Abstract
BACKGROUND AND OBJECTIVES: Testosterone plays an important role in regulating male development, reproduction and health. Declining levels across the lifespan may reflect, or even contribute to, chronic disease and mortality in men. METHODOLOGY: Relationships between testosterone levels and male mortality were analyzed using data from multiple samples of the cross-sectional National Health and Nutrition Examination Survey (n = 10 225). Target outcomes included known deaths from heart disease, malignant neoplasms, chronic lower respiratory diseases, cerebrovascular diseases, Alzheimer's disease, diabetes mellitus, influenza and pneumonia, kidney diseases, and accidents or unintentional injuries. RESULTS: Results of discrete-time hazard models revealed that lower levels of testosterone were related to higher mortality for the majority of disease categories in either an age-dependent or age-independent fashion. Analysis of all-cause mortality-which included deaths from any known disease-also revealed greater general risk for those with lower testosterone levels. For most disease categories, the hazard associated with low testosterone was especially evident at older ages when mortality from that particular ailment was already elevated. Notably, testosterone levels were not related to mortality risk for deaths unrelated to chronic disease (i.e. accidents and injuries). CONCLUSIONS AND IMPLICATIONS: While the causal direction of relationships between testosterone and mortality risk remains unclear, these results may reflect the decline in testosterone that accompanies many disease states. Accordingly, the relationship between testosterone and male mortality may be indirect; ill individuals are expected to have both lower testosterone and higher mortality risk.