Intracranial arteriosclerosis is not associated with cerebral amyloid deposition.

Background: Intracranial arteriosclerosis and cerebral amyloid beta (Aβ) are both involved in the etiology of Alzheimer's disease (AD) dementia, but the direct link between these two pathologies remains elusive.

Methods: In 633 participants (mean age 69 years, 51% women) from the population-based Rotterdam Study, we quantified cerebral Aβ accumulation on amyloid positron emission tomography (PET). We assessed calcification of the intracranial internal carotid (ICAC) and vertebrobasilar arteries (VBAC) as proxies of arteriosclerosis on non-enhanced computed tomography (CT). Using logistic and linear regression, we studied the relationship of presence, burden, and type of calcification with the presence and burden of Aβ.

Results: We found no associations of ICAC [odds ratio (OR): 0.85, 95% confidence interval (CI): 0.43, 1.72] or VBAC [OR: 0.59, CI: 0.26, 1.24] with cerebral Aβ. The results did not vary across ICAC subtypes.

Discussion: Intracranial arteriosclerosis was not associated with cerebral Aβ, underscoring their independence in the etiology of AD dementia.

Highlights: Comprehensive assessment of intracranial arteriosclerosis (e.g., including subtypes).Intracranial arteriosclerosis in different arteries and cerebral Aβ are not related.Arteriosclerosis and Aβ likely influence Alzheimer's disease dementia independently.