Table 1 Characteristics of the study subjects
Parameters | Never smokers | Smokers w/o COPD | GOLD I COPD | GOLD II-III * COPD | GOLD IV COPD | Overall p-value |
|---|---|---|---|---|---|---|
Subjects, n | 8 | 6 | 6 | 11 | 10 | |
Gender, male/female | 2/6 | 3/3 | 4/2 | 9/2 | 4/6 | |
Age, years | 66 (33–76) # | 55 (47–68) | 68 (56–75) | 73 (61–77) † | 62 (53–66) § | <0.01 |
Height, m | 1.6 (1.5-1.8) | 1.8 (1.6-1.8) | 1.8 (1.6-1.8) | 1.7 (1.6-1.9) | 1.7 (1.5-1.9) | 0.247 |
Body mass index, kg/m2 | 22.6 (19.8-29.7) | 22.2 (19.7-26.6) | 23.1 (20.3-26.8) | 25.3 (17.7-33.3) | 22.9 (18.0-27.2) | 0.462 |
Smoking history, pack-years | 0 | 40 (20–80) | 39 (25–66) | 47 (16–65) | 43 (25–60) | 0.783 |
Smoking status, ex-smokers/current | NA | 3/3 | 3/3 | 8/3 | 10/0 | |
FEV1, L | 2.5 (1.7-5.1) | 3.1 (1.9-3.5) | 2.9 (1.6-3.2) | 1.8 (1.2-2.3) | 0.6 (0.4-1.0) | <0.001 |
FEV1/(F)VC, % | 82 (66–121) | 78 (71–88) | 67 (65–70) | 53 (41–67) ≠ | 32 (20–39) | <0.001 |
FEV1, % of predicted | 109 (82–141) | 93 (82–120) | 86 (80–95) | 64 (43–74) ≠ | 23 (15–27) | <0.001 |
Inhaled β2-agonists | ||||||
Short-acting (yes/no/unknown) | 0/8/0 | 0/6/0 | 1/5/0 | 2/9/0 | 4/5/1‡ | |
Long-acting (yes/no/unknown) | 0/8/0 | 0/6/0 | 0/6/0 | 0/11/0 | 4/5/1‡ | |
Inhaled anticholinergics | ||||||
Short-acting (yes/no/unknown) | 0/8/0 | 0/6/0 | 1/5/0 | 2/9/0 | 3/6/1‡ | |
Long-acting (yes/no/unknown) | 0/8/0 | 0/6/0 | 0/6/0 | 0/11/0 | 5/4/1‡ | |
Inhaled short-acting β2-agonist plus anticholinergics (yes/no/unknown) | 0/8/0 | 0/6/0 | 0/6/0 | 0/11/0 | 3/6/1‡ | |
Corticosteroids | ||||||
Inhaled (yes/no/unknown) | 0/8/0 | 0/6/0 | 0/6/0 | 1/10/0 | 2/7/1‡ | |
Oral (yes/no/unknown) | 0/8/0 | 0/6/0 | 0/6/0 | 0/11/0 | 2/7/1‡ | |
Inhaled long-acting β2-agonist plus corticosteroids (yes/no/unknown) | 0/8/0 | 0/6/0 | 0/6/0 | 1/10/0 | 7/2/1‡ | |
Mucolytics (yes/no/unknown) | 0/8/0 | 0/6/0 | 2/4/0 | 0/11/0 | 5/4/1‡ |
- Values are median (range) or n. Statistical analysis was performed using Kruskal-Wallis nonparametric test followed by Dunn's multiple comparison post-test. COPD: chronic obstructive pulmonary disease; FEV1: forced expiratory volume in one second; (F)VC: (forced) vital capacity; GOLD: Global Initiative for Chronic Obstructive Lung Disease; NA: not applicable.
- *: Two patients with GOLD stage III COPD (median value of FEV1 % of predicted, 44.5%; range 43.2-45.9).
- #: The mean value of the study group is 63 years.
- ‡: One patient with unknown medical history.
- †: p < 0.01 vs. smokers without COPD.
- §: p < 0.05 vs. patients with GOLD stage II-III COPD.
: p < 0.001 vs. never smokers.
: p < 0.001 vs. smokers without COPD.
: p < 0.01 vs. patients with GOLD stage I COPD.- ≠: p < 0.01 vs. never smokers.
: p < 0.05 vs. patients with GOLD stage I COPD.
: p < 0.001 vs. never smokers.
: p < 0.001 vs. smokers without COPD.
: p < 0.01 vs. patients with GOLD stage I COPD.
: p < 0.05 vs. patients with GOLD stage I COPD.