CHICAGO -- Now that science has concluded that the long-term risks of hormone replacement outweigh the benefits for postmenopausal women, men may get their day.
A task force led by the Institute of Medicine and supported by the National Institute on Aging will evaluate the feasibility of conducting clinical trials of testosterone replacement in older men.
The idea of convening a panel of experts arose in part because of growing concern that men are taking testosterone supplements to boost their energy and libido, despite the absence of solid evidence of the risks and benefits.
"Many, many older men are starting to use testosterone," said Dr. Mitchell Harman, director of the Kronos Longevity Research Institute in Phoenix. "But we don't know anything worth knowing about testosterone in healthy, aging men."
Starting in a man's 20s, testosterone levels decline naturally by about 1 percent per year. Lower levels are associated with physical changes, such as more fat and less muscle, and with decreases in sexual and cognitive function, among other things.
Numerous small studies have suggested that testosterone can improve body composition, bone density, interest in sex and, perhaps, energy, muscle strength, memory and well-being. So, when young men suffer from below-normal testosterone levels, doctors agree they should receive a hormone supplement.
But in older men, the normal decline in hormone levels is not necessarily associated with symptoms. What's more, there are concerns that topping up testosterone could increase the risk of prostate cancer, strokes and heart attacks. Those concerns are at least partly responsible for the fact that no large-scale, long-term study of testosterone replacement has been conducted until now in healthy men with low testosterone.
The Institute of Medicine, part of the National Academy of Sciences, is setting up a task force that will include prominent epidemiologists, endocrinologists, urologists and oncologists. The panel will spend a year assessing what is known about testosterone replacement and will make recommendations about the design, safety and ethics of conducting clinical trials of hormone replacement in older men.