Screening men for cardiovascular risks before starting testosterone therapy may help avert dangerous blood clots.
Lessons learned from women’s health are helping doctors decipher the risks of hormone use in men.
For decades women have been cautioned that estrogen-containing medications such as birth control pills or postmenopausal hormone replacement therapy could increase their chances of developing blood clots. However, men taking the male hormone testosterone were thought to be immune to such cardiovascular problems. A sharp upswing in recent reports of venous thromboembolism (VTE)—including clots in the deep leg veins (deep-vein thrombosis) and lungs (pulmonary embolism)—among men on testosterone, has forced a re-examination of the risk.
Parallels to women’s health
Testosterone products in the form of gels, patches, and injections are sometimes used by men ages 65 and over to offset the decrease in muscle strength and stamina that may occur when natural hormone levels decline with age. Lately, testosterone therapy has been touted as a way younger men, too, can increase overall vitality. As a result, doctors are prescribing the hormone across a wider demographic.
“Testosterone treatment in men was thought to be a benign therapy. No one had a good explanation at first for why these cardiovascular events were happening,” says Dr. Gregory Piazza, assistant professor of medicine at Harvard-affiliated Brigham and Women’s Hospital. To get answers, researchers turned to the long history of hormone use in women. For some time, doctors have known that some women who are more prone to vascular problems with hormone medicines are likely to have an underlying genetic tendency to clot formation. When researchers began looking at similar factors in the men who suffered venous blood clots while on testosterone, they also found evidence of a genetic predisposition. “It’s essentially the same as with women, but we are just discovering it later. We may find that hormones are actually what uncover these tendencies,” says Dr. Piazza.
Better screening techniques
In June of 2014, the FDA added extra warnings on testosterone product labels concerning the risk of blood clots. Meanwhile, the agency continues to evaluate previously raised concerns that testosterone use in men may also raise risk for heart attack and stroke.
Although there are no specific guidelines in place, doctors are beginning to discuss better ways to screen men for potential VTE before prescribing testosterone. “It would be important to get a history of prior blood clots or other cardiovascular events and look for a family pattern of these events, much like we do for women who are starting birth control,” says Dr. Piazza. “And people with other strong risk factors such as high blood pressure, high cholesterol, and diabetes would need get those conditions under control before contemplating starting testosterone therapy,” he says.