Obstructive Sleep Apnea in Children with Down Syndrome: Demographic and Clinical Factors

INTRODUCTION: OSA is a disease characterized by obstruction of the airway during sleep leading to periodic reductions in airflow, hypoxemia, and hypercapnia and is the most common reason for this demographic to visit an otolaryngologist. Current research of factors predicting OSA in this population are non-linear, scarce, and inconclusive. Objective: The primary objective of this study was to use relatively large patient population to describe the demographic, clinical and polysomnographic characteristics of children with Down Syndrome (DS) suspected of having obstructive sleep apnea (OSA). The secondary objective was to identify demographic and clinical factors that predict severe OSA in children with DS. METHODS: A retrospective case-control study of children with DS who received PSG over 5 years was performed. Criteria for inclusion were age 2-18, negative history of adenotonsillectomy, data available on ethnicity, BMI z-score, medical comorbidities, clinical data including tonsil size and polysomnographic data. Severe OSA is defined by Apnea Hypoxia Index (AHI)>10 using polysomnography, the gold standard test for diagnosing OSA. RESULTS: Of a total of 106 children, 90% were diagnosed with OSA (AHI>1) and 44% were diagnosed with severe OSA (AHI?10). Obese compared to non-obese children had a significantly higher prevalence of severe OSA (56% versus 35%).The mean SaO2 nadir was significantly lower in obese compared to non-obese children (80 versus 85%). In children older than 12 years, the obese compared to non-obese children had a significantly higher mean AHI of 23 compared to 5.6. Tonsillar hypertrophy (grade III/IV) was not a predictive for OSA. Presence of other medical comorbidities including allergies, asthma, congenital heart disease, and hypothyroidism were not significant in predicting OSA. A multivariable logistic regression model predicting the likelihood of severe OSA in children with DS showed increasing weight (OR: 1.1, 95% CI 1.0-1.1, p=.015) was important in prediction of Severe OSA. Age (OR: .87, 95% CI: .6-1.3, p=.560) did not predict the risk of having severe OSA. CONCLUSIONS: In conclusion, a cohort of 106 children with Down Syndrome prior to corrective OSA surgery showed that weight was the primary risk factor of increasing AHI on PSG. Our study did not find an independent association between age and OSA severity in children with DS with older children, without obesity, showing no increased likelihood of severe OSA. This suggests that a major effort should be directed at avoiding obesity as children with DS as they reach adolescence.