The results of a randomized, double blind, placebo-controlled study found no associations between testosterone replacement therapy for "low T" and an increased risk of cardiovascular events.
As a man ages, testosterone levels slowly decrease, typically by around 1% per year starting at age 30. As this happens, some men begin to experience hypogonadism or low testosterone (low T).
Low T can cause symptoms such as fatigue, depressed mood, loss of strength, and reduced sex drive. However, testosterone replacement therapy (TRT) can help boost the levels of this hormone in the body and relieve many of these symptoms.
But health experts have questioned whether TRT can raise the risk of cardiovascular events. Because of the concerns, the FDA issued labeling requirements for testosterone products that included information about a possible increased risk of heart attacks and strokes in people using testosterone.
However, new research published on June 16 in The New England Journal of Medicine has found evidence that testosterone replacement therapy does not increase cardiovascular risks.
For the study, scientists recruited 5,246 men ages 45 to 80 with preexisting or a high risk of cardiovascular disease. The participants also had fasting testosterone levels of less than 300 ng per deciliter and symptoms of hypogonadism.
The men were randomly assigned to either a daily transdermal application of 1.62% testosterone gel or a placebo gel. The scientists adjusted the testosterone gel's dosage to maintain levels between 350 and 750 ng per deciliter.
After an average of almost two years of treatment, the research team found no differences in the rates of strokes, heart attacks, or fatal cardiovascular events between the participants receiving testosterone and those who applied a placebo.
For example, among all participants, 182 in the testosterone group and 190 in the placebo group experienced a cardiovascular event.
However, the team did observe a higher incidence of atrial fibrillation, acute kidney injury, and pulmonary embolism in the testosterone group.
Still, though this study appears to show no link between TRT and heart issues, more evidence is needed to prove these findings. Moreover, because the participants had a low T diagnosis, it's unknown whether testosterone use in men with adequate testosterone levels could increase cardiovascular risks.
In addition, testosterone can cause side effects such as increased red blood cell count, skin irritation, and worsening of sleep apnea. So, men who believe they are experiencing hypogonadism or low T should consult their healthcare provider for testing and to discuss the risks and benefits of treatment.
- FDA. FDA Drug Safety Communication: FDA cautions about using testosterone products for low testosterone due to aging; requires labeling change to inform of possible increased risk of heart attack and stroke with use.
- The New England Journal of Medicine. Cardiovascular Safety of Testosterone-Replacement Therapy.