Abstract
We tested the association between APOE-ε4 and processing speed and memory between ages 43 and 69 in a population-based birth cohort. Analyses of processing speed (using a timed letter search task) and episodic memory (a 15-item word learning test) were conducted at ages 43, 53, 60–64 and 69 years using linear and multivariable regression, adjusting for gender and childhood cognition. Linear mixed models, with random intercepts and slopes, were conducted to test the association between APOE and the rate of decline in these cognitive scores from age 43 to 69. Model fit was assessed with the Bayesian Information Criterion. A cross-sectional association between APOE-ε4 and memory scores was detected at age 69 for both heterozygotes and homozygotes (β = −0.68 and β = −1.38, respectively, p = 0.03) with stronger associations in homozygotes; no associations were observed before this age. Homozygous carriers of APOE-ε4 had a faster rate of decline in memory between ages 43 and 69, when compared to non-carriers, after adjusting for gender and childhood cognition (β = −0.05, p = 0.04). There were no cross-sectional or longitudinal associations between APOE-ε4 and processing speed. We conclude that APOE-ε4 is associated with a subtly faster rate of memory decline from midlife to early old age; this may be due to effects of APOE-ε4 becoming manifest around the latter stage of life. Continuing follow-up will determine what proportion of this increase will become clinically significant.
Highlights
Apolipoprotein E (APOE) is involved in the transport of cholesterol and other lipids between cellular structures.1 It is genetically associated with two single-nucleotide polymorphisms (SNPs) that mark three alleles, ε2, ε3 and ε4
While APOE-associated cognitive has been noted within birth cohort studies in the ninth decade 12, a longitudinal analysis conducted on a mixed age group sample of known APOE status noted an increased rate of decline in memory in homozygous ε4 carriers, manifesting prior to age 60 13
This paper aims to determine the association between APOE-ε4 and processing speed and episodic memory scores from age 43 to 69 in this population-based birth cohort, accounting for childhood cognitive ability
Summary
Apolipoprotein E (APOE) is involved in the transport of cholesterol and other lipids between cellular structures. It is genetically associated with two single-nucleotide polymorphisms (SNPs) that mark three alleles, ε2, ε3 and ε4. Apolipoprotein E (APOE) is involved in the transport of cholesterol and other lipids between cellular structures.. Apolipoprotein E (APOE) is involved in the transport of cholesterol and other lipids between cellular structures.1 It is genetically associated with two single-nucleotide polymorphisms (SNPs) that mark three alleles, ε2, ε3 and ε4. A multicohort consortium that included the Medical Research Council National Survey for Health and Development (NSHD) found that APOE genotype had no significant effects on multiple cognitive and functional domains across midlife and old age 7, consistent with other studies examining cognitive trajectories in younger individuals [8,9,10]. While APOE-associated cognitive has been noted within birth cohort studies in the ninth decade 12, a longitudinal analysis conducted on a mixed age group sample of known APOE status noted an increased rate of decline in memory in homozygous ε4 carriers, manifesting prior to age 60 13. With a follow up of 5 years, and age heterogeneity among the sample
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
