Men have higher blood levels of a molecule that enables the novel coronavirus to infect healthy cells than women, according to a study, published in the European Heart Journal.
The study also found that heart failure patients taking drugs such as angiotensin-converting enzyme (ACE) inhibitors, or angiotensin receptor blockers (ARBs), did not have higher concentrations of the coronavirus gateway enzyme ACE2 in their blood.
“Our findings do not support the discontinuation of these drugs in COVID-19 patients as has been suggested by earlier reports,” said Adriaan Voors, study co-author from the University of Groningen in the Netherlands.
Earlier studies had suggested that these drugs might increase the risk of COVID-19 for cardiovascular patients taking these drugs.
But the current study suggests otherwise.
“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 is has been modified by another protein on the surface of the cell, called TMPRSS2,” Voors said.
“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,” he added.
In the study, the researchers measured ACE2 concentrations in blood samples taken from two groups of heart failure patients from 11 European countries.
There were 1,485 men and 537 women in the first group, the index cohort, which was designed to test the researchers’ hypotheses and research questions.
Then the researchers validated their findings in a second group of 1123 men and 575 women, the validation cohort.
According to the study, the average age of the participants in the index cohort was 69 years for men, and 75 years for women, and in the validation cohort it was 74 and 76 years, respectively. The researchers assessed the number of clinical factors that could play a role in ACE2 concentrations, including the use of ACE inhibitors, a history of chronic obstructive pulmonary disease, and coronary artery by-pass graft.
They found that male sex was the strongest predictor of elevated ACE2 concentrations. In the index cohort, the scientists said ACE inhibitors were not associated with greater ACE2 plasma concentrations. In the validation cohort, they said that ACE inhibitors and ARBs were associated with lower ACE2 concentrations.
“To the best of our knowledge, this is the first substantial study to examine the association between plasma ACE2 concentrations and the use of blockers of the renin-angiotensin-aldosterone system in patients with cardiovascular disease,” Voors said.
The study, according to the researchers, found no evidence that ACE inhibitors and ARBs were linked to increased ACE2 concentrations in plasma. “In fact, they predicted lower concentrations of ACE2 in the validation cohort, although we did not see this in the index cohort,” Voors said.