PRS Brain Age Study

This study examines how genetic factors related to brain aging influence blood biomarkers.

---

Abstract

Background and Objectives To examine the association between genetic predisposition to accelerated brain aging—measured with polygenic risk scores (PRS) derived from BrainAge models—and plasma biomarkers of Alzheimer’s disease (AD), with attention to age and sex-specific effects.

Methods We analyzed 1994 cognitively normal participants from the A4/LEARN studies (71.5±4.8 years; 41% male). We computed the genetic risk of accelerated grey matter loss associated with age using GWAS data from previous studies. Baseline plasma biomarkers included pTau217 (N=980; Eli Lilly immunoassay), and GFAP and NfL (N=1636; Roche Elecsys immunoassay). General linear models tested associations between each PRS and each biomarker, including PRS-by-age interaction terms. Analyses were additionally stratified by sex.

Results BrainAge PRS moderated the association between age and pTau217 levels ($\beta=0.08 \pm 0.03$, $p=0.0086$), such that higher PRS for BrainAge was associated with increased pTau217 at older ages. Results were robust to covariates. This association was significant in females but not in males. No significant associations were found with GFAP or NfL.

Discussion Genetic risk for accelerated grey matter loss with aging is associated with elevated pTau217 levels in cognitively unimpaired older females. These findings suggest a sex- and age-specific genetic link between brain aging and early AD pathology.

---

Files

• PRSBrainAge.Rmd: The R Markdown source file containing the analysis and code for the study.
• PRSBrainAge.html: The HTML output generated from PRSBrainAge.Rmd, which can be viewed directly in a web browser.

---

How to Cite

If you use this work in your research, please cite:

BiorXiv coming soon.

---