Male hypogonadism, also known as testosterone deficiency, is a failure of the testes to produce the male sex hormone testosterone, sperm, or both.
This condition can be due to a testicular disorder or the result of a disease process involving the hypothalamus and pituitary gland.
Hypogonadism can have adverse effects on many organ functions as well as negatively influence a male's quality of life. The signs and symptoms of male hypogonadism depend upon the age of onset, the severity of the testosterone deficiency and whether or not there is a decrease in the major functions of the testes.
Because testosterone plays such an important role in a male's reproductive and overall health, any symptoms suggestive of hypogonadism should be discussed with and evaluated by a medical provider.
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Here are some key points about male hypogonadism. More detail and supporting information is in the main article.
- Hypogonadism may occur at any age, and consequences differ according to the age at onset
- If hypogonadism occurs in an infant before birth, sexual ambiguity may result
- If hypogonadism occurs before puberty, puberty does not progress; if it occurs after puberty, hypogonadism can result in infertility and sexual dysfunction
- Males with hypogonadism are at increased risk of bone fractures
- About 50% of men older than 80 years of age have subnormal testosterone levels
- Nearly 50% of older males with low testosterone have no symptoms
- In adult men, symptoms begin within a few weeks of the onset of testosterone deficiency
- A 500% increase in the sales of testosterone formulations in the US has been reported in recent years
- Testosterone blood levels are at their highest in the morning, and in the late summer and early autumn
- Hypogonadism has been shown to increase the risk for cardiovascular disease, type 2 diabetes, metabolic syndrome, premature death in elderly men and Alzheimer's disease.
Causes of male hypogonadism
Hypogonadism in a male refers to a decrease in either or both of the two major functions of the testes: sperm production and testosterone production. There are several causes for this condition.
Primary male hypogonadism is caused by testicular dysfunction that can be congenital or develop later in life.
In primary hypogonadism, the testicles do not respond to hormone stimulation. This can be due to a congenital disorder such as Klinefelter's syndrome, or acquired as a result of radiation treatment, chemotherapy, mumps, tumors or trauma to the testes.
In secondary hypogonadism, a disease state interferes with either the hypothalamus or pituitary gland, the main glands that release hormones to stimulate the testes to produce testosterone.
Situations that can cause secondary hypogonadism include:
- Systemic illness
- Medication side effects
- Liver cirrhosis
- Toxins (alcohol and heavy metals)
- Morbid obesity.
Finally, the term andropause is sometimes used to describe decreased testosterone due to the normal aging process. Testosterone levels in males increase until the age of 17 years. Then, starting at approximately 40 years of age, testosterone levels begin to decline at 1.2-2% per year.
Symptoms of male hypogonadism
Because testosterone affects many tissues, the lack of testosterone can cause many different symptoms.
Symptoms depend on the age of onset, amount of testosterone deficiency and how long the loss has been occurring for. Adolescents and young adults who have not yet completed puberty appear younger than their chronological age. They may also present with small genitalia, a lack of facial hair, failure of the voice to deepen and have difficulty gaining muscle mass in spite of exercise.
Symptoms of puberty-onset hypogonadism:
- Impaired sexual development
- Decreased testicular size
- Enlarged breasts (gynecomastia).
Symptoms of adult-onset hypogonadism:
When hypogonadism develops in adulthood, erectile dysfunction can be a prominent symptom in males.
- Erectile dysfunction
- Low sperm count
- Depressed mood
- Decreased libido
- Sleep disturbances
- Decreased muscle mass and strength
- Loss of body hair (pubic, axillary, facial)
- Osteoporosis and decreased bone mineral density
- Increased body fat
- Breast discomfort and enlargement
- Hot flashes
- Poor concentration and decreased energy.
Risk factors for developing hypogonadism include type 2 diabetes, obesity, renal failure, HIV, hypertension, chronic obstructive pulmonary disease (COPD) and taking glucocorticoid (steroids), opioid or antipsychotic medication therapy.
Tests and diagnosis of hypogonadism
The American Association of Clinical Endocrinologists (AACE) and other national and international medical societies and associations have similar published clinical practice guidelines for diagnosing, treating and monitoring hypogonadism.
An individual at risk of, or who has any of the signs and symptoms of hypogonadism should have a thorough medical history taken and undergo a physical examination, including necessary blood work.
A clinician does not make the diagnosis of male hypogonadism solely based on signs and symptoms, but must also have the results of two key laboratory drawn blood tests:
- Serum total
- Free testosterone.
The normal range of these blood tests has some variability, but most clinicians consider a reading between 300-1,000 nanograms per deciliter (ng/dL) as normal. These tests are decreased (below normal range) in people with hypogonadism.
For accuracy, the blood test should be drawn between the hours of 7 and 11 am on at least two occasions. Additional testing may be necessary to make the diagnosis of hypogonadism.
Treatment for hypogonadism
Testosterone replacement therapy can improve mood and overall quality of life in males with hypogonadism.
Testosterone replacement therapy (TRT) - most commonly administered as a topical gel, transdermal patch or by injection - is the recommended treatment for male hypogonadism. Oral forms of testosterone are not used due to the high risk of side effects such as upset stomach.
The risks associated with TRT are few, and in theory, some of the primary concerns are worsening of benign prostatic hyperplasia (BPH), acceleration of pre-existing prostate cancer and worsening of both sleep apnea and congestive heart failure. TRT should not be started without first attending to these conditions.
All males on TRT require ongoing medical evaluation to determine adequate response to treatment. Such evaluation will include regular blood work and periodic digital rectal exams.
TRT is contraindicated in men with erythrocytosis (high volume percentage of red blood cells in the blood).
Patients can also improve testosterone levels with lifestyle changes, including:
- Losing weight
- Managing stress
- Getting adequate sleep
- Avoiding alcohol
- Giving up smoking.
All of the lifestyle measures mentioned above can help toward maintaining normal testosterone levels.
There are many benefits to TRT, starting with the elimination of many - if not all - of the signs and symptoms of the male hypogonadism.
Benefits of testosterone replacement therapy include:
- Increased libido
- Mood improvement
- Increased bone mineral density
- Overall improved quality of life.
The response to TRT is individualized, and testosterone levels are not an indicator of who will respond to TRT and who will not. It is also worth noting that while testosterone replacement therapy can relieve symptoms of hypogonadism, it does not restore fertility.
Although male hypogonadism is becoming increasingly recognized, a large number of adult men who have the condition remain undiagnosed and untreated. Undiagnosed hypogonadism may negatively influence not only the quality of life in men but also their life span.
Any male who has symptoms of low testosterone should follow up with a health care provider. Most of the symptoms and risks of male hypogonadism are reversed by TRT. However, before starting treatment, all men should discuss the risks and benefits of TRT with their health care provider.
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