IOS, impulse oscillometry; FENO, fractional exhaled nitric oxide; CV,
Coefficient of variance; BMI, body mass index; FVC, forced vital
capacity; FEV1, forced expiratory volume in 1 second;
FEV3, FEV in 3 seconds; PEF, peak expiratory flow;
FEF25%, forced expiratory flow at 25% of FVC;
FEF50%, FEF at 50% of FVC; FEF75%,
FEF at 75% of FVC; FEF25%-75%, FEF at 25% to 75% of
FVC; EOS, eosinophils; ppb, parts per billion; PD20,
provocative dose causing a 20% fall in FEV in the first second; R5,
total airway resistance at 5 Hz; R20, central airway resistance at 20
Hz; R5-R20, peripheral airway resistance as the difference between 5 and
20 Hz; X5, reactance at 5 Hz; Fres,
resonant frequency.
Small-airway dysfunction was identified if 2 of the variables
FEF50%, FEF75% and
FEF25%-75% were lower than 80%.
†Mean (SD) values.
‡Median (IQR) values
§ n = 333, 92 for positive bronchial provocation, 241
for negative bronchial provocation
¶ n = 619, 153 for positive bronchial provocation, 466
for negative bronchial provocation
Bold font indicates statistical significance.
Table 2. Spearman correlation between PD20 and other
variables in BHR-positive subjects.