Table 1 Characteristics and baseline measurements of study subjects at first visit
Healthy controlsAsthmatic patients at first visit baselinep Value
Number29 (28 for Scond and Sacin)31
Mean (range) age (years)11.1 (5–16)10.6 (5–15)0.54
Sex (M/F)18/1117/14
Medication at time of testing
    Positive skin prick testing to aeroallergen58%
    Hay fever71%
Mean (range) height (cm)148 (118–180)144 (110–186)0.38
Median (range) Feno (ppb)18 (3–50)14 (5–300)0.63*
Mean (SD) FEV1 z-score−0.69 (0.88)−1.09 (1.28)0.16
Mean (SD) LCI (CEV/FRC)6.24 (0.47)6.69 (0.91)0.02
Mean (SD) Scond, Vt corrected0.017 (0.02)0.026 (0.02)0.06
Mean (SD) Sacin, Vt corrected0.12 (0.06)0.14 (0.02)0.23
Mean (SD) Vt (l)0.55 (0.24)0.45 (0.17)0.07
Mean (SD) FRC (l)2.14 (1.02)1.91 (0.78)0.31
Mean (SD) Vd/Vt ratio0.27 (0.06)0.27 (0.05)0.89
  • Comparison of groups at baseline.

  • CEV, cumulative expired volume; Feno, fraction of expired nitric oxide; FEV1, forced expiratory volume in 1 s; FRC, functional residual capacity; ICS, inhaled corticosteroid; LABA, long-acting β2 agonist; LCI, lung clearance index; Sacin, Scond, phase III (alveolar) slope of the acinar and conductive airways, respectively; Vd, dead space; Vt, tidal volume.

  • *Mann-Whitney non-parametric test.