Table 2.
Changes in sputum properties, pulmonary diffusing capacity and oxygen saturation during experiments A and B (N = 15)
| Experiment A | Experiment B | |||||||
|---|---|---|---|---|---|---|---|---|
| Variables | Pre-exercise | Post-exercise | 45 min post-exercise | P-value | Pre-exercise | Post-exercise | 45 min post-exercise | P-value |
| Sputum properties | ||||||||
| G’ 1 rad s−1 (Pa) | 6.7 (4.2, 9.7) | 10.3 (6.0; 20.3) | 14.1 (6.1, 19.0) | 0.057 | 7.5 (4.1, 13.0) | 8.8 (6.5, 13.8) | 13.3 (7.1, 14.6) | 0.085 |
| G’ 10 rad s−1 (Pa) | 10.2 (6.4, 14.4) | 15.9 (8.3, 28.1) | 20.9 (9.7, 26.0) | 0.062 | 11.5 (5.9, 20.1) | 13.6 (8.8, 18.0) | 20.0 (10.1, 23.0) | 0.155 |
| G” 1 rad s−1 (Pa) | 2.3 (1.7, 3.2) | 3.1 (2.1, 5.9) | 3.8 (2.0, 6.2) | 0.085 | 2.6 (1.3, 3.6) | 3.2 (2.3, 4.9) | 4.5 (2.5, 4.9) | 0.155 |
| G” 10 rad s−1 (Pa) | 2.9 (2.2, 4.0) | 3.7 (2.6, 6.6) | 4.2 (2.6, 6.7) | 0.085 | 3.6 (1.8, 4.3) | 3.7 (2.8, 5.7) | 5.3 (2.9, 6.1) | 0.282 |
| Dynamic yield stress (Pa) | 0.20 (0.10, 0.30) | 0.30 (0.20, 0.60) | 0.30 (0.20, 0.40) | 0.066 | 0.20 (0.10, 0.40) | 0.20 (0.18, 0.33) | 0.30 (0.2, 0.53) | 0.074 |
| Sputum solids content (%) | 5.3 (3.9, 7.4) | 6.2 (4.2, 9.7) | 6.5 (4.4, 8.1) | 0.038 | 4.5 (3.6, 5.8) | 6.2 (4.1, 7.5) | 6.9 (3.8, 8.4) | 0.672 |
| Spinnability (mm) | 6.7 (6.4, 8.2) | 7.7 (6.5, 21.0) | 6.7 (6.3, 8.2) | 0.155 | 9.2 (6.4, 12.4) | 6.2 (5.8, 8.3) | 8.9 (7.2, 31.0) | 0.089 |
| Ease of sputum expectoration (cm) | 8.1 (5.2, 8.3) | 7.7 (3.4, 9.3) | 8.2 (4.7, 8.9) | 0.180 | 7.1 (5.2, 8.7) | 6.5 (4.4, 9.1) | 5.3 (4.3, 9.2) | 0.482 |
| Pulmonary diffusing capacity | ||||||||
| DLNO (mL min− 1 mmHg− 1) | 78.1 (68.4, 141.6) | 86.9 (67.4, 140.6) | 79.2 (65.6, 134.0) | 0.015* | 84.7 (64.8, 143.1) | 83.8 (69.9, 135.2) | 82.6 (69.4, 147.8) | 0.482 |
| DLNO/VA (mL min− 1 mmHg− 1 L− 1) | 21.1 (19.8; 22.4) | 21.2 (20.0; 22.2) | 20.7 (18.2; 21.8) | 0.015♯ | 21.1 (19.7; 22.7) | 20.5 (19.2; 22.4) | 20.7 (18.3, 22.3) | 0.007♯ |
| DLCO (mL min− 1 mmHg− 1) | 22.4 (20.3, 31.9) | 24.6 (20.3, 36.2) | 21.5 (19.5, 31.1) | 0.002* | 23.7 (19.6, 34.3) | 24.2 (19.4, 34.0) | 22.9 (19.3, 32.5) | 0.011* |
| DLCO/VA (mL min− 1 mmHg− 1 L− 1) | 5.8 (5.2, 6.1) | 6.1 (5.4, 6.5) | 5.6 (5.3, 6.2) | 0.047* | 5.7 (5.4, 6.01) | 6.0 (5.3, 6.2) | 5.5 (5.0, 5.9) | < 0.001*♯ |
| DLNO/DLCO ratio | 3.8 (3.4, 4.1) | 3.6 (3.4, 3.8) | 3.6 (3.4, 4.1) | 0.025 | 3.8 (3.4, 4.2) | 3.5 (3.3, 3.9) | 3.7 (3.3, 4.1) | 0.005 |
| DMCO (mL min−1 mmHg− 1) | 52 (42, 112) | 56 (43, 88) | 53 (43, 92) | 0.612 | 58 (42, 106) | 54 (45, 89) | 56 (42, 118) | 0.717 |
| VA (L) | 3.8 (3.4, 6.0) | 4.2 (3.5, 6.1) | 3.9 (3.4, 5.6) | 0.001 | 3.9 (3.3, 5.9) | 3.9 (3.5, 5.5) | 4.0 (3.6, 6.0) | 0.420 |
| Vcap (mL) | 76 (69, 82) | 91 (77, 91) | 76 (67, 91) | < 0.001* | 75 (72, 94) | 82 (76, 92) | 75 (67, 83) | 0.015* |
| Oxygen saturation | ||||||||
| SpO2 (%) | 97.0 (95.8, 97.0) | 96.0 (94.8, 97.0) | 96.0 (95.5, 97.0) | 0.598 | 96.5 (96.0, 97.6) | 96.0 (96.0, 97.3) | 97.0 (96.8, 98.0) | 0.125 |
Data are displayed as median (interquartile range, IQR). DLCO, diffusing capacity of the lung for carbon monoxide; DLNO, diffusing capacity of the lung for nitric oxide; DMCO, alveolar-capillary membrane diffusing capacity for carbon monoxide; G’, storage modulus; G”, loss modulus; SpO2, oxygen saturation; VA, alveolar volume; Vcap, pulmonary capillary blood volume. Pulmonary gas diffusion variables were measured in SI units (mmol min− 1 kPa− 1) and converted to traditional units (mL min− 1 mmHg− 1) by multiplying with 2.987. Differences in outcome variables between the three different time points during each experimental condition (experiment A and B) were analyzed using the non-parametric Friedman test followed by a Wilcoxon-signed rank test. The Wilcoxon signed-rank test was only performed, if changes over time were significant (P < 0.05)
*indicates significant differences between pre- and post-exercise values based on Wilcoxon signed-rank test (P < 0.05)
♯ indicates significant differences between pre- and 45′ post-exercise values based on Wilcoxon signed-rank test (P < 0.05)