Sept. 29 (UPI) -- Use of testosterone replacement therapy among older men in the United States declined after warnings about the risks to those with heart disease, a study published Wednesday by JAMA Network Open found.
Prescriptions for the hormone replacement therapy fell by about one-third between 2011 and 2018, even in men without pre-existing heart disease, the data showed.
The drop in prescriptions coincided with warnings from the Food and Drug Administration and the Endocrine Society about the "potential risks for men with heart disease using testosterone," the researchers said.
"The public should be aware that there isn't good evidence showing that testosterone replacement therapy is safe or effective for older men with low testosterone levels unless they are caused by specific medical conditions," study co-author Alex Everhart told UPI in an email.
"However, there have been several studies showing that testosterone replacement therapy may increase risk of heart attacks and strokes," said Everhart, a post-doctoral research fellow at Harvard Medical School in Boston.
Testosterone is a hormone produced primarily in the testicles that, in men, helps maintain bone density, muscle strength, facial and body hair, sex drive and sperm production, according to the Mayo Clinic.
In most men, testosterone levels decline with age, affecting energy levels, among other health complications.
However, about 40% of men age 45 years and older have low testosterone levels, caused by injury or infection to the testicles, chemotherapy for cancer, chronic health conditions or medications such as opioids, hormones used to treat prostate cancer and steroids, according to the Cleveland Clinic.
To address these issues, testosterone replacement therapy has been prescribed as a treatment for low testosterone, or "low T," even though research has not confirmed "that just increasing testosterone levels is going to counteract aging," Everhart said.
In addition, testosterone replacement therapy can increase a person's risk for worsening sleep apnea, an enlarged prostate, growth of existing prostate cancer, enlarged breasts and blood clots, according to the Mayo Clinic.
As a result of these potential side effects, in 2014, the FDA issued a warning that advised against using testosterone replacement therapy in men with pre-existing heart disease, and the Endocrine Society, a professional group of physicians, followed suit a year later.
For this study, Everhart and his colleagues at the University of Minnesota, where he was working when the research was conducted, analyzed claims data for men age 50 and older covered by commercial health insurance or Medicare Advantage.
Medicare Advantage plans are medical coverage programs offered by private companies to people age 65 and older to extend Medicare coverage beyond what the federal government offers in the base federally funded program.
The analysis included data from nearly 45 million quarterly patient observations from people on either Medicare Advantage or private insurance.
Of these, up to one-quarter of the observations noted some form of heart disease, including irregular heart disease and congestive heart failure, the researchers said.
An estimated 3% to 4% of the patient observations reported low testosterone, which is also called hypogonadism, unrelated to aging, according to the researchers.
In 2011, before the FDA warning, about 28% of the men in the study covered by Medicare Advantage received a prescription for testosterone replacement therapy, the data showed.
By 2018, four years after the FDA advisory, that number dropped to just under 20%, the researchers said.
However, both men with and without heart disease stopped receiving prescriptions for testosterone replacement therapy during the study period, they said.
In addition, men ages 50 to 65 years covered by commercial insurance continued to receive testosterone therapy, despite having heart disease, according to the researchers.
This suggests the need for "for more nuanced testosterone prescribing," the researchers said.
"Unfortunately our study suggests some physicians aren't taking recent evidence and FDA safety communications to heart," Everhart said.
"Patients should consider asking their doctor about cardiovascular risks specifically before starting or continuing testosterone replacement therapy," he said.
