Association between APOE gene and stress coping strategies, memory, and family history of AD in a healthy middle‐aged Polish population: Preliminary results

Abstract

One of the best-known genes associated with late-onset Alzheimer's disease (AD) is the apolipoprotein E (APOE). It is thought that the ε4 allele of this gene increases the risk of developing AD. The aim of this study was to investigate the preclinical influence of APOE-ε4 on brain cognitive functions in a healthy population. 200 (F:108, M: 92) healthy middle-aged (50-64 years old; M=55) right-handed adults completed a series of psychometric questionnaires: RAVEN (Raven's Progressive Matrices, classical version), BDI (Beck Depression Inventory), Mini-COPE (Mini-COPE Questionnaire) and CVLT (California Verbal Learning Test). We also collected information about demography, family history of AD and health. APOE alleles were determined by sequencing their chosen variants (APOE SNPs rs429358/rs7412) using a traditional Sanger sequencing protocol. The group was divided according to the results of the genetic test for ε4-non carriers (150) and ε4-carriers (50). Both groups were equivalent in age, gender, and years of completed education. There were no differences in intelligence (RAVEN scores), depressive symptoms (BDI) nor memory test results (CVLT). More ε4-carriers had a family (parents) history of AD (Welch's t-test, t(75.21)=-2.11, p<0.05). In the Mini-COPE questionnaire ε4-carriers group also scored less points on two (out of 3) scales rating problem-focused (adaptation) strategies: Planning (2. scale) (trend: Welch's t-test t(77.45)=1.84, p=0.07) and Using Instrumental Support (8. scale) (Welch's t-test t(77.40)=2.07, p<0.05). Despite overall comparable memory performance, there was also a tendency for ε4-carriers to be statistically better at recalling words from List A (5) (Welch's t-test, t(112.72)=-2.14, p<0.05) in the CVLT test. These preliminary results indicate that even in a healthy middle-aged population APOE genotype could influence cognitive abilities and alter stress-coping strategies. Further research is needed to determine if better memory recall is present also in younger ε4-carriers or whether it is a (transient) benefit of mnemonics techniques developed later in life to cope with a slowly starting memory decline. Supported by Polish National Science Centre (NCN) grant no. 2018/31/N/HS6/03551.