Phenotypic and Polysomnographic Features of Children With Very Severe and Extreme OSA.

Abstract

To characterize the phenotypic and polysomnography (PSG) features associated with extreme versus very severe pediatric obstructive sleep apnea (OSA). Charts of children under 18 years diagnosed with extreme OSA (apnea-hypopnea index [AHI] > 100) or very severe OSA (AHI 30-100) were retrospectively reviewed. Data collected included demographics, comorbidities, body mass index (BMI) category, tonsil size, and PSG parameters. Groups were compared using χ² and Wilcoxon rank-sum tests, with p < 0.05 considered significant. Discriminative modeling was performed to differentiate between severity groups. 358 children were included (63% male): 288 with very severe OSA and 70 with extreme OSA. Race distribution was similar between groups. Children with extreme OSA were older (median 9.9 [IQR 6.3-13.8] vs. 7.6 [4.6-12.6] years; p = 0.03) and more likely to have Class 3 obesity (≥ 140% of the 95th percentile) (43% vs. 29%; p = 0.02). Extreme OSA was associated with more severe hypoxemia, including lower median oxygen saturation nadir (69% [IQR 63-77] vs. 76% [67-82]; p < 0.001) and lower mean oxygen saturation (93.5% [91-95] vs. 96% [95-97]; p < 0.001). No differences were observed in sex, ethnicity, tonsil size, comorbidities, or hypercapnia. Models using anatomic and demographic variables alone showed limited discrimination (AUC 0.55-0.63). Inclusion of hypoxemia indices markedly improved performance (AUC 0.81), with minimal change after adding anatomic and comorbidity variables (AUC 0.82). Extreme OSA was more common among older children and those with class III obesity. Among phenotypic and PSG parameters, oxygenation metrics were associated with extreme OSA.