P1 The utility of sleep studies and treatment options in children with Prader – Willi syndrome in the growth hormone era

Introduction

Prader – Willi Syndrome (PWS) is a rare genetic multisystem disorder, with high prevalence of sleep disordered breathing (SDB). Treatments include; non-invasive ventilation (NIV), oxygen therapy and adenotonsillectomy. Growth Hormone (GH) therapy is also now being used at an earlier age and may potentially worsen SDB due to adenotonsillar hypertrophy. Our primary aim was to evaluate cardio-respiratory sleep study (CRSS) results from PWS patient’s pre and post GH. A secondary aim was to evaluate the use of NIV as a treatment option in this population.

Methods

This was a retrospective study. Results from CRSS, pre and post GH initiation from 2013 to present were included. Main outcomes were apnoea hypopnoea index (AHI), the nature of the SDB and treatment provided.

Results

38 patients were included - 20 males, 18 females (mean age: 4.1 [2.8, 5.5], weight mean Z score: 0.1 [-0.72, 0.92]). 92% demonstrated SDB, 69% had Obstructive Sleep Apnoea (OSA) and 31% had Central Sleep Apnoea (CSA) (figure 1). There was no significant difference (P > 0.05) in OSA indices pre and post GH. Five patients (mean age: 2.98 [1.14, 4.82]) developed moderate/severe OSA, on average 16 months after starting GH. All had a subsequent adenotonsillectomy. 24% of the total patient population were established on NIV following an abnormal CRSS. Seven of the nine patients have remained on long term NIV. The incidence of treatment modalities and the occurrence pre and post GH therapy is shown (figure 2).

Discussion

This study shows the high prevalence of SDB in children with PWS and treatment interventions used. The risk of OSA development post-GH initiation demonstrates the importance of CRSS. As treatment options involve long term NIV, CRSS should play a major role in monitoring PWS patients over time.