Abstract Details

Title Longitudinal Changes in Brain Diffusion Characteristics Associated with Cognition and Vascular Risk Factors: The ARIC-NCS Study

Topic Aging, Dementia, and Behavioral Neurology

Presentation(s) S42 - Perspectives on Non-Alzheimer's Dementia Diagnostics and Therapeutics (1:00 PM-1:12 PM)

Poster/Presentation
Number 001

Objective We investigated whether annualized changes in fractional anisotropy (FA) and mean diffusivity (MD) are associated with changes in cognitive domains among nondemented older adults, and how these patterns differ by vascular risk factors.

Background It remains unclear whether longitudinal changes in brain microstructural integrity, measured by diffusion MRI, relate to cognition and vascular risks.

Design/Methods Data were longitudinally collected from the Atherosclerosis Risk in Communities Neurocognitive Study, conducted across 4 US sites with 6,471 participants attending the baseline assessment. Individuals who underwent diffusion MRI and neurocognitive evaluations at least twice between 2011 and 2019 were included; those with baseline dementia were excluded. Linear mixed-effects models assessed associations between FA and MD values in 140 brain regions and domain specific cognitive scores (executive function, language, and memory). Annualized changes in FA and MD values were compared between individuals with and without vascular risk factors.

Results 592 participants were followed for 6 years on average. A 1-SD decrease in FA values in the left cingulum bundle was associated with a 0.166- SD reduction in executive function and a 0.158-SD reduction in language. In addition, a 1-SD increase in MD values in the left hippocampus was associated with a 0.191-SD reduction in memory. Significant differences in annualized changes in these FA and MD values were found depending on the presence or absence of type 2 diabetes and smoking.

Conclusions Deterioration in microstructural integrity—reflected by lower FA in the left cingulum bundle and higher MD in the left hippocampus—was associated with declines in executive function, language, and memory. Furthermore, longitudinal changes in these FA and MD values had differences based on the presence of type 2 diabetes and smoking. These findings provide a foundational basis for future research to determine whether managing vascular risk factors can delay cognitive decline by affecting the microstructural integrity of the brain.

Authors/Disclosures
Yuto Uchida, MD, PhD PRESENTER	Dr. Uchida has nothing to disclose.
Kenichi Oishi, MD, PhD (Johns Hopkins University SOM)	The institution of Dr. Oishi has received research support from National Institutes of Health. The institution of Dr. Oishi has received research support from Gates Venture. The institution of Dr. Oishi has received research support from NeuroXT. Dr. Oishi has received personal compensation in the range of $0-$499 for serving as a Grant reviewer with National Institutes of Health.

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