restart testicular production if required. However there is a possibility, though extremely small, that testosterone supplementation would be required for life.
Some perceptions of specific risks of testosterone supplementation are inaccurate. In terms of prostate cancer risk, there is no evidence to support an association between testosterone supplementation and prostate cancer risk. Furthermore, guidelines support the use of testosterone supplementation in men previously treated for low- or intermediate-risk prostate cancer without signs of recurrence. Additionally, there is no evidence to support testosterone supplementation worsening urinary symptoms or sleep apnea.