Men at Higher Risk of Dying From COVID, Needing Intensive Care Treatment, Study Shows

New research suggests that COVID-19 has more fatal and serious impacts on men than on women.

A new study published in Nature Communications found that men infected with the virus are three times more likely to require hospitalization in an intensive care unit and are at a significantly higher risk of death.

While men and women are equally likely to contract COVID-19—"exactly half" of the confirmed cases were male patients—men are 39 percent more likely to die from the virus.

"These data may help doctors to recognize that sex is a risk factor for severe disease when managing patients," co-author Kate Webb told Agence France-Presse.

"Sex is an under reported variable in many studies and this is a reminder that it is an important factor to consider in research," Webb said.

Researchers, who analyzed over 3 million confirmed cases of coronavirus from 46 countries and 44 U.S. states, found the trend to be global.

The authors said two key biological differences put women at an advantage of fighting off grave forms of the virus.

For one, women naturally produce more type I interferon proteins, which is important for the early response in COVID-19.

"Type I interferon proteins are an important component of the immune response to viral infections," co-author Claire Deakin told Newsweek.

The "female" oestradiol hormone can also boost the response of T cells, which kill off infected cells, as well as increase the production of antibodies.

On the other hand, testosterone does the opposite and suppresses the immune system.

But the finding is not uncommon. There was also a higher mortality rate in men from the SARS epidemic and the MERS outbreak.

"Previous coronavirus outbreaks have demonstrated the same sex bias," the study said.

A man is given a Pfizer-BioNTech Covid-19 vaccine at Cardiff and Vale Therapy Centre on December 8 in Cardiff, Wales. A new study found that men are more likely than women to die from the virus. Matthew Horwood/Stringer

The study noted that there is limited data available on the role of other medical conditions. Based on preliminary data, cancer, kidney disease, obesity, heart conditions and type 2 diabetes are among underlying health conditions that increase the risk of severe illness from the virus.

However, the authors note hypertension and diabetes, the most commonly reported comorbidities in hospitalized COVID-19 patients, is found in similar proportions between men and women.

And while it is known that certain biological factors play a role in the immune systems of men and women, it is difficult to use this data to prevent men from having more serious cases of COVID-19, especially when it is uncertain which other factors may influence their responses to the virus.

"We can't say that sex hormones are the driver of this effect from our study and so can't speculate on the possibility of therapeutic manipulation of sex hormones," Deakin said.

"Although further studies are needed, these data have implications for the clinical management of COVID-19 and highlight the importance of considering sex as a variable in fundamental and clinical research," the study said.

In an early study published last month, researchers from the University of Miami in Florida also found that the coronavirus may negatively affect male fertility. However, the doctors noted more research needs to be conducted to fully understand COVID-19's effects on testis tissue.

Update 12/12/20 8:57 a.m. ET, with comments from Deakin.