Table 1

Participant characteristics, baseline arterial blood gases and spirometry

OHSControlsp Value
Age (years)48±1248±120.987
Gender (F/M)3/113/11
BMI (kg/m2)53±725±4<0.001
Weight (kg)154±2173±15<0.001
PaCO2 (kPa)6.7±0.55.5±0.4*<0.001
PaO2 (kPa)8.9±1.414.3±1.1*<0.001
SaO2 (%)92±398±1*<0.001
HCO3 (mmol/L)30.3±1.725.8±1.2*<0.001
A-aDO2 (kPa)3.6±1.40.9±1.2*<0.001
Haemoglobin (g/L)153±20143±110.156
FEV1 (L)2.39±0.723.71±0.710.001
FEV1% predicted73±14106±11<0.001
FVC (L)3.03±0.854.54±0.77<0.001
FVC % predicted77±14107±13<0.001
FEV1/FVC (%)79±682±50.231
  • 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.