Research from scientists at University of California Los Angeles (UCLA) shows that the risk for heart attack doubles after starting testosterone therapy for men under age 65 who also have a history of heart disease. The new study, published in the medical journal PLOS ONE, confirmed prior research that revealed the same increased risk for men over 65.
The heightened risk emerged from an analysis of the medical records of 55,593 men prescribed the hormone for medical reasons including low testosterone levels and sexual dysfunction. Popular drugs to treat erectile dysfunction, including Viagra and Cialis, may boost testosterone levels slightly but most of the therapies involve medications such as Androgel, which delivers the hormone via a gel. While it’s not clear why testosterone can harm the heart, some studies suggest that it can lower levels of HDL, or good cholesterol, and therefore increase the risk of heart disease.
“The extensive and rapidly increasing use of testosterone treatment and the evidence of risk of heart attack underscore the urgency of further large studies of the risks and the benefits of this treatment,” said senior author Sander Greenland, a professor of epidemiology at the UCLA Fielding School of Public Health in a statement. “Patients and their physicians should discuss the risk of heart attacks when considering testosterone therapy.”