Researchers in Australia analyzed data from 57 studies with an overall sample size of 587,280 individuals. Approximately 350,000 people in the pool had been infected with COVID-19 from Asia, Europe, and North and South America.
Findings from a study on coronavirus disease 2019 (COVID-19) and asthma reinforced that having the respiratory condition does not increase the risk of severe illness or death from COVID-19.
Researchers in Australia analyzed data from 57 studies with an overall sample size of 587,280 individuals. Approximately 350,000 people in the pool had been infected with COVID-19 from Asia, Europe, and North and South America. This patient pool had similar proportions of asthma to the general population, according to the study.
The results show that just over 7 in every 100 people who tested positive for COVID-19 also had asthma, compared to just over 8 in 100 in the general population with the condition. Additionally, the results showed that people with asthma had a 14% lower risk of acquiring COVID-19 and were significantly less likely to be hospitalized with the virus. There was no apparent difference in the risk of death from COVID-19 in people with asthma compared to those without.
"Chemical receptors in the lungs that the virus binds to are less active in people with a particular type of asthma and some studies suggest that inhaled corticosteroids—commonly used to treat asthma—can reduce their activity even further," said one of the study authors, Christine Jenkins, in a press release. "Also, initial uncertainty about the impact of asthma on COVID-19 may have caused anxiety among patients and caregivers leading them to be more vigilant about preventing infection."
Lead study author Anthony Sunjaya, MD, noted that although this study provides some reassurance about the risks of exposure to COVID-19 in people with asthma, physicians and researchers were still learning about the effects of the virus.
"While we showed that people with asthma do not seem to have a higher risk of infection with COVID-19 compared to those without asthma and have similar outcomes, we need further research to better understand how the virus affects those with asthma," Sunjaya said in a press release.
When the COVID-19 pandemic began, concerns were raised for many people with asthma regarding susceptibility to becoming infected or becoming sicker. Previous findings attest to these concerns, which showed that people with chronic respiratory conditions, such as asthma, were reported to be at greater risk during the Middle East respiratory syndrome (MERS) outbreak, caused by a virus with a similar structure, according to the current study.
"Respiratory infections like those caused by coronaviruses can exacerbate asthma symptoms and corticosteroid treatment may increase susceptibility to COVID-19 infection and its severity," Sunjaya said in a press release.
The review included an analysis of 45 hospital-based studies, 6 studies in the community setting, and 6 with mixed setting. Twenty-two of the studies were carried out in North America, 19 in Asia, 14 in Europe, and 2 in South America. Four of the studies, however, only included children, making up 211 of the participants.
The average age of the participants was roughly 52, whereas 52.5% were males, 11.75% were current smokers, and 16.2% were former smokers. Additionally, 54% had some form of comorbidities, 21% had diabetes, and approximately 8% had chronic obstructive pulmonary disease, according to the press release.
Thirty-six studies were peer-reviewed publications, with another 17 being preprints, 3 government reports, and 1 open dataset. The findings show increasing age is strongly associated with an increased risk of acquiring COVID-19 among asthmatics and explained 70% of the in-between study variance in the analysis.
"This is an expected finding and in line with other COVID-19 studies showing age as one of the most important predictors for vulnerability to COVID-19 and prognosis," the authors noted.
The review had limitations, including a short duration of follow-up, mainly self-reported asthma, and variable reporting of outcomes that may introduce bias in the pooled effect, according to the press release.
Asthmatics no higher risk dying from COVID, review of studies on 587,000 people shows. EurekAlert! https://www.eurekalert.org/pub_releases/2021-02/tfg-anh021821.php. Published February 18, 2021. Accessed February 19, 2021.