Study on Testosterone Therapy in Older Men

(November 4, 2009) - Low serum testosterone may contribute to a number of problems affecting older men, including decreased ability to walk, loss of muscle mass and strength, decreased vitality, decreased sexual function, impaired cognition, cardiovascular disease and anemia. (Read about "The Heart & Cardiovascular System" "Anemia") While testosterone normally decreases with age, in some men, low levels of testosterone may contribute to these debilitating conditions. A new national clinical trial will test whether these conditions can be favorably affected by testosterone therapy.

The study will be conducted at 12 sites across the nation, the Testosterone Trial will involve 800 men age 65 and older with low testosterone levels.

"We know that, as men get older, a significant proportion are unable to carry out activities of daily living and experience decreased physical and cognitive function and decreased independence," said National Institute on Aging (NIA) Director Richard J. Hodes, M.D. "We do not know the extent to which low levels of testosterone may contribute to these conditions."

The Testosterone Trial will include five separate studies. At each of the 12 sites, men 65 and older 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 three months and quarterly thereafter up to one year. Participants will be tested on a wide range of measures to evaluate physical function, vitality, cognition, cardiovascular disease, and sexual function.

"This study is important because testosterone products have been marketed for many years as treatments for a variety of conditions," said Evan C. Hadley, M.D., director of NIA's Division of Geriatrics and Clinical Gerontology. "We hope this trial will establish whether testosterone therapy results in clear benefits for older men."