Table 2.
Clinical characteristics and correlation between plasma GDF15 and pulmonary function in patients with IPF
| Cohort 1 | Cohort 2 | Cohort 3 | |
|---|---|---|---|
| No. of samples with spirometry | 62 | 90 | 103 |
| Age (SD), yr | 66.3 (8.9) | 67.7 (7.7) | 70.9 (6.6) |
| Men, n (%) | 38 (61%) | 61 (68) | 79 (77) |
| Smoking status, n (%) | |||
| No | 20 (33%) | 27 (30%) | 27 (26%) |
| Former | 38 (62%) | 60 (68%) | 73 (71%) |
| Current | 3 (5%) | 2 (2%) | 3 (3%) |
| FVC, mean (SD), % | 71 (18.7) | 62 (19.5) | 74 (17.0) |
| DlCO, mean (SD), % | 48 (14.3) | 43 (16.1) | 47 (16.2) |
| GAP, median (IQR) | 3 (2–5) | 4 (3–5) | 4 (3–5) |
| Method for measuring GDF15 | Luminex | ELISA | ELISA |
| Plasma GDF15 (SD), pg/ml | 1,918 (1,228) | 1,666 (779) | 1,712 (794) |
| Correlation with clinical characteristics, regression β (P value) | |||
| FVC% | −0.07 (0.57) | 0.03 (0.78) | −0.17 (0.089) |
| DlCO% | −0.30 (0.022) | −0.25 (0.03) | −0.23 (0.023) |
| GAP | 0.23 (0.07) | 0.09 (0.41) | 0.37 (<0.001) |
| Change in FVC%* | −5.9 (0.083) | −3.7 (0.23) | −5.9 (0.005) |
| Change in DlCO%* | 1.2 (0.71) | 3.3 (0.29) | NA |
Values are means (SD). DlCO, diffusing capacity for carbon monoxide; FVC, forced vital capacity; GAP, gender, age, and physiology score; GDF15, growth and differentiation factor 15; IPF, idiopathic pulmonary fibrosis; IQR, interquartile range; NA, not applicable; SD, standard deviation.
*
Annualized rate of change.