SOURCE: University of Texas Medical Branch at Galveston, news release, July 20, 2015
MONDAY, July 20, 2015 (HealthDay News) -- Testosterone therapy doesn't appear to increase the risk of blood clots in veins, a new study contends.
The most common forms of this problem -- called venous thromboembolism (VTE) -- are deep vein thrombosis (a clot in the leg) and pulmonary embolism (a clot in the lungs). VTE is the third most common type of cardiovascular problem, after heart attack and stroke, the researchers said.
There is conflicting information about the link between testosterone therapy and the risk of VTE. As a result, many men with low testosterone and their doctors are reluctant to start testosterone therapy, the study investigators said.
"In 2014, the [U.S.] Federal Drug Administration required manufacturers to add a warning about potential risks of VTE to the label of all approved testosterone products," study author Jacques Baillargeon, a professor of epidemiology at the University of Texas Medical Branch at Galveston, said in a university news release.
"The warning, however, is based primarily on post-marketing drug surveillance and case reports. To date, there have been no published comparative, large-scale studies examining the association of testosterone therapy and the risk of VTE," he noted.
Baillargeon and his colleagues looked at data from more than 30,000 American men, aged 40 and older. The researchers found that having a prescription for testosterone therapy was not associated with an increased risk of VTE.
The researchers also studied various forms of testosterone therapy, including topical creams, transdermal patches and intramuscular injections. No increased risk of VTE was found with any of these forms, the researchers said.
But due to the study's design, it's not possible to say definitively that there's no VTE risk associated with testosterone therapy.
Baillargeon said he recognized the need for more study. "It's also important to note that further research needs to be conducted to rigorously assess the long-term risks of testosterone therapy," he said.
The study was published July 20 in the journal Mayo Clinic Proceedings.
The U.S. National Library of Medicine has more about testosterone therapy.