RT Journal Article SR Electronic T1 Differences in NO airway diffusion after V̇O2-max test in asthmatic and non-asthmatic elite junior cross-country skiers JF ERJ Open Research JO erjor FD European Respiratory Society SP 00378-2020 DO 10.1183/23120541.00378-2020 A1 Marieann Högman A1 Lars Wedholm A1 Tomas Carlsson A1 Magnus Carlsson A1 Michail Tonkonogi YR 2020 UL http://openres.ersjournals.com/content/early/2020/11/12/23120541.00378-2020.abstract AB Asthma is common in cross-country skiers and is often treated with ß2-agonists and inhaled corticosteroids (ICS). Exhaled nitric oxide is often used to guide ICS treatment in asthma. This study investigated the change in the pulmonary NO dynamics before and after a maximum oxygen uptake (V̇O2-max) test.An extended NO analysis was performed among Swedish elite junior cross-country skiers (n=25), with and without declared asthma, before and after a V̇O2-max test using roller skis. Asthma was declared by six boys and two girls among whom five occasionally used ICS.There were no differences in the baseline NO parameters between those with and without declared asthma. The diffusion capacity over airway wall (DawNO) was 21 (17,25) mL·s−1 (median, quartiles), which is much increased for this age group. After the V̇O2-max test, there were statistically significant differences from the baseline fraction of exhaled nitric oxide (FENO50), NO-flux from airways, DawNO and alveolar NO values; but not in the NO content in airway wall (CawNO) for all subjects together as one group. However, in the asthma group, differences were only seen in the FENO50 and in CawNO.Interestingly, a majority of the subjects had an increase in the DawNO. An increase in DawNO has been found with allergic asthma together with elevated CawNO. The skiers did not have elevated CawNO, which indicates an absence of inflammation in the airway wall. Modelling of lung NO production clearly shows that the asthma among our skiers is distinct from the allergic asthma in non-athletes.FootnotesThis manuscript has recently been accepted for publication in the ERJ Open Research. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJOR online. Please open or download the PDF to view this article.Conflict of interest: Professor Marieann Högman has nothing to disclose.Conflict of interest: Lars Wedholm has nothing to disclose.Conflict of interest: Dr. Carlsson has nothing to disclose.Conflict of interest: Dr. Carlsson has nothing to disclose.Conflict of interest: Professor Michail Tonkonogi has nothing to disclose.