Background:  Children with Down syndrome (DS) are at high risk for obstructive sleep apnea (OSA). Increasing elevation is known to exacerbate underlying respiratory disorders and worsen sleep quality in non-DS persons, but whether altitude modulates the severity of OSA in DS is uncertain. In this study, we evaluate the impact of elevation (≤1500m vs. > 1500m) on the proportion of hospitalizations involving OSA in children with and without DS.
Methods:  Merging the 2009 Kids’ Inpatient Database with zip-code linked elevation data, we analyzed differences in the proportion of pediatric hospitalizations (ages 2-20 years) involving OSA, pneumonia, and congenital heart disease (CHD), with and without DS. We used multivariable logistic regression to evaluate the association of elevation with hospitalizations involving OSA and DS, adjusting for key comorbidities.
Results:  Proportionately more DS encounters involved OSA, CHD, and pneumonia within each elevation category than non-DS encounters. However, the risk difference for hospitalizations involving OSA and DS increased disproportionately at higher elevations (DS: 16.2% (95% CI 9.2%-23.2%); non-DS: 0.1% (95% CI -0.4%-0.7%)). Multivariable estimates of relative risk indicate increased risk of hospitalization involving OSA at higher elevations for persons with DS and in children age 2-4 years or with ≥2 chronic conditions.
Conclusion:  At elevations >1500m, children with DS and OSA have a disproportionately higher risk of hospitalizations than children with OSA without DS. This finding has not been described previously. With further validation, this finding suggests the need for greater awareness and earlier screening for OSA and its complications in patients with DS living at higher elevations.