Throughout the pandemic, doctors have seen evidence that men with COVID-19 fare worse, on average, than women with the infection. One theory is that hormonal differences between men and women may make men more susceptible to severe disease. And since men have much more testosterone than women, some scientists have speculated that high levels of testosterone may be to blame.
But a new study from Washington University School of Medicine in St. Louis suggests that, among men, the opposite may be true: that low testosterone levels in the blood are linked to more severe disease. The study could not prove that low testosterone is a cause of severe COVID-19; low levels could simply serve as a marker of some other causal factors. Still, the researchers urge caution with ongoing clinical trials investigating hormonal therapies that block or lower testosterone or increase estrogen as a treatment for men with COVID-19.
The study appears online May 25 in JAMA Network Open.
“During the pandemic, there has been a prevailing notion that testosterone is bad,” said senior author Abhinav Diwan, MD, a professor of medicine. “But we found the opposite in men. If a man had low testosterone when he first came to the hospital, his risk of having severe COVID-19 — meaning his risk of requiring intensive care or dying — was much higher compared with men who had more circulating testosterone. And if testosterone levels dropped further during hospitalization, the risk increased.”