Why men are more vulnerable to coronavirus: an explanation from scientists from the Netherlands

Earlier we reported that doctors from Beijing found out: men and women are equally often infected with a new type of coronavirus, but men are much more likely to be in intensive care and twice as likely to die from COVID-19. Now a team of scientists from the Netherlands has offered an explanation of why men are more vulnerable to the new coronavirus than women. Brief results are published as a preprint on the EurekAlert website!

A study conducted on several thousand patients shows that in men, the concentration of angiotensin-converting enzyme 2 (ACE2) in the blood is higher than in women. This may help explain why men, including those with heart failure, are more vulnerable to COVID-19 than women.

Dr. Adriaan Voors, professor of cardiology at the medical center at the University of Groningen (Netherlands), who led the study, explained that ACE2 is a receptor on the surface of cells. “It binds to coronavirus and allows it to penetrate and infect healthy cells after it has been modified by another enzyme on the surface of the cell called TMPRSS2. High levels of ACE2 are present in the lungs and therefore are believed to play a crucial role in the progression of lung diseases associated with COVID-19, ”says the researcher.

Professor Voors and his colleagues have already studied the differences in the markers of the disease in the blood of men and women before the outbreak of coronavirus. The results became available shortly after the pandemic.

Some recent studies have shown that RAAS inhibitors can increase the concentration of ACE2 in plasma, the liquid part of the blood, thereby increasing the risk of COVID-19 infection in patients with cardiovascular disease taking these drugs. However, a study by Dutch scientists showed that this is not so, although it only examined plasma concentrations of ACE2, and not in tissues such as, for example, the lungs. In addition, the findings mainly apply only to patients with heart failure who did not have coronavirus, therefore, researchers cannot find a direct relationship between the course of the disease and plasma ACE2 concentrations.

Researchers measured ACE2 concentrations in blood samples taken from two groups of heart failure patients from 11 European countries. The first group consisted of 1485 men and 537 women, whose average age was 69 and 75 years, respectively – this sample was intended to test hypotheses and research questions. Then, the researchers confirmed their results in the second group of 1,123 men and 575 women (the average age here was 74 and 76 years, respectively). And it turned out that men had a higher concentration of ACE2. Moreover, these cells were found not only in the lungs, but also in the heart, kidneys, and tissues lining the blood vessels, and especially high levels were in the testes. Researchers suggest that regulation of testicular function may partially explain higher ACE2 concentrations in men and why they are more vulnerable to the new coronavirus.

True, the study has a flaw – the researchers measured ACE2 concentrations only in plasma and not in tissues. However, it is believed that ACE2 is in the tissues of the lungs, and not blood, plays an important role in viral infection of the lungs.

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