Demographic characteristics of the patients with COPD and healthy volunteers
| Patients with COPD | Controls | P Value | |
|---|---|---|---|
| No. of subjects | 25 | 25 | |
| Sex (female) (%) | 16 | 16 | |
| Age (yr) (mean) | 69.2 ± 8.1 (58–84) | 68.0 ± 8.0 (57–86) | .59 |
| Education (yr) (mean) | 6.7 ± 3.9 | 7.5 ± 5.0 | .53 |
| Family history of COPD (%) | 4 | – | |
| Disease duration (yr) | 7.0 ± 5.7 | – | |
| Actual smokers (%) | 44 | 40 | .86 |