University of Florida seeking older males for national testosterone therapy trial

The University of Florida is recruiting men older than 65 to take part in a large national study to test whether giving testosterone to men who have depleted levels can help improve health and physical and mental function.

Testosterone is the main male hormone and it facilitates a healthy metabolism and promotes muscle and bone strength, sex drive, energy level and memory. As men age their testosterone levels fall. Lower than normal testosterone levels in the blood can lead to low energy, sexual dysfunction, physical impairment and anemia. Previous research suggests that some of those conditions that men experience as they age might be associated with declining testosterone levels. Up to 5 million men in the United States are estimated to have low testosterone levels.

Raising older men's blood testosterone to levels that are normal for younger men might help them function better in daily life. "We want to see if replacing testosterone in people in whom it is decreased would avert many of the symptoms related to lowered testosterone," said principal investigator Marco Pahor, M.D., director of the UF Institute on Aging.

There has been much controversy surrounding testosterone therapy and who should use it. Many studies have investigated giving testosterone to men who did not have lowered levels. Investigators hypothesize that the testosterone therapy will be most effective in people who have lowered levels, rather than in those with normal levels.

"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 which is the primary funder of the trial. "We hope this trial will establish whether testosterone therapy results in clear benefits for older men."

In young men who don't produce enough testosterone, treatment with the hormone generally leads to improved sexual function, muscle mass, feelings of well-being and improvements in red blood cell counts.

But in older men, whose decline in testosterone levels is a result of aging, the potential benefits or even safety of such therapy is unknown.

The Testosterone Trial, a randomized placebo-controlled double-blind study, seeks to fill that information gap.

"Such rigorous scientific research is needed to test whether this decline is inevitable, whether it is delayable, or whether it is a trajectory that can be changed through changes in lifestyle or with medications," said William Hazzard, M.D., a professor of medicine and a gerontologist at University of Washington and Puget Sound VA Medical Center, who is not involved the research. "Studies like this will help us do a better job when we care for the elderly, and that's the whole point."

Funded mainly by the National Institute on Aging, the study, nicknamed "The T Trial" will examine five health areas — sexual function, physical performance, mental sharpness, vigor and anemia, all of which have been shown to be associated with age-related decrease in testosterone levels.

The six-year study of 800 men will be conducted at 12 sites around the country, namely, UF, the Albert Einstein College of Medicine, the Baylor College of Medicine, Boston University, Northwestern University, the University of Alabama-Birmingham, the University of California-Los Angeles, the University of California-San Diego, the University of Minnesota, the University of Pittsburgh, the University of Washington and Yale University.

To be eligible for participation in the study, men must be 65 years or older, have testosterone levels below a certain concentration as measured by a blood test, and have symptoms and measurable signs of movement restriction, low libido or low vitality.

Participants will be in the study for two years and will receive study-related health and medical screening at no cost. Men who have prostate cancer are not eligible.

First, blood tests will be done to determine testosterone levels and eligibility for the study.

In the first year of participation, subjects will be given a gel to be applied to the skin every day. Men will be randomly assigned to either of two groups. One group will get a gel that contains testosterone, designed to keep levels of the hormone about the same as generally exist in young men. The prescription drug, called AndroGel, is provided by Solvay pharmaceuticals.

The second group will get a gel that does not contain testosterone.

Participants will not be told which of the gels they receive, and neither will study staff. Evaluations will be conducted throughout the year at the research clinic to measure potential effects of the therapy.

In the second year of participation, men will be asked to make one follow-up clinic visit and take one phone call in which they answer a number of questions.

The study has rigorous safeguards to protect patients' safety, researchers say. Subjects will be compensated for their participation.

Men older than 65 who are interested in enrolling in the trial or getting more information should call 352-273-5919 or 866-386-7730 and ask about "The T Trial."