Androgen deficiency is when the body has lower levels of male sex hormones, particularly testosterone, than is needed for health. This deficiency may be caused by problems in the areas of the brain that control the function of the testes (pituitary gland and hypothalamus), or by problems in the testes themselves. Treatment involves testosterone replacement therapy.
Androgen deficiency in older men should never be called ‘male menopause’ because it is not caused by a sudden drop in sex hormone production, as experienced by women. Men experience a modest and gradual drop in sex hormone levels over a longer period of time, from the age of about 30.
Androgens are sex hormones
Hormones can be thought of as chemical messengers. They communicate with tissues in the body to bring about many different changes.
Androgens are the group of sex hormones that give men their ‘male’ characteristics. They are crucial for male sexual and reproductive function. They are also responsible for the development of secondary sexual characteristics in men, including facial and body hair growth, and bone and muscle development.
The major sex hormone in men is testosterone, which is produced mainly in the testes. The pituitary gland is a small gland that controls the testes and is located in the brain.
The pituitary gland regulates the testes via two hormones – luteinising hormone and follicle-stimulating hormone – which are also known as the gonadotrophins. The pituitary gland is under the control of a nearby area of the brain called the hypothalamus.
The major androgen is testosterone. Some of the functions of testosterone in the male body include:
- starting and completing the process of puberty
- bone and muscle development
- growth of body hair, including facial hair
- change of vocal cords to produce the adult male voice
- sex drive (libido) and sexual function
- prostate gland growth and function
- sperm production.
Effects of androgen deficiency
Androgens have many effects on the body, not just on sexual function, but on other tissues such as muscle and bone. The term androgen deficiency means your body is not making adequate amount of androgens, particularly testosterone, for full health. The effects of this depend on how severe the deficiency is, its cause and the age at which the deficiency begins.
Symptoms of androgen deficiency
When there is not enough testosterone circulating in the body, it can cause a wide range of symptoms. However, a number of these symptoms may be non-specific and can mimic the symptoms of other diseases and conditions.
Some of the symptoms of androgen deficiency include:
- reduced sexual desire
- hot flushes and sweating
- breast development (gynaecomastia)
- lethargy and fatigue
- reduced muscle mass and strength
- increased body fat, particularly around the abdomen
- weaker erections and orgasms
- reduced amount of ejaculate
- loss of body hair
- reduced bone mass, therefore increased risk of osteoporosis.
Androgen deficiency in older men
Testosterone levels gradually decline after the age of about 30. A number of factors may contribute to a fall in testosterone, in addition to the ageing process itself. For example, any cause of poor general health, including obesity, will lower testosterone. Recent research suggests that testosterone levels may not drop at all in very healthy older men.
The impact of the fall in testosterone levels in older men is still not completely understood. There has been much media coverage of ‘andropause’ or ‘male menopause’, suggesting that many older men would benefit from testosterone treatment. However, there is little evidence to suggest benefit and the risks are not clear.
It is essential that careful diagnosis of androgen deficiency is undertaken before starting any such treatment. A full health assessment should be performed and testosterone levels should clearly have been shown to be low. Often, there are other causes of symptoms that should be treated first, which may render testosterone therapy unnecessary.
The effect of lower testosterone levels with increasing age and the effects of testosterone replacement therapy in men are currently being studied, including possible risks such as prostate cancer. Of concern are several recent studies suggesting a rise in cardiovascular disease after commencement of testosterone therapy in older men, but this remains controversial.
Androgen deficiency in boys
Boys who have not completed puberty should only be treated by paediatric hormone specialists (paediatric endocrinologists).
Causes of androgen deficiency
Some of the causes of androgen deficiency include:
- Testes – medical problems that affect the testes can prevent sufficient testosterone production. Some of these conditions are present from birth (for example, Klinefelter’s syndrome, a genetic disorder where there is an extra sex chromosome in the body’s cells). Other conditions may occur at various stages of a boy’s or a man’s life, such as undescended testes, loss of testes due to trauma or ‘twisting off’ of the blood supply (torsion), complications following mumps, and the side effects of chemotherapy or radiotherapy.
- Pituitary gland – the most common condition that affects the pituitary gland and leads to low testosterone levels is the presence of a benign tumour (adenoma). The tumour may interfere with the function of the pituitary gland, or it may produce a hormone that stops the production of the gonadotrophins, the hormones needed to signal the testes to produce testosterone.
- Hypothalamus – particular conditions, such as tumours or congenital abnormalities, can prevent the hypothalamus from prompting the pituitary gland to release hormones. This will inhibit testosterone production by the testes. This is a rare cause of androgen deficiency.
Diagnosis of androgen deficiency
- Androgen deficiency is diagnosed using a number of assessments, including:
- Medical history – a full history is taken, including details about fertility, sexual function, symptoms of androgen deficiency, other medical problems, occupation, medication and drug use (prescribed and non-prescribed).
- Physical examination – a thorough general examination is performed, including measuring the size of the testicles and checking for breast development.
- Blood tests – are taken to determine the level of testosterone in the blood. Ideally, a blood test should be taken in the morning to detect the body’s peak release of testosterone. Testosterone levels should be measured on two separate mornings. The pituitary hormone levels should also be measured.
- Other tests – may be required to determine if testosterone deficiency is due to another underlying medical condition. This may include blood tests to check for iron levels, genetic tests (to diagnose, for example, Klinefelter’s syndrome), or CT scans of the brain (to examine the pituitary gland). Semen analysis will help to determine the potential fertility of men with androgen deficiency.
Treatment of androgen deficiency
Treatment for proven androgen deficiency is based on testosterone replacement therapy. Testosterone can be administered by capsule or tablet, skin patch, gel or cream, or injection (short- or long-acting).
If the cause of testosterone deficiency is located in the pituitary gland, it may be appropriate to directly replace the luteinising hormone and follicle-stimulating hormone via injections. This is done for men whose partners wish to become pregnant.
Men who receive testosterone replacement therapy will have regular reviews with their doctor. Prostate examinations are performed according to a man’s age and other risk factors for prostate cancer.
Older men need to be checked for prostate cancer before testosterone therapy can be started, because increased levels of testosterone could make unrecognised prostate cancer grow.
Side effects of treatment of androgen deficiency
Once testosterone levels are restored to the normal range, side effects of testosterone replacement therapy are not common. Some of the possible side effects include:
- weight gain
- mild acne
- mood changes and increased aggression
- male pattern baldness
- breast development
- problems with urine flow (older men).
Where to get help
- Your doctor
- Andrology Australia Tel. 1300 303 878
Things to remember
- Androgens (including testosterone) are the hormones that give men their ‘male’ characteristics.
- Androgen deficiency means the body has had lower levels of male sex hormones, particularly testosterone, than is needed for health.
- Causes of androgen deficiency include problems and conditions of the testes, pituitary gland and hypothalamus.
- Androgen deficiency is treated with testosterone replacement therapy.
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