Testosterone for the elderly: good for the muscles, bad for the heart?

Aging comes with a lot of difficulties, including decreased mobility which limits an old person’s independence and overall quality of life. Health experts believe that impaired mobility in the elderly may be partly due to decreased muscle strength. Previous studies have shown that supplementation with the male hormone testosterone improve muscle strength.

The TOM (Testosterone in Older Men) trial investigated whether testosterone can improve mobility in older men with low testosterone levels. The study was designed as a randomized, double-blind, placebo-controlled clinical trial.  The study participants were 209 men aged, on average 74 years old who had testosterone levels and reduced mobility. Testosterone treatment was in the form of a topical gel applied on the skin daily for 6 months. The participants were assessed on their ability to walk and climb stairs. Of the 209 participants, 106 received testosterone gel and 103 received a dummy gel – a placebo. The trial was double-blinded, meaning neither the researchers conducting the study nor the study participants could distinguish between the two gels during the study period.

However, the trial was stopped rather prematurely due to adverse events, complications that were thought to be related to the testosterone treatment. The participants were told to stop using their medications. Of those who were treated with testosterone, 23 suffered from so-called cardiovascular events such as heart attack, heart rhythm disturbances and hypertension. One death possibly due to a heart attack was reported. In the group who received the placebo gel, only 5 cardiovascular events were reported.

It is not clear whether the testosterone was really responsible for the cardiovascular events because the study participants were old and many of them were suffering from chronic diseases such as diabetes and cardiovascular disease. The results were published in the New England Journal of Medicine.

“The authors caution that the ability to draw broader conclusions about the safety of testosterone therapy based on these findings is constrained by several factors, including this study’s small size and the fact that the study’s population was older and had higher rates of chronic diseases and mobility limitation than individuals in most other studies.”

However, the Data and Safety Monitoring Board (DSMB) which regularly monitors the safety of clinical trials believed the possible adverse effects of testosterone treatment seem to outweigh the benefits, and thus recommended that the study be halted.