Declining testosterone in HIV-positive men may be an early signal for the dangerous weight loss that occurs when AIDS develops, according to a Johns Hopkins study.
"A drop in testosterone may be an early way to identify patients at risk for losing too much weight," says Adrian S. Dobs, M.D., lead author and associate professor of medicine. "Helping them prevent or slow weight loss may become an important new treatment for AIDS."
Results of the study, funded by the National Institutes of Health, will be presented June 12 at the International Congress of Endocrinology's annual meeting in San Francisco.
In a related study, Hopkins researchers recently found that HIV-positive men who lose too much weight before developing AIDS are at risk for earlier death than those who maintain their weight. Two other ongoing Hopkins studies are investigating whether testosterone injections and testosterone skin patches help HIV-positive men regain lean body weight, possibly increasing life span and improving their quality of life. If the studies show the hormone is effective, researchers plan to test whether testosterone given before weight loss prevents wasting.
Researchers measured testosterone, the main male sex hormone, in 26 men infected with the human immunodeficiency virus, or HIV, to determine if hormone changes preceded or were linked to wasting (the loss of enough weight to cause illness) or if the weight loss caused the decline in hormones. Half the men had lost more than 10 percent of their original weight without diarrhea and opportunistic infections, while the other half had gained weight.
Researchers found six months later that testosterone levels declined significantly in all 13 men who lost at least 10 percent of their weight, while testosterone levels stayed the same in the 13 men who gained or maintained their weight. The men losing weight also lost white blood cells, which help fight infection. In AIDS, the virus damages certain white blood cells, called T-cells, crippling the body's ability to defeat infections.
Increased risk of death due to wasting is caused in part by an increase in the body's metabolic rate, the speed with which the body burns up food. Severe diarrhea and infections that strike AIDS patients whose immune systems are crippled can overwhelm the person's ability to maintain their weight, say researchers.
The patients were part of the Multicenter AIDS Cohort Study (MACS) of gay and bisexual men in Baltimore/Washington, D.C, Chicago Los Angeles and Pittsburgh. Other study authors were W.L. Few, Marc R. Blackman, M.D., S. Mitchell Harman, M.D., Ph.D., Donald Hoover, Ph.D. and Neil Graham, M.D.