Objective: The exercise challenge test can be used to diagnose asthma in patients with asthma-like symptoms but without reversibility on spirometry. However, the test is time-consuming and is not always practical. The aim of this study was to determine the potential factors that may predict the presence of a positive exercise challenge test in children with asthma-like symptoms but without reversibility on spirometry.

Material and Methods: All patients who presented at our outpatient clinic between November 2009-June 2012 with asthma-like symptoms but did not have reversibility on spirometry and on whom an exercise challenge test was done were analyzed retrospectively. The clinical features and laboratory results were analyzed with univariate and multivariate regression analysis.results: A total of 145 children between 7 and 17 years of age were analyzed. 76 out of 145 patients (52.4%) were female and their median age was 11 (Interquartile Range (IQR): 10-14) years of age. The exercise provocation test was positive in 50 (34.5%) patients. Fourteen patients with a positive exercise challenge test (28.7%) were obese. Multivariate logistic regression analysis revealed that obesity (odds ratio [OR]: 4.188, 95% confidence interval (CI): 1.512-11.60, p=0.006) and low basal FEF25-75 (OR:1.030, 95% CI:1.050-1.012, p=0.006) were risk factors for the presence of positive exercise challenge test when adjusted for the variables age, sex, atopy, familial allergic disease, passive smoking, peripheral blood eosinophil count greater than 500/mm³ and FEV1, FEV1/FVC parameters.conclusion: For patients with asthma-ike symptoms but without reversibility on spirometry, obesity and low FEF25-75 can be considered as the significant risk factors for the presence of a positive exercise challenge test

Keywords: Asthma, Children, Exercise test