Obesity is a risk factor for decrease in lung function after COVID-19 infection in children with asthma

Introduction: It is not clear whether asthma, the most frequent chronic disease in childhood, is a risk for severe SARS-CoV-2 infection in the pediatric population and how SARS-CoV-2 infection affects the lung functions in these patients.

Purpose: We aimed to investigate the course and the consequences of SARS-CoV-2 infection among children with asthma and determine the risk factors for the decline in lung function tests (LFTs).

Methods: In this retrospective study, asthmatic children with coronavirus disease 2019 (COVID-19) were compared with a random control group of asthmatic patients without COVID-19. In addition, the clinical course and the effect on LFTs of COVID-19 among children with asthma were also evaluated.

Results: One hundred eighty-nine patients who had COVID-19, and 792 who did not were included in the study. Fever, fatigue, and cough were the most frequent symptoms during COVID-19. Regarding the severity of COVID-19, 163 patients (87.6%) had a mild clinical condition, 13 (7%) had moderate disease, 1 (0.5%) had severe disease, and 2 had (1.1%) critically ill disease. Two patients were diagnosed with multisystem inflammatory syndrome in children (MIS-C), one patient suffered from pneumothorax. LFTs of the patients before and after COVID-19 infection were analyzed; no significant differences were found in FEV₁ % (91.7% vs. 90.9%, p = 0.513), FVC% (89.8% vs. 90.8%, p = 0.502) and FEV₁ /FVC (103.1% vs. 100.6%, p = 0.056), while FEF25%-75% values (107.6% vs. 98.4%, p < 0.001) were significantly lower after the COVID-19 infection. Obesity (odds ratio [OR]: 3.785, 95% confidence interval [CI]: 1.152-12.429, p = 0.028] and having a family history of atopy (OR: 3.359, 95% CI: 1.168-9.657, p = 0.025] were found to be the independent risk factors for ≥25% decrease in FEF25-75 after COVID-19 infection.

Conclusion: COVID-19 infection leads to dysfunction of the small airways in asthmatic children and obesity is an independent risk factor for a ≥25% decrease in FEF25-75. The long-term effects of COVID-19 infection especially on small airways require close monitoring in children with asthma.