Table 3.
Bronchial hyperresponsiveness measured as PD20met <8 μmol, fractional expired nitric oxide FENO >25 ppb, allergy and lung function variables presented as Z-score, and lower limit of normal (LLN) among elite athletes with doctor-diagnosed asthma and elite athletes without asthma.
| Variables | Current asthma | p value | |
|---|---|---|---|
| Yes (n = 43) | No (n = 90; 87; 91)# | ||
| PD20met <8 μmol, n (%) | 37 (86) | 14 (15) | <0.001∗ |
| FENO >25 ppb, n (%) | 11 (26) | 11 (12) | 0.079 |
| Allergy, n (%) | 18 (42) | 34 (39) | 0.850 |
| z-FEV1, mean (95% CI) | −0.50 (−0.78, −0.22) | 0.42 (0.25, 0.62) | <0.001∗ |
| z-FVC, mean (95% CI) | 0.34 (0.04, 0.63) | 0.50 (0.35, 0.68) | 0.288 |
| z-MEF25–75, mean (95% CI) | −0.53 (−0.85, −0.20) | 0.45 (0.25, 0.64) | <0.001∗ |
| z-FEV1/FVC, mean (95% CI) | −1.24 (−1.50, −0.97) | −0.21 (−0.38, −0.03) | <0.001∗ |
| LLN FEV1n (%) | 4 (9) | 0 (0) | 0.010∗ |
| LLN FVC n (%) | 0 (0) | 0 (0) | ns |
| LLN MEF25–75n (%) | 5 (12) | 0 (0) | 0.003∗ |
| LLN FEV1/FVC n (%) | 13 (30) | 3 (3) | <0.001∗ |
PD20met = provocation dose of methacholine causing 20% reduction in forced expiratory volume in the first second of expiration; allergy is defined as one or more positive skin prick tests; FEV1 = forced expiratory volume in one second; FVC = forced vital capacity; MEF25–75 = mean expiratory flow between 25 and 75% of FVC; LLN = lower level of normal defined as Z-score <−1.645. # = for the no asthma group; n = 89 for FENO, n = 87 for allergy, and n = 91 for LLN and lung function values ns = not significant ∗ = significant difference between asthmatic and non-asthmatic athletes.