Respiratory variables for all subjects and for pro-surfactant protein B (pro-SFTPB) quartiles
| Category | All | Pro-SFTPB quartiles (ng·mL−1) | ||||
|---|---|---|---|---|---|---|
| 1 (<16.93) | 2 (16.94–31.79) | 3 (31.80–56.66) | 4 (⩾56.67) | p-trend | ||
| Pro-SFTPB ng·mL−1 | 45.53±0.92 | 11.10±0.15 | 23.69±0.17 | 42.86±0.29 | 104.58±2.29 | |
| Patients | 2503 (100) | 626 (25) | 626 (25) | 626 (25) | 625 (25) | |
| CT emphysema total score | 1.13±0.02 | 0.81±0.04 | 1.06±0.05 | 1.20±0.05 | 1.44±0.05 | <0.001 |
| FEV1 L | 2.44±0.01 | 2.45±0.03 | 2.47±0.03 | 2.44±0.03 | 2.40±0.03 | 0.174 |
| FEV1 % predicted | 81.77±0.37 | 82.60±0.76 | 82.58±0.73 | 81.59±0.74 | 80.32±0.75 | 0.007 |
| FVC L | 3.57±0.02 | 3.53±0.04 | 3.61±0.04 | 3.59±0.04 | 3.55±0.04 | 0.880 |
| FVC % predicted | 92.44±0.35 | 92.39±0.72 | 93.03±0.67 | 92.72±0.68 | 91.63±0.72 | 0.349 |
| FEV1/FVC % | 68.43±0.20 | 69.38±0.41 | 68.60±0.40 | 68.12±0.40 | 67.59±0.42 | <0.001 |
| 1-year FEV1 change# mL·year−1 | −46.65±4.14 | −30.01±7.85 | −52.47±8.41 | −48.81±8.44 | −55.88±8.35 | 0.037 |
| 1-year FEV1 change# % | −1.46±0.19 | −0.77±0.38 | −1.70±0.38 | −1.49±0.39 | −1.91±0.37 | 0.034 |
| 2-year FEV1 change¶ mL·year−1 | −40.37±2.70 | −29.68±5.03 | −42.90±4.92 | −43.63±5.57 | −46.14±8.35 | 0.005 |
| 2-year FEV1 change¶ % | −2.85±0.24 | −1.88±0.46 | 3.21±0.46 | −3.01±0.51 | −3.39±0.50 | 0.037 |