Severity and phenotype of sleep-disordered breathing in Prader-Willi syndrome compared to obstructive sleep apnea syndrome in children

Abstract

Background

Sleep disordered breathing (SDB) is prevalent in individuals with Prader-Willi syndrome (PWS). However, its clinical characteristics, risk factors, and impact on sleep architecture remain incompletely understood. This retrospective case-control study aims to characterize respiratory events in PWS; asses body mass index (BMI)-SDB severity association; and quantify sleep architectural changes to inform PWS screening and management.

Methods

Children with PWS who underwent PSG in the Department of Respiratory Medicine, Children's Hospital of Soochow University from December 2020 to January 2025 were enrolled in this study. Age- and gender-matched control subjects of children diagnosed with obstructive sleep apnea-hypopnea syndrome (OSAS) without underlying comorbidities, evaluated using identical PSG equipment. SPSS30.0 was used to perform 1:2 matching according to age and gender. The clinical characteristics and PSG results were compared between groups. Correlations between BMI, adenoid/tonsil hypertrophy and the severity of SDB were analyzed.

Results

19 children with PWS underwent sleep monitoring, of whom 16 completed PSG. The PWS cohort (n = 16) included 9 males (56.3 %) and 7 females (43.8 %), ranging in age from 3.4 to 14.7 years (mean age: 8.4 ± 3.5 years), with a median BMI of 24.5 kg/m² (IQR: 21.6–35.1). All 16 PWS children were diagnosed with OSAS, 75 % presenting moderate-to-severe OSAS (P < 0.001). Compared with the OSAS control group, the PWS group exhibited significantly higher BMI values (P < 0.001),fewer awakenings (P = 0.007) and a reduced proportion of NREM3 sleep (P = 0.040). While OSA predominates in the SDB spectrum of PWS, central sleep apnea (CSA), mixed apnea, and hypoventilation events were also observed, with all respiratory event indices significantly higher in PWS than controls (all P < 0.05). PWS children demonstrated significantly lower mean oxygen saturation and lowest oxygen saturation (LSaO₂) (all P < 0.001), as well as higher oxygen desaturation index (ODI) and obstructive apnea-hypopnea index (OAHI) (all P < 0.005). BMI was positively correlated with obstructive apnea‐hypopnea index (OAHI) (r = 0.558, P = 0.025) and Hypopnea index (HI) (r = 0.639, P = 0.008), and negatively correlated with LSaO2 (r = −0.551, P = 0.027).

Conclusion

PWS children exhibit a diverse spectrum of SDB, with OSA as the dominant respiratory event type with abnormal arousal responses to respiratory events. The severity of SDB in PWS is strongly related to BMI. These findings highlight the critical role of obesity in exacerbating respiratory compromise and emphasize the necessity of routine PSG screening and targeted BMI management in PWS care.