Table 6.

Spearman’s Rank Correlation Coefficient Between Parameters of Respiratory Impedance at Rest, Spirometry, and Cardiopulmonary Exercise Testing at Rest (n=55)

	VT ex		VT ex/Te		fR		V’E		V’O2		VD/VT
Oscillometry
R5
Inspiratory	−0.260	NS	−0.193	NS	0.236	NS	−0.065	NS	−0.111	NS	0.175	NS
Expiratory	−0.176	NS	−0.048	NS	0.222	NS	0.050	NS	−0.105	NS	0.108	NS
R20
Inspiratory	−0.223	NS	−0.105	NS	0.252	NS	−0.002	NS	−0.033	NS	0.160	NS
Expiratory	−0.133	NS	−0.051	NS	0.150	NS	0.008	NS	−0.050	NS	0.062	NS
R5-R20
Inspiratory	−0.247	NS	−0.177	NS	0.220	NS	−0.052	NS	−0.136	NS	0.150	NS
Expiratory	−0.174	NS	−0.140	NS	0.182	NS	−0.031	NS	−0.189	NS	0.094	NS
X5
Inspiratory	0.365	**	0.246	NS	−0.257	NS	0.152	NS	0.289	*	−0.338	*
Expiratory	0.143	NS	0.119	NS	−0.153	NS	−0.005	NS	0.114	NS	−0.245	NS
Fres
Inspiratory	−0.356	**	−0.278	*	0.241	NS	−0.148	NS	−0.335	*	0.385	**
Expiratory	−0.174	NS	−0.194	NS	0.155	NS	−0.038	NS	−0.220	NS	0.303	*
ALX
Inspiratory	−0.372	**	−0.250	NS	0.258	NS	−0.155	NS	−0.296	*	0.314	*
Expiratory	−0.160	NS	−0.109	NS	0.179	NS	0.019	NS	−0.132	NS	0.217	NS
Spirometry
FVC	0.429	**	0.503	**	−0.093	NS	0.434	**	0.506	**	−0.156	NS
FEV1	0.352	**	0.419	**	−0.136	NS	0.304	*	0.467	**	−0.253	*
FEV1/FVC	0.039	NS	0.131	NS	−0.004	NS	0.006	NS	0.143	NS	−0.180	NS

Notes: *p<0.05; **p<0.01.

Abbreviations: ALX, low-frequency reactance area; FEV₁, forced expiratory volume in 1 second; f_R, breathing frequency; Fres, resonant frequency; FVC, forced vital capacity; NS, not significant; R5 and R20, respiratory system resistance at 5 and 20 Hz, respectively; Te, expiratory time; V’_E, minute ventilation; V’_O2, oxygen uptake; V_T ex, expiratory tidal volume; V_T ex/Te, mean expiratory flow; X5, respiratory system reactance at 5 Hz.