Study population.

<p>Data are presented as median (interquartile range). M/F: male/female; FEV1: forced expiratory volume in one second; % pred: % predicted; FVC: forced vital capacity. ¹: Stage 0 COPD is defined as FEV1, % pred >80; ²: Mild IPF is defined as FVC, % pred >80; ³: Stage 4 COPD is defined as FEV1, % pred <50; ⁴: Severe IPF is defined as FVC, % pred <50; ^a: data available for 3/4 Stage 0 COPD patients; ^b: data available for 5/10 Mild IPF patients;^c: data available for 9/10 Stage 4 COPD patients;^d: data available for 4/10 Severe IPF patients;^e: data available for 9/10 Mild or Severe IPF patients. *: p<0.05 compared with Stage 0 COPD patients; ^#: p<0.05 compared with Mild IPF patients.