Description of the study population

Males (n=892)Females (n=419)
Mean±sdRange or <LLN#Mean±sdRange or <LLN#
Age (years)47.3±11.618–8849.0±12.819–78
Height (m)1.79±0.071.53–2.041.65±0.071.46–1.82
Weight (kg)84.7±9.860–12368.4±9.535–94
BMI (kg·m−2)26.3±2.418.4–30.025.0±3.113.2–29.9
AHI (events·h−1)18.4±16.00–10412.1±13.80–88
FEV1 (z-score)0.31±0.99**1.90.29±1.00**2.6
FVC (z-score)0.30±0.93**1.60.26±0.94**2.1
FEV1/FVC (z-score)0.00±0.913.8−0.01±0.864.8
RV (z-score)0.37±0.64***0.10.58±0.65***0.0
FRC (z-score)−0.10±0.81***2.40.24±0.84***1.4
TLC (z-score)0.08±0.89**1.60.18±0.90***2.2
VC (z-score)−0.25±0.94**6.4−0.33±0.96**7.2
DLCO (z-score)−0.03±0.822.7−0.07±0.924.6
VA (z-score)−0.04±0.923.4−0.07±0.924.1
KCO (z-score)−0.01±0.821.3−0.01±0.893.4

LLN: lower limit of normal; BMI: body mass index; AHI: apnoea–hypopnoea index; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; RV: residual volume; FRC: functional residual capacity; TLC: total lung capacity; VC: vital capacity; DLCO: diffusing capacity of the lung for carbon monoxide; VA: alveolar volume; KCO: transfer coefficient of the lung for carbon monoxide. #: percentage of subjects with a z-score < −1.64 (based on the Global Lung Function Initiative). Data on static lung volumes were not available in n=14 males and n=5 females. Data on diffusing capacity were not available in n=12 males and n=4 females. Lung function values significantly different from 0 are indicated: **: p<0.01; ***: p<0.001.