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As men age, they lose testosterone. That can lower their sense of well-being and sexual desire. Supplements have received mixed reviews. Studies about their benefits and risks have been inconclusive until now. Research published in the New England Journal of Medicine finds clear benefits for some men aged 65 and over. NPR's Patti Neighmond reports.
PATTI NEIGHMOND, BYLINE: Dave Bostick lives in Pittsburgh. For years, he worked as a vocational counselor, helping people with disabilities find jobs. He loved what he did, and he loved his wife. But when he was in his 60s, he noticed some changes.
DAVE BOSTICK: Decline in libido, decline in enthusiasm for picking up new things.
NEIGHMOND: At work, his lack of ambition was so noticeable he decided it was time to retire. But he wasn't really happy, which is why, one day while at the university of Pittsburgh taking a course, he was drawn to a notice about a new study.
BOSTICK: I had looked at the announcement and said, yes, I'm 65. Yes, I feel low energy, low libido.
NEIGHMOND: The study at the University of Pittsburgh is one 12 sites nationwide looking at possible benefits of testosterone in healthy older men who happen to have abnormally low levels of the hormone, like Bostick. Researchers didn't know whether the men lost the hormone more rapidly than others or whether they produced less of it to begin with. Endocrinologist Peter Snyder with the University of Pennsylvania headed the study with nearly 800 men. About half were given placebo gel, and about half were given testosterone gel.
PETER SNYDER: The testosterone concentrations in the men in this trial, on average, were increased just to the middle of the normal range for young men.
NEIGHMOND: After one year, mood and physical activity improved among the testosterone group. But the biggest improvement, said Snyder, was in sexual function.
SNYDER: Testosterone improved selectivity and improved sexual desire and improved erectile function.
NEIGHMOND: During the year-long study, researchers found no increase in adverse events like heart attack, stroke or prostate conditions among the group on testosterone. But researcher Snyder says that does not mean long-term testosterone is safe. Far more research is needed, he says, which means larger studies for longer periods of time. Even so, endocrinologist Eric Orwoll with Oregon Health and Sciences University says the findings provide new, clear guidance for doctors and patients.
ERIC ORWOLL: I think we can be confident that there is some benefit for some men.
NEIGHMOND: Researchers don't know exactly which men might benefit. It should also be noticed that the supplement was given only to men with abnormally low testosterone as measured by a blood test. For these men, Orwoll says, they will now have options.
ORWOLL: Some men would say, yes, I want to take any chance that there might be that my sexual function will improve, even if it's modest. Other men will say, well, jeez, that doesn't sound like it's very encouraging. I don't want to go to the trouble of using testosterone, particularly when we don't know about long-term risks.
NEIGHMOND: The study is ongoing, and researchers will soon analyze whether supplemental testosterone also benefits cognitive function, bone health and the cardiovascular system. Patti Neighmond, NPR News.
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