June 5, 2007 -- Low testosterone levels may be linked to a higher death rate in men aged 50 and older.
That's according to a study presented today in Toronto at The Endocrine Society's 89th annual meeting.
The study included nearly 800 men in Rancho Bernardo, Calif. The men enrolled in the study between 1984 and 1987. At the time, they were 50-91 years old.
The men provided blood samples at the study's start. They were followed until death or July 2004, whichever came first.
The researchers included Gail Laughlin, PhD, an assistant professor in the department of family and preventive medicine at the University of California, San Diego.
Laughlin and colleagues found that most of the men had normal testosterone levels. However, 29% of the men had low testosterone levels.
During the study's average follow-up time of 18 years, 538 men died of any cause. Men with low testosterone levels were 33% more likely to die during the follow-up period than with men with normal testosterone levels.
In analyzing the data, the researchers considered the men's age, lifestyle habits (such as smoking, drinking, and physical activity), waist girth, and BMI (body mass index). BMI relates height to weight.
The results didn't appear to be due to health problems, such as diabetes or heart disease, that the men had at the study's start. However, metabolic syndrome was associated with low testosterone levels.
The study doesn't show exactly why the 538 men died, and it doesn't prove that low testosterone had anything to do with those deaths.
UCSD researchers plan to study testosterone supplements as a possible solution, but Laughlin and colleagues aren't making any recommendations yet.
"The study did show [that] there may be an association between low testosterone levels and higher mortality. It did not show that higher levels of testosterone are associated with decreased mortality," Laughlin says in a UCSD news release.
"We are very excited about these findings, which have important implications, but we are not ready to say that men should go out and get testosterone to prolong their lives," says Elizabeth Barrett-Connor, MD, in the news release.
Barrett-Connor is Distinguished Professor in the family and preventive medicine department and chief of the epidemiology division at UCSD.
- Would you supplement your testosterone? Tell us about it on the WebMD Men's Health: Man-to-Man board.