All issues > Volume 32(8); 1989

Original Article

J Korean Pediatr Soc. 1989;32(8):1074-1085. Published online August 31, 1989.

Post-Exercise Pulmonary Function Changes in Asthmatic Children.

Kyung Ae Yoon¹, Young Yull Koh¹, Hyung Ro Moon¹

¹Department of Pediatrics, College of Medicine, Seoul National University, Seoul, Korea

Received: October 4, 1988;  Accepted: November 22, 1988.

Abstract

To determine the frequency, severity, time course and relations of exercise induced changes in lung function, forty-one asthmatic children and fifteen control children were subjected to free running and forced vital capacity (FVC), one-second forced expiratory volume (FEV1), maximum mid-expiratory flow rate (FEF 25-75%), and peak expiratory flow rate (PEFR) were measured before and serially for 60 minutes following exercise. The results were as follows. 1) Significant post-exercise bronchospasm occurred in five to nineteen patients (12-46%) among forty-one asthmatic children, the frequency depending on the test used to determine exercise-induced abnormalities, and two (13%) among fifteen control subjects, though less marked in degree. Exercise- induced reduction in PEFR were less marked and less frequent than decreases in FEV1 and FEF 25 -75%, and reductions in FVC were the least severe and least often observed. 2) Pulmonary function abnormalities, regardless of severity, were usually most marked during first ten minutes after exercise and lessened thereafter. Mild EIA usually lasted for only 15 minutes or less; severe EIA imporved, but usually did not resolve within 30 minutes of exercise. There were statisti- cally significant linear correlations between the duration of EIA and the degree of exercise-induced abnormalities. 3) As the basal FEF 25-75% before exercise were deviated from the predicted values, the maximal responses after exercise were increased, suggesting that severe asthmatics would have a higher incidence and severity of EIA. 4) The magnitude of the post-exercise drop in FEV1 or FEF 25-75% could be correlated with serum IgE levels, which suggests that serum IgE levels serve some value in demonstrating the labile bronchial tree of EIA.

Keywords :Exercise induced asthma, IgE, Pulmonary function test