Table 1.
Characteristics of study participants.
| Controls | IPF | |
|---|---|---|
| Number of subjects | 30 | 52 |
| Sex (male/female) | 17/13 | 39/13 |
| Age (years), mean (SD) | 61.36 (7.26) | 68.21 (8.76) *** |
| Smoking exposure (pack-years) median (IQR) | 8 (0–25) | 26.5 (7.75–39) ** |
| Smoking status | ||
| never smokers, n (%) | 12 (40.00) | 12 (23.07) |
| ex-smokers, n (%) | 8 (26.67) | 37 (71.15) |
| current smokers, n (%) | 10 (33.33) | 3 (5.77) |
| GAP score, median (IQR) | N/A | 4.0 (3.0–4.5) |
| GAP index: | N/A | |
| Stage I, n (%) | 24 (46.15) | |
| Stage II, n (%) | 27 (51.92) | |
| Stage III, n (%) | 1 (1.92) | |
| CPI score, mean (SD) | N/A | 71.42 (8.41) |
| Time since diagnosis (years), median (IQR) | N/A | 1.17 (0.08–2.79) |
| FEV1 (l), mean (SD) | 3.07 (0.81) | 2.21 (0.56) **** |
| FEV1 (% of predicted), mean (SD) | 100.88 (14.59) | 77.16 (17.08) **** |
| FVC (l), mean (SD) | 4.09 (1.10) | 2.74 (0.78) **** |
| FVC (% of predicted), mean (SD) | 103.97 (14.74) | 72.96 (16.87) **** |
| FEV1/FVC%, mean (SD) | 75.26 (4.83) | 81.67 (7.61) **** |
| TLCO (mmol/min/kPa), median (IQR) | N/A | 3.7 (2.97–4.59) |
| TLCO (% of predicted), mean (SD) | N/A | 49.29 (13.61) |
| 6MWT (meters), mean (SD) | N/A | 378.37 (113.31) |
Notes: ** p < 0.01; *** p < 0.001; **** p < 0.0001. IPF—idiopathic pulmonary fibrosis, FEV1—forced expiratory volume in 1 second, FVC—forced vital capacity, TLCO—transfer factor of the lung for carbon mon oxide, 6MWT—six-minute walk test, GAP—gender, age, and 2 physiology variables (FVC and TLCO), CPI—composite physiologic index, N/A—not applicable.