IMPORTANCE: Obstructive sleep apnoea (OSA) may increase the risk of dementia
however, studies have reported variable findings. We investigated if undiagnosed OSA in healthy older adults is associated with cognitive decline, and whether low-dose aspirin could attenuate this. METHODS: This was conducted as a substudy of the ASPirin in Reducing Events in the Elderly study. Participants were aged 70 years and above, free of dementia, cardiovascular disease and known OSA. A limited channel home sleep study calculated the oxygen desaturation index. Participants were randomised to daily aspirin 100 mg or placebo RESULTS: Mild OSA, detected in 630 (49.0%) participants, and moderate/severe OSA, detected in 405 (31.5%) participants, were associated with lower 3MS scores over 3 years (mild OSA: β CONCLUSIONS: OSA was associated with a small decline in global cognition over 3 years in this healthy older cohort. This decline was not attenuated by aspirin.