|  | Patients with COPD | P value | |||
---|---|---|---|---|---|---|
 | Controls (n = 47) | All (n = 81) | Stable (n = 44) | Exacerbation (n = 37) | Control vs. all patients | Stable vs. exacerbation |
Age, yrs | 57.7 ± 1.5 | 58.3 ± 1.0 | 56.8 ± 1.3 | 60.0 ± 1.5 | 0.402 | 0.116 |
Male/female, n | 28/19 | 54/27 | 27/17 | 27/10 | 0.297 | 0.270 |
Smoking history, packs/year | 37.0 ± 1.7 | 42.9 ± 1.2 | 41.6 ± 1.1 | 44.3 ± 2.3 | 0.067 | 0.258 |
Smoking status Never/current/former, n | 25/12/10 | 0/49/32 | 0/28/16 | 0/21/16 | 0.420 | 0.528 |
FEV1/FVC, % | 82.9 ± 0.8 | 53.1 ± 1.4 | 56.1 ± 1.8 | 49.7 ± 2.2 | <0.001 | 0.027 |
FEV1, % predicted | 96.6 ± 1.6 | 54.7 ± 2.4 | 61.4 ± 3.2 | 46.7 ± 3.3 | <0.001 | 0.002 |
PaO2, mmHg | N/D | 74.2 ± 1.0 | 77.5 ± 1.0 | 70.3 ± 1.5 | ― | <0.001 |
PaCO2, mmHg | N/D | 43.1 ± 0.6 | 40.6 ± 0.7 | 45.9 ± 0.9 | ― | <0.001 |
CRP, mg/L | 3.5 ± 0.3 | 36.7 ± 3.6 | 14.2 ± 1.1 | 63.5 ± 4.5 | <0.001 | <0.001 |
Severity of COPDa | N/A |  |  |  | ― | 0.489 |
 GOLD I/II, n (%) |  | 47 (58.0) | 24 (54.5) | 23 (62.2) |  | |
 GOLD III/IV, n (%) |  | 34 (42.0) | 20 (45.5) | 14 (37.8) |  |  |
COPD treatments, n (%) | N/A |  |  |  | ― | 0.935 |
 ICS/LABA |  | 58 (71.6) | 32 (72.7) | 26 (70.3) |  |  |
 SABA or SAMA |  | 71 (87.7) | 38 (86.4) | 33 (89.2) |  |  |
 Theophylline |  | 51 (63.0) | 29 (65.9) | 22 (59.5) |  |  |