Extended diagnostic criteria used for indirect challenge testing in elite asthmatic swimmers

Abstract

The aim of the study was to investigate the prevalence of asthma with or without exercise induced symptoms among elite and elite aspiring swimmers and to compare sport specific exercise provocation with mannitol provocation. 101 adolescent swimmers were investigated with mannitol provocation and sport specific exercise challenge test. Mannitol positivity was defined as either direct FEV(1) PD15 (ordinary criteria) or as β(2)-reversibility ≥15% after challenge (extended criteria). A direct positive exercise test was defined as a drop in FEV(1) of 10% (ordinary criteria) or a difference in FEV of ≥15% either spontaneous, variability, or with β2-agonist, reversibility (extended criteria). We found a high prevalence of mannitol and/or exercise positivity. Twenty-six swimmers were mannitol direct positive and 14 were direct exercise positive using ordinary criteria. Using extended criteria 43 were mannitol positive and 24 were exercise positive. When including reversibility and variability to define a positive test the sensitivity for current asthma with or without exercise induced symptoms increased while the specificity remained roughly unchanged. Direct positivity for mannitol and exercise poorly overlapped using ordinary criteria but improved using extended criteria. We found a high prevalence of asthma among elite swimmers. The use of variability and reversibility (liability) as additional criteria to define a positive test provided to our mind relevant information and should be considered.