Presenter of 1 Presentation
THE MEDIATING ROLES OF NEURO-BIOMARKERS IN THE RELATIONSHIP BETWEEN EDUCATION AND LATER-LIFE COGNITION.
Abstract
Aims
Background: Increased education has been associated with reduced risk of Alzheimer’s disease and related dementias (ADRD). The role of neuropathies and neurovascular damage in the education-cognition relationship are poorly understood and may differ by sex.
Objective: To determine: 1) whether ADRD biomarkers mediate the relationship between education and cognitive function and 2) whether these mediating relationships differ by sex.
Methods
Methods: Participants included 537 adults (ages 55-94 years, mean=73) from the Alzheimer’s Disease Neuroimaging Initiative - 3 (ADNI 3) with complete data on education (years), cognition (episodic memory (EM), executive functioning (EF), language (LANG) composites), and neuroimaging. Neuroimaging mediators included hippocampal (HV), cortical grey matter (CGMV), and white matter hyperintensity (WMH) volumes and meta-temporal tau PET standard uptake value ratio. We performed causal mediation analyses with education as the exposure, HV, CGMV, WMH, and meta-temporal tau as separate mediating factors, and each cognitive domain score as separate outcomes, adjusting for age, race, sex, cardiovascular history, BMI, depression, and APOE4 status. Secondary analyses analyzed sex-stratified mediation models.
Results
Results: Across domains, HV mediated the largest percent of the relationship between education and cognition (EM: 15.7%, EF: 14.5%, LANG: 11.4%) compared to CGMV, WMH, and tau PET. In sex-stratified models, HV mediated education’s associations with EM and EF among women (EM: 20.2%, p=0.03; EF: 19.8%, p=0.05) but not men.
Conclusions
Conclusions: HV mediated the largest percent of the relationship between education and cognition. The neurobiological mechanisms (e.g., hippocampal and chronic vascular risk pathways) through which education impacts later-life cognition may vary between men and women.