Table 2.
Anthropometric, Lung Volumes, Blood Gas, and Sleep Data of Patients Classified by Presence of Nocturnal Hypoxia (TST90≥1.)
| TST90<1 % (n=94) | TST90 ≥1 % (n=362) | P-value (#) | |
|---|---|---|---|
| Mean ± SD | Mean ± SD | ||
| Sex (% (n) male) | 56.4 (53) | 67.1 (243) | 0.068 |
| Age (yr) | 50.5 ± 13.4 | 49.2 ± 11.9 | 0.3466 |
| BMI (Kg/m2) | 40.0 ± 12.6 | 43.4 ± 10.9 | 0.0086 |
| BSA (m2) | 2.19 ± 0.31 | 2.34 ± 0.32 | <0.001 |
| VC (% pred.) | 98.6 ± 15.1 | 92.9 ± 14.8 | <0.001 |
| FEV1 (% of pred.) | 96.7 ± 18.1 | 92.0 ± 17.4 | 0.0195 |
| FEV1/VC (abs value) | 78.5 ± 8.1 | 78.5 ± 8.4 | 0.9547 |
| FRC (% of pred.) | 80.5 ± 19.6 | 76.0 ± 21.0 | 0.0605 |
| VR (% of pred.) | 94.0 ± 20.7 | 89.4 ± 23.4 | 0.0878 |
| TLC (% of pred.) | 94.2 ± 12.4 | 90.5 ± 12.5 | 0.0117 |
| MEF50 (% of pred.) | 92.4 ± 36.4 | 91.7 ± 34.4 | 0.8713 |
| PaO2 (mm Hg) | 77.3 ± 8.0 | 70.2 ± 9.3 | <0.001 |
| PaCO2 (mm Hg) | 37.7 ± 3.7 | 40.3 ± 4.7 | <0.001 |
| AHI (event-hour−1) | 26.8 ± 23.2 | 54.0 ± 33.0 | <0.001 |
| ODI (event-hour−1) | 28.4 ± 26.0 | 54.9 ± 32.8 | <0.001 |
| PaO2 (% of pred) | 87.0 ± 9.2 | 78.5 ± 10.4 | <0.001 |
BMI = body mass index; BSA = body surface area; RV = residual volume; AHI = apnea and hypopnea index; ODI = oxygen desaturation index; TST90 = total sleep time spent with SaO2 <90%.
#
P-values were computed by t-tests of two independent populations with equal or unequal variances, and Fisher's exact χ2 test for sex.