Baseline demographics, clinical characteristics and functional respiratory imaging data of all groups
| Caucasian children | bA children | p-value | |
| Subjects n | 17 | 11 | |
| Age years | 4.6 (1.1–12.9) | 4.5 (0.8–12.8) | ns |
| Males/females n | 12/5 | 7/4 | ns |
| Obese/nonobese n | 3/14 | 2/9 | ns |
| BMI z-score | 0.6 (−2.6–3.4) | 0.3 (−3.8–3.7) | ns |
| Tonsil Brodsky score ≥3 | 67% | 64% | ns |
| oAHI at baseline events·h−1 mean (range) | 17.9 (4.6–49.0) | 23.1 (7.2–48.0) | ns |
| Children with mild OSA | 6% | 0% | ns |
| Children with severe OSA | 77% | 91% | ns |
| UA volume mm3 | 20 470 (7643–45 368) | 13 128 (3174–44 616) | ns |
| Zone 1 volume mm3 | 1604 (760–3145) | 1937 (324–5033) | ns |
| Zone 2 volume mm3 | 11 075 (2022–33 141) | 6174 (1323–32 963) | ns |
| Zone 3 volume mm3 | 1668 (382–3285) | 1314 (0–2924) | ns |
| Zone 4 volume mm3 | 1080 (206–11 821) | 594 (0–1544) | 0.04 |
| Zone 5 volume mm3 | 4515 (1323–6798) | 3606 (1500–6780) | ns |
| Minimal cross-sectional area mm2 | 29 (0–46) | 12 (0–53) | ns |
| Conductance | 3.2 (0–8.6) | 2.2 (0–8.3) | ns |
| Total upper airway obstruction | 18% | 27% | ns |
Data are presented as median (interquartile range) unless otherwise stated. Zone 1: nostril to bottom of inferior turbinate; zone 2: bottom of inferior turbinate to choanae; zone 3: choanae to tip of uvula; zone 4: uvula to epiglottis; zone 5: epiglottis to the first vertebra. bA: black African; BMI: body mass index; oAHI: obstructive apnoea–hypopnoea index; OSA: obstructive sleep apnoea; UA: upper airway.