Hormonal therapy tested in older men

Researchers reported results from the first 3 of 7 trials designed to examine the effects of testosterone in older men. Liz Gregg/Photodisc/Thinkstock

Normal testosterone production varies widely. As men age, they often produce less testosterone than they did during adolescence and early adulthood. Many older men have testosterone levels well below those found in healthy younger men. Symptoms common with increasing age that could be related to low testosterone include diminished sexual function, physical function, and vitality.

The Testosterone Trials (TTrials) are a set of 7 trials designed to determine if testosterone treatment can alleviate symptoms associated with low levels of the hormone. The trials are a key step before considering larger, lengthier trials to assess long-term risks and benefits. The TTrials were initiated by NIH’s National Institute on Aging (NIA) and are supported by NIA and other NIH components. Results for sexual function, walking, and vitality were reported in the New England Journal of Medicine on February 18, 2016. Results for other outcomes (cardiovascular, bone density, cognition, and anemia) will be reported in future papers.

A team led by Dr. Peter J. Snyder at the University of Pennsylvania School of Medicine enrolled 790 men, ages 65 and older, at 12 sites across the U.S. The men had serum testosterone levels consistently well below the average for young healthy men. For this set of 3 trials, low sexual function, difficulty walking, or low vitality were required for participation.

The men were randomized to receive testosterone gel or a placebo gel applied to the skin daily for 1 year. The trials were double blind—neither the participants nor the researchers knew who received which gel. Serum testosterone concentration was measured periodically for 12 months. The men were closely monitored for prostate and cardiovascular problems.

Among the men with low sexual function, testosterone treatment modestly increased sexual activity, sexual desire, and erectile function compared to placebo treatment.

Testosterone treatment didn’t significantly affect walking ability among men enrolled in the physical function trial. However, among the men in all 3 trials, walking speed and distance did improve with testosterone compared to placebo.

In the men with symptoms of low vitality and fatigue, testosterone treatment didn’t significantly affect fatigue symptoms. However, among the men in all 3 trials, those who received testosterone reported slight improvements in mood, energy, and depressive symptoms compared to those who received placebo.

The researchers found few adverse effects from testosterone treatment. However, larger and longer studies will be needed to better assess the risks of testosterone therapies in older men. The effects among men at high risk for prostate cancer and cardiovascular disease will also need to be considered, as these men were excluded from the trials.

“The results of the TTrials show for the first time that testosterone treatment of older men who have unequivocally low testosterone levels does have some benefit,” Snyder says. “However, decisions about testosterone treatment for these men will also depend on the results of the other 4 trials.” Older men considering a testosterone treatment should consult with a physician.