People with chronic obstructive pulmonary disease (COPD) who are overweight have increased levels of the protein that the SARS-CoV-2 virus — the virus that causes COVID-19 — uses to get into cells, a new study shows.
The results suggest that these individuals may be at greater risk of contracting COVID-19.
The study, “Increased ACE2 Expression in the Bronchial Epithelium of COPD Patients who are Overweight,” was published in the journal Obesity.
Although scientific understanding of COVID-19 is incomplete, both COPD and obesity have been cited as risk factors for more severe complications from COVID-19. Previous studies also have suggested that ACE2 levels are higher in the tissues of people with COPD and of people who are obese.
Researchers at the University of Manchester, U.K., investigated the levels of ACE2 in lung cells from people with COPD who were overweight compared to those who were not. The team dis not assess levels of the ACE2 protein itself, but the RNA that provides instructions for making the protein.
Samples from 37 people with COPD, obtained by bronchoscopy, were analyzed. Of these, 23 patients were overweight — defined as a body mass index (BMI) greater than 24.9 kilograms per height in square meters (kg/m2). About a third of this group of patients was female, and the average age was 62 years.
There were no significant clinical differences between individuals who were overweight and those who were not, except that overweight individuals reported more severe shortness of breath.
Data showed that ACE2 expression was higher in individuals who were overweight. A correlation was found between BMI and ACE2 but it was not statistically significant.
No significant associations between ACE2 expression and high blood pressure were found, and neither were there significant differences among individuals who were or were not taking ACE inhibitors (commonly prescribed therapies to treat high blood pressure).
A significant negative correlation between ACE2 expression and forced expiratory volume (FEV), a common measurement of lung function, was found. In other words, people with poorer lung function tended to have higher ACE2 expression, and vice versa.
Current smokers tended to have higher ACE2 expression than non-smokers; however, this difference did not reach statistical significance.
Different from ACE2, TMPRSS2 expression was not significantly different between COPD patients who were or were not overweight.
Overall, “if increased ACE2 expression allows greater virus uptake, then our data suggests that the subgroup of COPD patients who are overweight have a higher risk of developing severe COVID-19,” the researchers wrote.
“There is evidence that mortality from COVID-19 is higher in patients with medical conditions including COPD,” Andrew Higham, PhD, study co-author, said in a press release. “Our observations suggest being overweight and having COPD puts people at an even greater risk of catching the virus.”
Dave Singh, MD, the other study co-author added: “If you do have COPD and are overweight, then we think that it is extremely important to follow the guidance and continue to use shielding strategies to keep yourself safe from COVID-19.”