Written By: Longjam Dineshwori | Updated : May 13, 2020 8:00 AM IST
Smokers and people with COPD have a higher level of an enzyme called ACE-2, which is the entry point for coronavirus in lungs. © Shutterstock
No one is safe from COVID-19, but certain groups of people are apparently more susceptible to this deadly disease. Elderly people, those with underlying health conditions like diabetes, heart disease, etc., are said to be at greater risk of getting COVID-19 infection and complications.
Now, a new research has warned that current smokers and people with chronic obstructive pulmonary disease (COPD) also have an increased risk of severe complications and higher mortality with COVID-19 infection. COPD is a common, persistent dysfunction of the lung associated with a limitation in airflow. It is estimated to affect around 251 million people worldwide.
Smoking has been linked to a variety of health problems. But the new research, published in the journal PLOS ONE, indicated that smoking during the COVID-19 pandemic could be even more dangerous.
"Despite the low prevalence of COPD and smoking in COVID-19 cases, COPD and current smokers were associated with greater COVID-19 severity and mortality," said the researchers from University College London in the UK.
For the results, the researchers studied the data of a total of 2473 confirmed COVID-19 patients, of which 58 (2.3 per cent) had COPD while 221 (9 per cent) were smokers.
The findings showed that critically ill COVID-19 patients with COPD had a 63 per cent risk of severe disease and a 60 per cent risk of mortality. On the other hand, critically ill patients without COPD had only a 33.4 per cent risk of severe disease and 55 per cent risk of mortality.
The research also found that current smokers were 1.45 times more likely to have severe complications compared to former and never smokers.
A previous study, published in the journal American Journal of Respiratory and Critical Care Medicine, had also suggested an increased risk for the novel coronavirus gaining entry into the lungs of smokers than non-smokers.
Smokers and people with COPD have a higher level of an enzyme called 'angiotensin-converting enzyme II' (ACE-2), which is the entry point for coronavirus in lungs. This was the explanation given by another study, published in European Respiratory Journal.
Men have higher concentrations of ACE-2 in their blood than women. This is the reason why men are more vulnerable to COVID-19 infections and complications than women. According to researchers from the University of Groningen in the Netherlands, this enzyme enables the novel coronavirus to infect healthy cells in men. The European Heart Journal had published this study.
In this study, the researchers only looked at ACE2 concentrations in plasma, not in tissues such as lung tissue. As explained by them, ACE2 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, called TMPRSS2. "High levels of ACE2 are present in the lungs and, therefore, it may play a crucial role in the progression of lung disorders because of COVID-19," said the researchers.
ACE2 is particularly present in very high levels in the testes. The regulation of ACE2 in the testes may partially explain higher ACE2 concentrations in men, and why men are more vulnerable to COVID-19, the researchers noted.
A study published in Frontiers in Public Health revealed that men are more than twice as likely to die from the disease as compared to women.
With inputs from IANS
