Clinical characteristics analysis of persistent airflow limitation in asthmatic children

Abstract

Objective: To analyze the clinical characteristics of asthmatic children with persistent airflow limitation (PAL) in order to improve understanding of PAL and improve asthma management. Methods: The clinic data of asthmatic children aged 6 to 18 years with and without PAL, who visited the Department of Allergy at Children's Hospital of the Capital Institute of Pediatrics between January 2021 and June 2023, were analyzed retrospectively. The study included a total of 197 patients (153 males and 44 females), with a median age of 9.0 (7.0, 12.0) years. The analysis encompassed demographic features, disease-related factors, laboratory tests, and spirometry parameters. Quantitative data differences between the two groups were assessed using the Student's t-test or the Mann-Whitney U test. Qualitative data comparisons were made using the Chi-square test or Fisher's exact test. Results: This study included 100 non-PAL and 97 PAL patients. The female-to-male ratio in the two groups was 27/73 and 17/80, respectively. Age and BMI were 11.0 (10.0, 13.0) years and 20.3 (17.7, 24.1) kg/m2 in the PAL group, which was significantly higher than in the non-PAL group (P<0.001). Among the PAL group, 49.5% fell within the 9-12 age group. The PAL group had a higher percentage of patients with an asthma duration of more than 3 years (89.7% vs. 62.0%, P<0.001) and a history of pneumonia (13.4% vs. 4.0%, P=0.036) compared to the non-PAL group. Regarding laboratory tests, a higher percentage of patients in the PAL group had an elevated FeNO level (60.9% vs. 37.6%, P=0.002) and animal sensitization (50.7% vs. 30.7%, P=0.022) compared to the non-PAL group. Of the 69 patients who underwent spirometry before and after PAL development, FEV1%pred, FEV1/FVC, and MMEF%pred values gradually decreased, with a significant decline in the year preceding PAL development. Conclusions: Asthmatic children with PAL had characteristics such as relatively older age, higher BMI, longer duration of asthma, eosinophilic inflammation, and atopy. Lung function decline occurred several years before PAL development. Long-term follow-up should focus on the evolving trend of spirometry parameters.