| Measure | MNS | TB90% |
| Pao2 | 0.51 (p = 0.0001) | −0.44 (p = 0.001) |
| Paco2 | −0.34 (p = 0.02) | 0.31 (p = 0.03) |
| FEV1 | 0.23 (p = 0.09) | −0.23 (p = 0.08) |
| FEV1%predicted | 0.17 (p = 0.19) | −0.18 (p = 0.18) |
| FVC | 0.23 (p = 0.09) | −0.24 (p = 0.06) |
| FVC%predicted | 0.24 (p = 0.07) | −0.26 (p = 0.05) |
| BMI | −0.15 (p = 0.3) | 0.11 (p = 0.40) |
| Pack-year smoking history | 0.21 (p = 0.12) | −0.23 (p = 0.08) |
Results are presented as correlation coefficient (p value).
BMI, body mass index; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; MNS, mean nocturnal saturation; Pao2, arterial oxygen tension; Paco2, arterial carbon dioxide tension; TB90%, time spent with saturation below 90%.