The Spring 2014 issue of QUEST reported that the FDA is reviewing the risk of stroke, heart attack and death in men taking testosterone products. The review was prompted by the publication of two studies that linked testosterone therapy and increased risks cardiovascular events. However, some experts in the medical community question the validity of these studies.
The FDA cited a study published in JAMA in 20131. This observational study found an approximately 6% increased risk of stroke, heart attack and death in men who used testosterone compared with men who did not.
Critics of the study suggested that the methods used to calculate the weighted data were unclear, and the raw data favored the testosterone group. Others cited problems with the study population. On average, men in the treatment group received treatment for 1 year, which is generally considered short-term treatment. Some claimed that the men in the study were undertreated, which can carry its own set of risks. Also, 40% of men who took testosterone did not have adequate follow-up by having their testosterone and hematocrit levels re-tested after initiation of therapy. A possible side effect of testosterone therapy is an abnormal increase in red blood cells, found in hematocrit levels. Failure to monitor hematocrit could lead to an increased risk of cardiovascular events.
The second study cited by the FDA was published in the journal PLoS ONE2. The Spring 2014 issue of QUEST reviewed this study.
Critics of both studies noted that there is literature spanning 20 years that supports testosterone therapy for treatment of low testosterone verified by medical evaluation. In a recent statement, the Endocrine Society called for a large scale, prospective randomized controlled trial to further determine the risks and benefits of testosterone therapy.
At this time, the FDA review is ongoing.
1Vigen, R. et al. Association of testosterone therapy with mortality, myocardial infarction, and stroke in men with low testosterone levels. JAMA. 2013; 310(17):1829-1836
2Finkle, W. et al. Increased Risk of Non-Fatal Myocardial Infarction Following Testosterone Therapy Prescription in Men. PLoS ONE. 2014; 9(1):e85805