title: APOE ε4 is associated with longer telomeres, and longer telomeres among ε4 carriers predicts worse episodic memory.
abstract: Both leukocyte telomere length and the apolipoprotein ε4 allele have been associated with mortality, cardiovascular disease, cognition, and dementia. The authors investigated whether leukocyte telomere length was associated with APOE genotype or cognitive abilities in the context of APOE genotype. The setting for this cross-sectional study was 427 nondemented individuals aged 41-81 yr. The authors found that ε4 carriers overall exhibited significantly longer telomeres compared with non-carriers (difference of 268 bp, p = 0.001). This difference was greatest at the lower limit of the age span and nonsignificant at the upper limit, which translated into a significantly higher telomere attrition rate (p = 0.049) among ε4 carriers (37 bp/years) compared with non-carriers (21 bp/year). Further, longer telomeres among ε4 carriers significantly predicted worse performance on episodic memory tasks. No significant associations were found on tasks tapping semantic and visuospatial ability, or among ε3/ε3 carriers. In conclusion, APOE ε4 carriers had longer telomeres compared with non-carriers, but higher rate of attrition. Among them, longer telomeres predicted worse performance on episodic memory tasks. These observations suggest that the ε4 allele is associated with abnormal cell turnover of functional and possibly clinical significance.
authors.affiliation: Division of Psychiatry, Department of Clinical Sciences, Umeå University, SE-901 87 Umeå, Sweden. mikael.wikgren@psychiat.umu.se
authors.forename: Mikael
authors.initials: M
authors.lastname: Wikgren
authors.forename: Thomas
authors.initials: T
authors.lastname: Karlsson
authors.forename: Therese
authors.initials: T
authors.lastname: Nilbrink
authors.forename: Katarina
authors.initials: K
authors.lastname: Nordfjäll
authors.forename: Johan
authors.initials: J
authors.lastname: Hultdin
authors.forename: Kristel
authors.initials: K
authors.lastname: Sleegers
authors.forename: Christine
authors.initials: C
authors.lastname: Van Broeckhoven
authors.forename: Lars
authors.initials: L
authors.lastname: Nyberg
authors.forename: Göran
authors.initials: G
authors.lastname: Roos
authors.forename: Lars-Göran
authors.initials: LG
authors.lastname: Nilsson
authors.forename: Rolf
authors.initials: R
authors.lastname: Adolfsson
authors.forename: Karl-Fredrik
authors.initials: KF
authors.lastname: Norrback
mesh_terms: D000328:Adult; D000368:Aged; D053327:Apolipoprotein E4 / Q000235:genetics* / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000503:physiopathology*; D005260:Female; D006579:Heterozygote; D006801:Humans; D008297:Male; D061212:Memory, Episodic; D008875:Middle Aged; D013223:Statistics as Topic; D016615:Telomere / Q000235:genetics*; D059506:Telomere Shortening / Q000235:genetics*
chemical_list: D053327:Apolipoprotein E4; D015415:Biomarkers