Hippocampal atrophy rates and CSF biomarkers in elderly APOE2 normal subjects.

Publication Type Academic Article
Authors Chiang G, Insel P, Tosun D, Schuff N, Truran-Sacrey D, Raptentsetsang S, Jack C, Aisen P, Petersen R, Weiner M
Journal Neurology
Volume 75
Issue 22
Pagination 1976-81
Date Published 10/27/2010
ISSN 1526-632X
Keywords Alzheimer Disease, Apolipoprotein E2, Genetic Predisposition to Disease, Hippocampus, tau Proteins
Abstract OBJECTIVE: To determine whether elderly normal APOE E2 (APOE2) carriers exhibit slower rates of hippocampal atrophy and memory decline compared to APOE3/3 carriers. We also determined whether APOE2 carriers have less Alzheimer pathology as reflected by CSF biomarkers. METHODS: We included longitudinal data from 134 cognitively normal individuals (27 APOE2/2 or E2/3, 107 APOE3/3) from the Alzheimer's Disease Neuroimaging Initiative, a prospective cohort study. A linear mixed-effects model was used to determine how APOE2 affected rates of hippocampal atrophy and cognitive change over time. In a subsample of 72 individuals who also underwent CSF analysis, an ordinary least-squares regression was used to determine whether CSF β-amyloid (Aβ), total tau, and phosphorylated tau-181 (p-tau) differed by APOE2 status. RESULTS: APOE2 carriers demonstrated slower rates of hippocampal atrophy (p = 0.004). The mean rate of hippocampal atrophy among APOE2 carriers was -33 mm(3)/year (95% confidence interval -65 to +0.4), or -0.5%/year, compared to -86 mm(3)/year (95% confidence interval -102 to -71), or -1.3%/year, in the APOE3/3 group. No differences in the rates of episodic memory (p = 0.23) or overall cognitive change (p = 0.90) were detected. In the CSF subsample, APOE2 carriers had higher levels of CSF Aβ (p = 0.01), lower p-tau (p = 0.02), and marginally lower tau (p = 0.12). CONCLUSION: A slower rate of hippocampal atrophy in normal APOE2 carriers is consistent with the lower risk of Alzheimer disease in these individuals. We hypothesize that the slower atrophy rate is related to decreased preclinical Alzheimer pathology.
DOI 10.1212/WNL.0b013e3181ffe4d1
PubMed ID 20980669
PubMed Central ID PMC3014234
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