Demographic data for subjects
| Control | Asthma | COPD | |
| Subjects n | 66 | 26 | 72 |
| Age yrs | 61.6±1.5 | 64.6±4.0* | 73.2±0.7# |
| Males | 66 | 8 | 72 |
| Current smoker¶ | 25 | 4 | 12 |
| Brinkman's index | 1024.7±79.3 | 491.6±205.8* | 1368.5±101.3 |
| FEV1/FVC ratio | 0.80±0.01 | 0.71±0.03* | 0.56±0.01# |
| FEV1 L | 2.92±0.09 | 1.93±0.25# | 1.44±0.07# |
| FEV1 % pred | 94.5±1.9 | 68.1±4.2# | 55.85±2.5# |
| FVC L | 3.65±0.10 | 2.68±0.24# | 2.51±0.09# |
| LTOT | 0 | 0 | 22 |
Data are presented as mean±sem, unless otherwise stated. COPD: chronic obstructive pulmonary disease; Brinkman's index: the number of cigarettes per day×the number of years; FEV1: forced expiratory volume in one second; FVC: forced vital capacity; % pred: % predicted; LTOT: long-term oxygen therapy. ¶: at blood sampling. *: p <0.05; #: p <0.0001 (ANOVA, followed by Fisher's protected least-significant difference test).