Receiver operating characteristics of impulse oscillometry parameters for predicting obstructive sleep apnea in preobese and obese snorers

Table 2 Analysis of the relationships between PSG outcomes and BMI, lung volume, and IOS measurements in the sitting and supine positions

	RDI (events/h)	p-value (two-tailed)	BMI (kg/m²)	p-value (two-tailed)
BMI, kg/m²	0.39	0	-	-
Sitting position
ERV, L	−0.221	0.001	−0.178	0.009
FRC, L	−0.141	0.042	−0.176	0.010
Rrs0, kPa · s · L⁻¹	0.239	0.000	0.258	0.000
Zrs5, kPa · s · L⁻¹	0.230	0.001	0.257	0.000
R5, kPa · s · L⁻¹	0.217	0.001	0.255	0.000
X5, kPa · s · L⁻¹	−0.379	0.000	−0.308	0.000
Grs, L · kPa⁻¹ · s⁻¹	−0.240	0.000	−0.260	0.000
Gz, L · kPa⁻¹ · s⁻¹	−0.230	0.001	−0.257	0.000
Supine position
Rrs0, kPa · s · L⁻¹	0.425	0.000	0.306	0.000
Zrs5, kPa · s · L⁻¹	0.395	0.000	0.289	0.000
R5, kPa · s · L⁻¹	0.378	0.000	0.298	0.000
X5, kPa · s · L⁻¹	−0.517	0.000	−0.322	0.000
Grs, L · kPa⁻¹ · s⁻¹	−0.425	0.000	−0.305	0.000
Gz, L · kPa⁻¹ · s⁻¹	−0.395	0.000	−0.290	0.000

Abbreviations: BMI body mass index, ERV expiratory reserve volume, FRC functional residual capacity, Rrs0 resistance at zero-frequency, Zrs5 respiratory impedance at 5 Hz, R5 respiratory resistance at 5 Hz, X5 respiratory reactance at 5 Hz, Grs respiratory conductance, the reciprocal of Rrs0, Gz the reciprocal of Zrs5. All values are Spearman’s rank correlation coefficients (r)

ISSN: 1471-2466