VTE can lead to stroke, organ damage, heart attack, or even death.
Lead researcher Dr. Carlos Martinez explained, “Risk peaks rapidly in the first six months of treatment and lasts for about nine months, and fades gradually thereafter.”
Millions of men are taking some form of testosterone therapy to improve stamina, libido, and strength. Other studies have pointed to estrogen therapies contributing to blood clots in women.
The researchers reviewed data from 19,000 men with confirmed VTE. These men were compared to 909,000 age-matched men who made up the control group.
Within the first six months of testosterone therapy, there was a 63 percent increase in the risk of blood clots, compared to the men not taking testosterone therapy.
Past president of the American Heart Association Dr. Mark Creager explained, “My advice is to review the patient’s underlying risk factors for VTE, and weigh that risk against the potential benefit of testosterone therapy. These individuals should at least be made aware of the fact that their risk would be even higher with testosterone.”
Risk factors for VTE include obesity, prolonged immobility, older age, and prior episodes of blood clots.
Dr. Martinez concluded, “Future research is needed to confirm this temporal increase in the risk of venous thromboembolism.”
The findings were published in BMJ.