New York, Aug 12 (IANS): Although taking testosterone supplements will not lead to the hardening of the arteries in older men but the pills will not guarantee an improved sexual function in them either, finds a study led by an Indian-American researcher.

“The results of the trial suggest that testosterone should not be used indiscriminately by men for improving their sex life," said Shalender Bhasin, director of Brigham and Women's Hospital's research programme on men's health.

“We find that men with low and low normal testosterone are unlikely to derive benefits in terms of sexual function or quality of life, two reasons why men may seek testosterone therapy,” he explained.

The study, however, found that testosterone did not affect the rate of hardening of the arteries. “We need long-term data from large trials to determine testosterone's effects on other major cardiovascular events,” Bhasin added.

Testosterone sales have grown rapidly over the last decade worldwide but few studies have examined the long term effects of taking testosterone on cardiovascular health and other important outcomes.

Testosterone, a hormone primarily secreted by the testicles, plays a key role not only in male reproductive tissues but also in muscle growth, bone mass and body hair.

As men get older, their testosterone levels naturally decline - on average by one percent a year after age 40.

In the three-year trial, the research team enrolled more than 300 men over the age of 60 and measured two indicators of atherosclerosis: calcium deposits in the arteries of the heart (coronary artery calcification) and the thickness of inner lining of the carotid arteries that supply blood to the brain (common carotid artery intima-media thickness).

Participants applied a testosterone or placebo gel daily for three years.

“Our study has important implications for clinical practice, and for older men who are seeking testosterone therapy," Bhasin noted.

Many men, as they get older, experience a decline in testosterone and in sexual function and vitality.

“But our study finds that taking testosterone, when levels are in the low to low normal range, may not improve sexual function or quality of life,” he claimed in a paper which appeared in the Journal of the American Medical Association (JAMA).