[Evaluation of hyperresponsiveness to the exercise challenge test in school children]

Bronchial hyperresponsiveness (BHR) to the exercise challenge test was measured in 161 pupils randomly chosen from the epidemiologic survey of 2967 schoolchildren (13 to 14 yr of age). In the study group there were 73 pupils who were identified as "ever wheezers" by the ISAAC questionnaires, and 88 ones as the control group. BHR was measured as the percentage drops in FEV, FEF50, FEF25-75 from the baseline (% delta FEV1, % delta FEV50%, % delta FEF25-75%). The % delta FEV1 was significantly higher in the "ever wheezers" comparing to the control group, and this parameter was also significantly higher for the "wheezers in the last 12 mo" in comparison to "ever wheezers", who had no symptoms in the last year. The "ever wheezers" group had higher % delta FEF50%, % delta FEF25-75% but the value was not significant when compared to the control group. In the epidemiologic survey, the sensitivity and specificity for the exercise challenge test as a screening test (level %FEV1 > 11%) to identify "wheezers in the last 12mo" were 39% and 81%, respectively, and to identify the "diagnosed asthma" group were 40% and 76%. The BHR was modified by atopy (measured with the allergic skin tests) and the diagnosis of asthma.