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.