Study Links Heart Disease Deaths to Low Testosterone

Researchers followed more than 3,600 elderly men living on their own for about five years on average. Over that time, about 6% died of heart disease, with higher mortality in men with lower levels of free testosterone.

The results add to a confusing tangle of data. Some show low testosterone levels are linked to earlier deaths, including those due to heart disease, while other data don't.

Pharmaceutical companies are also promoting testosterone therapy for problems like grumpiness, lack of energy and decreased libido.

Dr. Frederick Wu, a hormone expert at the University of Manchester in the UK stated that, "Low T is associated with poor health." "But it does not mean that low T is the cause of poor health or increased mortality."

Earlier this year, a large meat-analysis concluded that declines in testosterone are unlikely to shorten a man's lifespan, but instead might be related to declining health.

Zoe Hyde of the Western Australia Centre for Health and Aging, who worked on the latest study, said that was not a likely explanation when it comes to heart disease.

"There is good evidence that testosterone has beneficial effects with regard to the cardiovascular system. For example, testosterone has been shown to increase lean mass (including muscle), whilst decreasing fat mass. It can also have some positive effects on cholesterol levels," she told Reuters Health in an email.

The researchers, who published their findings, did adjust for various risk factors.

But that still doesn't prove low testosterone is harmful to the heart, according to Dr. Wu. "This conclusion is somewhat premature," he said.

One recent clinical trial that tested a testosterone gel on elderly men had to be stopped early because the drug turned out to cause heart problems -- not prevent them. Hyde acknowledged that her study is not definitive.

"We need to wait for the results of clinical trials before we can properly understand both the benefits and also the risks of testosterone therapy," she said.