Trans Women at a Greater Risk for Blood Clots, Strokes, Study Finds

Researchers studied about 5,000 transgender women and men.

A new study is revisiting the link between hormone replacement therapy (HRT) and cardiovascular issues in trans women.

The research, published on July 9 in the Annals of Internal Medicine, studied some 2,800 transgender women and 2,100 transgender men. Participants were followed for about four years each, and 23% of them had undergone gender-affirming surgeries. Medical records from 48,000 cis men and cis women, matched with each participant for race, ethnicity, and birth year, were used to make comparisons.

And the results were eye-opening. Among transgender women, the risk of venous thromboembolism, a dangerous type of blood clot, nearly doubled. That risk seemed to stem from HRT, since trans women participants’ risk of blood clots was five times higher than cisgender men and three times higher than cisgender women. Trans women in the study also showed a higher rate of heart attacks and strokes than cis women, akin to what their risk factor would have been if they had not transitioned.

Researchers were not able to discern an increased cardiovascular health risk among transgender men because there were so few incidents of strokes, blood clots, or heart attacks reported.

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Notably, the study didn’t factor in differences in hormone doses, formulations, or combinations. Senior author Dr. Michael Goodman, an epidemiology professor at Emory University in Atlanta, says future research should take those discrepancies into account.

“Our hope is people will understand we’re not trying to scare anybody,” Goodman told Reuters. “We’re just saying there are some questions that need to be answered to guide the therapy. Risks comes with benefits, and benefits come with risks. It takes a thoughtful healthcare provider and a well-educated patient to make an informed decision.”

Dr. Vin Tangpricha, an endocrinologist at Emory University and a co-author of Goodman’s study, told NewNowNext in May that there are “still a lot of question marks” on the topic. Previously, Tangpricha presented a report analyzing nearly two dozen studies of more than 3,000 transfeminine patients, which found higher rates of cardiovascular issues among trans women than cis women or men.

Concerned about the health risks of starting HRT? Rather than eschewing a hormone regimen altogether, Tangpricha suggests taking common-sense steps to limit other risk factors for heart disease—smoking, hypertension, obesity—and increasing regular screenings for cardiovascular health issues.

Brooklyn-based writer and editor. Probably drinking iced coffee or getting tattooed.