A way to reduce HIV fat deposits
Low doses of human growth hormone can reverse some of the abnormal fat distribution caused by HIV therapy, lowering the risk of cardiovascular disease, but the treatment may produce an unnecessary risk for those who have early stages of diabetes, researchers said Sunday.
The hormone produced good results but would have to be used carefully to avoid inducing diabetes, said Dr. Steven Grinspoon of the Harvard Medical School, lead author of the paper.
He presented the results, which will be published this week in the Journal of the American Medical Assn., at the International AIDS Conference in Mexico City.
About 40% of males and 16% of females who take cocktails of anti-AIDS drugs for their HIV infections develop fat deposits in the stomach, neck and cheeks.
Called visceral fat, it is associated with higher levels of cholesterol and triglycerides and increases the risk of heart attacks and stroke.
Such patients typically have abnormally low levels of growth hormone and researchers had hoped that replacing it with genetically engineered human growth hormone -- the same drug used to treat below-normal growth rates and that is abused in athletics -- might reverse the effects.
But previous studies using higher levels of the hormone produced unacceptable side effects, including tissue swelling and pain in the joints.
Grinspoon and his colleagues studied 56 HIV-positive patients who had deposits of fat in their stomachs and low blood levels of the hormone.
Half were given daily doses of about 0.33 milligrams of the hormone, well below the 2 to 4 milligrams used in previous studies.
Half the subjects were given a placebo.
Over the 18 months of the study, stomach fat dropped by 8.5% in the patients receiving the hormone, compared with 1.6% in those getting a placebo. The team did not study their cardiovascular risk.
Tests showed some elevation of blood sugar in those receiving the hormone, particularly those who had abnormal glucose tolerance tests at the beginning of the trial.
Grinspoon said that future clinical trials should include a diabetes drug, such as metformin, to minimize side effects.
Another study in the special AIDS-themed issue of JAMA found that rifampicin, a drug commonly used to treat tuberculosis, can interfere with the treatment of AIDS. The finding was important because about a third of the HIV-positive people in the world also have tuberculosis.
Dr. Andrew Boulle and his colleagues at the University of Cape Town in South Africa studied nearly 4,000 people who began HIV treatment between 2001 and 2006. About half received the most commonly used AIDS drug, nevirapine, and the rest received efavirenz -- both of them so-called non-nucleoside reverse transcriptase inhibitors.
About 10% of those in the nevirapine group and about half of those in the efavirenz group also had tuberculosis.
At the end of six months, 16.3% of those who received nevirapine when they were already taking rifampicin for TB had treatment failure marked by high levels of HIV in their blood, compared with 8.3% of those who did not have TB.
But rifampicin did not interfere with the efavirenz treatment, Boulle told the meeting. It also did not interfere with nevirapine if the patients contracted TB while taking the AIDS drug. The researchers do not know why the drug interferes with HIV treatment.
A third study looked at HIV treatment of injection drug abusers. Some researchers have argued that treatment provides little benefit in this group because they are not motivated to take their AIDS drugs regularly.
Dr. Julio Montaner of the University of British Columbia and his colleagues treated 3,116 patients at Canadian clinics, including 915 who abused drugs.
After an average of five years of treatment, he reported, 26% of the drug abusers had died from all causes, compared with 22% of the other AIDS patients -- a difference that was not statistically significant.
Montaner noted that the drug abusers who were prescribed AIDS drugs were just as likely to use them as those whose infections arose from other sources.
But he cautioned that the injection drug abusers were less likely to receive a prescription in the first place, so that their overall death rate would remain higher.