Description of the study population
| Males (n=892) | Females (n=419) | |||
| Mean±sd | Range or <LLN# | Mean±sd | Range or <LLN# | |
| Age (years) | 47.3±11.6 | 18–88 | 49.0±12.8 | 19–78 |
| Height (m) | 1.79±0.07 | 1.53–2.04 | 1.65±0.07 | 1.46–1.82 |
| Weight (kg) | 84.7±9.8 | 60–123 | 68.4±9.5 | 35–94 |
| BMI (kg·m−2) | 26.3±2.4 | 18.4–30.0 | 25.0±3.1 | 13.2–29.9 |
| AHI (events·h−1) | 18.4±16.0 | 0–104 | 12.1±13.8 | 0–88 |
| FEV1 (z-score) | 0.31±0.99** | 1.9 | 0.29±1.00** | 2.6 |
| FVC (z-score) | 0.30±0.93** | 1.6 | 0.26±0.94** | 2.1 |
| FEV1/FVC (z-score) | 0.00±0.91 | 3.8 | −0.01±0.86 | 4.8 |
| RV (z-score) | 0.37±0.64*** | 0.1 | 0.58±0.65*** | 0.0 |
| FRC (z-score) | −0.10±0.81*** | 2.4 | 0.24±0.84*** | 1.4 |
| TLC (z-score) | 0.08±0.89** | 1.6 | 0.18±0.90*** | 2.2 |
| VC (z-score) | −0.25±0.94** | 6.4 | −0.33±0.96** | 7.2 |
| DLCO (z-score) | −0.03±0.82 | 2.7 | −0.07±0.92 | 4.6 |
| VA (z-score) | −0.04±0.92 | 3.4 | −0.07±0.92 | 4.1 |
| KCO (z-score) | −0.01±0.82 | 1.3 | −0.01±0.89 | 3.4 |
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.