# Associations of blood‐based biomarkers of vascular function with biomarkers of Alzheimer's Disease in individuals of admixed ancestry

## TL;DR

This study explores how blood-based markers of vascular health relate to Alzheimer's disease markers in people of mixed ancestry, finding that some vascular markers are linked to Alzheimer's indicators and influenced by African ancestry.

## Contribution

The study identifies novel associations between vascular biomarkers and Alzheimer's disease markers in admixed populations, highlighting the role of African ancestry in these relationships.

## Key findings

- VEGF, PlGF, VCAM-1, and HbA1c are associated with AD biomarkers like Aβ40, Aβ42, and p-tau181.
- African ancestry influences the relationship between vascular biomarkers and AD markers.
- Interactions between biomarkers and ancestry were observed, such as bFGF and Aβ40.

## Abstract

Poor cardiovascular health is a risk factor for cognitive decline and dementia, including Alzheimer's disease (AD). Development of ancestry‐informed blood‐based biomarkers for the small vessel diseases of the brain that contribute to vascular cognitive impairment across multiple populations is critical to identify individuals at risk. To begin addressing this, we examined the associations of blood‐based biomarkers of endothelial function and vascular disease with AD biomarkers and genetic ancestry in 1,534 admixed Hispanic and African American individuals from the PRADI and READD‐ADSP.

Biomarkers of endothelial function and vascular disease included VEGF, PlGF, bFGF, VCAM‐1, ICAM‐1, HbA1C, and plasma lipid levels. AD biomarkers included Aβ40, Aβ42, and p‐tau181. Adjusting for age and sex as covariates, linear regressions were modeled separately predicting the three AD biomarkers by all 7 cardiovascular biomarkers, as well as degree of African ancestry. Additional regression models were run predicting each AD biomarker by each cardiovascular biomarker individually while controlling for age and sex and examining the interaction between the endothelial/vascular biomarker and African ancestry.

Aβ40 is associated with VEGF, PlGF, VCAM‐1, HbA1c, and African ancestry (Table 1); Aβ42 is associated with VEGF, PlGF, HbA1c, and African ancestry (Table 2); and p‐tau181 is associated with VEGF and African ancestry (Table 3). In addition, an interaction between cardiovascular biomarker and degree of African ancestry was observed for bFGF (β = 0.83, P = .03) while predicting Aβ40, ICAM‐1 (β = ‐0.006, P = .04) while predicting Aβ42, and VEGF (β = 0.03, P = .02) and total cholesterol (β = ‐0.11, P = .002) while predicting p‐tau181.

Levels of VEGF, PlGF, VCAM‐1, and HbA1c predict levels of AD biomarkers in admixed individuals, and these associations are influenced by degree of African ancestry. While these findings need additional validation, they support the notion that endothelial disease contributes to cognitive impairment and that the assessed biomarkers may be valuable biomarkers for clinical settings. These results underscore the importance of biomarker research and validation in individuals from multiple populations.