Project Abstract Pediatric obstructive sleep apnea (OSA) is a significant health problem affecting approximately 50-100% of children with Down syndrome (DS) compared to 1-5% of children in the general population. This increased prevalence in children with DS is likely due to anatomic risk factors and increased risk for hypotonia and obesity that contribute to the pathophysiology of OSA. The NIH-funded parent grant “Randomized Control Trial of Oxygen Therapy in Children and Adolescents with Down Syndrome and Obstructive Sleep Apnea (DOSA)” aims to test the role of supplemental oxygen during sleep as a treatment for OSA in children with DS who have failed other treatments in children aged 5-17 years with DS, recruited from seven academic sites across the US. This grant is motivated by growing evidence for racial disparities in the diagnosis and severity of OSA. There are multiple reasons for these disparities; however, recent reports have suggested technology-related biases in children with darkly pigmented skin that may result in under-estimated of hypoxemia. Specifically, diagnosis of OSA is by polysomnogram (PSG), which requires measurement of oxygen saturation using a noninvasive pulse oximetry device (SpO2) on the finger as a proxy for blood measurement of arterial oxygen saturation (SaO2; the gold standard). Oximetry uses color sensing technology, and darkly pigmented skin has been shown to influence the accuracy of oximeters. Given the light-absorbing properties of melanin, it is hypothesized that skin pigmentation could affect how light is absorbed by the sensor leading to technology- related biases in oxygen measurements. This diversity supplement proposal is therefore designed to investigate potential oximetry measurement biases by race/ethnicity and skin pigmentation in children with DS who are potential candidates for oxygen supplementation. The primary outcomes will be the mean bias between SpO2-SaO2 measurement pairs, the severity of OSA-related hypoxemic events, and desaturation sensitivity using two commonly used pulse oximetry devices in children. We will first examine the differences between simultaneous SpO2 and SaO2 (gold standard) paired measurements in children. Next, to understand the impact of oximeter biases on identifying OSA-related hypoxemia in children with DS, we will leverage the established infrastructure of the DOSA trial to study oximetry-related biases in children with DS undergoing PSG screening. This study will fill critical knowledge gaps in evaluating the extent to which sleep-related breathing disturbances and hypoxemia are under-estimated in children with DS and darkly pigmented skin and quantifying the influence of co-morbidities common in children with DS (e.g., obesity, heart disease) on SpO2 measurements. Through this research, I will gain critical skills in clinical trials, disparities research, clinical effectiveness, and studies of special populations.

Project Narrative Pediatric OSA is highly prevalent in children with Down Syndrome, leading to significant morbidity if not accurately diagnosed or treated. Oxygen saturation measurement with pulse oximetry is critical in diagnosing obstructive sleep apnea (OSA) by polysomnography; however, growing data suggest that oximetry may underestimate hypoxemia in darkly pigmented skin, resulting in under-diagnosis and under-treatment. Therefore, understanding potential oximetry-related biases is vital in ensuring equitable diagnosis and treatment of OSA in high-risk children from diverse populations, including children with Down Syndrome. We propose to investigate to what extent oximetry-related biases impact the diagnosis and severity of OSA in children with Down Syndrome.