"Objective sleep apnea severity, cognitive impairment and AD pathology: Insights from the ALBION cohort".

OBJECTIVES: Obstructive sleep apnea (OSA) appears to be closely related to cognitive status. This study explored the association between the Apnea-Hypopnea Index (AHI), cognitive status, and cerebrospinal fluid (CSF) biomarker pTau181/Aβ42 (AD pathology) in non-demented individuals. METHODS: In this cross-sectional study, 115 non-demented participants from the ALBION cohort (mean age 64.4 ± 8.9 years, 70 % female, median education 14 years, median BMI 25.7 kg/m2) underwent a one-night WatchPAT evaluation to determine AHI (blood oxygen desaturation ≥3 %). Participants were categorized based on both cognitive status (patients with Mild Cognitive Impairment (MCI)[n = 27] or cognitively normal individuals (CN) [n = 88]) and AD pathology (AD+ [n = 25] or AD- [n = 90]). Binary logistic regression analysis, adjusted for age, sex, years of education, and BMI was used to assess the association of cognitive status and AD pathology with AHI. Participants were further divided into low (<15/h) and high (≥15/h) AHI levels and a joint analysis with AD pathology was performed with cognitive status as the outcome. RESULTS: After adjusting for confounders, for each unit increase in AHI, the odds of being classified as MCI were 7 % higher (OR = 1.07, p = 0.003) and the odds of being classified as AD+ were 4 % higher (OR = 1.04, p = 0.043). Compared to the reference group [AD (-)/AHI(low)], the odds ratio of being classified as MCI was 4.48 (p = 0.022) in the AD (-)/AHI(high) and 15.30 (p = 0.0017) in the AD (+)/AHI(high) group. CONCLUSIONS: We find that higher AHI levels may contribute to cognitive impairment, either independently or alongside AD pathology. Further longitudinal studies are warranted to clarify causality and potential therapeutic benefits of OSA management on cognitive health.