P101 Brain Amyloid Burden and Autobiographical Memory in Obstructive Sleep Apnoea: A Cross-sectional Study.

INTRODUCTION: Emerging literature reports an increased risk of Alzheimer’s disease in individuals with obstructive sleep apnoea (OSA). Established characteristics of Alzheimer’s disease include increased brain amyloid burden and impairment to episodic and autobiographical memory. Investigating these constructs in individuals with clinically confirmed OSA will contribute to understanding of OSA and neuronal implications. AIM: The aim of the study was to explore the relationship between brain amyloid burden and autobiographical memory in cognitively-healthy individuals with OSA. METHODS: Thirty-four participants with OSA (mean age=57.7, SD=8.5, 19 males), and 12 controls (mean age=57.1, SD=8.1, 6 males) participated in the study. Participants underwent a 11C-PiB positron emission tomography (PET) scan to quantify amyloid burden, and an assessment of autobiographical memory. Brain amyloid burden was quantified using the standardised uptake value ratio (SUVR), and the Autobiographical Memory Test (AMT) was used to assess the ability of participants to recall specific memories from their life. RESULTS: Individuals with OSA recalled significantly fewer specific autobiographical memories (M=6.66, SD=2.91) compared to controls (M=10.25, SD=2.09, t(45)=-3.930, p<.001). There was no significant difference in SUVR between groups, t(44)=1.465, p=.150. Recall of non-specific memories was significantly positively correlated with SUVR, r=.331, p=.026. DISCUSSION: Levels of brain amyloid burden did not differ significantly between groups however the results support existing literature suggesting amyloid burden is associated with autobiographical memory in individuals with OSA. Longitudinal studies investigating the trajectory of these constructs in the context of disease development should be conducted to further explore the impacts of OSA.