Nastasic/E+, Getty Images
(Nastasic/E+, Getty Images)

Testosterone therapy may boost hormone levels in older men, but it won’t help their arteries work better, new research shows.

The study, published Monday in the American Heart Association journal Hypertension, showed men ages 50 to 70 with a larger-than-normal waist size and low-to-normal level of testosterone could boost the health and function of their arteries through a 12-week, supervised exercise training program. Adding testosterone treatments boosted the men’s hormone levels but did nothing to improve artery health, the study found.

“Testosterone therapy may have some benefits, for example in increasing muscle mass in the legs,” study author Daniel J. Green, a cardiovascular exercise physiology researcher at the University of Western Australia in Perth, said in a news release. “However, we didn’t find any benefits in terms of artery function, which is a determinant of future cardiovascular risk.”

Research has shown a link between decreased levels of testosterone and an increased risk for heart disease. As men age, testosterone levels – and physical activity – naturally decline. This causes declines in artery health and function, which raises the risk for heart problems.

An increasing number of men are turning to testosterone replacement therapy, which has seen a 12-fold increase in sales in recent decades. It often is used to treat low energy, reduced muscle mass and reduced vigor. However, previous studies have left unclear whether testosterone therapy provides heart health benefits.

“The global increase in testosterone use has been very large, particularly among middle-aged and older men who might see it as a restorative hormone to increase energy and vitality,” Green said.

In the new study, 78 men were randomly placed into four treatment groups: topical testosterone therapy combined with a 12-week training program that included aerobic and strength exercises two to three times per week; testosterone therapy alone; placebo alone; or placebo combined with the exercise training.

Both exercise training and testosterone therapy individually boosted hormone levels among the men in the study, with levels highest among the two groups getting testosterone therapy. But improvements in artery health occurred only in the exercise groups.

Researchers measured artery function using a method that increases blood flow inside an artery. This assesses the inner lining and whether it can help the artery increase in size, or dilate. They found artery function improved 28% in the group that received exercise training alone; it improved just 19% in the group that received a combination of exercise training and testosterone therapy.

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