|
Classic asthma
|
Cough variant asthma
|
p-value
|
---|
|
n = 58
|
n = 55
| |
Age (yr)
|
44.4 ± 15.9
|
43.2 ± 16.5
|
0.71
|
Male/Female (No)
|
29/29
|
33/22
|
0.29
|
Disease duration at diagnosis (yr)
|
6.7 ± 10.0
|
2.8 ± 4.4
|
0.10
|
Current smoking (Yes, %)
|
19.0
|
5.2
|
0.029
|
Atopic status* (Yes, %)
|
71.4
|
67.9
|
0.69
|
Blood eosinophils (number/μl)
|
389 ± 247
|
310 ± 404
|
0.011
|
FEV1 (% predicted)
|
86.8 ± 19.2
|
92.1 ± 17.6
|
0.14
|
FEV1/FVC (%)
|
72.6 ± 11.3
|
81.8 ± 8.9
|
< 0.0001
|
Baseline Rrs (cm H2O/L/sec)
|
4.3 ± 2.0
|
4.0 ± 3.2
|
0.040
|
Log Dmin (units)
|
-0.20 ± 0.82
|
0.36 ± 0.60
|
< 0.0001
|
SRrs (cm H2O/L/sec/min)
|
2.9 ± 3.2
|
2.1 ± 2.1
|
0.042
|
Log C5 (μM)
|
1.51 ± 0.79 (n = 18)
|
1.17 ± 0.71 (n = 22)
|
0.15
|
- Values are given as the means ± SD.
- *: measured in 56 patients with classic asthma and 53 patients with cough variant asthma. Patients were considered atopic when 1 or more specific IgE antibodies were positive for cat dander, dog dander, weed, grass pollen, mold, or house dust mite.
- Abbreviation: Rrs, respiratory resistance. Dmin, cumulative dose of inhaled methacholine at the inflection point, where which respiratory resistance begins to increase. SRrs, slope of the methacholine dose-response curve for Rrs. C5, cough threshold, the lowest concentration of capsaicin that induces 5 or more cough.