Testosterone insufficiency increases death risk in older men

Testosterone insufficiency in older men is associated with increased risk of death over the following 20 years, independent of multiple risk factors and several pre-existing health conditions, according to researchers from the University of California, San Diego School of Medicine.

Gail A. Laughlin, MD, and colleagues studied 794 men, age 50 to 91 years, who had serum testosterone measurements at baseline (1984-1987) and followed them for mortality through July 2004.

During an average 11.8 year follow-up, 538 deaths occurred. Men whose total testosterone levels were in the lowest quartile (<241 ng/dL) were 40% more likely to die than were those with higher levels, independent of age, adiposity, and lifestyle (HR=1.40; 95% CI, 1.14–1.71). Additional adjustment for health status markers, lipids, lipoproteins, blood pressure, glycemia, adipocytokines, and estradiol levels had minimal effect on results.

The low testosterone-mortality association was also independent of the metabolic syndrome, diabetes, and prevalent cardiovascular disease, but was attenuated by adjustment for IL-6 and C-reactive protein. In cause-specific analyses, low testosterone predicted increased risk of cardiovascular (HR, 1.38; 95% CI, 1.02- 1.85) and respiratory disease (HR, 2.29; 95% CI, 1.25–4.20) mortality, but was not significantly related to cancer death (HR, 1.34; 95% CI, 0.89, 2.00). Results were similar for bioavailable testosterone.

The study will appear in the Journal of Clinical Endocrinology & Metabolism.