0525 Effect of Body Position and Sleep State on Obstructive Respiratory Events Distribution in Children with Down syndrome

Abstract

Abstract Introduction The influence of body position and sleep state on obstructive respiratory events distribution in children with Down syndrome (DS) need further studies. Methods This was a single center, retrospective study that included children younger than 18 years old with DS who were evaluated for suspected sleep disordered breathing and underwent a full overnight polysomnography in an academic sleep disorders center over a period of 10 years. DS children with Obstructive apnea hypopnea index (OAHI) ≥ 1.5 were included in this study. Total OAHI, apnea hypopnea index (AHI) in different body positions and in different sleep stages including rapid eye movement (REM) and Non-REM (NREM) sleep were collected. Results A total of 158 children with DS met the inclusion criteria. The median age was 5 years (IQR 8.0---), 53.2% were male with a median BMI z-score of 1.2. Median times (%) spent in REM and NREM sleep were 17 % and 83% respectively. Median times (minutes) spent in different body positions were supine 194.1, left side 53.5, right side 39 and prone 32. The overall median OAHI was 7.6, respiratory obstructive events were more common in REM sleep and in supine position. The median REM obstructive AHI was 20 events per hour (IQR: 10.1-34.5), whereas the median NREM AHI was 5.2 events per hour (IQR: 2.4-15 p < 0.0001). Similarly, supine obstructive AHI was 9.4 (IQR-4.15 – 24.1) and off supine AHI was 2.4 (IQR 0-8.9 p < 0.0001). Only 24 out of 158 subjects had NREM predominant OSA. Age was a significant predictor of NREM predominant OSA (P= 0.012) compared to other factors such as gender, race, BMI, tonsillar grade, hypothyroidism and congenital heart disease. For every one year increase in age, the odds of having NREM predominant OSA was 14% higher than having REM predominant OSA. Conclusion Obstructive respiratory events in children with DS occur predominantly in REM sleep and in supine position. Non-REM predominant distribution of respiratory events was seen in older children with DS. Support (if any)