Male patients produce a sex hormone called testosterone. Women produce the sex hormone estrogen. It is well known that women go through menopause and quit making estrogen setting off a chain of events from hot flashes to irritability. Men go through something similar although it is much subtler in onset. Until recently, the clinical picture of andropause or Low T was poorly defined. It is now estimated that about 2.4 million men between the ages of 40-49 years have low testosterone. About 40% of men above the age or 45 years have low testosterone according to the most recent estimates.
Testosterone is produced in the testis under the influence of luteinizing hormone or LH. It then feeds back to the level of the hypothalamus to regulate gonadotropin hormone releasing hormone (GnRH), which in turn stimulates the pituitary gland to secrete LH and FSH. About 6 bursts of testosterone a day are released. Usually, there is a morning high testosterone level and an evening low testosterone level. Only 1-2% of testosterone circulates as free testosterone. The remainder is bound to albumin or sex hormone binding globulin. The normal blood levels vary widely and range from 350 to 1,198. Usually, the higher levels are in younger patients. The free testosterone is 1-3% of the total testosterone.
The symptom most men associate with Low T is erectile dysfunction or ED.
There are, however, multiple more physiologic effects of low testosterone.The whole complex is much broader in scope. Other symptoms may include the following:
- Fatigue is the feeling of low energy requiring a change in lifestyle, a new onset of a sedentary lifestyle. Sedentary lifestyle may lead to an increased risk of diabetes, new or worsening hypertension, and an increase in cardiovascular conditions.
- A decrease in strength or stamina either at work or in sports may occur.
- Loss of muscle mass and an increase in fat are associated with Low T.
- Decline in memory (cognitive dysfunction) is associated with Low T.
- Onset or increase in clinical depression (mood alteration) may be a sign of Low T.
- Low T leads to loss of bone mass or osteoporosis.
- Loss of bone marrow stimulation leading to anemia may be found.
- Low testosterone was once thought to increase the risk of coronary artery disease due to increases in cholesterol. This may have been true of oral Methyltestosterone. This drug is no longer used in the USA. More recent studies suggest that there is actually a decrease in LDL, low-density cholesterol or bad cholesterol. Triglyceride levels may also decrease. There is an increase in high-density or HDL good cholesterol.
- Type 2 Diabetes and Low T appear to be linked with type 2 diabetics having double the risk of Low T over non diabetic men. About 33-50% of type 2 diabetes patients will have Low T. Type 1 diabetics do not have such an association. Type 1 diabetes patients do not lack insulin; they just develop insulin resistance. Type 2 diabetics may have a lack of insulin and testosterone production.
- Obesity is associated with low levels of free testosterone. As the BMI (Body Mass Index) increases, the free testosterone decreases. Free testosterone is the most active form of circulating male hormone. This decrease in free testosterone appears to be reversible with weight loss.
- Testosterone promotes muscle growth and a decrease in adipose or fat cell growth. Adipose tissue may convert some of the pre-testosterone blood factors into estrogen, which may counteract the testosterone. There may be an increase in breast enlargement and tenderness if this occurs.
Why do I have Low T?
Just as women go through menopause at different ages, there is no set age for onset of Low T. Low testosterone just happens as a part of aging. It is, however, found in men as young as their late 20s, so not all Low T is age related. Diabetics, especially insulin dependent diabetics, have an increase risk of having low testosterone. Chronic pain, requiring daily narcotics, frequently results in low testosterone. Chronic use of anabolic steroids, as used by athletes and body builders, leads to low testosterone when these high dose supplements are stopped.
Is there treatment for Low T?
Yes, there are several treatments available. While there are no pills available that are safe for long-term use, there are intramuscular injections, topical gels, subcutaneous pellets, and transdermal skin patches that work well.
- The Testosterone Cypionate or ethanate shots are given into the muscle of the thigh or buttock anywhere from every 7, 10, or 14 days. Blood levels should be drawn to see if your particular dose and schedule are right for you. A peak level is drawn 48 to 72 hours after injection. A trough level is drawn the day before the next injection. These 2 levels will tell if your dose and time schedule is right for you.
- The daily gels most closely mimic the normal daily cycle of testosterone production in a man. Multiple brands exist such as AndroGel, Testim, Fortesta, and Axiron. The usual doses are between 2.5gms-10gms of gel per day. All but Testim are dispensed from a metered dose pump. Testim is prepackaged in 5gram tubes. Your insurance usually dictates the doctor’s initial choice of gels. Most of these medications reach steady states in the blood stream in about 2 weeks. A blood level can be drawn to see if your daily dose is correct for you. These medications are applied to the skin of the shoulders, abdomen, thighs, or under arms. They must be applied daily to maintain a steady level.
- Daily patches are available under the brand name Androderm and produce daily levels similar to the gels but may take 30 days to reach a steady blood level. The patches may be applied to any non hair-bearing place on the body.
Striant is a twice daily, buccal, mucosal patch placed in the mouth on the gums. The testosterone is then absorbed through the gums into the blood stream.
- Testopel is a commercially available testosterone pellet. The pellets are placed under the skin through a small, 5mm, incision. They must be replenished every 4-6 months. This treatment requires no daily medication. Usually these are placed under the skin in the doctor’s office. The usual dose ranges from 5-10 pellets.
Benefits of Testosterone Replacement
Most men will experience a feeling of being younger or having more energy. There is a return of normal sex drive or libido. This includes better physical strength and stamina. Better memory, a sense of well being, and a decrease in depression have been observed. It does not always lead to better erections, but it can improve ED. Better quality of erection may occur.
Risks of Testosterone Replacement
As with all things in life, replacement is a calculated risk that the medicine will have a beneficial effect and not a hazardous effect.
- Replacement can cause an increase in red blood cell counts causing thickening of the blood resulting in heart attack, stroke, and blood clots. This is easily monitored by a blood test, the CBC, or complete blood count.
- If the man has benign prostate enlargement, testosterone replacement may cause some enlargement of the prostate resulting in a slowing of the urinary stream requiring treatment of the prostatic enlargement or BPH.
- It has been proposed that long-term use of testosterone will cause prostate cancer. Other studies show that very low and very high levels of testosterone can lead to prostate cancer. Therefore, a normal level is preferred. Simple monitoring of the PSA blood tests and annual digital rectal exams will detect cancer brought to light by the testosterone replacement therapy.
- Risk of transfer of the gels to women and children is usually easily avoided by the placement of the gel on skin covered by clothing. Simple contact precautions are advised. The peak absorption of most of the gels is at 4-6 hours after application. At that point, if the gel is washed off, you have still received 80-90% of your medication. Washing it off gets rid of the risk of transfer. While this is not routinely required, it may be useful in certain situations where close contact is anticipated.
- There have been reports of new onset of sleep apnea with initiation of testosterone replacement therapy. Ask your partner if you snore and/or quit breathing during your sleep. If you do, this needs to be addressed prior to starting any testosterone replacement therapy.
- There are some reported cases of breast enlargement and of new onset of breast tenderness in men beginning testosterone replacement therapy.
Should these conditions occur, tell your doctor. Men do occasionally develop breast cancer, and the therapy may have brought this to your attention.
Feel free to ask your urologist to explain these benefits and risks in greater detail if you have questions.