In:
Alzheimer's & Dementia, Wiley, Vol. 17, No. S5 ( 2021-12)
Abstract:
White matter hyperintensities (WMH) are regions that appear very bright on Fluid‐Attenuated Inversion Recovery (FLAIR) magnetic resonance images (MRI). They are generally attributed to cerebrovascular disease (CVD) and confer a greater risk for Alzheimer’s Disease (AD). Black individuals (BIs) typically have greater WMH burden than their white counterparts and have a two‐fold greater risk of developing AD in their lifetimes. For this project, we wanted to determine whether WMH were related to diagnostic category, and if this relationship differed according to race. Method Cohort 1 included middle‐aged cognitively normal black and white individuals (N=50). Cohort 2 included older black and white individuals on the dementia continuum (NC=47, MCI=10, AD=3). Data collection included a neuropsychological battery and magnetic resonance imaging (MRI). Fluid attenuated inversion recovery (FLAIR) MRI data were analyzed to obtain lobe specific WMH volumes (frontal, temporal, occipital, parietal, cerebellar). Because of age and diagnostic differences, we analyzed each cohort separately. We constructed multivariate linear models for each cohort with WMH volumes as the outcome variable, age, race, gender, and diagnostic category (Cohort 2 only) as independent variables. We included age X race, and race X diagnosis (Cohort 2 only) interaction terms. Result There were no racial or diagnostic differences in regional WMH volume. However, in Cohort 1, there was a significant race X age interaction in the parietal lobe such that in BIs, as age increased, WMH volume also increased (B=, t(3,46)=2.07, p =0.04). In Cohort 2, this relationship extended to the temporal (B=0.09, t(3,55)=2.95, p=0.04), and occipital lobes (B=0.09, t(3,55)=2.99, p=0.04). There was no such relationship observed in WIs. Conclusion Age conferred greater WMH volume in BIs than in WIs in cognitively normal individuals and individuals on the dementia spectrum. The relationship we observed between WMH and AD could be seen as additive rather than causative, as we observed only a relationship between age and WMH volume, not diagnostic category. The differential findings across race suggest that age has a greater effect on BIs on CVD and brain health. These findings, although not causal, should encourage AD researchers to collect more diverse samples, and consider underlying CVD in data analyses.
Type of Medium:
Online Resource
ISSN:
1552-5260
,
1552-5279
Language:
English
Publisher:
Wiley
Publication Date:
2021
detail.hit.zdb_id:
2201940-6
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