Table 2.

Comparison of FEV value, MEFV curve and IOS between the study group and the control (x̅±s)

	Control	COPD GOLD stage 0
FVC/pre (%)	96.14±9.72	95.33±8.41
FEV1/pre (%)	95.53±10.46	94.3±9.02
FEV1/FVC (%)	81.38±3.86	80.55±5.88
PEF/pre (%)	88.65±15.98	85.24±15.70
FEF25/pre (%)	89.46±12.40	84.68±10.46
FEF50/pre (%)	87.62±14.53	67.36±13.44*
FEF75/pre (%)	83.55±12.47	55.40±14.52*
Fres (Hz)	11.26±2.61	14.37±3.63*
Z5/pre (%)	104.69±20.64	135.65±19.37*
R5/pre (%)	100.60±20.98	128.46±20.14*
R20/pre (%)	96.73±17.95	101.51±16.07
R5-R20/pre (%)	109.31±80.05	282.34±192.83*
X5 (kPa·L-1·S-1)	-0.08±0.05	-0.14±0.05*

^* P < 0.05 when compared with the control.