Controversial Effects of Exogenous Testosterone on Cardiovascular Diseases

The use of testosterone (T) among men aged 40 years or older was increased more than 3 times from 0.81% in 2001 to 2.91% in 2011. Until recently, the majority of the studies did not show any increased cardiovascular (CV) risk by using T in male patients with hypogonadism. What is more, some studies had observed a protective effect of using T against CV diseases. However, in 2010, a randomized clinical trial (RCT) was intended to study the advantage of T gel in older men with limitations in mobility; the study was stopped due to unexpected high prevalence of CV adverse outcome. These findings were confirmed by 2 other studies published in November of 2013 and January of 2014. Consequently, the Food and Drug Administration (FDA) had announced in January 2014 that it will reassess the safety of those treatments. Meanwhile, the agency had not reached to a definitive conclusion that FDA-approved testosterone therapy raises the risk of stroke, heart attack, or death. A report released in the broadcast of the NBC Nightly News in September of this year that the FDA says "there's little evidence that T boosting drugs taken by millions of American men are actually effective." NBC notes that the agency also pointed out that it was not convinced that they carry serious risk either. "The condition has been marketed as low 'T', and the medications are offered to help with low sex drive and fatigue among some men," notes NBC. The European Medicines Agency EMA's Pharmacovigilance Risk Assessment Committee has also responded to the concern of potential CV adverse outcomes associated with the use of T, and they have concluded in their October meeting of this year that the use of T in men who do not produce enough T raises the risk of heart diseases. In our review, we highlighted the association between exogenous T and major adverse CV outcomes. Additionally, we focused on the interplay between exogenous T and some endocrine abnormalities such as diabetes mellitus type 2, metabolic syndrome, dyslipidemia, and obesity.