Testosterone Doubles Heart Attack Risk in Certain Men

Months after starting prescription testosterone treatment, the rate of heart attacks doubled in men ages 65 and up, in a new study recently published in PLoS One. That risk nearly tripled in patients younger than 65 with a previous diagnosis of heart disease. Funded by the National Institutes of Health, the study tracked 55,593 older and middle-aged men in the U.S. who were prescribed testosterone between 2008 and 2010. It was led by a team of researchers from the National Cancer Institute, the University of California, Los Angeles, and independent research firm Consolidated Research. The investigators compared the rate of heart attacks in the year prior to the participants’ initial prescription of testosterone and in the 90 days after starting the prescription. They observed a two-fold increase in the risk of heart attack in men ages 65 and older within 3 months of filling the initial prescription, regardless of their cardiovascular disease history. That risk was 2 to 3 times higher among younger men who had a history of heart disease. The under-65 participants who took prescription testosterone but had no history of heart problems did not show any signs of greater risk. For comparison, the researchers chose a separate group of men filling their first prescriptions for phosphodiesterase type 5 inhibitors (PDE5I), which have indications similar to testosterone. This group included 170,000 older and middle-aged men who filled their first prescriptions for sildenafil (Viagra, Pfizer) or tadalafil (Cialis, Lilly USA) between 2008 and 2010. The team found the men in this comparison group did not experience more heart attacks. “In the prescription-odds weighted regressions, we found no association between PDE5I prescriptions and the risk of MI, suggesting that the TT prescription-related risk of MI is more likely a drug effect, rather than a result of behavioral or other factors associated with prescription,” the authors concluded. In light of these findings and other recent studies that have identified cardiac problems as a potential side effect of prescription testosterone, some experts have been calling for more extensive warning labels on the drug. In a statement released on January 31, the U.S. Food & Drug Administration said it is investigating the risk of stroke, heart attack, and death in men taking FDA-approved testosterone products. “We have been monitoring this risk and decided to reassess this safety issue based on the recent publication of two separate studies that each suggested an increased risk of cardiovascular events among groups of men prescribed testosterone therapy,” the release says. The FDA plans to share its final conclusions and recommendations when its evaluation is complete. In the mean time, the agency recommends that health care professionals consider how the benefits of FDA-approved testosterone treatment for hypogonadism stack up against the potential risks of treatment. —Colleen Mullarkey Reference Finkle WD, Greenland S, Ridgeway GK, Adams JL, Frasco MA, et al. Increased risk of non-fatal myocardial infarction following testosterone therapy prescription in men. PLoS ONE. 2014;9(1):e85805.