Table 3– Impedance measurements in healthy subjects and patients with asthma
R5R20 kPa·L−1·sAX kPa·L−1R20 kPa·L−1·s
Healthy controls
 Baseline0.035 (0.020–0.053)0.330 (0.230–0.595)0.310 (0.260–0.363)
 Post-BD0.040 (0.020–0.050)0.290 (0.175–0.390)###0.285 (0.250–0.340)
Asthma
 GINA step 4
  Baseline0.080 (0.060–0.120)**0.935 (0.438–1.270)*0.355 (0.293–0.448)
  Post-BD0.070 (0.045–0.125)0.585 (0.325–1.263)0.340 (0.290–0.390)
 GINA step 5
  Baseline0.140 (0.095–0.305)###1.800 (0.613–3.640)***0.390 (0.340–0.475)***
  Post-BD0.130 (0.070–0.210)##1.305 (0.643–2.620)##0.40 (0.320–0.485)
  • Data are presented as median (interquartile range). R5R20: resistance at 5 Hz minus resistance at 20 Hz; AX: reactance area; R20: resistance at 20 Hz; BD: bronchodilator; GINA: Global Initiative for Asthma. *: p<0.05 compared with control group (using Kruskal–Wallis test with Dunn’s correction); **: p<0.01 compared with control group (using Kruskal–Wallis test with Dunn’s correction); ***: p<0.001 compared with control group (using Kruskal–Wallis test with Dunn’s correction); ##: p<0.01 compared with baseline (using Friedman’s test with Dunn’s correction); ###: p<0.001 compared with baseline (using Friedman’s test with Dunn’s correction).