A new national clinical trial will test whether testosterone therapy can favorably affect certain conditions that occur in older men.

Led by the University of Pennsylvania School of Medicine, Philadelphia, the trial will be conducted at 12 sites across the nation and will involve 800 men age 65 years and older with low testosterone levels. The trial will encompass five separate studies.

At each of the 12 sites, men with low serum testosterone and at least one of the following conditions—anemia, decreased physical function, low vitality, impaired cognition, or reduced sexual function—will be randomly assigned to participate in a treatment group or a control group. Treatment groups will be given a testosterone gel that is applied to the torso, abdomen, or upper arms; control groups will receive a placebo gel.

Serum testosterone will be measured monthly for the first 3 months and quarterly thereafter, up to 1 year. Participants will be tested on a wide range of measures to evaluate physical function, vitality, cognition, cardiovascular disease, and sexual function.

A key consideration in launching the trial is the use of testosterone as a therapy for certain conditions, rather than as a preventive measure.

"This is an unprecedented opportunity for older men to learn more about themselves and at the same time find out if testosterone will improve some of the afflictions of old age,” said principal investigator Peter J. Snyder, MD, of the University of Pennsylvania.

For more information, go to www.uphs.upenn.edu/news/News_Releases/2009/11/testosterone-therapy-study/.