Low Testosterone (Hypogonadism)
Hypogonadism (Low testosterone or Low T) is a medical term for a defect of the gonads that results in the underproduction of testosterone. The gonads (ovaries or testes) have two functions: produce hormones (testosterone, estradiol, antimullerian hormone, progesterone, inhibin B, activin) and produce gametes (eggs or sperm).
Late-onset hypogonadism (LOH), Andropause or Androgen Decline in the Aging Male (ADAM), is a syndrome caused by a decline in gonadal production of testosterone in males that occurs with aging. This "male menopause" can also cause hypogonadism. However, it occurs for certain men and not for the others.
Hypogonadism in men over 45 is often overlooked, as free testosterone levels drop by a little over 1% a year as men age. Since many of the individual symptoms initially appear minor, men often ignore their symptoms or attribute them to getting old. In 2006 a large 2,000 man study concluded that 38.7% had hypogonadism.
Effects of low testosterone in men may include: (not all are present in any single individual)
- Poor libido (Low sexual desire)
- Fatigue (medical) always tired
- Muscle loss/atrophy
- Erectile Dysfunction
- Increasing abdominal fat
- Glucose intolerance (early diabetes)
- High Cholesterol/Lipid
- Poor sleep
- Difficulty concentrating
- Memory Loss-difficulty in choosing words in language
- Psychological and relationship problems
- Increase size of chest
- Hot flushes
- Decrease in growth of, or loss of, beard and body hair
- Loss of bone mass (osteoporosis)
- Shrinking of the testicles
- Decrease in firmness of testicles
- Frequent urination (polyuria) without infection/waking at night to urinate
- Achy muscles
- Night sweats
- Dry Skin and/or cracking nails
Effects of low estrogen levels in women may include: (not all are present in any individual)
- Hot flashes
- Poor libido
- Loss of, or failure to develop, Menstruation
- Loss of body hair
- Loss of bone mass (osteoporosis)
- Heart disease
- Sleep disturbances
- Symptoms of urinary bladder discomfort like frequency, urgency, frequent infections, lack of lubrication, discharge
- Shrinking of breasts
- loss of or non existent sense of smell
Low Testosterone can be identified through a simple blood test performed by a laboratory, ordered by a physician. This test is typically ordered in the morning hours, when levels are highest, but even in men over 60 levels can drop by as much as 13% during the day.
Normal total testosterone levels range from 300 – 1000ng/dl
Treatment is often prescribed for total testosterone levels below 350 ng/dl If the serum total testosterone level is between 230 and 350 ng/dl, repeating the measurement of total testosterone with sex hormone-binding globulin (SHBG) to calculate free testosterone or free testosterone by equilibrium dialysis may be helpful. However, there are no widely accepted diagnosis or reference ranges for Free Testosterone or Bioavailable Testosterone due to large discrepancies in the reference ranges for these tests between different testing labs.
Total Serum Testosterone – Most widely accepted but does not account for SHBG or Albumin binding of total testosterone. The better test would be to get a Total and Free Testosterone, as the diagnosis and treatment with just the total testosterone only would be undesirable.
Free Testosterone by Clinical Pathology Laboratories – Most accurate test available
Free Testosterone by RIA – Least Accurate
Free Testosterone by Saliva Test – Results cannot be compared to other testing methods
Calculated Free Testosterone – An estimation of free testosterone, calculated using SHBG and Total Testosterone
Free Androgen Index – A simple ratio of Total Testosterone to SHBG, no longer widely used.
Similar to men, the LH and FSH will be used, particularly in women who believe they are in menopause. These levels change during a woman's normal menstrual cycle, so the history of having ceased menstruation coupled with high levels aids the diagnosis of being menopausal. Commonly, the post-menopausal woman is not called hypogonadal
Hypogonadism is often discovered during evaluation of delayed puberty, but ordinary delay, which eventually results in normal pubertal development, wherein reproductive function is termed constitutional delay. It may be discovered during an infertility evaluation in either men or women.
Male hypogonadism is most often treated with testosterone replacement therapy (TRT). Commonly-used testosterone replacement therapies include transdermal (through the skin) using a patch or gel, injections, or pellets. Oral testosterone is no longer used in the U.S. because it is broken down in the liver and rendered inactive. Like many hormonal therapies, changes take place over time. It may take as long as 2-3 months at optimum level to reduce the symptoms, particularly the wordfinding and cognitive dysfunction. Testosterone levels in the blood should be evaluated to ensure the increase is adequate. Levels between 500-700 ng/l are considered adequate for young, healthy men from 20 to 40 years of age, but the lower edge of the normal range is poorly defined and single testosterone levels alone cannot be used to make the diagnosis. Modern treatment may start with 200mg intramuscular testosterone, repeated every 10-14 days. Getting a blood level of testosterone on the 13th day will give a "trough" level, assisting the physician in deciding whether the correct dose is being given.
Recently some have reported using Arimidex, an aromatase inhibitor used in women for breast cancer, to decrease conversion of testosterone to estrogen in men, and increase serum testosterone levels.
While historically men with prostate cancer risk were warned against testosterone therapy, that has shown to be a myth.
Other side effects can include an elevation of the hematocrit to levels that require blood to be withdrawn (phlebotomy) to prevent complications from it being "too thick". Another is that a man may have some growth in the size of the breasts (gynecomastia), though this is relatively rare. Finally, some physicians worry that Obstructive Sleep Apnea may worsen with testosterone therapy, and should be monitored.
Another feasible treatment alternative is human chorionic gonadotropin (hCG).
For both men and women, an alternative to testosterone replacement is Clomifene treatment which can stimulate the body to naturally increase hormone levels while avoiding infertility and other side effects as a consequence of direct hormone replacement therapy.
For women, estradiol and progesterone are replaced. Some types of fertility defects can be treated, others cannot. Some physicians will also give testosterone to women, mainly to increase libido.