Asthma, Peripheral Cytokines and the Adolescent Swimmer

Abstract

It is well recognized that elite level swimmers have elevated rates of asthma and exercise‐induced bronchoconstriction (EIB) either due to chronic exposure to chlorinated compounds or intense endurance training. The purpose of this study was to determine whether the peripheral cytokine levels (PCL) would be altered by a very brief but high intensity laboratory‐based exercise bout, and to see if changes were correlated with pulmonary function (PF) in elite adolescent swimmers with and without asthma. Following medication washout, 13 asthmatic and 24 control swimmers conducted the 8‐min ATS clinical EIB challenge (intensity = 85% of max.) on cycle ergometer. Spirometry was measure before and post exercise (up to 20 min.). Blood was collected before and end exercise. PCL increased significantly following exercise for the entire group; TNFα (p=.0005), IFNγ (p<.0001), P selectin (p<.0001), and TGFβ1 (p=.0008). No exercise effect was observed for IL6 or IL10. TGFβ1 levels decreased in female controls (p=.03) but increased in all other groups. There was a main effect for gender with IL4, males had greater increases than females (p=.009). Neither baseline or exercise‐induced alterations in PCL correlated with any of the PF parameters, EIB or asthma diagnosis. This study was funded by USA Swimming and NIH T32AR047752, R01HL080947, P01 HD048721 and M01RR00827.