A simple exercise test in assessment of asthma.
Exercise-induced asthma (EIA) is a manifestation of the bronchial hyper-responsiveness of asthmatic patients. Laboratory methods for measuring EIA are now well standardised. We compared a stepping test with a standard treadmill exercise test to determine whether the sensitivity of the latter could be maintained with the simplified test. We used heart rate as a measure of exercise intensity and changes in forced expiratory volume in 1 second (FEV1) to record bronchial responsiveness. In 32 adolescent asthmatic patients we demonstrated a fall in FEV1 of 10% or more in 27 following the treadmill test and in 25 following the stepping test. There was a strong correlation between the maximum falls of FEV1 following the two exercise challenges (r = 0.92 p less than 0.0001). There was poor agreement between the patient's history of EIA and the demonstration of a 10% fall of FEV1 after exercise in 11 patients. Notably all six patients who claimed no association of exercise with their asthma symptoms clearly demonstrated a fall in FEV1 of 10% or more following the treadmill challenge. We conclude that a simplified exercise test can be both objective and sensitive in detecting EIA and therefore useful in the assessment of the asthmatic patient and the effect of therapy.
Young
R P
RP
Wellington School of Medicine.
Holst
P E
PE
D000293:Adolescent; D001249:Asthma / Q000175:diagnosis*; D001250:Asthma, Exercise-Induced / Q000175:diagnosis* / Q000503:physiopathology; D005080:Exercise Test; D005541:Forced Expiratory Volume; D006339:Heart Rate; D006801:Humans; D008297:Male