Study disputes benefits of testosterone gel
Latest government research challenges anti-aging claims of popular supplements
CHICAGO — Testosterone treatment did not improve older men’s memory or mental function in the latest results from landmark government research that challenges the anti-aging claims of popular supplements.
While testosterone use for one year appeared to strengthen bones and reduce anemia, it also showed signs of worsening artery disease and questions remain about other potential risks. The researchers said more studies are needed to determine long-term effects — the kind of research the U.S. Food and Drug Administration has already asked supplement makers to conduct.
The results are from the final four studies in a seven-part project mostly funded by the National Institute on Aging, involving nearly 800 U.S. men aged 65 and older with low testosterone levels. The goal was to see if rubbing testosterone gel on the skin daily for a year could treat problems linked with low levels of the male hormone, which declines with age. Half the men in each group used the real thing and half used fake gel.
Results published a year ago from the same research linked testosterone with mostly modest improvement in sexual performance, walking strength and mood. The key new findings:
Testosterone had no effect on memory or mental function, based on tests given before, halfway and at the end of treatment to nearly 500 men with agerelated memory decline.
Among almost 140 men who underwent heart artery imaging tests to see if the hormone slowed progression of plaque, those who used testosterone had more plaque buildup and narrower arteries after a year than the fake gel group. Those changes could signal increased chances for heart attacks, although none occurred in the study. Men in this substudy were already more vulnerable for heart problems because of conditions including artery disease, obesity and high blood pressure.
Among about 200 men given bone imaging tests before and at the end of treatment, those on testosterone showed increases in bone density and strength, especially in the spine, while minimal changes were found in the group that used fake gel.
Among 126 men with anemia, a fatigue-linked condition involving inadequate red blood cells, those on testosterone showed substantial improvement.
By the study’s end, anemia had vanished in almost 60 percent of men on testosterone compared with 22 percent of the fake gel group. The hormone group also reported having more energy.
The studies were published Tuesday in the Journal of the American Medical Association and JAMA Internal Medicine. AbbVie Pharmaceuticals provided its gel for the study and helped pay for the research but had no other role in the study.
The research was not designed to look at risks and does not apply to younger men or those with normal levels of testosterone, said study leader Dr. Peter Snyder, a University of Pennsylvania hormone specialist.
A separate study published Tuesday in JAMA Internal Medicine found that men aged 40 and up using prescription testosterone gel, patches or injections had fewer heart attacks and strokes during about three years of follow-up than nonusers.