TUESDAY, April 27, 2004 (HealthDayNews) -- Small doses of testosterone may give infected women more muscle -- literally -- in their fight against HIV/AIDS, researchers report.
About a quarter of the estimated 300,000 women infected with HIV in the United States suffer from muscle wasting related to infection with the virus. Testosterone replacement therapy has long been standard treatment for HIV-positive men, and now a new study finds that "replacing testosterone, the male hormone, improves muscle function in female patients" too, said lead researcher Dr. Steven Grinspoon of Massachusetts General Hospital.
The study appears in the April 26 issue of Archives of Internal Medicine.
HIV has long been associated with declines in muscle mass. "It's quite common in HIV-infected patients. In fact, in some of the initial descriptions of HIV disease in Africa, it was called 'Slim disease'," Grinspoon said.
Even among HIV patients treated with powerful antiretroviral drugs, muscle strength declines, on average, by one third the level found in healthy individuals.
"It affects your daily living," Grinspoon said. "There are people who report a lot of pain, trouble with daily activities. Life is just harder when you're weaker."
While the exact causes of this slimming remain unknown, experts believe it may be linked to lowered levels of testosterone seen in HIV-positive patients. While testosterone is known as the "male hormone," it is also found in women at levels about 10 percent of those seen in males, he said.
Research conducted in the 1990s confirmed that testosterone-replacement therapy helps men infected with HIV regain lost muscle mass. The treatment has since become standard therapy for many male patients.
"Now we've made the same observation for women," Grinspoon said.
In the study, 29 HIV-positive women with significant weight loss wore a special testosterone-emitting skin patch for six months, while another 28 infected women wore a non-medicated placebo patch. All of the women were on standard HIV-suppressing drugs throughout the study period.
According to the researchers, women on the testosterone patch experienced a rise in blood levels of testosterone back to normal levels, as well as moderate increases in both muscle mass and strength. No such change was seen in women placed on the placebo.
There were also few side effects linked to testosterone-replacement therapy, the researchers said, probably because the women received only enough hormone to replace what they had lost due to their infection with HIV.
"It's not taking a sledgehammer and giving everyone high-dose testosterone," Grinspoon explained. "It's just a nice physiologic quantity that simply brings up the level to what's seen normally in women."
Dr. Beverly Alston Smith, a medical officer at the U.S. National Institute of Allergy and Infectious Diseases' division of AIDS, called the study "well designed."
She also said it was "critical" that research into testosterone therapy for HIV-positive women continue because "disease processes, treatment responses, toxicities and tolerability may differ by gender."
Grinspoon agreed. Providing women with testosterone is more complicated than providing it to men, he said, and testosterone-replacement therapy has not yet received Food and Drug Administration approval for use in female patients.
"The whole issue of testosterone for women is in its infancy," Grinspoon explained. "You can give a man testosterone, and it'll just make him more manly. If you give a woman too much testosterone you'll make her less 'womanly.' "
In pregnant women, especially, excess testosterone can trigger masculine traits in a female fetus, he pointed out.
Still, Grinspoon hopes that a prescription-only, small-dose patch like that used in the study might soon be available.
He also believes testosterone replacement might be of benefit to a much wider range of female patients, not just those with HIV.
"In any kind of severe chronic illness, there's often muscle wasting, testosterone levels are low and replacement can increase muscle mass and function" Grinspoon said. "There have also been some studies showing that patients in rehabilitation homes rehabilitate faster if they're receiving testosterone."
For more on the prevention and treatment of HIV infection, visit the National Institute of Allergy and Infectious Diseases and the Centers for Disease Control and Prevention.