Bronchodilator responses for resistance and reactance of the respiratory system and spirometry parameters in the healthy asymptomatic (HealthyAsym) group and remainder

ParameterHealthyAsym (n=577)LLN or ULNRemainder (n=568)
ΔRrs6, cmH2O·s·L−1−0.23 (−0.57–0.04)LLN −1.38−0.36 (−0.81– −0.01)
ΔRrs6, %−6.4 (−17.2–1.3)LLN −30.0−11.3 (−20.4– −0.2)
ΔRrs6, Z-score−0.31 (−0.73–0.03)LLN −1.42−1.1 (−2.4– −0.3)
ΔRrs6,insp, cmH2O·s·L−1−0.31 (−0.67– −0.04)LLN −1.38−0.41 (−0.93– −0.11)
ΔRrs6,insp, %−8.5 (−20.7–1.3)LLN −42.9−12.7 (−25.6– −0.2)
ΔXrs6, cmH2O·s·L−10.09±0.26ULN 0.570.28±0.57
ΔXrs6, Z-score0.25±0.67ULN 1.360.5±0.8
Δ Xrs6,insp, cmH2O·s·L−10.12±0.23ULN 0.530.22±0.40
ΔEFLi, cmH2O·s·L−10.039±0.281LLN −0.37−0.099±0.592
ΔFEV1, mL76±119106±135
ΔFVC, mL34±17639±208

Data are presented as median (interquartile range) or mean±sd, unless otherwise stated. Responses for resistance are defined as the fifth percentiles and upper limits of normal (ULNs) for reactance are defined as the 95th percentiles. LLN: lower limit of normal; Δ: post-bronchodilator minus pre-bronchodilator change; Rrs6: resistance of the respiratory system measured at 6 Hz; insp: inspiratory; Xrs6: reactance of the respiratory system measured at 6 Hz; EFLi: expiratory flow limitation index; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity. p<0.002 for HealthyAsym compared with remainder all Rrs6 parameters (Mann–Whitney); p<0.001 HealthyAsym compared with remainder for all Xrs6 parameters (t-test).