Higher Educational Attainment and Accelerated Tau Accumulation in Alzheimer Disease

JAMA Neurol. 2025 Jul 7. doi: 10.1001/jamaneurol.2025.1801. Online ahead of print.

Abstract

Importance: The impact of educational attainment (EA) on longitudinal tau accumulation remains largely underexplored.

Objective: To investigate the association of EA with tau accumulation in Alzheimer disease (AD).

Design, setting, and participants: This cohort study used 3 independent samples: the Alzheimer's Disease Neuroimaging Initiative (ADNI; October 2015-July 2022, mean follow-up: 3.0 years), Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease study (A4; 2014-2022, mean follow-up: 4.7 years), and Greater-Bay-Area Healthy Aging Brain Study (GHABS; July 2021-August 2024, mean interval from plasma collection to tau positron emission tomography [PET]: 1.0 years). The ADNI and GHABS represent Northern American and Southern Chinese populations, respectively. A4 is a multicenter trial. Participants with amyloid β (Aβ) and subsequent tau PET were included from ADNI, A4, and GHABS, and a subset had plasma phosphorylated tau (p-tau) 217 (p-tau217) and resting-state functional magnetic resonance imaging (RS-fMRI) data. Data were analyzed from July 2022 to January 2025.

Exposures: EA, Aβ-PET, tau-PET, plasma p-tau217, and RS-fMRI.

Main outcomes and measures: Participants were classified as high EA and low EA based on median years of EA. Longitudinal tau changes were compared across Aβ-PET positivity and EA groups. Interactions of EA status with Aβ burden, entorhinal tau, and plasma p-tau217 on tau accumulation were investigated in Aβ-positive (Aβ+) individuals. Connectivity-associated tau spread was compared across different Aβ/EA groups. Whether or not Aβ-targeting treatment attenuated tau accumulation in Aβ+ high-EA individuals was also evaluated.

Results: This study included 887 participants: 377 from ADNI (mean [SD] age, 73.3 [7.2] years; 191 female [50.7%]), 395 from A4 (mean [SD] age, 71.9 [4.8] years; 223 female [56.5%]), and 115 from GHABS (mean [SD] years, 66.0 [7.4] years; 76 female [66.1%]). In the Aβ-negative group, high-EA individuals exhibited slower tau accumulation than low-EA individuals (right middle temporal gyrus: estimate = -0.002; 95% CI, -0.003 to -0.0002; P = .03). Conversely, higher EA in the Aβ+ group was correlated with accelerated tau accumulation (left middle temporal gyrus: estimate = 0.003; 95% CI, 0.0003-0.005; P = .03) and stronger Aβ-associated (left visual region: estimate = 0.38; 95% CI, 0.11-0.65; P = .006), entorhinal tau-associated (left middle temporal gyrus: estimate = 0.35; 95% CI, 0.08-0.63; P = .01), and plasma p-tau217-associated tau accumulation (left inferior temporal gyrus: estimate = 0.46; 95% CI, 0.02-0.90; P = .04), as well as increased connectivity-associated tau spread compared with lower EA (estimate = 0.33; 95% CI, 0.003-0.67; P = .048). Aβ-targeting treatment appeared to mitigate plasma p-tau217-associated tau accumulation in patients with AD and higher EA (estimate = -0.52; 95% CI, -0.80 to -0.24; P < .001).

Conclusions and relevance: Results of this cohort study suggest that higher EA was associated with faster tau accumulation and spread in Aβ+ individuals, highlighting the importance of Aβ clearance in mitigating tau progression in patients with AD and higher EA.