Effects of Testosterone Treatment in Older Men
Serum testosterone concentrations decrease as men age, but is there a risk or benefit of raising testosterone levels in older men with symptoms of “low T”?
Seven hundred and ninety men, 65 years of age or older, with a serum testosterone concentration of <275 ng/dl and symptoms suggesting hypoandrogenism were randomized to receive either testosterone gel or placebo gel for 1 year. Each participated in one or more of three trials: the Sexual Function Trial, the Physical Function Trial, and the Vitality Trial. The primary outcome of each of the individual trials was also evaluated in all participants.
A total of 51,085 men were screened to enroll 790. Only 15% qualified based on testosterone levels. Mean age was 72 years with high rates of obesity and hypertension, about 20% had obstructive sleep apnea, and 15% had a history of myocardial infarction. Testosterone treatment increased serum testosterone levels to the mid-normal range for men 19-40 years of age. The increase in testosterone levels was associated with significantly increased sexual activity (p < 0.001), as well as significantly increased sexual desire and erectile function. The percentage of men who had an increase of at least 50 m in the 6-minute walking distance did not differ significantly between the two study groups, but did differ significantly when men in all three trials were included (20.5% of men who received testosterone vs. 12.6% of men who received placebo, p = 0.003). Testosterone had no significant benefit with respect to vitality, but men who received testosterone reported slightly better mood and lower severity of depressive symptoms than those who received placebo. The rates of adverse events were similar in the two groups.
In symptomatic men 65 years of age or older, raising testosterone concentrations for 1 year from moderately low to the mid-normal range for men 19-40 years of age had a moderate benefit with respect to sexual function and some benefit with respect to mood and depressive symptoms, but no benefit with respect to vitality or walking distance. The number of participants was too few to draw conclusions about the risks of testosterone treatment.
This report from the National Institutes of Health-sponsored Testosterone Trials provides results for three of the seven primary endpoints; the remainder include cardiovascular disease status, bone density, cognitive function, and anemia. It is premature to conclude treating symptomatic men over 65 years of age with ‘low T’ is safe, particularly in relationship to prostate cancer and cardiovascular disease. Sexual desire improved but erectile function improvement was less than that reported with the phosphodiesterase-5 inhibitors. The study provided no criteria from which to identify men more or less likely to respond favorably to testosterone therapy.
Keywords: Depression, Hypertension, Libido, Male, Motor Activity, Myocardial Infarction, Obesity, Penile Erection, Primary Prevention, Prostatic Neoplasms, Sexual Behavior, Sleep Apnea, Obstructive, Testosterone
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