Preliminary investigation of obstructive sleep apnea and Alzheimer's disease in down syndrome

This study provided a preliminary examination of indices of obstructive sleep apsnea (OSA) and sleep disruptions in adults with Down syndrome (DS), and their associations with Alzheimer's disease (AD) pathology and symptomatology. A total of 93 adults with DS (aged 25-61 years) from the Alzheimer Biomarker Consortium - DS completed cognitive assessments, MRI and positron emission tomography (PET) scans (assessing amyloid-beta [Aβ] and tau), and a one-night home sleep study using the WatchPAT-300 device. Study partners also reported on depressive symptoms and diagnoses. Correlational analyses examined relationships between sleep variables, PET biomarkers, and AD symptomatology (cognitive functioning and depressive mood), controlling for sociodemographics. A total of 81 participants (87 per cent) completed valid WatchPAT data. Of these, 60 (74 per cent) screened positive for OSA, and an additional 11 had a prior OSA diagnosis and used CPAP during the test night. Nearly half (45 per cent) of those screening positive for OSA had no prior diagnosis, indicating under-detection. Among the 22 participants using OSA treatment, 50 per cent continued to show sleep-disordered breathing, suggesting suboptimal treatment effectiveness. Higher wake percentage and shorter total sleep time were associated with greater Aβ and tau burden. Cognitive performance was negatively associated with wake percentage, total sleep time, and oxygenation indices (minimum oxygen, desaturation, and time ≤ 88 per cent oxygen). Depressive symptoms were negatively related to total sleep time. These findings add preliminary evidence linking sleep disruption and OSA with AD-related pathology and symptomatology. Larger, longitudinal studies are needed to confirm these associations and evaluate whether improving sleep quality and treating OSA may help delay AD onset in this high-risk population. Statement of Significance These preliminary findings suggest that sleep problems may often go undetected and that treatment compliance may be suboptimal in adults with DS, highlighting the potential need for developing screening approaches and management strategies in this population. However, given the modest sample size and cross-sectional design, these results should be interpreted with caution, and further research is needed to inform evidence-based guidelines. Our findings add to the preliminary evidence linking OSA and sleep disturbances with AD pathology and symptomatology in DS, suggesting that OSA may represent a modifiable target for interventions aimed at delaying AD onset in this high-risk population.