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The Male Menopause or 'Andropause': Fact
or Fiction? |
Category: Practitioners
Dr Steven Soule, Senior Specialist, Endocrine-Diabetes Unit, Groote Schuur
Hospital
Introduction
The idea that the testes produce some magical substance that increases
vigour has flourished since ancient times. Galen asked in Perispermatos
‘what is it, therefore, the cause that castrates slow down in their
whole vital capacity?’ It was not long before experimentation with
hormone replacement began – Pliny, over 2000 years ago, prescribed
eating testicles to improve sexual vigour. The renowned physician Brown-Sequard
described how he reversed his own age-related problems by injecting himself
with testicular extracts. In the 1920’s a physician named Voronoff
charged up to $5000 for a chimpanzee testicular transplant, a procedure
which was popular amongst the upper social classes in Europe (although
presumably not amongst the chimps). Proponents of testicular transplants
were scathingly referred to as the ‘erector doctors’ and were
criticised by respected endocrinologists for ‘the exploitation of
the idea of rejuvenation by hormones’.
By the1940’s testosterone had been chemically manufactured and was
shown to be of clear benefit in patients with definite testicular disease
who have a dramatic reduction in circulating testosterone levels. These
patients, who suffer from severe tiredness, loss of muscle bulk and strength
and a tendency to osteoporosis, have a marked deficiency of testosterone
and it is now widely accepted that they benefit from testosterone therapy.
But is there any reason to give testosterone to normal elderly men? Is
the so-called ‘andropause’ a disease or merely an expression
of the inability of the fragile male ego to cope with the natural decline
in physical, intellectual and sexual prowess? This brief article will
examine these fascinating questions which are relevant to one half of
the world’s population.
A brief look at physiology
Testosterone, a hormone produced by the testes, has a broad range of actions.
In the mother’s womb it is responsible for the development of the
male infant’s penis, it has a role in increasing muscle and bone
strength and it also produces all the changes in the male body at puberty,
namely beard growth, acne, increased body hair and the inevitable mood
swings. However, testosterone is an essential hormone throughout life
and patients who lack the hormone (perhaps because of damage to the testes
by mumps or trauma) have many symptoms which rapidly resolve when they
are treated with testosterone.
What happens to testosterone levels with ageing? There is now convincing
evidence that there is a fall in testosterone levels as normal men age.
In fact, around two thirds of men over the age of 65 years have levels
of testosterone which are below the normal values of men aged 30-45 years.
This fall in testosterone levels occurs at a time when men may be experiencing
many features which also occur with severe testosterone deficiency. These
include a marked rise in the incidence of impotence to over 50% in men
aged 60 to 70, a tendency to become plump in the abdomen (the all too
familiar ‘middle-aged spread’), a loss of muscle tissue and
strength and an increasing tendency to develop osteoporosis and fractures.
These physical changes result in weakness, reduced mobility and balance,
and poor endurance. They also increase the risk of falls, fractures and
loss of independence; falls contribute to 40% of admissions to nursing
homes.
It is therefore particularly important to consider whether treating with
testosterone in elderly males will reduce some or all of these changes
which many of us regard as an inevitable part of the ageing process. It
is vital to appreciate that just because the fall in testosterone and
the ageing process occur at the same time does not necessarily imply that
testosterone treatment will prevent ageing – going grey may be part
and parcel of ageing, but tinting the hair doesn’t make one any
younger! The only way to answer the question as to whether testosterone
treatment is useful in elderly men with low normal levels is to perform
a well conducted clinical trial with adequate numbers of subjects, half
of whom receive testosterone and half placebo. What then are the results
of these studies?
Studies of testosterone replacement in healthy elderly men –
any good news?
Impotence
A decrease in male sexual activity with increasing age is common but many
factors are involved, including psychological (fear of failure, boredom
with partner) and physical issues (decreased penile sensation, the effect
of medications and impaired blood supply to the penis). Interestingly,
the levels of testosterone are similar in impotent elderly men when compared
with those who report normal sexual function suggesting that hormonal
changes and impotence are two unrelated issues in older men. Research
has, however, suggested that sexual interest (libido) can be increased
by testosterone supplementation, although of the ten men in one study
who had a definite improvement in sexual function only three felt that
the treatment was adequate. It thus seems as if there is a greater effect
on improving libido than performance, a potential source of frustration
in elderly men. The fact that men with testicular disease and extremely
low levels of testosterone usually have a normal erection in response
to erotic stimuli emphasises that normal levels of testosterone are certainly
not a prerequisite for a normal erection. In summary, there is scanty
evidence to support a beneficial role for testosterone in elderly men
with low normal testosterone levels and problems with erections.
Loss of muscle and gain of fat
To date, studies of the effects of testosterone therapy on muscle in older
men have enrolled generally healthy men with low normal levels of testosterone.
The aim of therapy in this group has been to assess whether raising the
testosterone level into the middle-to-upper range of normal for young
adult men might increase muscle bulk and function. One can summarise the
research by stating that, in those who received testosterone, muscle mass
increased by around 5%, while there was a variable reduction in the amount
of fat tissue. Obviously an increase in the amount of muscle is encouraging,
but is of limited value if not accompanied by an increase in strength.
The research is disappointing in this regard as, although most of the
evidence suggests there is a small increase in grip strength, there is
no work that reports an increase in function and mobility. Once again,
therefore, the evidence of benefit is disappointing and testosterone therapy
is certainly not a panacea for the middle-aged spread.
Osteoporosis
Testosterone, after being altered to oestrogen, is essential for the normal
development of the male skeleton. Males with testosterone deficiency occurring
at the time of puberty or subsequently are therefore at great risk of
osteoporosis if left untreated. The critical role of testosterone in maintaining
normal bone density has led to speculation that treating otherwise healthy
elderly osteoporotic men with testosterone would increase bone density
and prevent fractures. What is the evidence? There have been only three
studies of the effect of testosterone therapy on bone in elderly men.
Despite some evidence that testosterone has a favourable effect on the
balance between bone formation and bone resorption, there is no proven
benefit on bone density or fracture rates in these subjects. Once again,
we are left with little information to encourage the more widespread use
of testosterone in normal elderly men.
Potential problems with testosterone therapy in elderly men
– the bad news
If one is considering ‘treating’ elderly men with testosterone
it is vital to consider any potential adverse effects. Firstly, there
is a wealth of evidence that the prostate gland is exquisitely sensitive
to testosterone, whether it originates from the testes or the needle and
syringe. In fact, one of the mainstays of treatment for cancer of the
prostate is to reduce the circulating level of testosterone either by
drug therapy or by surgically removing the testes. This, together with
the knowledge that over 80% of men older than 70 years have symptoms of
an enlarged prostate, immediately makes one hesitant to use a drug which
is known to increase the size of the prostate when given to patients who
are definitely short of testosterone. These concerns about promoting prostate
cancer and prostate enlargement have dampened the enthusiasm of doctors
for prescribing testosterone to healthy elderly men.
The other major concern is the potential harmful effect of certain testosterone
preparations on the blood cholesterol levels. It is thought the women
are largely protected from heart attacks until after the menopause by
the favourable effects of oestrogen, the female hormone, on cholesterol
levels. Men, by way of contrast, do not have the protective benefits of
oestrogen. They may suffer the consequences of being awash with testosterone
which may increase the ‘bad cholesterol’ (LDL) and reduce
the ‘good cholesterol’ (HDL). There is therefore reasonable
concern that treating elderly men with testosterone may result in potentially
dangerous changes in cholesterol, although the evidence for this is flimsy
at best.
Final thoughts
The so-called andropause is a poorly defined collection of symptoms in
a group of men who may have low but also may have normal levels of testosterone.
Unlike the proven benefits of oestrogen replacement in women, the effects
of testosterone supplementation in men are questionable. It may increase
sexual interest, but rarely to a level thought adequate by the patient.
It has no proven benefit on impotence and there is increasing concern
about the impact of sustained increases in testosterone levels on the
male prostate. In short, there is no scientifically valid study that shows
any sizeable benefit for testosterone supplementation in this not uncommon
group of patients. This does not imply that further research will not
uncover groups of elderly males who may benefit substantially, perhaps
those with the lowest testosterone levels. As the elderly population increases,
our aim should be not only to extend the duration of life, but also to
ensure that any reductions in the quality of life are confined to a relatively
brief period. Investigating the hormonal changes that accompany the ageing
process may be one way of maintaining quality of life in the elderly.
Published on
2005-06-08