No Link Between TRT for Hypogonadism and Blood Clots, Study Finds

— But findings don't conclusively debunk DVT risk, researcher says

MedicalToday

SCOTTSDALE, Ariz. – Men with hypogonadism who developed deep vein thromboses (DVTs) weren't more likely to have recently been on testosterone-replacement therapy (TRT), a new study found, challenging other research that has suggested that testosterone supplementation does cause blood clots.

In the new study, investigators compared two groups of men with hypogonadism and found that those who suffered from DVT were just as likely to have been treated (34.96%) or not treated (33.04%) with TRT (HR 1.049, 95% CI 0.85-1.29).

The data were presented here at the annual scientific meeting of the Sexual Medicine Society of North America by Eduardwil Hernandez-Vegas, MD, a research fellow at the University of Utah in Sale Lake City.

"The message overall is that TRT does not appear to elevate risk," study co-author , also of the University of Utah, told , noting, however, that the findings should not be considered conclusive. "More prospective research is needed."

There's been debate for years over whether TRT boosts the risks of blood clots. "The concern is that testosterone might increase DVT in men as estrogen-replacement therapy increases the risk of DVT in women and men," explained , chief of medicine at the University of Washington Medical Center in Seattle, who was not involved with the study.

"The theory is that there might be an effect on the coagulation system that increases the risk of blood clots," he told . "There's not much data to support that theory."

A linked TRT to greater than twofold higher rates of venous thromboembolism in general in men with hypogonadism.

"There are some small case series and case reports that have associated DVT in patients with high risk of DVT or history of DVT," Anawalt added. "Those patients may get DVTs independent of any medication or circumstance, so the association does not prove causality. But that is the biggest question out there: does TRT increase the risk in patients at high risk of DVT?"

For the new study, Hernandez-Vegas and colleagues tracked 1.85 million men with hypogonadism for 12 months and focused on 1.16% who developed DVT (n=21,414). While those who developed DVT were not more likely to be on TRT per an analysis adjusted for possible confounders, the team did report that an association was "more pronounced" in patients in late middle-age and in those with chronic disease.

Anawalt called the analysis "a little odd." The best approach is to "analyze the number of patients who developed DVT while on TRT -- or within a short period of time on TRT -- versus not on TRT for that short time or ever -- not the percentage of patients with DVT that had TRT or not," he said.

Why might the findings of the 2019 study, which identified a higher risk of clots in TRT, conflict with the new analysis? The studies examined different things: venous thromboembolisms in the older study, and DVTs in the newer one. Also, Hotaling noted that his team's study adjusts for multiple cofounders other than just age. (The authors of the 2019 study declined to comment on the new research.)

Anawalt said that in the big picture, physicians should understand that "TRT is a systemic therapy that may have adverse effects for patients who do not have hypogonadism. For patients with bona fide HG [hypogonadism], the benefits of TRT generally outweigh the risks. But the risks and benefits should be carefully considered," he cautioned.

  • author['full_name']

    Randy Dotinga is a freelance medical and science journalist based in San Diego.

Disclosures

No specific funding was noted for the study.

Hernandez-Vegas, Hotaling, and co-authors reported no disclosures.

Anawalt reported no disclosures.

Primary Source

Sexual Medicine Society of North America

Hernandez-Vegas E, et al "Testosterone replacement therapy (TRT) is not associated with a higher risk of DVT: retrospective analysis of US claims data" SMSNA 2021; Abstract 032.