Presenter of 1 Presentation
CEREBRAL MICROBLEEDS ARE ASSOCIATED WITH AMYLOID POSITIVITY IN AN AGE-DEPENDENT MANNER: THE AMYLOID BIOMARKER STUDY.
Abstract
Aims
Cerebral microbleeds (CMBs) are common in persons with Alzheimer’s disease (AD) and are associated with hemorrhage and cognitive decline. The aim of this study was to examine the association between CMBs and amyloid pathology in individuals with normal cognition (NC), mild cognitive impairment (MCI) and dementia.
Methods
We included 781 participants with NC, 355 participants with MCI and 230 participants with dementia from 8 cohorts included in the Amyloid Biomarker Study. Amyloid-beta positivity was determined with amyloid-PET (center-specific cutoffs) or aß42 level in CSF (data-driven cutoffs). Participants were classified as having any CMBs (≥1) yes/no. Associations of amyloid positivity, APOE-e4 carriership, cognitive status, sex and age with CMBs were assessed using generalized-estimating-equations.
Results
Forty-seven percent of participants were amyloid-beta positive, 38% were APOE-e4 carrier, 48% were female and 19% had CMBs. The mean age was 68.5 years (SD11.2). CMB prevalence increased with age (p<0.001) and was associated with amyloid-beta status, depending on age (p<0.001). In those under 75 years of age, CMBs were more common in amyloid positive than amyloid negative participants. This association was reversed at older ages, where amyloid negative participants had CMBs more often. Cognitive status, APOE-e4 carriership and sex were not associated with CMB occurrence in this sample, most of whom were memory clinic patients.
Conclusions
CMB prevalence is associated with amyloid positivity in an age-dependent manner. This sheds light on the underlying pathophysiology. Future research on the background incidence rate of CMBs considering AD biomarker status would be helpful for clinical trial design and safety evaluations of AD therapies.
