New research suggests that asthma may not be a significant risk factor for developing coronavirus disease 2019 (COVID-19) that is severe enough to require hospitalization and intubation.

According to the CDC, individuals with asthma are at higher risk of hospitalization due to COVID-19, such as those with obesity, hypertension, and diabetes. New research has found, however, that the proportion of patients with asthma among those hospitalized with COVID-19 was relatively similar to the overall prevalence of asthmatics at several investigated health systems. 

Fernando Holguin, MD, MPH, and co-authors compared the prevalence of asthma among hospitalized patients as reported in 15 peer-reviewed studies with the prevalence among the corresponding population. They also compared the study’s asthma prevalence with the 4-year prevalence of asthma in influenza hospitalizations.

“The CDC places people with asthma at higher risk for COVID-related hospitalization,” Holguin said in a press release. “However, many international studies show low numbers of asthmatics among hospitalized COVID-19 patients. These findings challenge the assumption about asthma as a risk factor.”

After performing a focused review of English language scientific literature, researchers agreed on 15 studies to include in their analysis. Using local data from hospitalized patients with COVID-19, they determined the relationship between asthma status and intubation after taking into account patients’ age, gender, and body mass index.

In addition to finding that the proportion of hospitalized COVID-19 patients with asthma was similar to the proportion of asthmatics in the overall population, the investigators also found that among COVID-19 patients, asthmatics did not seem more likely to be intubated.

“Using data from our hospital, we also observed that among COVID-19 patients, those with asthma, which had a 12% prevalence rate, did not seem to be more likely to be intubated than non-asthmatics,” the researchers said in a press release.

Although it requires further research, the investigators theorized that the corticosteroid inhalers used by many patients with asthma may make it more difficult for coronaviruses to enter their airways. Specifically, those patients may have lower levels of expression of angiotensin-converting enzyme2 (ACE2), a protein that binds to the severe acute respiratory syndrome coronavirus 2.

“The contribution of ACE2 receptor expression levels to COVID-19 susceptibility is still unclear, however, it should certainly be further investigated,” Holguin concluded.

REFERENCE
Asthma May Not Be a Significant Risk Factor for Severe COVID-19 or COVID-Related Intubation [news release]. American Thoracic Society; August 31, 2020. https://www.thoracic.org/about/newsroom/press-releases/journal/2020/asthma-may-not-be-a-significant-risk-factor-for-severe-covid-19-or-covid-related-intubation.php. Accessed September 9, 2020.