0772 OSA Improvement Due to Ato-oxy in Children with down Syndrome Predicts Improved Quality of Life

Abstract Introduction Obstructive sleep apnea (OSA) is highly prevalent in children with Down syndrome (DS). Current OSA treatments for children with DS have limited effectiveness, as positive airway pressure therapy is poorly tolerated and adenotonsillectomy is not curative in most children with DS. We recently showed that the combination of atomoxetine and oxybutynin (ato-oxy) reduced OSA severity by 51% in a small trial of children with DS. Health-related quality of life (HRQOL) scores improved with ato-oxy, but the improvement was not statistically significant when examined across all trial participants. Therefore we evaluated if HRQOL improvements were greater in participants with more significant improvement in OSA. Methods We compared baseline characteristics and changes in HR-QOL in children with DS age 7-17 years old who had a response (defined as obstructive apnea-hypopnea index oAHI improvement of 50% and reduction of oAHI to 5 events/hour) vs. those who did not respond to ato-oxy. Participants received 4 weeks of ato-oxy (0.5 mg/kg atomoxetine and 5 mg oxybutynin) with polysomnography and assessment of HR-QOL using the PedsQL along with behavioral assessment using the Conners at baseline and after 4 weeks of treatment. Paired t-tests or chi square tests were used to compare baseline participant characteristics and linear regression with adjustment for baseline was used to compare treatment outcomes. Results 12 participants had data at both baseline and on ato-oxy. 42% of participants had a significant response to ato-oxy. There were no significant differences at baseline between treatment responders and non-responders in demographics, body mass index or OSA severity. Quality of life was significantly higher in ato-oxy responders compared to non-responders. Adjusted mean total PedsQL score was 75 (95% confidence interval: 64, 87) in responders compared to 61 (51, 70) in non-responders, p=0.048. Responders had better scores across Conners domains including attention and behavior, but these were not statistically significant compared to non-responders. Conclusion No characteristics predicted ato-oxy response for OSA treatment in children with DS. Children who had a significant response to ato-oxy had significant improvement in their quality of life. Support (if any) Funding provided by NIH (HL151254 and HD109777) as well as the Lumind-IDSC foundation.