Study Finds Testosterone Therapy May Have Cardioprotective Benefits
MAY 28, 2014
New research presented at the 2014 annual meeting of the American Association of Clinical Endocrinologists (AACE) indicates that testosterone replacement therapy may reduce the risk of cardiovascular events, contradicting two widely reported studies.
“The study suggests a protective effect of testosterone against MI (myocardial infarctions) and strokes,” said lead author Robert Tan, MD, of OPAL Medical Clinic in Houston, TX.
“Further, there was no evidence of worsening of pre-existing MI or strokes in patients treated with testosterone.”
A team led by Tan performed a retrospective analysis on 19,968 hypogonadal men who received testosterone therapy between 2009 and 2014 at 40 Low T Centers nationwide.
Among those patients, 4 suffered nonfatal myocardial infarctions (MI) and 2 appeared to suffer fatal MIs, leading researchers to calculate an MI rate of 30 per 100,000. Another 46 patients suffered MIs prior to treatment, but none of them had any subsequent cardiac events during the study period.
Another 2 patients receiving testosterone replacement therapy had strokes during the years studied, so the total calculated stroke rate was 10 per 100,000. Another 12 patients had strokes before starting testosterone, but, again, none of them suffered any adverse events during the study period.
The researchers did not include any natural control arm in the study because the Low T Centers did not have any subsequent records for nearly 20,000 patients whose testosterone levels were not quite low enough for treatment.
They therefore used general population data from Kaiser Permanente Northern California, which showed an MI rate of 208 per 100,000, and the Northern Manhattan Registry, which showed a stroke rate of 93 per 100,000.
Based on these figures as comparison, the men who were treated for low testosterone had only about one-seventh the risk of MI (0.14, 95% CI: 0.098-0.211, P<0.0001) and one-ninth the risk of stroke (0.107, CI: 0.06-0.21, P<0.0001).
The findings contradict 2 other recent studies — one published in JAMA and the other in PLoS One — which both concluded that testosterone therapy increases the risk of MI, stroke, or both.
Both of those studies have come under attack. Indeed, a group of doctors from the Androgen Study Group has petitioned JAMA to retract its publication after several corrections.
But those same works have led the US Food and Drug Administration and its European equivalent to announce they will reassess the safety of the approved treatments.
Given that large-scale retrospective data analysis has reached conflicted results, nearly everyone quoted in stories from the AACE meeting in Las Vegas agreed that there’s only one way to settle the debate.
“You need a truly high-level, classy randomized trial to make definitive conclusions,” said AACE president-elect, George Grunberger, MD, FACP, FACE, who went on to note that one major obstacle to such trials is that “it would cost hundreds of millions of dollars.”
Still, Grunberger said the size of Tan’s sample and the magnitude of his findings make his work significant.
“There were tens of thousands of patients, so the fact that you have something that is fairly civilized, should maybe take away some of the element of fear. The last thing you want is appropriate patients, who are doing well, to stop treatment because of some stupid headline.”