Table 1.
General demographics
| Variable | Controls | COPD Patients | P Value |
|---|---|---|---|
| n | 18 | 18 | |
| Anthropometry | |||
| Age, yr | 50.3 ± 1.6 | 57.1 ± 1.9 | <0.05 |
| Height, cm | 170.0 ± 2.7 | 174.2 ± 2.1 | NS |
| Weight, kg | 97.9 ± 6.6 | 86.5 ± 4.1 | NS |
| BMI, kg/m2 | 31.6 ± 1.6 | 28.6 ± 1.2 | NS |
| Sex | 12M; 6 F | 12M; 6 F | NS |
| Lung volumes | |||
| FEV1, liters | 3.1 ± 0.2 | 1.9 ± 0.2 | < 0.05 |
| FEV1/FVC, % | 79 ± 1.2 | 54 ± 2.6 | <0.05 |
| TLC, liters | 5.9 ± 0.3 | 6.7 ± 0.2 | < 0.05 |
| RV, liters | 1.9 ± 0.1 | 3.0 ± 0.2 | <0.05 |
| FRC, liters | 2.8 ± 0.2 | 4.0 ± 0.2 | < 0.05 |
| RV/TLC, % | 33.8 ± 1.8 | 45.5 ± 2.4 | <0.05 |
| Polysomnography | |||
| TST, min | 365.6 ± 10.7 | 353.7 ± 15.9 | NS |
| Sleep efficiency, %TST | 86.9 ± 2.0 | 79.4 ± 3.0 | <0.05 |
| NREM, %TST | 84.7 ± 1.5 | 83.9 ± 1.9 | NS |
| Stage 1 | 19.2 ± 2.4 | 27.1 ± 5.2 | NS |
| Stage 2 | 60.2 ± 2.5 | 50.8 ± 4.3 | NS |
| Stage 3 | 5.2 ± 1.8 | 6.0 ± 2.3 | NS |
| REM, %TST | 15.3 ± 1.5 | 16.1 ± 1.9 | NS |
| Total AHI, events/h | 28.9 ± 8.1 | 28.9 ± 8.6 | NS |
| NREM AHI, events/h | 27.8 ± 8.1 | 28.2 ± 8.6 | NS |
| REM AHI, events/h | 36.1 ± 7.7 | 33.3 ± 10.0 | NS |
| %Hypopnea NREM | 76.9 ± 6.1 | 75.9 ± 6.7 | NS |
| %Hypopnea REM | 73.3 ± 7.3 | 62.2 ± 8.6 | NS |
| Arterial SaO2, % | |||
| Average baseline value | 96.4 ± 0.4 | 93.9 ± 0.5 | <0.05 |
| Average low value | 91.5 ± 0.7 | 90.2 ± 0.6 | NS |
Values are averages ± SE of main demographic parameters for both groups; n, no. of subjects. COPD, chronic obstructive pulmonary disease; BMI, body mass index; M, male; F, female; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; TLC, total lung capacity; RV, residual volume; FRC, functional residual capacity; TST, total sleep time; NREM, non-rapid eye movement; REM, rapid eye movement; AHI, apnea hypopnea index; SaO2, arterial O2 saturation; NS, nonsignificant.