Low circulating choline levels correlate with Alzheimer’s disease pathology severity and cognitive impairment

Abstract

AbstractBackgroundModifiable environmental risk factors may help reduce Alzheimer’s disease (AD) incidence. Choline plays key roles in healthy body and brain function (Blusztajn, 1998) and supplementation above the adequate daily intake (ADI) reduces AD pathology (Velazquez et al., 2019). Choline deficiency increases AD risk and pathology (Dave et al., 2023; Yuan et al., 2022). Notably, recent reports estimate that ∼90% of Americans do not reach the ADI for dietary choline (Zeisel, 2017), making it imperative to better understand the link between choline and AD risk.MethodWe obtained serum samples from severe AD (AD‐Sev; Braak stage VI), moderate AD (AD‐Mod; Braak stage IV), and healthy control (CON; < Braak stage III) subjects (n = 12/group; balanced for sex) from the Banner Sun Health Research Institute’s Brain and Body Donation Program. Cognitive test scores (Mini‐Mental State Examination (MMSE)), plaque burden, and Braak stage was characterized by Banner Sun Health. We assessed free choline, acetylcholine (ACh), and TNFα levels. Gas‐chromatography‐mass spectrometry was used to profile aqueous metabolites and short‐chain fatty acids.ResultThere were no significant group differences for post‐mortem interval (M = 3.79). We found disease associated differences, where AD‐Sev and AD‐Mod patients had lower levels of free choline and ACh, and higher levels of pro‐inflammatory cytokine TNFα, than CON. AD‐Mod showed a significant difference in all these measurements compared to AD‐Sev. Free choline and ACh were positively correlated to MMSE scores, whereas free choline and ACh levels were negatively correlated with total plaque and Braak Stage. Free choline and ACh were negatively correlated with TNFα. Metabolomics analysis revealed significant differences (p < 0.05) in the metabolisms of beta‐alanine, linoleic acid, and of taurine and hypotaurine.ConclusionCollectively, as free choline and ACh levels decreased, AD pathology increased. Free choline was also associated with MMSE score. Increased TNFα was observed in cases with lower choline, illustrating increased inflammation. Together, this data expands on our recent (Dave et al., 2023) and others (Yuan et al., 2022) publications, highlighting links between low choline and AD risk.