Table 1.
Subject characteristics by disease status*
| Healthy (n = 15) | COPD (n = 20) | p value | |
| Age, years | 51 (47 – 60) | 59 (54 – 61) | 0.02 |
| Sex, n (%) | |||
| Male: | 9 (60%) | 8 (40%) | 0.24 |
| Female: | 6 (40%) | 12 (60%) | |
| Race, n (%) | |||
| African-American: | 8 (53%) | 6 (30%) | 0.12 |
| White: | 6 (40%) | 14 (70%) | |
| Asian: | 1 (7%) | 0 | |
| Smoking status, n (%) | |||
| Never: | 5 (33%) | 0 | 0.03 |
| Fomer: | 3 (20%) | 8 (40%) | |
| Current: | 7 (47%) | 12 (60%) | |
| Tobacco exposure, pack years | 12.5 (0 – 30) | 53.3 (43 – 74.3) | <0.0001 |
| Inhaled corticosteroid (ICS) use, n (%) | 0 (0%) | 11 (55%) | 0.001 |
| ICS use by smoking status, n (%) | |||
| Never: | 0 (0%) | 0 (0%) | N/A |
| Fomer: | 0 (0%) | 4 (50%) | 0.24 |
| Current: | 0 (0%) | 7 (58%) | 0.02 |
| FEV1, %predicted | 102% (96% – 109%) | 48% (34% – 65%) | <0.0001 |
| FVC, %predicted | 100% (88% – 108%) | 80% (68% – 94%) | 0.001 |
| FEV1/FVC, %predicted | 100% (98% – 106%) | 59.5% (48.5% – 74.5%) | <0.0001 |
| TLC, %predicted | 105% (90% – 111%) | 117% (106% – 127%) | 0.007 |
| RV, %predicted | 98% (88% – 109%) | 165.5% (145% – 199.5%) | <0.0001 |
| DLCO, % predicted | 99% (84% – 117%) | 61.5% (48.5% – 68%) | <0.0001 |
| SP-D, ng/mL | 714 (445 – 1078) | 449 (310 – 664) | 0.03 |
| SP-D by smoking status, ng/mL | |||
| Never: | 1078 (1065 – 1239) | N/A | N/A |
| Fomer: | 1067 (861 – 1110) | 502 (449 – 765) | 0.01 |
| Current: | 445 (334 – 704) | 334 (290 – 533) | 0.45 |
*All values expressed as median (IQR) unless otherwise specified