- Introduction to testosterone deficiency
- What is testosterone deficiency in ageing men?
- Prevalence of testosterone deficiency in ageing men
- Is there such a thing as male menopause?
- Diagnosing testosterone deficiency in ageing men
- Treatment and advice for ageing males with testosterone deficiency
Testosterone deficiency is a condition in which a man has lower than normal levels of testosterone in his blood. In ageing males (those over 40 years of age) it is sometimes referred to as late-onset hypogonadism, andropause or male menopause. Testosterone deficiency in ageing men is caused by a natural reduction in testosterone production as a man ages.
Testosterone is the primary sex hormone produced by the male body. It regulates the male sex drive, supports sperm production and causes the development of secondary sex characteristics (e.g. genitals, body hair, deep voice). Testosterone is primarily produced in the interstitial cells of Leydig (or Leydig cells), which are found in the testes. Its production occurs in response to hormone signals from the hypothalamus and pituitary gland in the brain.
As a man ages beyond 40 years, testosterone production naturally decreases, at a rate of about 1% each year. Decreased testosterone production causes the levels of testosterone in the blood to decline. Testosterone production declines partly because the number of Leydig cells in the testes decline with ageing, and also appears to be related to changes in the hypothalamus and pituitary glands.
The testosterone produced in an ageing man’s body is also less efficient in performing its functions. This is because older men produce more of a hormone called sex hormone binding globulin, which binds to testosterone and reduces the amount available to fulfil its functions. Thus, while testosterone production declines by only around 1% each year, there is a 2–3% per year reduction in the amount of testosterone available to support the male sex drive and secondary sex characteristics.
Chronic illnesses (e.g. diabetes) and the medicines used to treat them also reduce testosterone levels. Elderly men are more likely to have these chronic illnesses than their younger counterparts.
The numerous challenges the male body faces in maintaining testosterone levels whilst ageing sometimes lead to testosterone deficiency.
There is no data on the number of ageing Australian men with testosterone deficiency. Data from surveys conducted in other developed countries indicate that around 20% of men aged > 50 years have either low levels of testosterone in their blood, or exhibit symptoms of testosterone deficiency (e.g. excessive breast growth, loss of facial hair, rising voice).
According to Australian guidelines, a man must have low levels of testosterone in his blood and must display symptoms of testosterone deficiency to be diagnosed with hypogonadism. When these criteria are used, it is estimated that 5% of men > 50 years of age are testosterone deficient.
There is considerable debate amongst health professionals about the criteria that should be used to define testosterone deficiency in ageing men. Some argue that clinical symptoms are important markers of testosterone deficiency, even in the absence of low blood testosterone levels. They argue that men with clinical symptoms should be eligible for testosterone replacement therapy. However, others (including the Endocrinology Society of Australia, which produces the country’s guidelines for testosterone treatment) argue that treating ageing men with naturally declining testosterone levels with testosterone replacement therapy is largely unnecessary and akin to attempting to reverse the ageing process. They argue that treatment of testosterone deficiency in these men should focus on co-existing conditions such as diabetes and obesity instead.
|For more information, see Male Hypogonadism.|
Testosterone deficiency resulting from the ageing process is sometimes compared to menopause and labelled male menopause or andropause. However, there are considerable differences between the two.
Menopause in women involves the cessation of menstrual cycles and a rapid decline in production of the female sex hormone oestrogen, compared to the gradual decline of testosterone in andropause. In addition, while menopause affects all women, testosterone decline does not affect all men. Some men will have normal testosterone values past 80 years of age.
In Australia, evidence suggests that testosterone deficiency is over-diagnosed in ageing men, and there are considerable challenges a doctor faces when attempting to make the diagnosis. The symptoms of testosterone deficiency may occur with other health conditions, and often occur in ageing men who do not have testosterone deficiency. Thus, a diagnosis cannot be made on evidence of clinical symptoms alone, and there should also be evidence of low blood testosterone levels. However, because testosterone levels reduce naturally with age and older men have naturally lower levels of testosterone than their younger counterparts, it is difficult to determine a “normal” blood testosterone level to use as a reference for diagnosing testosterone deficiency in older men.
Testosterone deficiency has a range of side effects, including:
- Loss of energy;
- Reduced libido;
- Erectile dysfunction: Testosterone deficiency may occur in up to 45% of cases of erectile dysfunction in older men;
- Joint pain;
- Mental health conditions, including impaired memory function, irritability and depression;
- Excess body fat.
Men with testosterone deficiency have an increased risk of:
- Diabetes mellitus;
- Metabolic syndrome;
- Cardiovascular disease;
- Obesity: An Australian study reported that ageing obese men were almost twice as likely to be testosterone deficient than their non-obese counterparts;
- Alzheimer’s disease;
- Excessive alcohol consumption;
- Excessive physical or psychological stress;
- Reduced life expectancy.
Testosterone deficiency in younger men (≤ 40 years) is typically treated with testosterone replacement therapy. However, there is considerable debate about whether or not testosterone replacement therapy is beneficial in ageing men (> 40 years). Scientific evidence suggests that testosterone replacement therapy in older men does not improve their bone or muscle quality, quality of life or libido. Testosterone replacement therapy is not currently recommended in ageing men.
Some men ask their doctor to prescribe testosterone replacement, for example because they have seen it advertised as a libido enhancer. A doctor will only prescribe testosterone replacement therapy for men who meet the diagnostic criteria (have both clinical symptoms and low levels of testosterone in their blood).
|For more information on testerone deficiency in men, see Testosterone Deficiency.|
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