Are testosterone supplements linked to cardiovascular problems?

By Charlie Schmidt

It’s normal for men to lose some physical vitality as they age. But a growing number of men are trying to hold on to their youthful vigor by taking testosterone. Marketers hawk testosterone with the promise of a better sex drive, increased energy, more muscle mass and other age-defying benefits. That’s been a successful strategy. Fueled by direct-to-consumer advertising, the number of American men with prescriptions for testosterone surged from 1.3 million in 2011 to 2.3 million in 2013, mostly in the 40-64 year age group.

The Food and Drug Administration (FDA) has approved testosterone products only for men who don’t make enough of the hormone. These men have a clinically diagnosable condition called hypogonadism, characterized by testosterone levels that are below normal, usually meaning less than 300 nanograms of testosterone per deciliter of blood. Testosterone supplements can relieve symptoms in these men, such as erectile dysfunction, low energy levels, decreased muscle mass, and poor bone strength.

But mounting evidence suggests that testosterone therapy might also cause cardiovascular problems, including heart attacks and strokes, especially in men with pre-existing heart disease. The evidence is by no means certain—some studies have found these risks, others haven’t.

While the benefits of taking testosterone likely outweigh the risks for hypogonadal men, the same may not be true for aging men who take testosterone because they think it will make them look and feel younger. Indeed, recent evidence shows that nearly a quarter of men with a prescription for testosterone have never even had their hormone levels checked. Whether aging men in this so-called “low-T” population benefit from taking testosterone is an open question.

Concerns over possible health hazards have prompted the FDA to investigate the risk of heart attack, stroke, and death in men taking FDA-approved testosterone products.

The evidence

Two recent studies raised health concerns over testosterone. The first, published last year in JAMA, linked the use of testosterone supplements to a nearly 30% increase in the risk of death from heart attack, stroke, or any other cause among more than 8,700 men with low testosterone levels enrolled in the Veterans Affairs Health System between 2005 and 2011. It is possible that pre-existing heart disease may have contributed to worse outcomes with testosterone treatment.

The second study detected a two-fold increased risk of heart attack among men older than 65 within 90 days of their obtaining a testosterone prescription. This study, published last year in PLoS One, found that younger men with a history of heart disease had an even greater three-fold risk of heart attack within 90 days of going on testosterone supplements. No such increase was seen in younger men without pre-existing heart disease.

As part of its review process, the FDA convened an expert panel and gave it the task of reviewing key studies. After completing its review, the panel made a number of recommendations:

• Doctors should be required to document signs and symptoms of low testosterone in a man before prescribing the hormone
• The label on testosterone products should specify the potential for cardiovascular risk
• Before a man starts taking testosterone, his doctor should check his cardiovascular history and do routine followups to determine when and if the treatment should be halted.

FDA’s review of testosterone health risks is still ongoing, and officials emphasize that approved testosterone products have not been conclusively shown to increase the risk of heart attack, stroke, or death. A final determination will be rendered once the FDA’s review is complete.

“We await the results of ongoing randomized studies and the final deliberations of the FDA,” said Dr. Marc B. Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, who served on the FDA panel. “In the meantime, men should be cautious about these new issues that have been raised.”