Table 3. Correlations of percentage of time spent with oxygen saturations below 90% (CT90) with clinical and metabolic variables obtained in the univariate analyses.
| Variable | r | p |
| Age | 0.242 | 0.022 |
| BMI | 0.162 | 0.127 |
| AHI | 0.547 | <0.001 |
| Average SaO2 | 0.856 | <0.001 |
| Lowest SaO2 | −0.632 | <0.001 |
| FVC | −0.388 | <0.001 |
| FEV1/FVC ratio | −0.176 | 0.107 |
| TLC | −0.241 | 0.040 |
| RV | 0.097 | 0.416 |
| PaO2 | −0.477 | <0.001 |
| PaCO2 | 0.475 | <0.001 |
| ESS | 0.302 | 0.005 |
| Fasting glucose | 0.097 | 0.366 |
| HbA1c | 0.102 | 0.549 |
| Systolic blood pressure | 0.164 | 0.143 |
| Diastolic blood pressure | 0.195 | 0.081 |
| Total cholesterol | −0.017 | 0.885 |
| LDL cholesterol | 0.009 | 0.936 |
| HDL cholesterol | −0.112 | 0.335 |
| Triglycerides | 0.072 | 0.537 |
AHI: apnea-hipoapnea index; SaO2: arterial oxygen saturation; FVC: forced vital capacity (percentage of predicted); TLC: total lung capacity (percentage of predicted); RV: residual volume (percentage of predicted); PaO2: arterial oxygen pressure; PaCO2: arterial carbon dioxide pressure; ESS: Epworth Somnolence Score.