Plasma biomarkers predict cognitive trajectories in an ethnoracially and clinically diverse cohort: Mediation with hippocampal volume
![Figure: Conceptual mediation model. Association between plasma biomarkers (amyloid β 42/40 [aβ 42/40], total‐tau [t‐tau], neurofilament light [NfL]) and cognitive trajectories (executive function [EF] and episodic memory [EM]) are mediated by hippocampal volume.](/sites/g/files/dgvnsk16256/files/media/images/Plasma%20biomarkers%20predict%20cognitive%20trajectories%20in%20an%20ethnoracially%20and%20clinically%20diverse%20cohort%3A%20Mediation%20with%20hippocampal%20volume.png)
Abstract
Introduction
We examine whether the association between key plasma biomarkers (amyloid β [aβ] 42/40, total tau (t-tau), neurofilament light [NfL]) and cognitive trajectories (executive function [EF] and episodic memory [EM]) is mediated through neurodegeneration.
Methods
All participants were recruited from the University of California, Davis-Alzheimer's Disease Research Center (n = 473; baseline age range = 49-95 years, 60% women). We applied an accelerated longitudinal design to test latent growth models for EF and EM, and path and mediation analyses. Age was centered at 75 years, and all models were adjusted for sex, education, and ethnicity.
Results
HV differentially mediated the association aβ 42/40 and NfL on EF and EM level and change. Hippocampal volume (HV) did not mediate the association between t-tau and cognitive performance.
Discussion
Neurodegeneration as represented with HV selectively mediates the association between key non-invasive plasma biomarkers and cognitive trajectories in an ethnoracially and clinically diverse community-based sample.