O014 Feasibility of evaluating early markers of neurodegeneration in a sleep clinic setting

Abstract Introduction Obstructive sleep apnea (OSA) is an emerging risk factor for cognitive decline. Sleep clinics are well positioned to screen for early biomarkers. We will evaluate the feasibility of cognitive testing and neurodegenerative blood-biomarker collection in a sleep clinic. Methods Males and females (>40 years) referred for polysomnography on suspicion of OSA, who consent to be contacted regarding research were invited to participate. Exclusions included existing OSA or any neurological condition. Participants underwent in-laboratory overnight polysomnography and questionnaires, with additional blood sampling and abbreviated neuropsychological testing. Results Over 16 months of recruitment, 968 patients >40 were referred for polysomnography. Of 73 contactable patients who met all eligibility criteria, 59 (80.8%) stated willingness to participate. The only reason for non-participation was unavailability for morning testing (n=14, 19.2%). In preliminary analysis, 57 participants (female=17, age 56.0±10.2) had completed testing. Moderate-severe OSA (AHI>15) was diagnosed in 24 (42.1%) participants (median(IQR) 13.3 (7.6-32.3). 10 (18%) participants showed mild impairment on the Montreal Cognitive Assessment (MoCA) (score<26) (mean± SD 27.3±1.9). The test of premorbid functioning (TOPF) was high (116±8.8). Discussion Over 80% of patients were receptive to additional brain health screening during routine sleep assessments. There were fewer instances of mild impairment compared with recent literature (Beaudin 2021). The TOPF scores indicate high premorbid functioning that may be protective. Data collection will be continued including 12-month follow-up. Future analyses will explore quantitative sleep metrics, further cognitive domains and blood-based biomarkers of neurodegeneration which may detect early changes in this representative sleep clinic cohort.