Objective: Our aim was to study the behavior and validity of PEFR and FEV1 in the free-running exercise test in order to diagnose exercise-induced asthma during childhood.
Patients and methods: We studied 30 asthmatic children and 30 healthy children as controls. A provocation test was performed by means of free-running exercise in an indoor sports center. Environmental temperature and humidity were equal in both groups. Forced breathing spirometry and the "Mini-Wright peak flow meter" test were recorded before and two, five, fifteen and twenty minutes after the exercise challenge. The spirometric values representing two standard deviations below the mean for each variable studied in the control group were considered as reference values (FEV1 > or = 83.5% and PEFR > or = 81.5%).
Results: There was a decrease in FEV1 in 17 asthmatic children (56.7%) and a decrease in PEFR occurred in 14 children (46.7%). No statistically significant differences were found in either test. Specificity was 100% for FEV1 and 96.7% for PEFR. The greatest decrease in both spirometric parameters occurred at five minutes.
Conclusions: According to our results, in a free-running provocation test if we maintain previously controlled environmental conditions and exercise intensity "forced breathing spirometry" and "Mini-Wright peak flow" can be used interchangeably in order to diagnose exercise-induced asthma.