Seniors seek
vitality in growth hormone but questions remain about safety, efficacy
By Elizabeth Weise, USA
Today
November 4,
2003
Thousands of seniors believe they've found the fountain
of youth. They say it makes them leaner and more muscular, gives them more
energy and improves their sex lives.
What is this elixir? It's human growth hormone: The
potent substance that has been the subject of a highly charged debate.
The U.S. Food and Drug Administration this summer
approved giving the synthetic hormone to healthy kids likely to become
very short adults. The ethics of that decision have been questioned by
those who fear that it's part of a quest for designer children.
But there's growing concern among health experts about
older Americans, as many as 50,000 of them a year, who are getting daily
injections of the hormone. Some researchers say this practice, for which
the users pay between $5,000 and $10,000 a year, can have serious and
potentially deadly side effects.
Other researchers are hopeful that it might keep the
elderly independent for longer.
''The goal of anti-aging medicine is to maintain our
metabolism as youthful as we can for as long as we can,'' says Ronald
Klatz, president of the American
Academy
of
Anti-Aging Medicine
.
And seniors aren't the only ones hoping for miracles:
It's a hot commodity among high-performance athletes. (But a different
thing entirely from THG, the designer steroid at the center of a
developing sports scandal.)
Don Catlin, a member of the International Olympic
Committee's Medical Commission, terms growth-hormone use ''substantial.''
The IOC, in fact, is paying scientists to find a way to
test for growth hormone use. The committee meets next spring to discuss
whether that test can be ready for the Athens Olympics next August.
Growth hormone is vital to life. Produced in the
pituitary, the body's ''master gland,'' it is called somatotropin by
scientists. Without it, embryos don't grow, children don't thrive and
adults can become fat, lethargic and depressed. Peak production is during
adolescence. The body makes less of it as the individual ages.
This summer, the FDA approved the use of synthetic
growth hormone as a treatment for children of ''extremely short stature''
-- boys likely to become adults shorter than 5-foot-3 and girls likely to
be shorter than 4-foot-11.
These children are rarely deficient in growth hormone --
their stature could be the byproduct of a host of genetic and other
factors. So some bioethicists say giving potent drugs to these healthy
kids just because they're going to be short adults is unethical.
But the extra hormone could add three to five inches in
height. The FDA concluded that being very short is such a handicap that
those extra inches could make a big difference in the quality of a life.
Growth hormone also is approved for children who aren't
growing because of illnesses such as Turner's syndrome or as a result of
kidney dialysis.
Hormone treatment is approved for adults and kids who
are deficient because of damage from pituitary tumors, surgery, radiation
treatment or trauma.
For patients who have stopped producing growth hormone
all together, replacement therapy can be a godsend. Mary Lee Vance, an
endocrinologist at the
University
of
Virginia
in
Charlottesville
, has seen it help dozens of her patients whose pituitary glands were
removed because of tumors.
The hormone is also given to AIDS patients to overcome
the muscle wasting and abnormal fat distribution caused by the potent
drugs they take.
These are all ''on label'' uses, meaning that they have
been approved by the FDA for a specific condition.
'Off-label' uses
When growth hormone is prescribed for healthy older
people, it's considered ''off-label,'' meaning that the doctor is
prescribing a drug that he or she feels will benefit the patient but it's
not for the FDA-specified condition.
Billie Russell, 79, of the
La Jolla
section of
San Diego
, started taking growth hormone shots four years ago, along with estrogen,
testosterone, thyroid hormone and vitamins and minerals
''I was not able to walk a block four years ago. Now I
can walk a mile on my treadmill. I just feel great. I have a sex drive
again. I feel like a young woman again,'' the former model says. ''Before
I started this I didn't want to get up in the morning; I wasn't interested
in going anywhere. I was just dull, like so many older women get when you
have no hormones raging through your body anymore.''
Growth hormone changed her mood and her energy. ''I give
large dinner parties, I have a garden, I canned 100 quarts of beets and
bread-and-butter pickles this year.
''It's been a miracle for me. My husband keeps saying,
'What has happened to you? Where's the old lady gone?' ''
A San Francisco-area venture capitalist, who asked not
to be identified, has been taking growth hormone for three years and says
the effects are ''subtle.'' The 51-year-old says he has had a more
positive attitude and moister, more elastic skin ''that's a little
better-looking.''
Though he doesn't expect it to make him live longer, ''I
do expect it to make me feel better during the years I have to live. I
expect when I'm 70, 80 or 90 I'll feel better than I otherwise would.''
But will he?
Forever young?
After almost a decade of research, the answer isn't
clear. One major new study compares people taking the hormone, people
exercising and people doing both.
What researchers found, says George Merriam, a professor
of medicine at the University of Washington-Seattle, is that although
growth hormone ''can resculpt your body composition, it won't get you up
out of bed.''
In other words, it can melt some abdominal fat and add
some muscle, but it didn't help subjects on the precise Continuous
Scale-Physical Function Performance test, which measures life skills using
a simulated bus stop, grocery store, kitchen and bedroom.
Only exercise clearly improved functional status,
endurance and strength, researchers found. Their one positive finding was
that while the drug alone didn't improve physical performance, it did
appear to stop it from getting worse.
''People are looking for a magic bullet,'' says
Christine Cassel, an expert on geriatric medicine and the president of the
American Board of Internal Medicine. ''The message that the key to
vigorous old age is activity -- physical, mental and social -- just isn't
one our society wants to hear.''
Merriam doesn't think growth hormone is ready for prime
time.
''My parents are in their 90s, and I have not
recommended it. It's not the sort of thing where you feel you know enough
about the benefits (to know) that it's worth the high price tag,'' he
says.
And that price tag may be very high indeed in terms of
side effects.
Carl Grunfeld, a professor of medicine at the University
of California-San Francisco, did some of the first studies of growth
hormone in healthy older people. ''They complained a lot,'' he says.
''They got edema (swelling), aches and pains, carpal tunnel. They did not
like it.''
Of the 26 men taking growth hormone in Grunfeld's study,
22 reported one or more side effects and six had to have their doses
decreased because of those side effects. While the men studied lost
abdominal fat and gained muscle, they didn't increase their functional
ability. These side effects have shown up in at least some patients in
most research studies.
Klatz, however, is contemptuous of ''all the baloney
about these adverse side effects that just do not occur outside the
laboratory.'' He makes an exception for joint swelling, which he says
disappears when the dose is reduced.
''Our patients and all of the legitimate study patients
were outpatients, at home under their normal regimens. They were not 'in a
laboratory,' '' Grunfeld counters. ''Those on growth hormone had
significantly more symptoms than those on placebo. No ifs, ands or buts
about it.''
But those are just the obvious side effects. There's
also evidence that in older people, high doses can affect blood pressure
and blood sugar and perhaps cause diabetes. Children do not appear
vulnerable to these ailments.
And then there's cancer. While research has tended to
show that use of growth hormone doesn't cause new cancers, the jury's
still out on whether it might cause tiny, hidden cancers to grow into
something dangerous. One recent British study found an increase in cancer
while two others did not.
An 'enormous' potential
But not all researchers are against giving the elderly
growth hormone. Proponents see it as a way to mitigate the effects of
aging, and there are people who report no side effects.
''The next big market to be explored is the treatment of
frailty,'' says Peter Sonksen, professor emeritus of endocrinology at
King's College London School of Medicine. ''If it keeps people a bit less
frail and a bit more independent for a bit longer, there's an enormous
potential.''
Though athletes may take high doses, older people tend
to be on lower -- and cheaper -- regimes. The drug comes either as a
liquid or a powder that's mixed with sterile water. Most formulations
require refrigeration and all are injected just under the skin, typically
in the abdomen. Because our bodies produce most growth hormone at night,
patients usually inject themselves before bedtime.
And it's all perfectly safe, Klatz says. ''If this was a
dangerous substance you'd be hearing about it. Not from some ivory tower
guy, but from the Centers for Disease Control, who would be reporting on
all the adverse side effects reported to them from the emergency rooms.''
In children, those problems might not have had enough
time to surface, cautions Selna Kaplan, a pediatric endocrinologist at the
University of California-San Francisco who was one of the pioneering
growth hormone researchers.
Growth hormone wasn't given to children in numbers big
enough to study until 1985, when the synthetic version was first released.
Even the oldest patients are only in early adulthood. There's no way to
know what will happen to them in their 40s, 50s and 60s.
''All we can say is that at the moment it doesn't seem
to have any adverse effects,'' Kaplan says.
As for adults, it has been hypothesized that the decline
in growth hormone with age actually protects against age-related cancers
such as prostate and breast cancer. Perhaps by lowering growth hormone
levels, the body is working to slow down the growth of those cancers, says
Mark Blackman, an expert on neuroendocrinology and aging.
Researchers don't yet know, Blackman says, but it's
something they're thinking about.
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