In this study, led by a team at the University of Western Australia, the researchers combined the results of 11 high-quality studies (known as a meta-analysis) investigating the effect of testosterone levels on lifespan. The studies followed men for at least five years and found that participants with the lowest testosterone levels were more likely to die.

Death in this study was from any cause, but digging deeper into the analysis reveals that this is mostly due to heart disease—still the leading cause of death in men globally. Low testosterone in men associated with an early death (medicalxpress.com)