Treating older men with testosterone can improve their sexual function and mood, according to new research published February 18th in the New England Journal of Medicine.
The study adds much to the medical community’s insights on testosterone’s benefits and risks.
Men’s testosterone levels gradually decline as they age. For some, this means declines in sexual desire and difficulty with erections. Men may also feel weak, moody, and tired.
Testosterone replacement therapy is often prescribed for these men. However, the effectiveness of this strategy has been unclear.
The double-blind, placebo-controlled study, which involved 790 men over age 65 in 12 locations, was comprised of three separate trials: the Sexual Function Trial, the Physical Function Trail, and the Vitality Trial. Men could participate in more than one trial, if appropriate.
All of the men had testosterone levels below 275 ng/dL. They were randomly assigned to receive either a testosterone gel (AndroGel 1%, provided by AbbVie) or a placebo gel for one year. Doses started at 5 g daily, but were adjusted as needed to maintain levels similar to the normal range for men between the ages of 19 and 40.
Testosterone levels were measured at 1, 2, 3, 6, and 9 months. At each follow up visit, men were assessed for adverse events, including cardiovascular problems. They also completed questionnaires and assessments pertinent to their particular trial. Seven hundred five men finished the study.
The researchers found the following:
• In the Sexual Function Trial, men taking testosterone had greater sexual activity, improved sexual desire, and better erectile function compared to those in the placebo group. Men’s sexual activity increased across all trial groups.
• In the Physical Function Trial, there were no significant differences between the testosterone and placebo groups on an evaluation of 6-minute walking distance. When all three trials were considered, men on testosterone did have better scores in this area. Men who took testosterone were more likely to say that their walking ability had improved.
• In the Vitality Trial, the scientists found no significant benefit based on assessment scores, except for “small but significant” improvement in mood and depressive symptoms. Men in the testosterone group tended to report better energy compared to men the placebo group.
• Rates of adverse events, including prostate-related and cardiovascular events, were similar for the testosterone and placebo groups.
The researchers noted that this study was not large enough to address the potential risks of testosterone replacement therapy, including cardiovascular risk.
They also emphasized that the results applied to men over age 65 with testosterone levels below 275 ng/dL.
“These results, together with those of [four other completed trials] should inform decisions about testosterone treatment for men 65 years of age or older whose levels are low for no apparent reason other than age,” they wrote.
“Such decisions will also require knowing the risks of testosterone treatment, which will necessitate larger and longer trials,” they added.
Resources
Medical Daily
Castillo, Stephanie
“Treating Low Testosterone Levels May Improve Physical Activity, Sexual Function In Older Men”
(February 17, 2016)
http://www.medicaldaily.com/testosterone-levels-physical-activity-older-men-373918
The New England Journal of Medicine
Snyder, Peter J. M.D., et al.
“Effects of Testosterone Treatment in Older Men”
(February 18, 2016)
http://www.nejm.org/doi/full/10.1056/NEJMoa1506119
The New York Times
Kolata, Gina
“Testosterone Gel Has Modest Benefits for Men, Study Says”
(February 17, 2016)
http://www.nytimes.com/2016/02/18/health/testosterone-gel-men-health-benefits.html
Yale News
Kashef, Ziba
“Testosterone therapy boosts sexual function and mood in older men”
(February 17, 2016)
http://news.yale.edu/2016/02/17/testosterone-therapy-boosts-sexual-function-and-mood-older-men