Clot Risk Not Higher in Older Men Taking Testosterone

Pam Harrison

May 18, 2015

In elderly men with hypogonadism, the risk for a thrombotic event is no higher with testosterone treatment than without, a retrospective study suggests. However, all-cause mortality is higher without testosterone supplementation.

"The US Food and Drug Administration has asked all physicians to advise patients of the potential thrombotic risk before prescribing testosterone therapy," said Ranjith Ramasamy, MD, from the Center for Reproductive Medicine and Infertility at the Baylor College of Medicine in Houston.

"We actually ask patients to sign a consent form listing all of the potential risks of testosterone," he told Medscape Medical News.

However, "given our study results, we can confidently say that the risk of thrombosis does not appear to be higher in men who are treated, compared with men who go untreated," he reported at the American Urological Association 2015 Annual Meeting in New Orleans.

Dr Ramasamy and his colleagues retrospectively reviewed the medical records of 217 hypogonadal men older than 65 years.

Of the 153 men who received testosterone therapy, 53 were treated with injections, 47 were treated with gel, and 53 were treated with pellets, which are placed intramuscularly beneath the skin. The remaining 64 men did not receive testosterone therapy.

Median follow-up was similar in the treated and untreated groups (3.8 vs 3.5 years), and median age was 74 to 75 in the two groups.

Although scores on the Charlson Comorbidity Index were similar, total testosterone levels were higher in the treated than in the untreated group (475 vs 236 ng/dL; P < .001).

There were fewer deaths in the treated than in the untreated group (1 vs 6; P = .003). In addition, there were more myocardial infarctions in the treated than in the untreated group (1 vs 0), more cerebrovascular accidents (2 vs 1), and more pulmonary embolisms (1 vs 0), but these differences were not significant.

"One of the limitations of the study is its small sample size," Dr Ramasamy acknowledged.

We can confidently say that the risk of thrombosis does not appear to be higher in men who are treated.

However, unlike in epidemiologic studies, "the biggest advantage of our study is that we actually saw these patients, we treated them, we know what their testosterone levels were, we managed them appropriately, and we followed them," he explained. Therefore, "despite the small sample size, the study lends a lot more validity to the argument that testosterone therapy does not appear to increase the development of thrombotic events."

Weak Link

Evidence supporting any link between testosterone supplementation and cardiovascular events, including thrombosis, is weak, said Ajay Nangia, MD, from the University of Kansas Medical in Kansas City.

However, "a weak signal from a safety standpoint is unfortunately not something that the FDA can ignore," he told Medscape Medical News. "Hence, the label change happened."

Dr Nangia said that he, too, informs patients about the potential risks associated with supplemental testosterone before prescribing it, and he documents the discussion in the patient's electronic medical record.

Dr Nangia and Dr Ramasamy said they agree on the need for prospective long-term randomized trial data that clearly demonstrate the safety and efficacy of replacement testosterone therapy in older men.

In fact, after the FDA called for such a trial to take place, the National Institutes of Health initiated the Testosterone Trial, known as TTrial, to evaluate whether or not testosterone helps with physical, sexual, and cognitive function in men 65 years and older.

It is speculated that data from the TTrial — involving some 800 older men from 12 cities in the United States — will be released shortly.

Dr Ramasamy and Dr Nangia have disclosed no relevant financial relationships.

American Urological Association (AUA) 2015 Annual Meeting: Abstract PD37-01. Presented May 18, 2015.


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