Diagnostic Value of Fractional Exhaled Nitric Oxide and Small Airway Function in Differentiating Cough-Variant Asthma from Typical Asthma

Table 2

Pulmonary function test results of subjects with TA and CVA.

	TA (n = 102)	CVA (n = 104)
FEV1% (%)	78.43 (19)	101.19 (14)	<0.001
FVC (%)	96.57 ± 14.01	106.44 ± 10.87	<0.001
FEV1/FVC	70.29 ± 6.56	78.94 ± 6.40	<0.001^∗∗∗
FEV1/VCmax	68.44 (9)	98.81 (9)	<0.001
PEF (%)	86.09 ± 18.75	99.89 ± 18.01	<0.001
MMEF75%/25% (%)	40.10 (17)	74.40 (29)	<0.001
FEF50% (%)	44.20 (21)	80.82 (30)	<0.001
FEF25% (%)	32.42 (17)	61.89 (28)	<0.001
PD20 (µmoL)	0.89 (2)	2.52 (4)	<0.001
DLCO	82.86 ± 19.72	90.14 ± 17.11	0.005
RV/TLC	112.35 (16)	103.25 (13)	<0.001
TLC	91.52 ± 11.27	96.75 ± 9.16	<0.001
RV	101 (25)	102.2 (19)	0.451
Z5 (pred)	1.23 (0)	1.09 (0)	0.014
Fres (Hz)	16.88 (7)	13.47 (5)	<0.001^∗∗∗
R5 (pred)	1.17 (1)	1.08 (0)	0.640
R20 (pred)	1.08 (0)	1.11 (0)	0.268
R5-R20 (kPa·L^−1·s^−1)	0.45 (1)	0.34 (0)	<0.001
X5	−1.30 (1)	−1.14 (1)	<0.001
X20	0.25 (1)	0.62 (0)	<0.001
FeNO (ppb)	45 (37)	27 (18)	0.007

CVA, cough-variant asthma; TA, typical asthma, FeNO, fractional exhaled nitric oxide; PEF, peak expiratory flow; MMEF_75%/25%, forced expiratory flow between 25% and 75%; FEF_50%, forced expiratory flow at 50% of the FVC; FEF_25%, forced expiratory flow at 25% of the FVC; TLC, total lung capacity; RV, residual volume. Data were expressed as mean ± standard deviation or median (interquartile range). ; ; .