Clinical characteristics for the subject groups and bivariate correlations between particles in exhaled air (PExA) mass and small and large airways parameters

CharacteristicsCtrlComRClinRPersAKruskal–Wallis p-value
Subjects n18121618
Age years56 (53–61)46 (43–55)54 (47–60)60 (49–63)0.044
Female6 (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 % pred113.6±12.0108.1±9.584.5±23.181.3±17.2<0.001
PC20 methacholine>8>80.8 (0.1–2.8)0.6 (0.3–2.2)
PExA mass ng·L−15.68 (3.01–9.57)4.87 (2.90–6.45)3.15 (0.71–5.63)2.67 (0.49–4.02)0.017+
Age yearsSpearman0.0950.455
Body mass index kg·m−2Spearman−0.2030.107
 Blood eosinophils ×109 cells·L−1 #Pearson−0.1820.154
 Sputum eosinophil differentiation %Spearman−0.4490.013
 Reversibility pre–post %Spearman−0.469<0.001
 PC20 methacholine slope  mg·mL−1 #Pearson−0.483<0.001
 PC20 AMP slope mg·mL−1Spearman−0.4410.001
 FEV1/FVC ratio pre-salbutamol %Spearman0.3550.004
 FEV1 % pred pre-salbutamolPearson0.4170.001
 IOS R20 HzPearson−0.3860.002
 IOS R5R20 HzSpearman−0.3080.014
 IOS AX Hz·kPa·L−1Spearman−0.3420.006
 RV % predSpearman−0.431<0.001
 RV/TLC % predSpearman−0.3400.006
 MBNW Scond×VTSpearman−0.3800.003
 MBNW Sacin×VTSpearman−0.2500.056
 FEF25–75% % predPearson0.3400.006
 Alveolar FENO ppbSpearman−0.2540.100
 CT PRM-fSAD %Spearman−0.0510.717
 CT PRM inferior to superior  gradient ΔHUPearson−0.1970.152

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.