Thursday September 6, 2001
Hormone Treats HIV Patients' Abnormal Fat Deposits
NEW YORK (Reuters Health) - Recombinant human growth hormone (GH) may become a new treatment option for people suffering from abnormal body fat distribution associated with HIV infection, according to the results of a recent pilot study.
However, further studies are needed to determine the best dose and safest GH regimen before this ``treatment can be recommended in clinical practice,'' lead investigator Dr. Joan C. Lo told Reuters Health.
Patients with this fat distribution abnormality, or lipodystrophy, experience changes in body shape such as sunken cheeks, an increase of fat in the face and around the waist, and the appearance of a fat pad on the back of the neck.
Lo, of the University of California, San Francisco, and colleagues tested the effects of 3 milligrams per day of GH in eight men with HIV-associated lipodystrophy. All received daily injections of GH on an outpatient basis for 6 months.
GH therapy decreased body fat while increasing lean body mass, the investigators report in the August issue of The Journal of Clinical Endocrinology and Metabolism. However, GH also caused a short-term impairment in glucose tolerance after 1month of treatment, which improved somewhat over the course of the study. Glucose tolerance is the ability of the body to remove glucose, or sugar, from the blood.
Moreover, patients experienced an average fourfold increase in levels of insulin-like growth factor I (IGF-I), a markedly higher increase than has been observed in prior studies of GH. IGF-I is a hormone that influences the growth and repair of muscle cells. The natural decline in the hormone--along with decreases in GH levels--as people age is believed to cause the loss of muscle mass that occurs in older people.
One patient with previously undiagnosed diabetes experienced very high blood sugar within 2 weeks of treatment, indicating a need for strict screening before GH administration.
``Because of the high IGF-I levels we observed at 3 mg/day, we do not recommend long-term GH exposure at these doses, ''Lo told Reuters Health in an interview. Despite this drawback, she believes the findings are encouraging and that further studies of GH treatment at lower doses are needed.
Until these studies are done, individuals treated with GH should be monitored closely for IGF-I levels, fasting glucose levels and glucose tolerance, Lo explained. The researchers also advise against GH treatment in HIV-infected patients with evidence of impaired glucose tolerance.
In a related editorial, Dr. Steven Grinspoon of Harvard Medical School in Boston, Massachusetts, and Dr. Marie Gelato of the State University of New York Health Sciences Center at Stony Brook agree that studies should be conducted to identify safer but effective doses of GH.
``Whether low-dose GH might actually improve insulin resistance is also an important question'' for this population of HIV-infected patients, they add. Insulin resistance occurs when the body loses its ability to respond to this hormone, which helps the body to clear sugar from the blood and use it for fuel.
Overall, the editorialists stress that the risks and benefits of GH therapy must be weighed against those of alternative treatments under investigation for HIV-associated lipodystrophy, some of which have known cardiovascular and metabolic benefits.
SOURCE: Journal of Clinical Endocrinology and Metabolism 2001;86:3478-3479, 3480-3487.