Associations of self‐reported obstructive sleep apnea with cognition and dementia risk in cognitively unimpaired middle‐aged adults

INTRODUCTION: Obstructive sleep apnea (OSA) is a potential risk factor for cognitive impairment and dementia; however, its contribution in midlife and interactions with APOE ε4 remain unclear. METHODS: Participants were 2795 cognitively unimpaired, middle-aged adults enrolled in the Healthy Brain Project. OSA status was determined by self-report. Cognition was assessed using the Cogstate Brief Battery, and dementia risk using the Cardiovascular Risk Factors, Ageing, and Incidence of Dementia (CAIDE) score. RESULTS: Participants with OSA demonstrated poorer memory than those without OSA, although this association was attenuated after adjusting for vascular risk. Individuals with OSA (with or without APOE ε4) had significantly higher CAIDE scores than those with neither risk factor. APOE ε4 did not moderate OSA-cognition associations. DISCUSSION: OSA may be associated with poorer memory and greater dementia risk, irrespective of APOE ε4 carriage. These findings highlight the need for early OSA screening to identify individuals at elevated dementia risk.