Table 1. Characteristics of study cohort.
| Total | Non-Smokers | Smokers | GOLD I/II | GOLD III/IV | p | |
| Patients (n) | 185 (100%) | 30 (16%) | 15 (8%) | 75 (41%) | 65 (35%) | |
| Demographics | ||||||
| Age in years | 66.6 (0.5) | 66.4 (1.1) | 66.8 (1.7) | 66.9 (0.7) | 66.3 (0.7) | 0.94 |
| Males (n) | 135 (73%) | 21 (70%) | 11 (73%) | 54 (72%) | 49 (75%) | 0.95 |
| Body Mass Index (BMI) | 26.0 (0.4) | 26.0 (0.8) | 26.3 (0.8) | 27.3 (0.5) | 24.3 (0.7) | <0.001 |
| Pack years | 45.3 (2.2) | 0.5 (0.2) | 42.9 (5.3) | 51.9 (2.9) | 58.8 (3.1) | <0.001 |
| Current smokers (n) | 59 (32%) | 0 (0%) | 10 (67%) | 30 (40%) | 19 (29%) | <0.001 |
| Systemic steroid use (n) | 25 (14%) | 0 (0%) | 0 (0%) | 5 (2.7%) | 20 (11%) | <0.001 |
| Theophylline use (n) | 20 (11%) | 0 (0%) | 0 (0%) | 2 (1.1%) | 18 (9.7%) | <0.001 |
| Metabolic Syndrome | ||||||
| Metabolic syndrome (n) | 88 (48%) | 13 (43%) | 10 (67%) | 44 (59%) | 21 (32%) | 0.006 |
| Lung Function Parameters | ||||||
| Post bronchodilator FEV1% predicted | 65.0 (43.0 – 96.0) | 114.0 (108.5 −125.0) | 100.0 (92.5 − 107.0) | 75.0 (62.0 − 85.0) | 36.0 (27.0 − 45.0) | <0.001 |
| Post bronchodilator FEV1/FVC ratio | 56.1 (43.8 − 72.8) | 78.3 (75.8 − 80.9) | 76.7 (74.8 − 78.7) | 60.2 (51.2 − 65.8) | 39.1 (34.0 − 46.0) | <0.001 |
| DLCO % predicted (Hb corrected) | 60.1 (39.5 − 74.8) | 80.2 (74.8 − 89.1) | 70.9 (61.5 − 81.6) | 61.0 (51.7 − 73.0) | 31.6 (24.8 − 42.1) | <0.001 |
Data are expressed as the number of subjects (% of subjects), mean (SEM) or median (Interquartile range) for lung function parameters. COPD subjects were grouped as GOLD I/II (mild/moderate) and GOLD III/IV (severe/very severe).