The New England Journal of Medicine
October 14, 1999 "Growth
Hormone Therapy in Adults and Children"
by Mary Lee Vance, M.D. and Nelly Mauras, M.D. Abstract of
Review Article
Note: The review article represents the most current,
authoritative medical information on the subject
of growth hormone therapy
in children and adults. This abstract, verbatim excerpts from the
original
article, will concentrate
on growth hormone therapy in adults only. Parties interested in
growth hormone
therapy in children are
requested to read the original article in its entirety.
The goals of growth hormone therapy in adults is to restore
normal body composition, improve muscle
and cardiac function,
normalize serum lipid concentrations, and improve the quality of
life.
Clinical Manifestations
There is evidence that
growth hormone deficiency in adults is deleterious, increasing the
risk of death
from cardiovascular
disease. As compared with age- and sex-matched normal subjects,
adults with
growth hormone deficiency
have increased fat mass, reduced muscle mass and strength, smaller
hearts and
lower cardiac output, lower bone density, and higher serum lipid
concentrations. They also have
decreased vitality,
energy, and physical mobility; emotional lability; feelings of
social isolation; and
disturbances in sexual
function, despite adequate correction of hormonal deficiencies other
than growth
hormone deficiency.
Response to Growth Hormone
Among 125 adults treated
with placebo or growth hormone for 12 months, the growth
hormone-treated
patients had significant
improvements in scores on standard psychological tests of energy,
emotional
reactions to stress, and
social isolation, so that their scores were similar to those of
normal subjects. A
possible explanation for
the improvement in energy is that the changes in the metabolic rate
and in
muscle and fat mass
allowed the patients to become more physically active, but a direct
effect of growth
hormone on the brain
cannot be ruled out.
Side Effects
The most common side
effects of growth hormone treatment in adults are edema and
arthralgia or
myalgia. These effects are
dose-dependent. The daily dose of growth hormone used in these
trials ranged
from 6 to 26 micrograms
per kilogram, with dose reductions of 25 to 50 percent if side
effects developed
or if the serum
concentration of insulin-like growth factor I increased above
normal. In most patients,
these effects resolved
with a reduction in the dose. There is no present evidence that
growth hormone
replacement therapy
affects the risk of cancer or cardiovascular disease.
Conclusions
Growth hormone therapy is
beneficial in adults primarily as replacement therapy. Other uses of
growth
hormone are under
investigation, and the results of these studies will probably show
additional benefits.