Although the association of low serum testosterone levels with mortality has gained strength in recent research, there are few population-based studies on this issue. This study examined whether low serum testosterone levels are a risk factor for all-cause or cause-specific mortality in a population-based sample of men aged 20-79. We used data from 1954 men recruited for the prospective population-based Study of Health in Pomerania, with measured serum testosterone levels at baseline and 195 deaths during an average 7.2-year follow-up. A total serum testosterone level of less than 8.7 nmol/L (250 ng/dL) was classified as low. The relationships of low serum testosterone levels with all-cause and cause-specific mortality were analysed by Cox proportional hazards regression models. Men with low serum testosterone levels had a significantly higher mortality from all causes than men with higher serum testosterone levels (HR 2.24; 95% CI 1.41-3.57). After adjusting for waist circumference, smoking habits, high-risk alcohol use, physical activity, renal insufficiency, and levels of dehydroepiandrosterone sulfate, low serum testosterone levels continued to be associated with increased mortality (HR 2.32; 95% CI 1.38-3.89). In cause-specific analyses, low serum testosterone levels predicted increased risk of death from cardiovascular disease (CVD) (HR 2.56; 95% CI 1.15-6.52) and cancer (HR 3.46; 95% CI 1.68-6.68), but not from respiratory diseases or other causes. Low serum testosterone levels were associated with an increased risk of all-cause mortality independent of numerous risk factors. As serum testosterone levels are inversely related to mortality due to CVD and cancer, it may be used as a predictive marker.
