Baseline demographics, clinical characteristics and functional respiratory imaging data of all groups

Caucasian childrenbA childrenp-value
Subjects n1711
Age years4.6 (1.1–12.9)4.5 (0.8–12.8)ns
Males/females n12/57/4ns
Obese/nonobese n3/142/9ns
BMI z-score0.6 (−2.6–3.4)0.3 (−3.8–3.7)ns
Tonsil Brodsky score ≥367%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 OSA6%0%ns
Children with severe OSA77%91%ns
UA volume mm320 470 (7643–45 368)13 128 (3174–44 616)ns
Zone 1 volume mm31604 (760–3145)1937 (324–5033)ns
Zone 2 volume mm311 075 (2022–33 141)6174 (1323–32 963)ns
Zone 3 volume mm31668 (382–3285)1314 (0–2924)ns
Zone 4 volume mm31080 (206–11 821)594 (0–1544)0.04
Zone 5 volume mm34515 (1323–6798)3606 (1500–6780)ns
Minimal cross-sectional area mm229 (0–46)12 (0–53)ns
Conductance3.2 (0–8.6)2.2 (0–8.3)ns
Total upper airway obstruction18%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.