| Entire sample (n = 306) | AHI ⩽1 (n = 127) | 1< AHI ⩽5 (n = 133) | AHI >5 (n = 46) | p Value (trend) | |
| Age (y) | 10.4 (1.7) | 10.4 (1.7) | 10.6 (1.6) | 10.1 (1.6) | 0.59 |
| Male gender (n (%)) | 199 (65) | 72 (57) | 92 (69) | 35 (76) | 0.008 |
| Body height (cm) | 139.6 (10.5) | 139.0 (10.4) | 140.2 (10.8) | 139.5 (10.1) | 0.58 |
| Body weight (kg)*† | 36.4 (10.6) | 34.2 (9.4) | 37.5 (11.5) | 39.6 (10.3) | <0.001 |
| Body mass index (m/kg2)*† | 18.4 (3.4) | 17.4 (2.9) | 18.7 (3.5) | 20.1 (3.4) | <0.001 |
| Body mass index z score*†‡ | 0.48 (1.04) | 0.18 (0.97) | 0.56 (1.04) | 1.07 (0.94) | <0.001 |
| Normal weight (n (%))*†‡ | 204 (66.7) | 103 (81.1) | 85 (63.9) | 16 (34.8) | |
| Overweight (n (%))*†‡ | 59 (19.3) | 16 (12.6) | 28 (21.1) | 15 (32.6) | <0.001 |
| Obese (n (%))*†‡ | 43 (14.1) | 8 (6.3) | 20 (15.0) | 15 (32.6) | |
| Waist circumference (cm)*†‡ | 63.7 (9.5) | 60.9 (8.1) | 64.7 (9.9) | 68.7 (9.5) | <0.001 |
| Hip circumference (cm)*† | 74.4 (9.5) | 72.5 (9.0) | 75.2 (10.0) | 77.5 (8.3) | <0.001 |
| Waist to hip ratio*†‡ | 0.86 (0.06) | 0.84 (0.05) | 0.86 (0.05) | 0.89 (0.06) | <0.001 |
| Epworth sleepiness scale score | 6.5 (4.1) | 6.2 (4.1) | 6.6 (4.2) | 6.8 (3.9) | 0.32 |
| Rapid eye movement sleep (%) | 21.0 (4.1) | 21.0 (3.9) | 21.0 (3.9) | 20.8 (5.1) | 0.78 |
| Slow wave sleep (%) | 22.8 (5.2) | 23.1 (5.4) | 22.4 (5.1) | 23.2 (5.0) | 0.80 |
| Non-slow wave sleep (%) | 56.2 (5.9) | 55.9 (6.0) | 56.6 (5.6) | 56.0 (6.5) | 0.68 |
| Sleep efficiency (%) | 82.1 (10.7) | 82.7 (10.0) | 81.3 (10.9) | 82.4 (12.2 | 0.64 |
| Apnoea–hypopnoea index (/h)*†‡ | 1.2 (0.3–2.9) | 0.2 (0.0–0.5) | 2.0 (1.3–2.8) | 8.2 (6.5–13.1) | <0.001 |
| Oxygen desaturation index (/h)*†‡ | 0.4 (0.1–1.0) | 0.1 (0.0–0.4) | 0.5 (0.2–1.0) | 3.1 (1.1–6.1) | <0.001 |
| Arousal index (/h)*†‡ | 6.8 (5.2–8.8) | 5.7 (4.5–7.5) | 7.0 (5.6–8.8) | 12.2 (8.0–16.3) | <0.001 |
| Spo2 nadir (%)*†‡ | 91.5 (3.2) | 92.4 (2.1) | 91.6 (2.6) | 88.9 (5.1) | <0.001 |
Mean (SD), median (IQR) and number (%) are presented for parametric, non-parametric and categorical data, respectively. The percentages of normal weight, overweight and obese patients do not always sum to 100% because of rounding errors.
*Post-hoc test, p<0.05, normal group vs mild OSA group.
†Post-hoc test, p<0.05, normal group vs moderate to severe OSA group.
‡Post-hoc test, p<0.05, mild OSA group vs moderate to severe OSA group.
AHI, apnoea–hypopnoea index; Spo2, oxygen haemoglobin saturation.