Alzheimers Dement: Different races have different long-term trends in Alzheimer's-related indicators

Alzheimer's disease (AD) is an irreversible neurodegenerative disease that affects 6 million Americans, and cases are expected to more than double by 2050
.

To design prevention trials for AD, biomarkers are important for establishing appropriate inclusion/exclusion criteria and tracking disease progression
.

These studies further suggest that the neuropathological process of AD begins years or even decades before symptoms appear, and that changes in biomarkers follow a time series with early Aβ accumulation and deposition in the brain, followed by the formation of NFTs, neuronal death and changes in brain structure
.

However, nearly all of these important findings were based on predominantly white cohorts, and the few biomarker studies reporting racial differences in AD biomarker changes were based on cross-sectional data
.

From this, Chengjie Xiong et al.
, University of Washington, assessed longitudinal differences between blacks and whites in all major AD biomarkers, including CSF, amyloid PET, and structural MRI
.

A total of 179 blacks and 1180 whites who were cognitively normal at baseline and had longitudinal data on at least one biomarker pattern were analyzed for their annual rate of change
.

They found that CSF amyloid beta (Aβ)42/Aβ40 declined more slowly (P=0.
0390) and accumulated amyloid (PET) more slowly (P=0.
0157) in blacks
.

Changes in CSF Aβ42 over time were in opposite directions in blacks and whites (P = .
0039)
.

The annual growth rate of CSF total tau and phosphorylated tau181 in blacks was about half that of whites
.

The significance of this study is the observation of longitudinal ethnic differences in amyloid biomarkers
.