Impaired pulmonary function in the university students who had asthma in childhood

Abstract

Background: Bronchial asthma in children often resolves as they grow. In persons with resolved asthma, spirometry measurements such as FEV1 and FEV1/FVC show almost normal values. The forced oscillation technique (FOT) is a new index of pulmonary function, and seems to be useful in detecting small changes that are not seen on spirometry. This study aimed to compare spirometry, exhaled nitric oxide fraction (FeNO), and FOT between the subjects with resolved asthma and normal subjects.
Methods: We recruited 484 subjects from our university (mean age, 18.5; male, 257). A questionnaire about past history including bronchial asthma and other allergic diseases, spirometry, FeNO measurement, and FOT were completed by 119 resolved asthma patients and 365 normal subjects.
Results: FEV1/FVC was significantly lower and FeNO was higher in resolved asthma patients than in controls. There were significant differences between resolved asthma patients and controls in X5, Fres, and ALX as reactance parameters. There were, however, no differences in the resistance parameters such as R5, R20.
Conclusions: There is a group of patients whose childhood asthma has resolved with respiratory impairment. Further study will be required to determine whether spirometry, FeNO, and FOT are useful in making an early diagnosis of asthma relapse.