Men considering testosterone treatments have a little more to go on thanks to another round of results from the T-Trials, the largest trials to date of testosterone treatment in men 65 and older who have low t. And the results are a mixed bag, with positive findings for anemia and bone density, but no change in cognitive functions such as memory. The studies also found a disturbing increase in arterial plaques that can lead to heart attacks and stroke.

Testosterone supplementation in older men remains controversial, much as hormone replacment therapy for menopausal women is. Both are works-in-progress.

Nearly 800 men were given testosterone gel or a placebo that they applied daily to the skin for a full year at 12 study sites across the country.

The main T-Trial, published last year, found improvements in sexual function and in mood among men given testosterone. Yet some doctors question the size and generalizability of those benefits and whether they offer a strong enough reason to prescribe testosterone to older men with low t.

Follow-Up T-Trials

Four sub-trials have just been published in four papers: two in the Journal of the American Medical Association (JAMA) and two in JAMA Internal Medicine, along with an editorial placing the findings in context. The studies reviewed cognitive function, anemia, bone density and cardiovascular health respectively. Nearly 800 men were given testosterone gel or a placebo that they applied daily to the skin for a full year at 12 sites across the country.

Cognitive Function These results are probably the most straightforward. After one full year, there was no significant change found in verbal memory, visual memory, executive function or spatial ability in either the testosterone group or the placebo group.

Anemia After one year of treatment, 54% of the men with unexplained anemia and 52% of those with anemia from known causes had clinically significant increases in hemoglobin levels, compared with 15% and 12% of those in the placebo group.

Bone Density After one year, men who took testosterone had significant increases in both bone mineral density — a marker of fracture risk — and estimated bone strength compared to men who took placebo. These effects were stronger in the spine than in the hip.

Cardiovascular Health This study found the amount of non-calcified coronary artery plaque — gummy material that clogs arteries — increased significantly more in the coronary arteries of men taking testosterone than in the placebo group.

This result is probably the hardest to interpret. Added plaque is expected to increase the likelihood of strokes and heart attacks. Yet none were reported in this study — it could be that it was neither large enough nor long enough to draw conclusions on the actual effects of this extra plaque. And other factors such as plaque type may be more important than the amount of plaque. Taken together, these considerations cause the researchers to conclude that, “Larger studies are needed to understand the clinical implications of this finding.”

“…[L]ow testosterone levels due to obesity and other aging comorbidities are better addressed by lifestyle measures…”

To cloud the issue even further, another study of testosterone and cardiovascular risk, not part of the T-Trials, found that when men with low testosterone were given prescriptions for testosterone, they had a lower risk of cardiovascular problems over the roughly three-year follow up period.

Lifestyle Changes Work Better
In an editorial in JAMA, David J. Handelsman, a professor of reproductive endocrinology and andrology, offers his opinion on what these four trials mean: “Overall, the findings from subtrials of the T-Trials do not materially change the unfavorable balance of safety and efficacy to initiate testosterone treatment for age-related hypogonadism. Rather, low testosterone levels due to obesity and other aging comorbidities are better addressed by lifestyle measures directed at those comorbidities.”

In other words, men hoping to improve their sex lives and health in general will find that losing some weight and joining a gym or changing your diet are likely to have a bigger and better effect than testosterone treatment.