Testosterone Trials Show Mixed Results for Users

LOS ANGELES—Testosterone replacement therapy appears to be a mixed blessing for older men with low levels of the hormone, according to recently published studies.

Results of four trials published online by JAMA and JAMA Internal Medicine suggest users showed improved bone density and strength, as well as reduced anemia, after one year of testosterone therapy. One the other hand, the therapy is linked with a 20% increase in arterial plaque and appears to have no effect on improving cognitive function.1,2

The TTrials, are the largest studies to examine the efficacy of testosterone treatment in men 65 and older whose testosterone levels are reduced due to age. Conducted at 12 study sites across the country, 790 participants were given testosterone gel or a placebo applied daily to the skin. Over a year, the National Institutes of Health (NIH) funded clinical research trial sought to determine if testosterone treatment of men aged 65 and older improved their mobility, vitality, sexual function, memory, blood count and cardiovascular risk.

The studies involved researchers from the Minneapolis VAMC and the Puget Sought VA Health Care System in Seattle.

Cardiac effects ended up being most disturbing, according to researchers who reported that the participants who received a placebo had just a 1% rise in plaque volumes vs. 20% for those receiving the actual testosterone treatments for a year. 

Here are the other key findings by category:

  • Anemia trial: After one year of treatment with testosterone, 54% of the men with unexplained anemia and 52% of those with anemia from known causes had clinically significant increases in hemoglobin levels, compared with 15% and 12%, respectively, of those in the placebo group.
  • Bone trial: After one year of testosterone treatment, participants significantly increased volumetric bone mineral density and estimated bone strength compared to controls, with results greater in the spine than hip.
  • Cognition trial: After one year, there was no significant change in either the treatment or the placebo group in cognition, as measured by verbal memory, visual memory, executive function and spatial ability.

These are the second set of results from the long-term TTrials, which demonstrated the benefit of testosterone therapy on sexual function in older men with low testosterone in a report published last year.

“Looking globally at testosterone therapy, the strongest evidence is for sexual function,” said Thomas Gill, MD, a lead author from Yale University, New Haven, CT.

  1. Snyder PJ, et al. Testosterone Treatment and Coronary Artery Plaque Volume in Older Men With Low Testosterone. JAMA, February 2017 DOI: 1001/jama.2016.21043
  2. Snyder PJ, et. al. Effect of Testosterone Treatment on Volumetric Bone Density and Strength in Older Men With Low Testosterone: A Controlled Clinical Trial. JAMA Internal Medicine, February 2017 DOI: 1001/jamainternmed.2016.9539

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