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P1‐383: APOE‐ε4 IS ASSOCIATED WITH LESS ANTERIOR CINGULATE CORTEX AND INFERIOR FRONTAL GYRUS THICKNESS IN LATE‐ONSET AD
Author(s) -
Li Jie,
Huang Xinying,
Lei Dan,
Mao Chenhui,
Dong Liling,
Liu Caiyan,
Hou Bo,
Qiu Ling,
Feng Feng,
Peng Bin,
Cui Liying,
Gao Jing
Publication year - 2019
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2019.06.938
Subject(s) - apolipoprotein e , medicine , anterior cingulate cortex , pathophysiology , dementia , cardiology , disease , neuroscience , psychology , psychiatry , cognition
Disease, have a strong impact on hippocampal volume in cognitively unimpaired individuals. Structural MRI now allows to characterize hippocampal subfields and to assess their selective vulnerability. Here we estimated subfield volumes in cognitively unimpaired participants and looked for associations with age and APOE.Methods: We includedN1⁄41168 cognitively unimpaired participants aged between 45 and 74 (mean: 59.4H6.8) including 73 ε4 homozygotes (HO), 417 heterozygotes, 678 non-carriers (NC). T1 images were acquired with 0.75-mm isotropic voxels on a single 3T MR scanner and hippocampal subfields were segmented using FreeSurfer 6.0. We assessed the effect of APOE on each subfield and its interaction with age using a general linear model. Age was modeled as a quadratic term centered at age 55. Sex, education and total intracranial volume were included as confounders. Contrasts were assessed for dominance (ε4 carriers vs NC), recessivity (HO vs others) and additivity (correlation with the number of ε4 alleles). Significance threshold was set at p<0.05 (FWE-corrected). Results: APOE-ε4 carriers showed significantly reduced volumes as compared to NC (Figure 1). This effect was bilateral in CA3, CA4, dentate gyrus, hippocampal tail and whole hippocampus, and found in both recessive and additive contrasts. Only the fimbria showed larger volumes in ε4 carriers. Finally, left hippocampal fissure showed larger volumes in APOE ε4 carriers in the dominant contrast. All subfields displayed a significant negative association with age, except right hippocampal fissure. The strongest effect of age was found, in decreasing order of magnitude, in the whole hippocampus, hippocampal tail, CA1, presubiculum, subiculum, dentate gyrus, CA4, fimbria, HATA, left hippocampal fissure and parasubiculum (Figure 2). Conclusions: Our results confirm the negative impact of both age and the APOE ε4 allele on the volume of the hippocampal subfields. Both factors show a distinct effect across subfields with APOE showing a pattern more closely related to that of AD. With the uniquely high number of homozygotes in our dataset, our study shows that carrying two copies of the ε4 allele is also associated with a significantly higher impact. P1-383 APOE-ε4 IS ASSOCIATEDWITH LESS ANTERIOR CINGULATE CORTEX AND INFERIOR FRONTAL GYRUS THICKNESS IN LATE-ONSETAD