researchers have found.
Low testosterone has long been linked to multiple chronic conditions, including obesity, heart disease, and type 2 diabetes, as well as acute conditions, such as heart attack and stroke. A study published earlier in the pandemic suggested that suppressing the sex hormone might protect against COVID-19. The new study, published in JAMA Network Open, is among the first to suggest a link between low testosterone and the risk for severe COVID.
Researchers at Washington University in St. Louis evaluated data from 723 unvaccinated men who had been infected with SARS-CoV-2. Of those, 116 had been diagnosed with hypogonadism, and 180 were receiving testosterone supplementation.
The study found that men whose testosterone levels were less than 200 ng/dL were 2.4 times more likely to experience a severe case of COVID-19 that required hospitalization than were those with normal levels of the hormone. The study accounted for the fact that participants with low testosterone were also more likely to have comorbidities such as diabetes and obesity.
Paresh Dandona, MD, PhD, distinguished professor of medicine and endocrinology at the State University of New York at Buffalo, called the findings “very exciting” and “fundamental.”
“In the world of hypogonadism, this is the first to show that low testosterone makes you vulnerable” to COVID, added Dr. Dandona, who was not involved with the research.
Men who were receiving hormone replacement therapy were at lower risk of hospitalization, compared with those who were not receiving treatment, the study found.
“Testosterone therapy seemed to negate the harmful effects of COVID,” said Sandeep Dhindsa, MD, an endocrinologist at Saint Louis University and lead author of the study.
Approximately 50% more men have died from confirmed COVID-19 than women since the start of the pandemic, according to the Sex, Gender and COVID-19 Project. Previous findings suggesting that sex may be a risk factor for death from COVID prompted researchers to consider whether hormones may play a role in the increased risk among men and whether treatments that suppress androgen levels could cut hospitalizations, but researchers consistently found that androgen suppression was not effective.
“There are other reasons women might be doing better – they may have followed public health guidelines a lot better,” according to Abhinav Diwan, MD, professor of medicine at Washington University in St. Louis, who helped conduct the new study. “It may be chromosomal and not necessarily just hormonal. The differences between men and women go beyond one factor.”
According to the researchers, the findings do not suggest that hormone therapy be used as a preventive measure against COVID.
“We don’t want patients to get excited and start to ask their doctors for testosterone,” Dr. Dhindsa said.
However, viewing low testosterone as a risk factor for COVID could be considered a shift in thinking for some clinicians, according to Dr. Dandana.
“All obese and all [men with] type 2 diabetes should be tested for testosterone, which is the practice in my clinic right now, even if they have no symptoms,” Dr. Dandana said. “Certainly, those with symptoms [of low testosterone] but no diagnosis, they should be tested, too.”
Participants in the study were infected with SARS-CoV-2 early in 2020, before vaccines were available. The researchers did not assess whether the rate of hospitalizations among participants with low testosterone would be different had they been vaccinated.
“Whatever benefits we saw with testosterone might be minor compared to getting the vaccine,” Dr. Dhindsa said.
Dr. Diwan agreed. “COVID hospitalization continues to be a problem, the strains are evolving, and new vaccines are coming in,” he said. “The bottom line is to get vaccinated.”
Dr. Dhindsa has received personal fees from Bayer and Acerus Pharmaceuticals and grants from Clarus Therapeutics outside the submitted work. Dr. Diwan has served as a consultant for the interpretation of echocardiograms for clinical trials for Clario (previously ERT) and has received nonfinancial support from Dewpoint Therapeutics outside the submitted work. Dr. Dandana has disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.