NEW YORK (Reuters Health) - Older men considering taking testosterone for low libido, fatigue, irritability or muscle loss should be made aware of the heart-related risks of testosterone therapy, according to a statement from the Endocrine Society.
Drug companies tout testosterone as a near panacea for such conditions. But the U.S. Food and Drug Administration (FDA) has approved testosterone products only for hypogonadism, when the testicles do not produce enough testosterone.
"Testosterone isn't approved for age-related conditions and age-related decline in testosterone levels," said statement co-author Dr. Shalender Bhasin of Harvard Medical School in Boston.
Testosterone levels naturally begin to decline after age 30.
Past studies have found most U.S. men receiving testosterone therapy don't have documented testosterone measurements, Bhasin said.
He added that testosterone sales have been growing rapidly. A market valued between $18 and $20 million in 1988 was worth about $2.2 billion in 2013, Bhasin said.
In its statement, the Endocrine Society cautioned against widespread use of testosterone drugs until large-scale trials can be completed. The statement was partly a response to a decision by the FDA to investigate the risk of stroke, heart attack and death in men taking prescription testosterone (see Reuters story of January 31, 2014 here: reut.rs/MGNnYF).
Bhasin noted that estrogen generated similar hype until results from the Women's Health Initiative published in the early 2000s sounded alarms about potential risks. After the results of that study, estrogen prescriptions dropped off enormously among women, he said.
"Until more information on the risks of testosterone becomes available, older men who have pre-existing heart disease should be particularly careful about testosterone," Bhasin said.
In January, findings from a PLOS ONE study of more than 55,000 men suggested those with a history of heart disease roughly double their heart attack risk in the first 90 days on testosterone therapy. Another study looking at male patients from the Veteran Affairs system linked testosterone to an increased risk of death, heart attack or stroke (see Reuters Health story of November 5, 2013 here: reut.rs/OamNYN).
In 2010, the National Institute on Aging (NIA) halted a testosterone trial after more cardiovascular-related problems were reported in the testosterone group.
The NIA has another ongoing low testosterone trial that includes about 800 men.
Men with hypogonadism who have been on stable testosterone therapy should not stop their medication without consulting their doctor, Bhasin said.
But for other men, it's important to remember that "low T is not a condition, it is a number - and a number is not a disease," he said.
"Patients need to be informed about both what is known and what is not known about the risks and benefits of testosterone therapy before making a personal decision about such therapy," Dr. Robert Hoover wrote in an email to Reuters Health.
Hoover, from the National Cancer Institute in Bethesda, Maryland, was a co-author of the PLOS ONE study.
"Until all of the major benefits and risks of testosterone therapy are established by randomized trials and other studies, caution should be exercised in treatment decisions, particularly among men with existing heart disease and among older men, among whom undiagnosed heart disease is common," Hoover wrote.
SOURCE: bit.ly/1gqfBPS (pdf) Endocrine Society, online February 7, 2014.