GFAP and Alzheimer disease: Given that neurodegenerative protein deposition typicallyincreases, and vascular health typically decreases with advancing age, we also expectedolder individuals to show disproportionately stronger adverse relationships between bloodpressure and fluid biomarker concentrations [27].Finally, given the APOE-ε4 gene is linked to increased AD risk andcardiometabolic dysfunction, we hypothesized that ε4 carriers would demonstratestronger associations between blood pressure and all biomarkers evaluated (GFAP, NfL,pTau181, Aβ42/40) [28].