GAINESVILLE, Fla. — A year of testosterone treatment improved bone density and anemia among older men with low testosterone but also increased coronary artery plaque and had no effect on patients’ cognitive function. The findings by a team that includes University of Florida Health researchers are published today in the Journal of the American Medical Association and JAMA Internal Medicine.
The papers are the final primary results from The Testosterone Trials, a group of seven studies that assessed the effects of testosterone treatment for one year compared with a placebo in nearly 790 men age 65 and older with low testosterone. The research was conducted at UF Health, the University of Pennsylvania’s Perelman School of Medicine and 12 other medical centers.
The studies showed that the results of testosterone treatments aren’t universal for older men, said Marco Pahor, M.D., director of the UF Institute on Aging and a co-author of the papers. For example, a patient with anemia may benefit from testosterone treatment, but it might not be appropriate for someone with a history of cardiovascular issues.
“Physicians really need to weigh the benefits and risks of testosterone treatment for each patient individually,” he said.
The researchers found that the treatment improved bone density and bone strength in older men with low testosterone. Bone strength was especially improved in the spine, compared with the hip, researchers noted.
In another trial, more than half of the 126 men with anemia had clinically significant increases in red blood cell levels after getting testosterone treatment, compared with 15 percent or less among two placebo groups.
The cardiovascular trial showed more coronary artery plaque buildup among those who received the testosterone treatment than those who did not. The study found that plaque volume increased “significantly more” in the testosterone-treated group, though researchers noted that because just 170 patients were assessed for plaque buildup using a specialized heart scan, the clinical importance of the finding is uncertain. Among all 788 men in the trials, the number of adverse cardiovascular events was similar among those who received testosterone and those who got a placebo. Researchers say a larger, longer trial is needed to establish any clinical significance of testosterone treatment’s effect on plaque.
In the cognition trial, 493 men met the criteria for age-associated memory impairment. After one year of testosterone treatment, there was no significant change in spatial ability, verbal memory or visual memory when compared with a placebo group.
Pahor said he was encouraged by testosterone’s positive effect on anemia, which suggests it could be an additional treatment for the condition. He said other findings, particularly those involving bone density, need to be subjected to longer-term follow-up studies.
“The results on diverse outcomes indicated the potential trade-offs between benefits and risks of testosterone treatment in older men,” said Evan Hadley, M.D., director of the National Institute on Aging’s division of geriatrics and clinical gerontology. “However, clarifying the effects of testosterone on many major clinical outcomes such as cardiovascular events, fractures and disability will require longer, larger-scale trials. The results also illustrate that decisions about testosterone treatment need to be individualized, taking into account each patient’s balance of risks for the various conditions that testosterone could affect.”
The latest findings come a year after results from the first three of the testosterone trials, which examined sexual function, physical function and vitality, including mood and depressive symptoms, walking speed and walking distance. The researchers found that the treatment increased the blood testosterone level from moderately low to mid-normal in men ages 19-40 and improved all aspects of sexual function. Across the first three trials, adverse events including heart attack, stroke and prostate conditions were similar in men who received testosterone and those who received a placebo.
The impetus for the testosterone trials was a 2003 report by a group known then as the Institute of Medicine, which concluded there wasn’t enough evidence to support a beneficial effect of testosterone use among men with low levels of the hormone.
The trials were supported by grants from the National Institute on Aging and the National Institutes of Health. Additional support was provided by the National Heart, Lung and Blood Institute, the National Institute of Child Health and Human Development, the National Institute of Neurological Diseases and Stroke and the pharmaceutical company AbbVie.