O041 Prevalence, patterns and clinical associations of sleep disordered breathing in children with neuromuscular disorders

Abstract Objectives to determine prevalence, patterns and clinical associations of sleep disordered breathing in a cohort of children with neuromuscular disorders. Methods children from three sites had a laboratory polysomnogram and clinical data collection. Sleep disordered breathing (SDB) was defined as the presence of obstructive sleep apnoea (OSA), hypoventilation and/or central sleep apnoea (CSA). Results 64 children aged 6.0-16.7 years (median 11.5) were included, 72% were male and diagnoses were Duchenne Muscular Dystrophy (DMD) (40%), spinal muscular atrophy (SMA) (28%), congenital muscular dystrophy (CMD) (13%) and congenital myopathy (CM) (19%). Scoliosis was present in 50%, 51% could ambulate and median BMI z-score was -0.23. Of the 13 (20%) who used non-invasive ventilation (NIV), 6 (46%) had SMA and 10 (77%) used NIV during the entire polysomnogram. Sleep disordered breathing was present in 48%, OSA in 31%, CSA in 14%, hypoventilation in 16% and mixed SDB in 23%. SDB was present in 50% of children with DMD, SMA and CM, most often OSA in DMD (70%) and SMA (78%). Hypoventilation was most common in children with CM (83%) and CMD (100%). SDB and OSA were associated with older age and OSA with inability to ambulate (OR 4.45). Hypoventilation was significantly more common in CM, CMD and those with lower BMI z-scores. Conclusions The prevalence of SDB was high and likely under-estimated due to use of NIV, particularly in those with SMA. The findings reflect the heterogeneity of the cohort and suggest individual risk factors for each type of SDB.