Taking testosterone might sound like a good idea for an older man, but a new study suggests the treatment might be bad news for his heart.
Men who took it showed a slightly increased risk of heart attack and stroke in the first few years.
"Our findings show that the use of testosterone therapy was associated with an increased risk of stroke, TIAs (mini-strokes), or cardiac arrest during the first two years of use," said study author Dr. Christel Renoux. She is from the departments of epidemiology, biostatistics, and occupational health, and the department of neurology and neurosurgery at McGill University in Montreal.
"There is limited evidence on the long-term clinical benefits of testosterone therapy to effectively treat the modestly declining levels of natural testosterone levels of aging but healthy men," Renoux said. "We strongly recommend that clinicians proceed with caution when considering prescribing testosterone therapy and first discuss both the potential benefits and risks with patients."
The team analyzed data from about 15,400 British men, aged 45 and older, with age-related low testosterone levels.
Those who took testosterone replacement therapy had a 21% higher risk of cardiovascular events such as heart attack, stroke or mini-stroke than those who did not take the therapy. That increased risk translated into 128 more cardiovascular events.
However, the increased risk declined after two years of testosterone treatment, according to the study published recently in The American Journal of Medicine.
Further studies should be conducted to confirm this study's findings, Renoux recommended.
"Until such time, the potential cardiovascular risk of testosterone therapy should be weighed against the perceived and expected benefits among aging men," she said in a journal news release.
While reported rates of low testosterone have remained stable, prescriptions for testosterone replacement therapy have soared in the last 20 years.
Increasingly, testosterone replacement therapy is prescribed to treat general symptoms of aging, including fatigue and slight declines in sexual functioning.
One of the other study findings was that current use of testosterone replacement therapy was associated with a lower risk of death from any cause, while past use was associated with an increased risk.
While this suggests that testosterone replacement therapy may reduce the risk of death, it could also be because doctors halt the therapy in men with declining health, the researchers noted.