A man brought to the Novomoskovsky multipurpose medical center for patients with suspected coronavirus infection in Moscow, Russia, on April 30.
Mikhail Metzel/TASS/Getty Images
While Covid-19 can sicken anyone, the illness appears to have a more severe impact on older men with chronic conditions — and a new study suggests why.
The study, published in the European Heart Journal today, finds that men with heart failure tend to have higher concentrations of a certain enzyme — angiotensin-converting enzyme 2 or ACE2 — in their blood than women with heart failure.
Higher ACE2 concentrations might lead to increased vulnerability to the coronavirus, the study’s authors suggest, but more research is needed, especially since the adults in the study were not Covid-19 patients.
“ACE2 is a receptor on the surface of cells. It 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,” Dr. Adriaan Voors, professor of cardiology at the University Medical Center Groningen in the Netherlands, who led the study, said in a press release.
“High levels of ACE2 are present in the lungs and, therefore, it is thought to play a crucial role in the progression of lung disorders related to COVID-19,” Voors said.
The types of drugs known as “ACE inhibitors” are often administered to help lower blood pressure and treat heart, blood vessel and kidney problems. Yet in the new study, ACE inhibitor medications were not associated with the ACE2 concentrations found in the plasma samples. This differs with previous reports suggesting these drugs increase concentrations and therefore increase the risk of Covid-19.
About the study: The new study involved measuring ACE2 concentrations in blood plasma samples from 1,485 men and 537 women with heart failure in 11 European countries. Those results were validated in another, independent cohort of 1,123 men and 575 women with heart failure in Scotland.
The researchers found that in both cohorts, plasma ACE2 concentrations were higher in men than in women. The mean plasma concentration was 5.38 in men compared with 5.09 in women among the original cohort of adults and then in the validation cohort, the mean plasma concentration was 5.46 in men compared with 5.16 in women, according to the study.
Remember: The study had some limitations, including that it only involved heart failure patients. More research is needed to determine whether similar findings would emerge among a more diverse group of adults, including either healthy adults or those with Covid-19. Additionally, ACE2 concentrations in the study were only measured in plasma and not tissue samples from patients.
Overall, “in two large cohorts of patients with heart failure, plasma ACE2 concentrations were higher in men than in women, possibly reflecting higher tissue expression of this receptor for SARS coronavirus infections,” the researchers wrote in the study. “This could explain why men might be more susceptible to infection with, or the consequences of, SARS-CoV-2. Patients receiving ACE inhibitors or ARBs did not have higher plasma concentrations of ACE2, and any effect of MRAs was small and inconsistent, supporting the continued use of these agents in patients with heart failure during the current SARS-CoV-2 pandemic.”