| Study group | Mean FVC-L (SD) | Mean PaO2 before HCT-kPa (SD) | Mean PaO2 at the end of HCT-kPa (SD) | Mean distance walked during ISWT-metre (SD) | Mean minimum SpO2 during ISWT % (SD) |
| OHS (n = 7) | 2.4 (0.7) | 10 (0.2) | 6.3 (0.5) | 151 (141) | 93 (1.8) |
| Untreated OSA (n = 7) | 4.1 (0.5) | 10.8 (1.5) | 7.9 (1) | 407 (169) | 93 (3.8) |
| Treated OSA (n = 12) | 4.3 (1) | 10.2 (1) | 8.3 (1.6) | 451 (181) | 91 (4.7) |
HCT, hypoxic challenge test; ISWT, incremental shuttle walk test; OSA, obstructive sleep apnoea.