Skiers with or without asthma have increased airway diffusion rate of NO from the airways

Exercise induced bronchoconstriction (EIB) is common in skiers and often treated with β2-agonists and inhaled corticosteroids (ICS). We examined 25 elite junior cross-country skiers (17 boys and 8 girls, age 18±1 y) pre and post a VO2max test to see how NO parameters of the lung changed. A health declaration was filled in and 6 boys and 2 girls declared that they had asthma diagnosed by a physician, whereas 5 of them were on ICS treatment. NO analysis was done with multiple flows (Hogman-Merilainen algorithm) before and within 10 min after the VO2max test. FENO50 was at rest 17 (11, 24) ppb (median, quartiles). CANO was 1.5 (1.1, 1.9) ppb, JawNO 0.75 (0.56, 1.55) nL/s, and CawNO 51 (26, 63) ppb. DawNO was 21 (17,25) mL/s, with only three skiers with values in the range of upper and lower quartiles for reference values. There were no differences in NO parameters between those declaring or not declaring asthma. After the VO2max test FENO50 decreased by 5 (3, 8) ppb (p CANO=alveolar NO, JawNO=NO-flux from airways, CawNO=NO content in airway wall, DawNO=diffusion capacity over airway wall