Results of a new large study may offer some clarity in an area replete with conflicting findings from small studies in older men or registry studies in special populations.
Men with low testosterone levels who take testosterone replacement therapy do not increase their risk for experiencing a major adverse cardiac event, such as a non-fatal myocardial infarction (MI) or stroke, according to a new study.
“The literature is conflicting regarding the cardiovascular risks of testosterone replacement or supplementation, with some reports showing harm and others no risk or even benefit,” Dr Jeffrey Anderson, Director of Research at the Intermountain Medical Center Heart Institute in Murray, Utah, told ConsultantLive. “Many of these reports have come from small, randomized trials in older men or registry studies in special populations. Our study was large, comprehensive, and represents a broad, all-inclusive experience of how supplementation actually has been used in a US population in a large health care system with excellent up to 5-year follow-up to assess outcomes.”
Dr Anderson and colleagues studied nearly 5700 men between the ages of 53 and 71 who had initial low testosterone levels. They found that men who received testosterone supplementation to achieve normal or high testosterone levels had reduced overall rates of major adverse cardiac events at 1 and 3 years after their initial low levels of testosterone were measured, compared with other men who had persistently low levels of testosterone. The lower rate of cardiac events included a reduction in the adjusted risk of death and a reduction in MIs.
“We used a virtual controlled study design that allowed comparisons between those with low testosterone to begin with and who remained low, to those supplemented to normal or high levels,” Dr Anderson said. “We were reassured to find that the composite of death, MI, and stroke was not increased (indeed it decreased), although a small signal to increased MI/stroke (but not death) risk was noted in those supplemented to high levels, which should be avoided.”
He added that this result “provides some reassurance as to cardiovascular safety for those with symptoms related to low testosterone.”
Although these results appear to be promising in terms of safety, “we urge giving conservative advice. That is, until additional large studies are available, including randomized studies in the relevant patient populations, we recommend treating only those with low testosterone levels to begin with and who have symptoms related to low testosterone. We do not advocate supplementation for cardiovascular prevention. Also, we recommend treating with doses sufficient only to ameliorate symptoms and not to levels above the normal range.”
Dr Anderson noted: “Given that our study is observational and not randomized or placebo-controlled, it is subject to uncorrected selection bias, so it should not be seen as supporting a role to prevent poor health outcomes, such as death, MI, or stroke. However, it does provide some reassurance as to the safety of supplementation to treat symptoms related to low testosterone.”
Dr Anderson presented the results of the study on November 18, 2014, at the American Heart Association Scientific Sessions in Chicago. (Abstract 13220)