bei gesunden älteren Männern wirkungslos ?
Dr. med. Jochen Kubitschek
in den USA erhielten im Jahr 2002 rund 800.000 Männer - oft
auf deren ausdrücklichen Wunsch - von ihren Ärzten das
männliche Sexualhormon Testosteron verordnet - meist in Form
von Testosteron-Gel. Jetzt legte eine hochrangige Untersuchergruppe
die Resultate einer kritischen Durchleuchtung der vorliegenden
wissenschaftlichen Beweise für die Wirksamkeit der Therapie
Gegensatz zu den aggressiv vorgetragenen Werbeaussagen der Produzenten
von Testosteron-Präparaten konnten die unabhängigen
Wissenschaftler bei ansonsten gesunden Männern im fortgeschrittenen
Lebensalter keinerlei Hinweise auf eine Wirkung der Therapie mit
Testosteron finden. Damit wird die These bestätigt, dass
Testosteron nur bei jenen Männern Anwendung finden sollte,
deren Testosteronproduktion, z.B. aufgrund der operativen Entfernung
der Hoden, völlig versiegt ist. Im Gegensatz zu den Frauen
nimmt die Hormonproduktion im Alter bei den meisten Männern
nicht nahezu automatisch ab. Wenn aber kein deutlicher Hormonmangel
vorliegt, kann die Zufuhr von zusätzlichen Sexualhormonen
keine positive Wirkung entfalten. Zumindest beim Sexualhormon
Testosteron gilt der Spruch "Viel hilft auch viel!"
Derided As a Health Supplement - Report Discourages Widespread
is no evidence that the testosterone being used by a growing number
of American men to boost their strength, mood or virility is doing
them any good despite the claims being made for the hormone, an
expert panel of doctors concluded recently.
a major report from the congressionally chartered Institute of
Medicine (IOM), the panel said testosterone is "inappropriate
for wide-scale use to prevent possible future disease or to enhance
strength or mood in otherwise healthy older men." The Food
and Drug Administration has approved its use only for men with
a particular medical condition, but many more have sought it.
was prescribed for more than 800,000 men last year, the panel
found, including many who believe it can help them build muscle,
sharpen their thinking, increase their libido and slow aging.
But the IOM panel concluded that there is insufficient research
to document these benefits in otherwise healthy men, or to gauge
the magnitude of known increased risks of prostate cancer and
men whose testosterone is already in the normal range, there is
no proof that it makes them better in any way," said panel
member Deborah Grady of the University of California at San Francisco.
"If there is no proven benefit for them, they shouldn't be
taking testosterone no matter what the risk."
women undergo a sudden decline in the female sex hormone estrogen
during menopause, most men experience a gradual tapering off in
testosterone production that begins in their forties and continues
at about 1 percent a year. That decline, sometimes referred to
as "andropause," is the subject of medical debate, with
some researchers saying it is predictable and normal and others
saying it is associated with diseases and conditions that can
be kept at bay by taking additional testosterone.
FDA has approved testosterone only for hypogonadism, a steep decline
in hormone production triggered by surgery or disease that harms
the testes or pituitary gland. But the IOM panel concluded that
a significant majority of the more than 1.75 million testosterone
prescriptions in 2002 were for men who did not have the condition.
Once the FDA has approved a drug for one condition, doctors can
legally prescribe it for any medical purpose. Such "off-label"
uses are widespread -- and sometimes controversial.
sharp increase in testosterone use since 1999 coincided with the
FDA's approval of new and easier ways to administer the drug.
Testosterone used to be given only by monthly injections, but
men can now get it as a patch or a gel. Because of the way testosterone
acts in the body, it is not given in pill form in the United States.
panel, which the National Institute on Aging and the National
Cancer Institute asked to review the issue, called for a series
of small studies to determine whether the hormone can help men
cope with some of the predictable effects of aging. It said the
studies, which have been on hold while the IOM studied the issue,
should not include younger men because they were expected to receive
less benefit for the same risks.
several points in its report, the panel referred to the dramatic
turnaround among researchers and doctors regarding the usefulness
and safety of estrogen therapy for post-menopausal women. The
hormone had been widely prescribed to reduce the physical discomforts
that can accompany menopause and to potentially improve the long-term
health of older women until a major federal study found last year
that the risks of estrogen outweigh the limited benefits. As a
result, usage has plummeted.
even as the medical consensus on estrogen was changing sharply,
men were increasingly asking doctors for testosterone. The IOM
study reported that the number of men taking it more than doubled
between 1999 and 2002, and the number of prescriptions almost
tripled. Panel Chairman Dan G. Blazer of Duke University Medical
Center said the number of men taking the drug has continued to
increase sharply, with more than 2 million prescriptions expected
of the increase has been driven by aggressive advertising, much
of which holds out the hope of the very benefits that the report
said have never been confirmed by rigorous clinical trials. On
the Web site for the market leader AndroGel, for instance, manufacturer
Solvay Pharmaceuticals asks: "Fatigued? Depressed mood? Low
sex drive? Could be your testosterone is running on empty."
Braswell, spokeswoman for Solvay, said the company is pleased
by the IOM recommendation for more study and did not quarrel with
the panel's concerns about broad testosterone use. "We believe
it is appropriate to use [AndroGel] for the conditions approved
by the FDA," she said.
said that his group was not urging doctors to stop prescribing
testosterone off-label for otherwise healthy men, but that physicians
and their patients need to "be thinking more carefully about
Hazzard, a professor at the University of Washington School of
Medicine, said the testosterone issue is becoming increasingly
important with the aging of the baby-boom generation. "We're
concerned that a population-based drive to increase testosterone
use could be trumping science at this instance," he said.
a statement, the National Institute on Aging said it would consider
conducting new studies. The statement added that "although
some older men who have tried these treatments report feeling
'more energetic' or 'younger,' testosterone therapy remains a
scientifically unproven method for preventing or relieving any
physical or psychological changes that men with normal testosterone
levels may experience as they get older."
doctors, however, said the report seems to miss the fact that
testosterone has been beneficial to many men. "There is a
disconnect between some of the conclusions and recommendations
that come out of this, and what I and other doctors see in clinical
practice," said Abraham Morgentaler, a professor at Harvard