Not only is there no increased risk of myocardial infarction among older men with testosterone therapy, there may be a protective effect.
Testosterone therapy does not increase the risk of myocardial infarction (MI) among older men, according to a comprehensive new study.
“We believe this is a methodologically rigorous study and should be thoughtfully weighed, critiqued, and discussed alongside the other studies of testosterone therapy and cardiovascular outcomes,” lead author Jacques Baillargeon, PhD, Director, Epidemiology Division and Associate Professor of Preventive Medicine & Community Health at the University of Texas Medical Branch in Galveston, told ConsultantLive.
“Although recent observational studies have reported an increased risk of cardiovascular disease associated with testosterone use, there is a large body of evidence that is consistent with our finding of no increased risk of MI associated with testosterone use,” Dr Baillargeon said. He noted that there are cardiovascular risks associated with untreated hypogonadism and those should be factored into a clinician’s risk-benefit assessment about testosterone therapy.
Testosterone prescriptions for older men in the United States have increased more than 3-fold over the past decade. This trend has been driven by increases in direct-to-consumer marketing; rapid expansion of clinics specializing in the treatment of low testosterone; the development of new drugs and improved delivery mechanisms, particularly dermal gels; and greater diagnostic awareness of hypogonadism, stated Dr Baillargeon.
The retrospective study used information from 25,000 Medicare beneficiaries aged 66 years and older. It compared more than 6300 men treated with testosterone for 8 years with more than 19,000 who were not treated with testosterone. “We found that use of intramuscular testosterone therapy was not associated with an increased risk of MI,” Dr Baillargeon said.
In fact, testosterone was associated with a possible protective effect-a reduced risk of MI in patients with the highest prognostic risk index. There were no differences in risk in patients in the lower quartiles of MI prognostic score.
There are a number of physiologic pathways whereby testosterone therapy may affect the risk of adverse cardiovascular events. “Some have reported that testosterone therapy may improve cardiovascular health by way of decreasing fat mass, insulin sensitivity, and lipid profile,” said Dr Baillargeon. “Also, testosterone may possess anti-inflammatory and anticoagulant properties that may reduce carotid intima media thickness.”
He continued, “It is possible that our findings of a protective effect among men in the highest MI prognostic group reflect a process whereby testosterone reduces peripheral vascular resistance, thereby reducing stress on the heart among those who have some degree of coronary artery disease. It is important to note that there are also postulated mechanisms through which testosterone may increase the risk of cardiovascular disease. Given the broad range of proposed biologic pathways, it is important to conduct further research on this topic.”
Several recent studies have raised concerns about cardiovascular risks associated with testosterone therapy, in particular for older men. On June 19, the FDA expanded labeling on testosterone products to include a general warning about the risk of blood clots in veins. The FDA and European Medicines Agency also are further examining the safety of these products.
The researchers reported their results in the July 2, 2014 issue of the Annals of Pharmacotherapy.