COVID-19: Why men get sick more often - this enzyme seems crucial

Why do men get COVID-19 more often?

The coronavirus pandemic causes significantly more men than women to suffer serious illnesses. The question is why? According to a recent study, higher concentrations of a special enzyme in the men's body could play a crucial role here.

The current study by the University of Groningen found that an enzyme that is increasingly found in the male body enables the coronavirus to infect healthy cells. This could explain why men are more susceptible to COVID-19 than women. The results of the study were published in the European Heart Journal.

Men have higher levels of ACE2 in the blood

The study of several thousand people shows that men have higher levels of angiotensin converting enzyme 2 (ACE2) in the blood. The special enzyme serves as a so-called transmembrane protein and enables the coronavirus to infect healthy cells in the body.

How does ACE2 help the corona virus?

The corona virus uses ACE2 as a receptor. With the help of the transmembrane protein, the virus can penetrate and infect healthy cells, the researchers report. For example, high concentrations of ACE2 are present in the lungs, which is why it is assumed that ACE2 plays a crucial role in the progression of lung diseases associated with COVID-19.

ACE2 concentrations in blood samples were examined

The research group measured ACE2 concentrations in blood samples from two groups of heart failure patients from eleven European countries. In the first group, the index cohort, there were 1,485 men and 537 women. The results were validated in a second group of 1,123 men and 575.
The ACE2 concentration was therefore much higher in men than in women, which could explain why men are more likely to die of COVID-19 than women.

Male sex with elevated ACE2 values

The researchers examined a number of clinical factors that may play a role in ACE2 concentrations, such as the use of ACE inhibitors, ARB (angiotensin receptor blockers) and mineralocorticoid receptor antagonists (MRA), or a history of chronic obstructive pulmonary disease ( COPD), coronary by-pass transplantation and atrial fibrillation. However, the male gender was the strongest predictor of increased ACE2 concentrations overall, the research team reported.

Increased ACE2 levels from medication?

The researchers also found no evidence that drugs such as ACE inhibitors and ARB can be associated with increased ACE2 concentrations in plasma. Some recent research has suggested that, for example, in people with heart failure who are taking drugs that target the renin-angiotensin-aldosterone system (RAAS) (RAAS inhibitors), the concentration of ACE2 in the blood plasma may be increased. However, the current study found no evidence for this. (as)

Author and source information

This text corresponds to the requirements of the medical literature, medical guidelines and current studies and has been checked by medical doctors.


  • Iziah E Sama, Alice Ravera, Bernadet T Santema, Harry van Goor, Jozine M ter Maaten et al .: Circulating plasma concentrations of angiotensin-converting enzyme 2 in men and women with heart failure and effects of renin – angiotensin – aldosterone inhibitors, in European Heart Journal (Published May 10, 2020), European Heart Journal

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