Clinical characteristics for the subject groups and bivariate correlations between particles in exhaled air (PExA) mass and small and large airways parameters
| Characteristics | Ctrl | ComR | ClinR | PersA | Kruskal–Wallis p-value |
| Subjects n | 18 | 12 | 16 | 18 | |
| Age years | 56 (53–61) | 46 (43–55) | 54 (47–60) | 60 (49–63) | 0.044 |
| Female | 6 (33.3) | 4 (33.3) | 7 (43.8) | 7 (38.9) | 0.918¶ |
| Smoking pack-years median (min–max) | 0 (0–5) | 0 (0–6) | 0 (0–1) | 0 (0–2) | 0.104 |
| FEV1 % pred | 113.6±12.0 | 108.1±9.5 | 84.5±23.1 | 81.3±17.2 | <0.001 |
| PC20 methacholine | >8 | >8 | 0.8 (0.1–2.8) | 0.6 (0.3–2.2) | |
| PExA mass ng·L−1 | 5.68 (3.01–9.57) | 4.87 (2.90–6.45) | 3.15 (0.71–5.63) | 2.67 (0.49–4.02) | 0.017+ |
| Parameter | Test | R-value | p-value | ||
| Age years | Spearman | 0.095 | 0.455 | ||
| Body mass index kg·m−2 | Spearman | −0.203 | 0.107 | ||
| Inflammatory | |||||
| Blood eosinophils ×109 cells·L−1 # | Pearson | −0.182 | 0.154 | ||
| Sputum eosinophil differentiation % | Spearman | −0.449 | 0.013 | ||
| Large | |||||
| Reversibility pre–post % | Spearman | −0.469 | <0.001 | ||
| PC20 methacholine slope mg·mL−1 # | Pearson | −0.483 | <0.001 | ||
| PC20 AMP slope mg·mL−1 | Spearman | −0.441 | 0.001 | ||
| FEV1/FVC ratio pre-salbutamol % | Spearman | 0.355 | 0.004 | ||
| FEV1 % pred pre-salbutamol | Pearson | 0.417 | 0.001 | ||
| IOS R20 Hz | Pearson | −0.386 | 0.002 | ||
| Small | |||||
| IOS R5–R20 Hz | Spearman | −0.308 | 0.014 | ||
| IOS AX Hz·kPa·L−1 | Spearman | −0.342 | 0.006 | ||
| RV % pred | Spearman | −0.431 | <0.001 | ||
| RV/TLC % pred | Spearman | −0.340 | 0.006 | ||
| MBNW Scond×VT | Spearman | −0.380 | 0.003 | ||
| MBNW Sacin×VT | Spearman | −0.250 | 0.056 | ||
| FEF25–75% % pred | Pearson | 0.340 | 0.006 | ||
| Alveolar FENO ppb | Spearman | −0.254 | 0.100 | ||
| CT PRM-fSAD % | Spearman | −0.051 | 0.717 | ||
| CT PRM inferior to superior gradient ΔHU | Pearson | −0.197 | 0.152 | ||
Data are presented as median (interquartile range), n (%) or mean±sd, unless otherwise stated. Ctrl: healthy controls; ComR: complete asthma remission subjects; ClinR: clinical asthma remission subjects; PersA: persistent asthma patients; FEV1: forced expiratory volume in 1 s; PC20: provocative concentration causing a 20% fall in FEV1; FVC: forced vital capacity; IOS: impulse oscillometry; R20: resistance at 20 Hz; R5: resistance at 5 Hz; AX: area of reactance; RV: residual volume; TLC: total lung capacity; MBNW: multiple-breath nitrogen washout; Scond: conductive ventilation heterogeneity; Sacin: acinar ventilation heterogeneity; VT: tidal volume; FEF25–75%: forced expiratory flow at 25–75% of the pulmonary volume; FENO: fraction of exhaled nitric oxide; CT PRM: computed tomography parametric response mapping; fSAD: functional small airways disease. #: data were log2-transformed to obtain normal distribution; ¶: p-value based on Chi-squared test; +: p-value based on ANOVA.