The National Institute on Aging (NIA) commends the Institute of Medicine (IOM) for its thoughtful report evaluating the pros and cons of conducting clinical trials of testosterone replacement in older men. The NIA appreciates the effort and care that went into formulating the report and its recommendations, including those regarding the design, safety and ethics of conducting such trials.
One of the reasons the NIA requested this IOM report is because of growing concern about the increase in the number of men using testosterone replacement therapy in the absence of sufficient scientific information about its risks and benefits. This concern remains. This report offers an initial approach to addressing this problem.
We will consider the IOM recommendations very carefully, including options for implementing the type of trials suggested in the IOM report. In particular, the recommendation that researchers focus their initial efforts on conducting short-term, randomized, double blind, placebo-controlled studies of testosterone in symptomatic older men with low testosterone levels to determine the potential risks and benefits seems to be a reasonable strategy. While there may be risk of yet unknown consequences, there is also some prospect of potential benefit for men with low testosterone levels who have one or more symptoms that might be related to deficiency of this hormone. Consideration of any trials to assess longer term risks and benefits of testosterone therapy should be contingent on the results of these shorter-term studies.
We concur with the IOM's recommendation that any trial be designed in such a way that it elicits useful information about the effects of testosterone therapy on a variety of conditions associated with deficiencies of this hormone. These problems, including frailty, disability and sexual and cognitive disorders, are serious concerns for older men, and it is important to learn more about the potential risks and benefits of testosterone treatment for older men who suffer from these conditions. However, it is also important to point out that these initial studies will not address generalized use of testosterone therapy in men—regardless of age—who do not have extreme deficiencies of this hormone.
The NIA shares the IOM Committee's concern about minimizing the risk and protecting those participating in clinical trials of testosterone therapy. Therefore, we will do our utmost to adhere to the Committee's recommendations regarding the safety of trial participants. As is common practice in all National Institutes of Health sponsored clinical studies, we will carefully communicate the potential risks and benefits of participation to all volunteers prior to enrollment.
Finally, although some older men who have tried these treatments report feeling "more energetic" or "younger," testosterone therapy remains a scientifically unproven method for preventing or relieving any physical or psychological changes that men with normal testosterone levels may experience as they get older. Except for a relatively few younger and older men with extreme deficiencies, testosterone treatment is not deemed appropriate therapy for most men at this time. For now, the risks and benefits of testosterone therapy for most men who do not have extreme deficiencies of the hormone are unknown, and there is insufficient evidence for making well-informed decisions on whether this therapy is suitable in these individuals. The clinical trials and other studies recommended by the IOM could do much to clarify the future role of testosterone therapy in aging men.