Negative DH | Positive DH | p-value | |
Number of patients | 20 | 30 | |
Age years | 53.3±8.7 | 63.7±10.9 | 0.001 |
Sex males/females# | 4/16 | 5/25 | 0.76 |
Atopic predisposition n (%)# | 16 (80) | 24 (80) | 1.00 |
BMI kg·m−2 | 21.3±2.7 | 24.7±3.8 | 0.001 |
Treatment step according to GINA (2/3/4/5)# | 1/14/5/0 | 2/14/13/1 | 0.33 |
Disease duration years | 8.8±10.4 | 11.5±12.4 | 0.43 |
ICS daily maintenance dose FP equivalent μg | 345.5±120.1 | 415.7±202.4 | 0.17 |
ACT | 24.0±1.5 | 23.1±2.2 | 0.15 |
Blood eosinophil % | 4.1±2.8 | 4.3±2.5 | 0.78 |
Serum periostin ng·mL−1¶ | 89.7±23.7 | 107.0±30.7 | 0.04 |
FeNO ppb¶ | 29.1±15.8 | 38.1±31.9 | 0.24 |
FVC % predicted | 108.7±9.9 | 94.8±13.3 | 0.0002 |
FEV1/FVC % | 77.0±6.0 | 73.2±11.5 | 0.18 |
FEV1 % predicted | 101.0±13.0 | 85.9±21.0 | 0.006 |
IC baseline mL | 2277.5±538.6 | 2140.7±93.5 | 0.11 |
ΔIC20 % | 1.0±5.6 | 7.2±5.4 | 0.0003 |
ΔIC30 % | 2.7±4.6 | 14.2±7.0 | <0.0001 |
ΔIC40 % | 3.8±3.8 | 18.3±6.9 | <0.0001 |
Data are presented as n or mean±sd, unless otherwise stated. A comparison between the two groups was done by a Chi-squared test or unpaired t-test. BMI: body mass index; GINA: Global Initiative for Asthma; ICS: inhaled corticosteroid; FP: fluticasone propionate; ACT: asthma control test; FeNO: fractional exhaled nitric oxide; FVC: forced vital capacity; FEV1: forced expiratory volume in 1 s; IC: inspiratory capacity; ΔIC: the reduction percentage of IC from baseline (ICrest) for each breathing frequency (ΔIC20, ΔIC30 and ΔIC40); DH: dynamic hyperinflation; Negative DH: patients with the maximal reduction percentage of IC <10%; Positive DH: patients with the maximal reduction percentage of IC ≥10%. #: Chi-squared test; ¶: analysed after log transformation.