Basilar artery dilatation relates to Alzheimer dementia, particularly among APOE4 non‐carriers

Abstract

AbstractBackgroundBrain arterial dilatation has been associated with higher risk of dementia and cognitive decline in population‐based studies. Whether the association is related to brain amyloid or tau, pathological hallmarks of Alzheimer disease, is uncertain.MethodWe analyzed existing and de novo data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) regarding participants’ demographics, hypertension, dementia status, APOE4 genotype. We used composite PET measures of gray matter regions of beta amyloid (AV‐45) and neurofibrillary tangles (AV‐1451). We obtain de novo cross‐sectional carotid and basilar artery diameters using axial T2 MRI sequences. For cognitive outcomes, we used the Alzheimer's Disease Assessment Scale–Cognitive Subscale (ADAS‐Cog) and clinical dementia rating (ordinal CDR) scores. All models were adjusted for age, sex, years of education, APOE4 carrier status and hypertensionResultWe included 478 ADNI participants (56% men, mean age 77±7, 36% cognitively normal, 48 with mild cognitive impartment and 16% with dementia). Combined carotid and basilar artery diameters were not associated with ADAS‐13 cog score (B=0.07 per SD, P=0.46), ordinal CDR (B=0.13, P=0.32), amyloid (B=‐0.001, P=0.57) or tau (B=0.02, P=0.45). Stratifying by anterior versus posterior circulation artery showed that basilar artery diameters, but not carotid diameters, were associated with a higher ADAS‐13 cog score (B=0.17, P=0.01), higher CDR (0.25, P=0.009), but not with amyloid (B=0.01, P=0.46). The association between basilar artery diameters and CDR was stronger among APOE4 non‐carriers (B=0.37, P=0.004) than in carriers (B=0.05, P=0.70, P for the interaction 0.12).ConclusionBrain arterial dilatation is associated with poorer cognitive outcomes, and the association is stronger among APOE4 negative participants. Investigation of how brain arterial dilatation relates to dementia and whether such relationship interacts with amyloid and/or tau may reveal novel aspects of the vascular contributions to dementia.