Low Testosterone Could Kill You

June 6, 2007 — -- Low testosterone may lead to a greater risk of death, according to a study presented Tuesday at the annual meeting of the Endocrine Society in Toronto.

Men with low testosterone had a 33 percent greater death risk over their next 18 years of life compared with men who had higher testosterone, according to the study conducted by Dr. Elizabeth Barrett-Connor and colleagues at the University of California at San Diego.

"It's very exciting and potentially a groundbreaking study," said Barrett-Connor. "But it needs to be confirmed."

The study tracked nearly 800 men, 50 to 91 years old, living in California. Their testosterone level was measured at the beginning of the study, and their health was then tracked over the next 20 years.

Testosterone normally declines as men get older. However, a clear definition of "low" testosterone does not yet exist.

"No one knows what low really is," said Dr. Joel Finkelstein, endocrinologist and associate professor at Harvard Medical School. "The study authors defined it at 250 [nanograms per deciliter], which is a definition, but no one has figured out what low is."

Barrett-Connor and her colleagues found that nearly 30 percent of the men they studied met their criterion score of 250 or lower for low testosterone.

They noted that many men with this definition of low testosterone were "healthy men in the community who would not know that they had low testosterone."

Symptoms of low testosterone depend on how low the level is. At the lowest levels, men will have hot flashes, much like those experienced by women during menopause.

"At levels not quite that low, men have decreases in their libido, erectile dysfunction, fatigue and physiological changes many will not immediately recognize," Finkelstein said, adding that these could include loss of strength, decrease in bone density and decreased muscle mass.

However, absent symptoms, there is no reason to get testosterone treatment.