Covid-19: Men are more affected by an enzyme
A study published by the European Heart Journal points to the enzyme ECA2, which is found in large amounts in men. This cell surface receptor binds to the coronavirus and allows it to infect the body.
Figures vary by country and experts, but the observation is the same: men are more vulnerable to the coronavirus than women. Why ? Researchers at the University Medical Center in Groningen, The Netherlands noted a higher concentration of angiotensin-converting enzyme 2 (ECA2) in the blood, which could explain this difference.
The study was published in a special issue of the European Heart Journal. Blood samples were taken from 11 different European countries. A first group of 1,485 men and 537 women was used to test the scientists' hypotheses. And a second group of 1,123 men and 575 women served as a validation cohort.
An enzyme found in the testicles and lungs.
The average age of the participants in the first group was 69 for men and 75 for women. In the second group, they were 74 and 76 years old. All suffered from heart failure, but were not infected with the coronavirus.
Professor Adriaan Voors, who participated in this work, told the European Society of Cardiology: "ECA2 is a receptor located on the surface of cells. It binds to the coronavirus and allows it to penetrate and infect healthy cells after being modified by another protein. High levels of ECA2 are present in the lungs and therefore are believed to play a crucial role in the progression of COVID-19 related lung disorders".
The enzyme is also found in the heart, kidneys, and tissues that line blood vessels. Its levels are particularly high in pesticides. This factor would partially explain, according to the study authors, why men are more vulnerable than women.
The researchers also looked at the effect of the drugs used by the volunteers to treat their heart failure. "Our conclusions do not support discontinuation of these medications in patients with COVID-19, as suggested by previous reports," they recall. "They are a very effective treatment for heart failure, and the hypothetical effects on viral infection must be carefully weighed against their proven benefits".
Recent research has suggested that certain treatments may increase ACE2 levels in the blood, increasing the risk of coronavirus for cardiovascular patients taking these drugs. The current study indicates that this is not the case, although it only examined the concentrations of the enzyme in plasma and not in tissues such as lung tissue.