This is because men have higher levels of angiotensin-converting enzyme 2 or ACE-2 compared to women, according to a team of European researchers.
According to earlier research, ACE-2 works as a blood pressure regulator, a task it manages to complete by breaking down or cleaving specific amino acids in the body.
Aside from regulating the body’s blood pressure however, the enzyme has one other unlikely task: it can facilitate a successful coronavirus infection.
“ACE2 binds to the coronavirus and allows it to enter and infect healthy cells after it has been modified by another protein on the surface of the cell, called TMPRSS2,” Adriaan Voors, the study’s lead researcher and a professor of cardiology at the University Medical Center Groningen (UMCG) in the Netherlands, said.
This enzyme is usually found in several of the body’s organs, including the heart, lungs and kidneys, as well as in the lining of blood vessels, and, in the case of men, in the testes.
In their study, which was published in the European Heart Journal, Voors and his team noted that while men and women are equally likely to contract a coronavirus infection, men are more likely to suffer the disease’s more severe effects and complications — an effect that could probably be linked to the higher levels of ACE-2 in their systems.
Voors and his team measured ACE-2 concentrations in blood samples taken from more than 3,500 heart failure patients from 11 European countries, namely the Netherlands, the U.K., Germany, France, Greece, Slovenia, Serbia, Italy, Norway, Poland and Sweden. None of the patients had COVID-19. (Related: “We’re risking a backslide”: Public health experts concerned that emerging from lockdown can bring on a second wave of coronavirus infections.)
The latter detail stems from the fact that they started their research before the onset of the coronavirus pandemic, which is said to have originated in the city of Wuhan, in China’s Hubei Province.
According to the researchers, it was only when other studies began to point to ACE-2 as key to the way the SARS-CoV-2 virus gets into cells that they saw important overlaps with their study.
“When we found that one of the strongest biomarkers, ACE-2, was much higher in men than in women, I realized that this had the potential to explain why men were more likely to die from COVID-19 than women,” Iziah Sama from UMC Groningen, one of the study’s authors, said.
A global trend?
The findings listed by Voors’ team mirror that of several other studies investigating the disparity in COVID-19 deaths in terms of gender.
For example, a study conducted by the Chinese Center for Disease Control and Prevention and published in the Chinese Journal of Epidemiology found that 2.8 percent of Chinese men diagnosed with COVID-19 as of the second week of February, ultimately died. This is a much higher number compared to the 1.7 percent of women who died.
A similar result was recorded in Italy, in which an analysis of more than 25,000 COVID-19 cases found that male patients had a fatality rate of 8 percent, compared to 5 percent for Italian women. In fact, according to data supplied by the Italian National Health Service, men make up around 70 percent of the total coronavirus deaths in Italy.
“Being male is as much a risk factor for the coronavirus as being old,” said Sabra Klein, a scientist who studies sex difference in viral infections at Johns Hopkins Bloomberg School of Public Health, in an interview with the New York Times regarding the disparity in death rates in the European nation, adding that people need to be aware of the “pattern.”
“Just like being old means you’re at higher risk, so does being male. It’s a risk factor,” Klein said in her interview.
The same trend can be found in Spain, in which an analysis conducted by the Carlos III Health Institute found that while men only represented around 52 percent of the country’s coronavirus cases, they made up 66 percent of the country’s total coronavirus-related deaths.
Aside from ACE-2 levels, other researchers have raised other theories as to why men seem to be more vulnerable overall to COVID-19, such as preexisting conditions and poor health habits.
In a statement, Fernando Simón, the director of the Spanish Health Ministry’s Coordination Center for Health Alerts, noted that the Institute’s findings suggest that certain groups, such as those with high blood pressure, people with respiratory problems and diabetics, are more at risk of the disease.
“The illness affects certain risk groups more: those with high blood pressure, people with respiratory problems, diabetics – they all have higher mortality rates. These illnesses affect men more than women, which is why it is normal that they suffer higher death rates,” Simón said.
A poll, meanwhile, found that one in 20 American men rarely wash their hands with soap after going to the bathroom at home. The World Health Organization (WHO) previously said that handwashing with soap is critical in the fight against coronavirus.
As of this writing, the COVID-19 pandemic has infected 4.4 million people around the world and killed 298,174.