A new study finds that long-term testosterone replacement therapy is associated with a decreased—and not increased—risk for cardiovascular disease.i The findings were the result of a large population-based study published in Lancet Diabetes & Endocrinology and presented at the 2016 annual meeting of the American Urological Association.
Robert Nam, MD, senior investigator at Sunnybrook Health Sciences Center, says that this “answers” the controversy begun by the US Food and Drug Administration (FDA) that suggests the opposite is true. Dr. Nam continues that “we can conclude that long-term testosterone is safe” and that the research data offers powerful findings that can be confirmed by further in-depth study.
While the FDA recently required testosterone products to use a warning label linking the products to possible cardiovascular risks, this ruling was based on research studies with short durations and follow-ups, no dose-response analysis, and more (for more on this issue, see our article “Does Testosterone Therapy Cause Heart Problems?”).
Let’s learn more about the findings of this study.
This new study sought to address the problems of older research by increasing the sample size (over 38,000 male subjects with varying ages) and length of the study to five years. Researchers were also careful to adjust for what is known as “immortal time bias,” where researchers treat the effects of a drug or therapy over a short period (a few days) and a long period (years) with the same weight.
At the end of this time, researchers found an overall lower mortality rate in men treated with testosterone replacement therapy than the men who were not treated with this therapy. In other words, it was more than just “no-connection” or “negative connection” between testosterone treatments and heart health: the researchers found a positive benefit.
Michael Lauer, MD, from the National Institutes of Health in Bethesda, Maryland, suggests that while we still do not know for certain, these “thoughtful observational analyses” can “provide important insights into a vexing clinical problem.”
Robert Kloner, MD, PhD, from the Huntington Medical Research Institutes in Pasadena and the Keck School of Medicine at the University of Southern California in Los Angeles, also agrees that while this paper “does not resolve the controversy,” physicians should enact “increased vigilance” when they begin administering these therapies.
So What Does This Mean?
Dr. Kloner, said it best: “Until a large randomized, blinded, placebo controlled study is performed, the controversy regarding the safety of testosterone will remain unresolved.” In other words, while these new findings suggest potential benefits that still needed to be studied, they certainly call into question the studies relied upon by the FDA, making it impossible to know definitively the links between testosterone therapies and cardiovascular health.
We strongly encourage more robust studies to continue. In the meantime, please reach out to your Universal Men’s Clinic medical provider to learn more about the methods they use to address low testosterone and the appropriate testosterone treatments that would be right for you.
Download a PDF copy of the research discussed in this post.
 Johnson, Kate. C.J. “Longterm Testosterone May Decrease Cardiovascular Risk” Medscape. May 10, 2016.