Participant characteristics, baseline arterial blood gases and spirometry
| OHS | Controls | p Value | |
|---|---|---|---|
| Age (years) | 48±12 | 48±12 | 0.987 |
| Gender (F/M) | 3/11 | 3/11 | – |
| BMI (kg/m2) | 53±7 | 25±4 | <0.001 |
| Weight (kg) | 154±21 | 73±15 | <0.001 |
| pH | 7.395±0.030 | 7.414±0.019* | 0.055 |
| PaCO2 (kPa) | 6.7±0.5 | 5.5±0.4* | <0.001 |
| PaO2 (kPa) | 8.9±1.4 | 14.3±1.1* | <0.001 |
| SaO2 (%) | 92±3 | 98±1* | <0.001 |
| HCO3− (mmol/L) | 30.3±1.7 | 25.8±1.2* | <0.001 |
| A-aDO2 (kPa) | 3.6±1.4 | 0.9±1.2* | <0.001 |
| Haemoglobin (g/L) | 153±20 | 143±11 | 0.156 |
| FEV1 (L) | 2.39±0.72 | 3.71±0.71 | 0.001 |
| FEV1% predicted | 73±14 | 106±11 | <0.001 |
| FVC (L) | 3.03±0.85 | 4.54±0.77 | <0.001 |
| FVC % predicted | 77±14 | 107±13 | <0.001 |
| FEV1/FVC (%) | 79±6 | 82±5 | 0.231 |
Data presented as mean±SD; p value represents two-tailed significance from independent t tests comparing control and OHS groups.
*Data reported from n=13, as arterial blood gas could not be performed in one control participant.
A-aDO2, alveolar-arterial oxygen difference; BMI, body mass index; FEV1, forced expired volume in 1 s; FVC, forced vital capacity; HCO3−, bicarbonate; OHS, obesity hypoventilation syndrome; PaCO2, arterial partial pressure of CO2; PaO2, arterial partial pressure of O2.