Testosterone Therapy Improves Sexual Interest, Function in Older Men

Largest placebo-controlled study to date finds testosterone can address low libido, erectile dysfunction

Newswise, June 30, 2016—Older men with low libido and low testosterone levels showed more interest in sex and engaged in more sexual activity when they underwent testosterone therapy, according to a new study published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism.

The study is the largest placebo-controlled trial in older men conducted on the subject to date. The sexual function study is part of the Testosterone Trials, a series of seven studies examining the effectiveness of hormone therapy in men who are 65 or older, who have low testosterone levels and are experiencing symptoms of testosterone deficiency. The research is supported primarily by the National Institutes of Health.

Testosterone is a key male sex hormone involved in maintaining sex drive, erectile function and sperm production. The Endocrine Society’s Clinical Practice Guidelinerecommends using testosterone therapy to treat men with symptoms of androgen deficiency and low levels of testosterone. Androgen deficiency occurs when a man has consistently low levels of testosterone and resulting symptoms such as sexual dysfunction.

In the past 15 years, use of testosterone therapy has rapidly expanded among men.

Testosterone levels decline as men age, and some men develop low testosterone levels and symptoms. Since 2000, the number of men beginning testosterone therapy has almost quadrupled in the United States, according to a 2014 study published in The Journal of Clinical Endocrinology & Metabolism.

“Our findings indicate low testosterone is one cause contributing to reduced libido and erectile dysfunction in older men,” said the study’s first author, Glenn R. Cunningham, MD, of Baylor College of Medicine and Baylor St. Luke’s Medical Center in Houston, TX. “Men experiencing these symptoms should be evaluated for testosterone deficiency.”

The study was designed to investigate the effectiveness of testosterone therapy. It was not large enough or long enough to address issues related to cardiovascular events or clinical prostate cancer.

The placebo-controlled, double-blinded trial examined the effect of testosterone therapy on sexual function in a group of 470 men. The men were enrolled in the study through 12 academic medical centers.

The participants were at least 65 years old and had low testosterone levels, based on the average results of multiple tests. All of the men had a heterosexual partner.

During the year-long study, the men were assigned to receive either testosterone gel or a placebo applied to the skin. The participants answered questionnaires about sexual function at the outset and every three months during the 12-month study.

The men treated with testosterone therapy displayed consistent improvement in libido and in 10 of the 12 sexual activity measurements, including frequency of intercourse, masturbation and nighttime erections.

 In comparison, men who received the placebo did not change their questionnaire responses significantly over the course of the year-long study.

“For symptomatic older men with low testosterone levels, testosterone therapy led to consistent improvement in most types of sexual activity,” Cunningham said.

The research was supported by a grant from the National Institutes of Health’s National Institute on Aging, with additional support from the National Heart, Lung, and Blood Institute; the National Institute of Neurological Disorders and Stroke; the National Institute of Child Health and Human Development; the Claude D. Pepper Older Americans Independence Centers, the Department of Veterans Affairs Puget Sound Health Care System; and the National Institute of Diabetes and Digestive and Kidney Diseases. Pharmaceutical manufacturer AbbVie, the maker of a testosterone gel called AndroGel, provided funding as well as the testosterone gel and placebo for the study.

The study, “Testosterone Treatment and Sexual Function in Older Men with Low Testosterone Levels,” will be published online at http://press.endocrine.org/doi/10.1210/jc.2016-1645, ahead of print.

Testosterone Treatment Improves Sexual Activity, Physical Function and Mood in Men Over 65

Newswise, February 19, 2016 – As men age, their testosterone levels decrease, but prior studies of the effects of administering testosterone to older men have been inconclusive.

Now, a new study shows testosterone treatment for men age 65 and older improves sexual function, walking ability and mood, according to findings published in the New England Journal of Medicine by a team of researchers from 12 medical centers, including Cora E. Lewis, M.D., of the University of Alabama at Birmingham.

The Testosterone Trials, or TTrials, are a coordinated group of seven trials, and researchers have analyzed the results of the first three — sexual function, physical function and vitality. They found that testosterone treatment increased the blood testosterone level in the study subjects to the mid-normal range for younger men.

Testosterone treatment led to modest improvements in all aspects of sexual function, including sexual activity, sexual desire and the ability to get an erection. It also resulted in small improvements in indexes of mood and depression and some but not all measures of physical function. Treatment did not improve overall energy level.

With 51,085 men screened and 790 who qualified, the TTrials are now the largest trials to examine the efficacy of testosterone treatment in men 65 and older whose testosterone levels are low due seemingly to age alone.

Lewis, a professor in the UAB Division of Preventive Medicine and co-author on the testosterone study, says this new research fills a prominent gap in the evidence for the possible benefits of testosterone in men in this age group, a gap identified by a 2003 report from the Institute of Medicine. Additional evidence will come from the studies in other trials on cognitive function, bone health, cardiovascular disease and anemia.

“We now have some evidence on the specific symptoms that seem to respond, or don’t respond, to testosterone therapy in men 65 years old and over,” Lewis said. “However, there are still big questions about overall benefits and risks. The negative effects of testosterone treatment are still unclear.”

Across the three trials, adverse events including heart attack, stroke and prostate problems were similar in men who received testosterone and men who received placebo. So, while the TTrials did not find harmful effects, Lewis says a larger and longer clinical trial comparing testosterone therapy to placebo to definitively assess the risks is needed.

Lewis says men considering testosterone treatment should consult their doctor.

“Men should discuss their symptoms and their health history with their doctor since testosterone treatment seems to affect some symptoms and not others,” she said. “Men should have their testosterone levels checked to be sure they have low testosterone.”

She also adds that it is important to have levels checked in the morning since testosterone levels naturally change over the course of a day.

The TTrials were supported by a grant from the National Institute on Aging of the National Institutes of Health and funding from other institutes of the NIH.