TUESDAY, Sept. 16, 2014 (HealthDay News) -- The U.S. Food and Drug Administration is focusing on the "Low T" fad, questioning whether the boom in testosterone replacement therapy is helping or harming the health of aging American males.
At a joint meeting scheduled for Wednesday and Thursday, two key FDA committees will discuss whether doctors are prescribing testosterone therapy for too many men, and if misuse of the male hormone increases the risk of stroke and heart attack.
The Baby Boom generation has turned to testosterone replacement therapy in response to the sagging muscles, lower energy levels and sexual problems that can accompany natural aging, the FDA noted in a review provided to committee members in advance of the meeting.
"There's a large group of men out there who are getting older, and they are looking for ways to evade the consequences of aging," said Dr. Bradley Anawalt, an endocrinologist from the University of Washington in Seattle.
However, the FDA review pointed out there's no clear scientific evidence showing testosterone replacement can reverse some of the effects of aging. Yet the "Low T" craze has been aided by consumer advertising for remedies that promise renewed vitality and strength for aging men, the report said. It also noted that there's growing evidence many men who are receiving testosterone replacement therapy do not need it.
At the joint FDA committee meeting in Hyattsville, Md., the panelists will be asked to vote on two key issues: Whether the agency should revise current indication for testosterone therapies, and whether sponsors of testosterone products should conduct studies to further assess a potential cardiovascular risk.
Anawalt said he hopes the FDA hearing will signal increased government oversight of testosterone therapy and increased public funding for studies on its effectiveness.
"This is a hormone that has been used as a therapy for decades without much scrutiny," he added.
The number of patients with a testosterone prescription nearly doubled over three years, leaping from 1.3 million people in 2010 to 2.3 million in 2013, according to the FDA review, done by Dr. Christine Nguyen, the agency's deputy director for safety, and Dr. Hylton Joffee, director of the FDA's division of bone, reproductive and urologic products.
An FDA analysis found that only about one-half of men now taking testosterone therapy have been diagnosed with hypogonadism, the specific medical diagnosis for testosterone deficiency.
Further, 25 percent of men started the therapy without lab testing to confirm that they had low levels of testosterone, the report said. More than one in four never received a lab test during the course of their therapy, which is crucial to making sure the patient's hormone levels are within the normal range, according to the FDA.
"Many endocrinologists feel that testosterone is being prescribed for men without a clear indication for its use, or for men who are not indicated for it at all," said Anawalt.
Testosterone therapy, even if used correctly, could have serious consequences for heart health, the FDA report added.
One recent study found a 30 percent increased risk of stroke or heart attack in a group of men recently prescribed testosterone therapy, the FDA said. Another found that men 65 and older experienced a two-fold increase in heart attack risk within the first three months of receiving a testosterone prescription, according to the agency.
In June, the FDA announced that testosterone supplement products must now carry a warning label on the general risk of blood clots in the veins.
Until a decade ago, testosterone deficiency tended to be a little recognized and undertreated illness, said Dr. Ronald Tamler, director of the Mount Sinai Diabetes Center in New York City.
"Then all of a sudden, the [pharmaceutical] industry started picking up on this and realized that testosterone was a fantastic business, and realized some patients had needed this medication for decades," Tamler said.
Unfortunately, he added, doctors who aren't hormone experts are performing testosterone level tests at the wrong time of the day, which can lead to overdiagnosis of low T.
Testosterone levels are at their peak early in the morning and decline naturally throughout the day. Because of this, endocrinologists know to perform testosterone tests first thing in the morning, Tamler said.
But some doctors have been performing hormone tests at all times of the day, diagnosing some men as having low testosterone when in fact their levels are normal, Tamler said.
"We swiftly went from one extreme to the other extreme, which was overtesting for it, overdiagnosing it and overtreating it," he said.
At the same time, the science is "murky" on the link between testosterone and increased risk of stroke or heart attack, Tamler said. The FDA review agreed, noting that some studies found potential harm, while others found none.
Dr. Daniel Yadegar, a New York City cardiologist who specializes in anti-aging therapies, argues that studies showing a link between testosterone therapy and poor heart health did not consider the role that other hormones might play.
Yadegar noted that a man receiving too much testosterone will begin to convert the hormone into estrogen, which has been shown to increase heart disease risk in men.
"Perhaps it's high estrogen levels that are causing the cardiovascular events, but we would never know that because they didn't measure the estrogen levels," he said.
Yadegar added that the earlier studies relied on blood tests for testosterone, which some research has shown are less accurate than saliva tests for the male hormone.
For more information on the FDA's meetings on testosterone replacement therapy, visit the U.S. Food and Drug Administration..