Impulse oscillometry for detection of small airway dysfunction in subjects with chronic respiratory symptoms and preserved pulmonary function

Table 1 Characteristics of healthy controls and subjects with chronic respiratory symptoms and PPF

	Symptomatic subjects with PPF (n = 209)	Healthy controls (n = 85)	P value
Demographics
Age (years)	39.53 ± 12.79	36.92 ± 10.21	0.067
BMI (kg/m²)	22.09 ± 3.12	22.68 ± 2.57	0.123
Sex: male, n (%)	97 (46.4)	40 (47.1)	0.920
Spirometry
FEV₁ (% predicted)	104.61 ± 12.41	106.58 ± 10.73	0.201
FVC (% predicted)	105.90 ± 13.09	106.65 ± 12.85	0.656
FEV₁/FVC	83.78 ± 6.97	85.16 ± 5.81	0.108
FEF_25–75% (% predicted)	86.48 ± 22.71	93.02 ± 21.01	0.023
FEF_50% (% predicted)	90.98 ± 22.95	100.53 ± 22.64	0.001
FEF_75% (% predicted)	81.37 ± 30.57	85.50 ± 27.61	0.281
IOS
R5 (kPa/L s)	0.32 ± 0.07	0.28 ± 0.06	< 0.001
R20 (kPa/L s)	0.29 ± 0.06	0.26 ± 0.06	< 0.001
R5–R20 (kPa/L s)	0.0219 ± 0.0273	0.0193 ± 0.0238	0.449
X5 (kPa/L s)	− 0.1009 ± 0.0279	− 0.1007 ± 0.0280	0.966
Fres (Hz)	11.38 ± 2.58	10.49 ± 2.10	0.005
AX (kPa/L)	0.24 (0.17, 0.34)	0.20 (0.14, 0.30)	0.015

The data are presented as mean ± SD for normally distributed variables and median (interquartile range) for nonnormally distributed variables
BMI body mass index

ISSN: 1465-993X