Research finds testosterone treatment improves sexual activity, physical function

A new study published in the New England Journal of Medicine shows testosterone treatment for men over 65 years old not only improves sexual function but also slightly improves mood and physical ability. A team of researchers from 12 medical centers across the United States, including Northwestern Memorial Hospital, participated in the study. "In recent years, talk about low testosterone and its treatments have become part of the public discussion," said Mark E. Molitch, MD, a Northwestern Medicine endocrinologist and one of the authors of the study. "Yet questions have always lingered about the treatment's effectiveness and safety. I believe the results of this large, nationwide study will provide doctors and patients answers and guidance they've been looking for."

As men age, their testosterone levels decrease and they often become more fatigued and experience a decreased sex drive. Whether these symptoms are due to this drop in testosterone and whether testosterone should be given to older men with low testosterone levels has been controversial and earlier studies of testosterone treatments have been inconclusive.

This study monitored 790 men over the age of 65 who had low blood testosterone along with possible symptoms associated with low testosterone levels, such as decreased sexual desire and activity or decreased physical function. Results showed taking testosterone in the form of a gel applied to the skin raised testosterone levels to the middle of the normal range for men aged 19 to 40 years old for one year. The treatment did not improve energy but did improve mood and depressive symptoms.

"Men in the study experienced an increased sexual desire and small improvements in mood and physical function," said Molitch, who is also the Martha Leland Sherwin professor in medicine-endocrinology at the Northwestern University Feinberg of Medicine. "Importantly, there was no evidence of an increase in heart or other cardiovascular issues in those who received testosterone compared to a placebo. And we monitored the men in this study for at least a year after receiving treatment."

The study also found testosterone treatment did not significantly improve distance walked in six minutes when only men enrolled in the physical function trial were considered, but did increase the distance walked when all men in the trail were considered.

In 2003, the Institute of Medicine reported that there was insufficient evidence to support any beneficial effect of testosterone in such men. This report was the impetus for this nationwide study, which is the largest trail to examine the efficacy of testosterone treatment in older men whose testosterone levels are low due seemingly to age alone. The study was supported by a grant from the National Institute on Aging and National Institutes of Health.

Source: Northwestern Memorial HealthCare