Education as a Moderator of the Relationship Between Episodic Memory and Amyloid Load in Normal Aging

摘要

The current study explored whether education, a proxy of cognitive reserve, modifies the association between episodic memory (EM) performance and beta eta-amyloid load (A beta), a biomarker of Alzheimer's disease, in a cohort of cognitively normal older adults. One hundred and four participants (mean age 73.3 years) evenly spread out in three bands of education were recruited. Participants underwent neuropsychological assessment, structural MRI as well as PET imaging to quantify A beta load. Moderation analyses and the Johnson-Neyman technique were carried out to examine the interaction of education with A beta load to predict EM performance. Linear regressions were then performed within each group of education to better illustrate the interaction effect (all analyses were controlled for age and sex). The interaction between education and A beta load was significant (p < .05) for years of education, reaching a cutoff point of 13.5 years, above which the relationship between A beta load and EM was no longer significant. Similarly, significant associations were found between A beta and EM among participants with secondary (p < .01) and pre-university education (p < .01), but not with a university degree (p = .253). EM performance is associated with A beta load in cognitively normal older individuals, and this relationship is moderated by educational attainment.