Table 1.
Baseline characteristics.
| BPAP (n = 16) | CPAP (n = 16) | All (n = 32) | |
|---|---|---|---|
| Age (y) | 57 (9.7) | 65 (10.7) | 61 (10.9) |
| Sex (% female) | 50 | 13 | 31 |
| BMI (kg/m2) | 45 (7.8) | 40 (5.8) | 43 (7.2) |
| Neck circumference (cm) | 46 (4.9) | 49 (3.5) | 47 (4.4) |
| Waist circumference (cm) | 132 (10.2) | 133 (10.7) | 133 (10.3) |
| Hip circumference (cm) | 137 (14.1) | 131 (14.8) | 134 (14.5) |
| Spirometry | |||
| FEV1 (L) | 1.3 (0.6) | 1.5 (0.5) | 1.4 (0.6) |
| FEV1 (% predicted) | 45 (19.8) | 51 (17.5) | 48 (18) |
| FVC (L) | 2.0 (0.9) | 2.6 (0.7) | 2.3 (0.8) |
| FVC (% predicted) | 58 (23) | 68 (20) | 64 (22) |
| FER (%) | 62 (8) | 59 (11) | 60 (10) |
| ABG | |||
| PaCO2 (mm Hg) | 57 (8) | 52 (5.6) | 54 (7.4) |
| PaO2 (mm Hg) | 60 (11) | 57 (9) | 59 (10) |
| Bicarbonate (mmol) | 33 (5) | 31 (3.8) | 32 (4.6) |
| Base excess (mmol) | 6.5 (4.5) | 5.5 (3.4) | 6 (4.0) |
| pH | 7.39 (0.03) | 7.39 (0.03) | 7.39 (0.03) |
| PSG | |||
| AHI (events/h) | 57 (34) | 61 (37) | 59 (35) |
| % TST < 90% | 93 (70–99) | 84 (58–96) | 85 (68–98) |
| % TST < 80% | 28 (17–47) | 17 (5–37) | 23 (7–43) |
| % NREM sleep | 90 (9) | 87 (9) | 89 (9) |
| % REM sleep | 10 (9) | 13 (9) | 11 (9) |
| TcCO2 mean (mm Hg) | 57 (13) | 50 (6) | 54 (11) |
| TcCO2 peak (mm Hg) | 69 (15) | 65 (9) | 67 (12) |
Values displayed as mean (standard deviation), except for % TST < 90% and % TST < 80%, which are displayed as median (interquartile range). Please note TcCO2 data were only available for 7 patients in the BPAP arm and 5 patients in the CPAP arm. ABG = arterial blood gas, AHI = apnea-hypopnea index, BMI = body mass index, BPAP = bilevel positive airway pressure, CPAP = continuous positive airway pressure, FER = forced expiratory ratio, FEV1 = forced expiratory volume in 1 second, FVC = forced vital capacity, NREM = nonrapid eye movement, PSG = polysomnography, REM = rapid eye movement, TcCO2, transcutaneous CO2, TST = total sleep time.