Subject characteristics
| Baseline | Before expedition | After expedition | |
|---|---|---|---|
| Subjects (M/F) | 13/5 | ||
| Age (years) | 39.6±11.3 | ||
| Inhaled steroids, n (%) | 13 (72%) | 16 (89%) | |
| High dose | 2 (11%) | 3 (17%) | |
| Medium dose | 3 (17%) | 8 (44%) | |
| Low dose | 8 (44%) | 5 (28%) | |
| LABA, n (%) | 12 (67%) | 15 (83%) | |
| SABA alone, n (%) | 5 (28%) | 2 (11%) | |
| LTRA, n (%) | 6 (33%) | 5 (28%) | |
| Pre-BD FEV1 (% pred) | 92.0±21.5 | 90.2±12.0 | 83.6±10.3† |
| Pre-BD FVC (% pred) | 116.0±14.4 | 116.8±14.4 | 102.7±15.9†† |
| FEV1/FVC (%) | 66.0±14.5 | 66.0±12.0 | 69.5±9.5 |
| FeNO (ppb) | 17.2–27.8–35.3 | 14.4–18.1–24.3‡ | 8.0–13.5–23.8 |
| ACT | 22.0±1.4 | 22.0–1.9 | 18.2±4.3 |
| History of allergy | 18 (100%) | ||
| Total IgE (kU/L) | 45.2–93.1–228.3 | ||
| Sputum analysis | |||
| Total cell count (×106/mL) | 0.4–0.8–1.4 | 0.6–0.9–1.9 | 1.0–1.7–1.8 |
| Eosinophils (%) | 0.0–2.0–6.3 | 0.0–0.0–0.0§ | 0.0–0.0–0.0* |
| Neutrophils (%) | 2.3–9.5–20.8 | 16.8–30.5–51.8 | 40.0–51.0–74.0** |
| Macrophages (%) | 77.0–87.0–95.8 | 44.0–64.0–85.0 | 26.0–45.0–54.0** |
| Lymphocytes (%) | 0.0–0.0–1.0 | 0.0–1.0–8.0 | 2.0–5.0–7.0** |
Lung function parameters, ACT and are represented as median and IQR (lower quartile-median-upper quartile).
Total IgE was measured by ImmunoCAP. Sputum differential cell counts were prepared by cytocentrifugation.
FeNO measurements at baseline and before expedition were performed using the Niox Flex (Aerocrine) and after expedition using the NObreath analyser (Bedfont Scientific Ltd).
*p<0.01, **p<0.001 (Dunn's multiple comparison test compared with before expedition).
†p=0.004, ††p=0.0001 (paired t test compared with before expedition).
‡p=0.002 (Wilcoxon signed rank test compared with baseline).
§p<0.001 (Dunn's multiple comparison test compared with baseline).
ACT, Asthma Control Test; BD, bronchodilator; FeNO, fractional expired nitric oxide; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; LABA, long-acting β2 agonist; SABA, short-acting β2 agonist; LTRA, leukotriene receptor antagonist.