Dec. 11, 2007 -- More and more clinics and infomercials are popping up touting the antiaging benefits of hormones for men. But researchers are warning prospective patients to view the claims with a healthy dose of skepticism.
Male hormones like testosterone are well known to bulk up muscle mass and cut down on body fat.
But there's growing interest over the last several years in "testosterone replacement" therapy for men who are aging normally. The idea is that replacing naturally waning testosterone can make men more robust and possibly healthier as they age.
One recent study from Australia showed that giving otherwise healthy, non-obese men testosterone replacement over the course of a year helped them avoid some of the muscle loss and fat gain associated with aging. The men were all over 55 years of age but were not "deficient" in testosterone when they started the study.
The study suggests that "replacement" could be a help to men. Especially if the benefits seen in deficient men -- such as improving bone strength and reducing cardiovascular risk -- translate to naturally aging men.
But that "if" is a big if, experts say. They say the results of the study and others like it are giving too many people an excuse to claim that testosterone and human growth hormone replacement is a fountain of youth for men.
Testosterone Therapy and Healthy Men
Marc R. Blackman, MD, a professor of medicine at Johns Hopkins University in Baltimore, says no one has ever shown that otherwise healthy men get any healthier if they gain some muscle or lose some fat on testosterone therapy.
At the same time, gains in muscle mass haven't even been shown to improve older men's ability to perform normal activities like climbing stairs or carrying groceries.
"Nobody's ever shown that. And coupled with an absence of proof of meaningful effectiveness is the absence of long-term safety information," Blackman tells WebMD at a conference sponsored by the Endocrine Society in Washington, D.C.
Without proof of improved strength or help in avoiding disease, all that can be concluded now is that the benefits of testosterone therapy are "absolutely cosmetic," he says.
Testosterone Therapy: U.S. vs. Europe
Experts, including Blackman, say they're worried about growing prescriptions for testosterone, along with evidence of growing gray-market purchases over the Internet. That use is at least in part fueled by studies like the Australian study in 60 men.
Glenn R. Cunningham, MD, a professor of medicine at Baylor College in Houston, says testosterone does show some benefits in men who are clinically deficient. But in men whose testosterone wanes normally, the benefits are unproven.
"We don't treat those men," Cunningham says. "Most of the clinical trials in this area are small. You don't get the information you need to truly address effectiveness and safety in studies this small."
Researchers including Cunningham and Blackman are trying to get the government to fund a large-scale trial of testosterone use in older men. They want to see if the drug can be managed effectively so that patients could derive benefits while avoiding risks.
In the meantime, Blackman points to an attitude that he says differs between the U.S. and Europe, where testosterone therapy is not nearly as popular. In the U.S., both men and women tend to place a high "prize" on appearance, sometimes with unhealthy consequences, Blackman says.
In Europe the attitude is: "Aging is part of the normal life cycle. Live with it."