Men may not live as long if they have low testosterone, regardless of their age, according to a new study. The results will be presented at The Endocrine Society's 90th Annual Meeting in San Francisco.

The new study, from Germany, adds to the scientific evidence linking deficiency of this sex hormone with increased death from all causes over time-so-called "all-cause mortality."

The results should serve as a warning for men with low testosterone to have a healthier lifestyle, including weight control, regular exercise and a healthy diet, said lead author Robin Haring, a PhD student from Ernst-Moritz-Arndt University of Greifswald, Institute for Community Medicine.

"It is very possible that lifestyle determines levels of testosterone," he said.

In the study, Haring and co-workers looked at death from any cause in nearly 2,000 men aged 20 to 79 years who were living in northeast Germany and who participated in the Study of Health in Pomerania (SHIP). Follow-up averaged 7 years. At the beginning of the study, 5 percent of these men had low blood testosterone levels, defined as the lower end of the normal range for young adult men. The men with low testosterone were older, more obese, and had a greater prevalence of diabetes and high blood pressure, compared with men who had higher testosterone levels, Haring said.

Men with low testosterone levels had more than 2.5 times greater risk of dying during the next 10 years compared to men with higher testosterone, the study found. This difference was not explained by age, smoking, alcohol intake, level of physical activity, or increased waist circumference (a risk factor for diabetes and heart disease), Haring said.

In cause-specific death analyses, low testosterone predicted increased risk of death due to cardiovascular disease and cancer but not death of any other single cause.