The new research looks at more than 8,000 male veterans with low testosterone. Researchers compared the rates of cardiovascular ills
among those who'd received testosterone supplementation and those who
had not, and found that men who used testosterone were 29 percent more
likely to die, have a heart attack or a stroke after three years of use.
This difference could be seen even after the researchers took into account age, blood pressure, the presence of heart disease and various
other factors.Testosterone supplementation is a billion-dollar industry
that has experienced a more than five-fold increase from 2000 to 2011,
according to the study, with U.S. doctors writing 5.3 million
prescriptions each year. Men take testosterone for a variety of reasons,
from the hope that it will improve their sexual function to increasing
their muscle mass and strength.
Dr. Michael Ho, a cardiologist at the University of Colorado and lead author of the study, said he was surprised when he found that the
risks of testosterone supplementation appeared to be the same for men
regardless of whether they had existing coronary artery disease.
"This study provides some information about potential adverse effects [of testosterone supplementation]," Ho said. "This study should
help inform the discussion between patient and providers about the risks
and benefits before making an individualized decision."
Dr. Steven Nissen, chairman of cardiovascular medicine at the Cleveland Clinic, who was not involved in the study, said the finding
underscores concerns that he and other cardiologists already had about
testosterone supplementation.
"The widespread use of testosterone replacement in men is concerning, with no studies that show long-term safety," he said, adding
that the findings should serve as a "warning to slow down the rush to
place large numbers of men on hormone replacement therapy."The problem,
Nissen explained, is that direct-to-consumer advertising of
low-testosterone treatments has led many men to ask their doctors about
supplementation.
"It is now imperative that the FDA insist on large randomized controlled trials to find out if this therapy is safe or not," he said.
Dr. Anne Cappola, an endocrinologist at the University of Pennsylvania and author of an accompanying editorial to the JAMA study,
said she prescribed testosterone "to those for whom it is indicated and
may derive benefit," according to guidelines from the Endocrine Society.
But, she said, "a large number of men are taking testosterone, and it is not clear that all are doing so based on the right indications. …
Men should make sure they are on testosterone for the right reasons, as
there may be risks involved."
