Recent Studies Link Testosterone Replacement Therapy to Increased Risk of Heart Attacks and Strokes
Testosterone replacement therapy was approved to treat a condition known as hypergonadism, a condition where the body does not produce enough testosterone (Low T). It has been used in healthy older men to treat diminished strength and physical function. Although a small number of men may actually need testosterone therapy, the industry has enticed millions of men with promises of increased sex drive, better muscle tone and more energy to aging males. Many find these promises irresistible, which is why the use of testosterone replacement medications has skyrocketed in recent years.
As with many promises of eternal youth and vigor by the pharmaceutical industry, the AndroGel and other testosterone replacement medications are turning out to have significant and sometimes fatal downsides. Two recent studies have shown that men taking testosterone therapy medications have a significantly increased risk of heart attack and stroke.
In an article published by Vigen, et al., in the Journal of the American Medical Association, a cohort of 8,709 men in the VA health care system who had undergone coronary angiography were studied to compare incidence of heart attack or stroke in those receiving testosterone therapy for Low-T and those that did not. The testosterone therapy group had a 25.7% incidence of myocardial infarction (heart attack) and ischemic stroke (stroke of blood clot origin) compared to a 19.9% risk in the control group. The risk increased with the length of time a patient was receiving testosterone replacement therapy. There was no significant difference in the incidence of side effects of testosterone therapy among those with and without coronary artery disease.
The authors of the Vigen study discussed several proposed mechanisms by which testosterone replacement medications may increase cardiovascular risk. One involved testosterone's effect on platelets, the component of blood principally associated with clotting and also with coronary plaque formation. Another theory is that testosterone can increase smooth muscle proliferation and a chain reaction that can lead to an increase in atherosclerosis. Testosterone replacement therapy has also been shown to worsen sleep apnea, which itself is a risk factor for atherosclerosis. The authors concluded by calling for further studies to properly characterize the increased risk of heart attacks and strokes in men taking testosterone supplements.
The authors of a second study found that in older men, and also in younger men with pre-existing diagnosed heart disease, the risk of heart attacks following initiation of testosterone replacement therapy was substantially increased. For men receiving Low T medication the relative risk of heart attack was increased by 36%. However, for the subgroup over 65 years of age, the relative risk was more than double. The risk seemed to worsen the older the men were as the relative risk for those taking the medication who were between ages 70-74 was triple the risk of those of this age group who were not taking the medication. The authors concluded that clinical trials are urgently needed to determine the true risks and benefits of testosterone replacement therapy and that based on the risks determined in the study all patients should be cautioned accordingly.
These two studies followed other studies of smaller groups of patients published in 2010 and earlier in 2013 raising the same concerns.
As a result of these studies the FDA announced on January 31, 2014 that it is evaluating the increased risk of stroke, heart attack and death associated with FDA-approved testosterone products. More recently, on April 11, 2014 the European Medicines Agency (EMA) launched a similar review.