"It does not mean that replacing or normalizing levels of testosterone would reverse the outcome," he said. "There are other hormones in the blood that are related to other risk factors, such as diabetes and hypertension."
In any case, a testosterone replacement regimen "would not be a walk in the park," Montori said. "It would be a major intervention."
According to Dr. Jorge Plutzky, director of the Vascular Disease Prevention Program at Brigham and Women's Hospital in Boston, the experience of women taking hormone replacement therapy (HRT) shows that hormonal regimens can have their dangers.
Beginning in the 1990s, millions of older American women took HRT, which replaced two female hormones, estrogen and progestin. Early trials had indicated that the therapy might reduce the risk of cardiovascular diseases such as heart attack and stroke in older women.
Instead, the Women's Health Initiative, a major study released in 2002, found that women taking HRT were at increased incidence of stroke, blood clots and breast cancer, noted Plutzky, who is also a spokesman for the American Cancer Society. HRT prescriptions dropped off precipitously after the study's release.
So, much more research is needed on the link between testosterone levels and mortality before doctors can recommend the regimen to men, Khaw said. Such studies might provide "insights and better understanding of disease mechanisms, such as how and why testosterone might be related to poorer health through, for example, insulin metabolism, lipid metabolism or inflammation," she said.
There's more on testosterone at the U.S. National Library of Medicine.
SOURCES: Kay-Tee Khaw, MBBChir, professor,
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