SUNDAY, Oct. 17, 2004 (HealthDayNews) -- In older men, flagging sexual prowess, decreased muscle mass, a tendency to pack on pounds, and a general lack of energy may all point to what some call "male menopause."
To fight back against that decline in circulating testosterone, many American men are turning to hormone therapy.
Experts are urging caution, however. They say there is no reliable data on the benefits and risks of treating this age-related decline.
In fact, even finding an acceptable name for the condition has been tough.
"Although some people talk about 'male menopause,' obviously, men don't have menopause. It's a misnomer," said Dr. Glenn Cunningham, a spokesman for the Endocrine Society, and a professor at Baylor College of Medicine in Houston.
"In women, menopause is relatively abrupt, and it occurs at a standard age. But in men the decline is gradual, takes place over decades, and isn't complete -- it's usually only a partial loss of hormone," he said.
Cunningham said another popular term -- "andropause" is probably incorrect for similar reasons. "It's been picked up by the lay press and used for some time now, however, so it's what people understand," he said.
What is clear is that all men experience some level of gradual decline in physical, sexual and hormonal activity as they enter middle age.
"There's also no question that testosterone levels decline with advancing age," said Dr. Shalender Bhasin, chief of the division of endocrinology at Charles R. Drew University in Los Angeles, and a professor of medicine at UCLA School of Medicine.
"But are the [physical] declines seen in older men related to declining testosterone levels? On that point there's no agreement," Bhasin said.
A large-scale, prospective clinical trial into the risks and benefits of testosterone replacement therapy could provide answers, of course. But at this point, "there's only about a dozen studies, all of them short-term studies that included a small number of men," Bhasin said.
While some men enrolled in these smaller trials did experience some improvement, "none of these studies was large enough to show clear-cut benefits on the health of older men," Bhasin added.
Risks associated with long-term use of a powerful hormone such as testosterone are equally unclear, he added. "The two major areas of controversy are whether giving testosterone therapy to older men will increase their risk of prostate disease, including cancer, and whether it will increase or decrease their risk for heart disease. There's no evidence right now in either direction."
Bhasin and three other expert endocrinologists recently applied for a grant to fund a large-scale clinical trail into the issue, but were turned down.
While he understands that decision, Bhasin said, "the practical consequence of this is that studies demonstrating the risks of testosterone supplementation won't even be initiated in the coming decade."
In the meantime, increased media attention and an aging population have led thousands of American men to turn to supplemental testosterone use in the absence of good scientific data, he said.
"Testosterone sales have been growing exponentially," Bhasin said. "In each of the past four years sales have doubled, and they are projected to have exceeded half a billion dollars this past year. Some of these sales are for unapproved indications, and in the age of the Internet, getting androgen products isn't very difficult."
On the other hand, this surge in demand indicates a legitimate and growing need among older men, he said. "People are living longer, and older men and women are interested in having a better quality of life," Bhasin said. "And that's not unreasonable."
Cunningham points out that declines in testosterone vary widely between individual men, and replacement therapy is certainly not for everyone. "I think only those men who are testosterone-deficient should be considered for replacement therapy," he said. "And if men who are 40 or 50 choose to be on treatment, they should be followed carefully."
In the meantime, debate continues.
"There's tremendous polarization of opinion," Bhasin said. "There are proponents who almost recommend putting testosterone in the water supply, and then there are opponents who believe treatment would be tantamount to malpractice. And the fact is that we just don't know."
For more on hormone therapy and aging, visit the National Institute on Aging.