Table 1. Demographics, PFTs and six-minute walk.
| Stratum 1 | Stratum 2 | Stratum 3 | Stratum 4 | |
|---|---|---|---|---|
| Never Smokers | Non-Diseased Smokers | Mild-Moderate COPD | Severe COPD | |
| N | 11 | 18 | 38 | 31 |
| Age | 55.4 ± 6.4 | 56.2 ± 8.4 | 64.7 ± 8.3 | 63.3 ± 8.5 |
| BMI | 26.9 ± 4.5 | 29.5 ± 5.9 | 27.7 ± 5.1 | 26.6 ± 5.9 |
| Gender, % Male | 36 | 61 | 76 | 61 |
| Current Smokers % | 0 | 72 | 54 | 30 |
| Pack Years | 0 | 41.2 ± 19.4 | 47.3 ± 19.6 | 47.5 ± 19.0 |
| Race, % | ||||
| White | 64 | 56 | 71 | 81 |
| Black | 18 | 28 | 21 | 13 |
| Hispanic | 18 | 5 | 3 | 6 |
| Asian | 0 | 6 | 0 | 0 |
| American Indian | 0 | 6 | 3 | 0 |
| FVC L (% Predicted) | 4.19 ± 1.30 (106.2) | 3.87 ± 0.75 (97.5) | 3.77 ± 1.0 (94.9) | 2.92 ± 1.09 (72.7) |
| FEV1 L (% Predicted) | 3.42 ± 1.04 (110.4) | 2.99 ± 0.63 (97.7) | 2.27 ± 0.71 (75.9) | 1.14 ± 0.48 (38.1) |
| FEF25-75% L/sec (% Predicted) | 3.75 ± 1.16 (130.1) | 2.84 ± 0.96 (101.0) | 1.16 ± 0.56 (46.2) | 0.46 ± 0.37 (18.0) |
| FEV1 /FVC (% Predicted) | 103.6 | 100 | 79.4 | 52.9 |
| Bronchodilator Response (% change)+ | ||||
| FEV1 (n) | 5.5 ± 9.9 (10) | 4.8 ± 5.8 (16) | 12.6 ± 12.7 (25) | 24.8 ± 24.2 (11) |
| FVC (n) | 0.06 ± 6.0 (10) | 0.81 ± 3.8 (16) | 11.1 ± 10.3 (25) | 18.0 ± 17.7 (11) |
| 6-Min Walk Distance (M) | 486.3 ± 46.6 | 426.5 ± 86.8 | 403.3 ± 111.3 | 329.3 ± 135.4 |
Values are means ± SD; n = number of subjects used in the analysis. Stratum 1 = Non-Smokers (FVC > LLN and FEV1/FVC >0.7); Stratum 2 = Non-Diseased Smokers (FVC > LLN and FEV1/FVC >0.7); Stratum 3 = COPD FEV1 >50% and FEV1/FVC <0.7; Stratum 4 = COPD FEV1 <50% and FEV1/FVC <0.7. Strata 2–4 are current or former smokers with >20 pack year smoking history.
+ Analysis was restricted to subjects who had not used any long-acting bronchodilator in the past 48 hours or a LABA within the past 24 hours, Tiotropium within the past 48 hours, a SABA within 6 hours or ipratropium within the last 8 hours of the baseline visit.