title: Longer leukocyte telomere length is associated with smaller hippocampal volume among non-demented APOE ε3/ε3 subjects.
abstract: Telomere length shortens with cellular division, and leukocyte telomere length is used as a marker for systemic telomere length. The hippocampus hosts adult neurogenesis and is an important structure for episodic memory, and carriers of the apolipoprotein E ε4 allele exhibit higher hippocampal atrophy rates and differing telomere dynamics compared with non-carriers. The authors investigated whether leukocyte telomere length was associated with hippocampal volume in 57 cognitively intact subjects (29 ε3/ε3 carriers; 28 ε4 carriers) aged 49-79 yr. Leukocyte telomere length correlated inversely with left (r(s) = -0.465; p = 0.011), right (r(s) = -0.414; p = 0.025), and total hippocampus volume (r(s) = -0.519; p = 0.004) among APOE ε3/ε3 carriers, but not among ε4 carriers. However, the ε4 carriers fit with the general correlation pattern exhibited by the ε3/ε3 carriers, as ε4 carriers on average had longer telomeres and smaller hippocampi compared with ε3/ε3 carriers. The relationship observed can be interpreted as long telomeres representing a history of relatively low cellular proliferation, reflected in smaller hippocampal volumes. The results support the potential of leukocyte telomere length being used as a biomarker for tapping functional and structural processes of the aging brain.
authors.affiliation: Division of Psychiatry, Department of Clinical Sciences, Umeå University, 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: Johanna
authors.initials: J
authors.lastname: Lind
authors.forename: Therese
authors.initials: T
authors.lastname: Nilbrink
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: Göran
authors.initials: G
authors.lastname: Roos
authors.forename: Lars-Göran
authors.initials: LG
authors.lastname: Nilsson
authors.forename: Lars
authors.initials: L
authors.lastname: Nyberg
authors.forename: Rolf
authors.initials: R
authors.lastname: Adolfsson
authors.forename: Karl-Fredrik
authors.initials: KF
authors.lastname: Norrback
mesh_terms: D000367:Age Factors; D000368:Aged; D000483:Alleles; D053318:Apolipoprotein E3 / Q000235:genetics*; D053327:Apolipoprotein E4 / Q000235:genetics; D001284:Atrophy / Q000235:genetics / Q000473:pathology; D015415:Biomarkers / Q000378:metabolism; D049109:Cell Proliferation; D003071:Cognition; D005260:Female; D006624:Hippocampus / Q000473:pathology / Q000502:physiology*; D006801:Humans; D007962:Leukocytes / Q000502:physiology* / Q000648:ultrastructure; D008297:Male; D061212:Memory, Episodic; D008875:Middle Aged; D055495:Neurogenesis / Q000235:genetics; D016615:Telomere / Q000235:genetics*
chemical_list: D053318:Apolipoprotein E3; D053327:Apolipoprotein E4; D015415:Biomarkers