Demographic and clinical characteristics of the study population
| All study participants | All COPD patients | COPD GOLD stage | Controls | p-value# | p-value¶ | ||||
| A | B | C | D | ||||||
| Subjects | 129 | 107 | 6 | 52 | 4 | 45 | 22 | ||
| Demographics | |||||||||
| Age years | 64.0±10.1 | 64.6±10.4 | 65.3±10.1 | 63.7±11.8 | 73.3±4.3 | 64.8±8.8 | 60.9±7.7 | 0.21 | 0.12 |
| Male | 70 (54.3) | 58 (52.2) | 3 (50.0) | 29 (55.8) | 1 (25.0) | 25 (55.6) | 12 (54.5) | 0.83 | 0.98 |
| BMI kg·m−2 | 26.2±5.1 | 25.9±5.3 | 26.8±6.0 | 26.3±4.8 | 23.6±3.5 | 25.5±5.9 | 27.6±4.0 | 0.55 | 0.18 |
| Smoking history | |||||||||
| Pack-years | 30 (0–150) | 30 (0–150) | 17.5 (2–40) | 30 (0–125) | 40 (20–60) | 40 (0–150) | 30 (5–150) | 0.22 | 0.20 |
| Current smoker | 26 (20.2) | 22 (20.5) | 1 (16.7) | 13 (25.0) | 2 (50.0) | 6 (13.3) | 4 (18.2) | 0.69 | 0.35 |
| Ex-smoker | 98 (75.9) | 80 (74.8) | 5 (83.3) | 35 (67.3) | 2 (50.0) | 38 (84.4) | 18 (81.8) | 0.21 | 0.49 |
| Never-smoker | 5 (3.9) | 5 (4.7) | 0 (0) | 4 (7.7) | 0 (0) | 1 (2.2) | 0 (0) | 0.46 | 0.31 |
| α1-Antitrypsin deficiency | 6 (4.7) | 6 (5.6) | 1 (16.7) | 2 (3.8) | 1 (25.0) | 3 (6.7) | 0 (0) | 0.22 | 0.21 |
| Cardiovascular risk factors | |||||||||
| Arterial hypertension | 60 (46.5) | 50 (46.7) | 4 (66.7) | 20 (38.5) | 2 (50.0) | 24 (53.3) | 10 (45.5) | 0.32 | 0.41 |
| Diabetes mellitus | 15 (11.6) | 13 (12.1) | 0 (0) | 6 (11.5) | 0 (0) | 7 (15.6) | 2 (9.1) | 0.57 | 0.50 |
| Dyslipidaemia+ | 46 (35.7) | 39 (36.4) | 2 (33.3) | 19 (36.5) | 2 (50.0) | 16 (35.6) | 7 (31.8) | 0.44 | 0.33 |
| Obesity | 27 (20.9) | 23 (21.5) | 1 (16.7) | 13 (25.0) | 0 (0) | 9 (20.0) | 4 (18.2) | 0.69 | 0.44 |
| Familial disposition | 37 (28.7) | 27 (25.2) | 2 (33.3) | 16 (30.8) | 0 (0) | 9 (20.0) | 10 (45.5) | 0.51 | 0.40 |
| Comorbidities | |||||||||
| Coronary heart disease | 23 (17.8) | 23 (21.5) | 3 (50.0) | 12 (23.1) | 1 (25.0) | 7 (15.6) | 0 (0) | 0.002 | 0.004 |
| Pulmonary hypertension | 10 (7.8) | 10 (9.3) | 0 (0) | 5 (9.6) | 1 (25.0) | 4 (8.9) | 0 (0) | 0.25 | 0.06 |
| Cardiovascular medication use | |||||||||
| Platelet inhibitor | 27 (20.9) | 27 (25.2) | 3 (50.0) | 13 (25.0) | 2 (50.0) | 9 (20.0) | 0 (0) | 0.02 | 0.001 |
| β-Blocker | 39 (30.2) | 39 (36.4) | 1 (16.7) | 21 (40.4) | 3 (75.0) | 14 (31.1) | 0 (0) | 0.007 | 0.003 |
| Statin | 25 (19.4) | 25 (23.4) | 3 (50.0) | 12 (23.1) | 1 (25.0) | 9 (20.0) | 0 (0) | 0.05 | 0.005 |
| Digitalis | 3 (2.3) | 3 (2.8) | 0 (0) | 1 (1.9) | 0 (0) | 2 (4.4) | 0 (0) | 0.80 | 0.43 |
| Amiodarone | 2 (1.6) | 2 (1.9) | 0 (0) | 1 (1.9) | 0 (0) | 1 (2.2) | 0 (0) | 0.96 | 0.52 |
| Anti-obstructive and anti-inflammatory medication use | |||||||||
| Long-acting β2-agonist | 78 (60.5) | 78 (72.9) | 1 (16.7) | 36 (69.2) | 3 (75.0) | 38 (84.4) | 0 (0) | <0.001 | <0.001 |
| Long-acting anticholinergic | 68 (52.7) | 68 (63.6) | 0 (0) | 29 (55.8) | 1 (25.0) | 38 (84.4) | 0 (0) | <0.001 | <0.001 |
| Inhaled glucocorticoid | 46 (35.7) | 46 (43.0) | 0 (0) | 0 (0) | 3 (75.0) | 43 (95.6) | 0 (0) | <0.001 | <0.001 |
| Systemic glucocorticoid | 7 (5.4) | 7 (6.5) | 0 (0) | 0 (0) | 0 (0) | 7 (15.6) | 0 (0) | <0.001 | 0.05 |
| PDE-4 inhibitor (roflumilast) | 19 (14.7) | 19 (17.8) | 0 (0) | 0 (0) | 1 (25.0) | 18 (40.0) | 0 (0) | <0.001 | 0.02 |
| Home oxygen therapy | 21 (16.3) | 21 (19.6) | 0 (0) | 0 (0) | 2 (50.0) | 19 (42.2) | 0 (0) | <0.001 | 0.003 |
Data are presented as n (%), mean±sd or median (range), unless otherwise stated. COPD: chronic obstructive pulmonary disease; GOLD: Global Initiative for Chronic Obstructive Lung Disease; BMI: body mass index; PDE-4: phosphodiesterase type 4. #: intercohortal comparison was performed by defining controls as the COPD GOLD 0 group, p-values refer to data comparison between all five groups (COPD GOLD 0 through D); ¶: p-values refer to data comparison between the entire COPD group and controls; +: dyslipidaemia was defined on the basis of total cholesterol and low-density lipoprotein cholesterol levels [13].