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Wybitul M, Buchmann A, Langer N, Hock C, Treyer V, Gietl A. Trajectories of amyloid beta accumulation - Unveiling the relationship with APOE genotype and cognitive decline. Neurobiol Aging 2024; 139:44-53. [PMID: 38593527 DOI: 10.1016/j.neurobiolaging.2024.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 03/18/2024] [Accepted: 03/24/2024] [Indexed: 04/11/2024]
Abstract
Amyloid beta (Aβ) follows a sigmoidal time function with varying accumulation rates. We studied how the position on this function, reflected by different Aβ accumulation phases, influences APOE ɛ4's association with Aβ and cognitive decline in 503 participants without dementia using Aβ-PET imaging over 5.3-years. First, Aβ load and accumulation were analyzed irrespective of phases using linear mixed regression. Generally, ɛ4 carriers displayed a higher Aβ load. Moreover, Aβ normal (Aβ-) ɛ4 carriers demonstrated higher accumulation. Next, we categorized accumulation phases as "decrease", "stable", or "increase" based on trajectory shapes. After excluding the Aβ-/decrease participants from the initial regression, the difference in accumulation attributable to genotype among Aβ- individuals was no longer significant. Further analysis revealed that in increase phases, Aβ accumulation was higher among noncarriers, indicating a genotype-related timeline shift. Finally, cognitive decline was analyzed across phases and was already evident in the Aβ-/increase phase. Our results encourage early interventions for ɛ4 carriers and imply that monitoring accumulating Aβ- individuals might help identify those at risk for cognitive decline.
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Affiliation(s)
- Maha Wybitul
- Institute for Regenerative Medicine, Faculty of Medicine, University of Zurich, Schlieren 8952, Switzerland; Department of Psychology, Faculty of Philosophy, University of Zurich, Zurich 8050, Switzerland
| | - Andreas Buchmann
- Institute for Regenerative Medicine, Faculty of Medicine, University of Zurich, Schlieren 8952, Switzerland
| | - Nicolas Langer
- Methods of Plasticity Research, Department of Psychology, University of Zurich, Zurich 8050, Switzerland
| | - Christoph Hock
- Institute for Regenerative Medicine, Faculty of Medicine, University of Zurich, Schlieren 8952, Switzerland; Neurimmune, Schlieren 8952, Switzerland
| | - Valerie Treyer
- Institute for Regenerative Medicine, Faculty of Medicine, University of Zurich, Schlieren 8952, Switzerland; Department of Nuclear Medicine, University of Zurich, Zurich 8091, Switzerland.
| | - Anton Gietl
- Institute for Regenerative Medicine, Faculty of Medicine, University of Zurich, Schlieren 8952, Switzerland; University Hospital for Geriatric Psychiatry, Zurich 8008, Switzerland
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Royall DR, Palmer RF. Statin use moderates APOE's and CRP's associations with dementia and is associated with lesser dementia severity in ε4 carriers. Alzheimers Dement 2024; 20:1627-1636. [PMID: 38055626 PMCID: PMC10984456 DOI: 10.1002/alz.13543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/21/2023] [Accepted: 10/01/2023] [Indexed: 12/08/2023]
Abstract
INTRODUCTION We tested the effect of statins on C-reactive protein (CRP) and apolipoprotein E (APOE)'s associations with dementia severity. METHODS A total of 1725 participants of the Alzheimer's Disease Neuroimaging Initiative (ADNI) were assigned from 12-month follow-up data into the following groups: (1) ε4 (-)/statin (-), (2) ε4 (-)/statin (+), (3) ε4 (+)/statin (-), and (4) ε4 (+)/statin (+). Dementia severity was assessed by a δ homolog: "dHABS." A mediation model was stratified on statin use and moderation effects tested by a chi-square difference. RESULTS Plasma CRP level decreased with ε4 allelic dose. Statins had no effect on the dHABS d-score in non-carriers but were associated with better scores in carriers. Treated carriers did not have more severe dementia than non-carriers. Statin use moderated the mutual adjusted effects of APOE and CRP. CRP was not a mediator of APOE's effect. DISCUSSION Statins may provide a protective effect on the dementia severity of ε4 carriers. HIGHLIGHTS δ is a dementia-specific phenotype related to general intelligence "g" and is assessed via a "d-score." Apolipoprotein E (APOE) and plasma C-reactive protein (CRP) are independently associated with δ. Plasma CRP decreases with ε4 allelic dose. Statins were associated with better (less demented) d-scores in ε4 carriers but had no effect in non-ε4 carriers. Treated ε4 carriers did not have more severe dementia than non-carriers. Statin use moderated the effects of APOE and CRP on δ. CRP was not a mediator of APOE's effect on δ.
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Affiliation(s)
- Donald R. Royall
- Department of PsychiatryUniversity of Texas Health Science CenterSan AntonioTexasUSA
- Department of MedicineUniversity of Texas Health Science CenterSan AntonioTexasUSA
- Department of Family and Community MedicineUniversity of Texas Health Science CenterSan AntonioTexasUSA
- Glenn Biggs Institute for Alzheimer's and Neurodegenerative DisordersSan AntonioUSA
| | - Raymond F. Palmer
- Department of Family and Community MedicineUniversity of Texas Health Science CenterSan AntonioTexasUSA
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Apolipoprotein E ɛ4-related effects on cognition are limited to the Alzheimer's disease spectrum. GeroScience 2021; 44:195-209. [PMID: 34591236 PMCID: PMC8811053 DOI: 10.1007/s11357-021-00450-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 08/23/2021] [Indexed: 11/29/2022] Open
Abstract
Whether the deleterious effects of APOE4 are restricted to the Alzheimer’s disease (AD) spectrum or cause cognitive impairment irrespectively of the development of AD is still a matter of debate, and the focus of this study. Our analyses included APOE4 genotype, neuropsychological variables, amyloid-βeta (Aβ) and Tau markers, FDG-PET values, and hippocampal volumetry data derived from the healthy controls sample of the ADNI database. We formed 4 groups of equal size (n = 30) based on APOE4 carriage and amyloid-PET status. Baseline and follow-up (i.e., 48 months post-baseline) results indicated that Aβ-positivity was the most important factor to explain poorer cognitive performance, while APOE4 only exerted a significant effect in Aβ-positive subjects. Additionally, multiple regression analyses evidenced that, within the Aβ-positive sample, hippocampal volumetry explained most of the variability in cognitive performance for APOE4 carriers. These findings represent a strong support for the so-called preclinical/prodromal hypothesis, which states that the reported differences in cognitive performance between healthy carriers and non-carriers are mainly due to the APOE4’s capability to increase the risk of AD. Moreover, our results reinforce the notion that a synergistic interaction of Aβ and APOE4 elicits a neurodegenerative process in the hippocampus that might be the main cause of impaired cognitive performance.
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Stickel AM, McKinnon AC, Matijevic S, Grilli MD, Ruiz J, Ryan L. Apolipoprotein E ε4 Allele-Based Differences in Brain Volumes Are Largely Uniform Across Late Middle Aged and Older Hispanic/Latino- and Non-Hispanic/Latino Whites Without Dementia. Front Aging Neurosci 2021; 13:627322. [PMID: 33716715 PMCID: PMC7952627 DOI: 10.3389/fnagi.2021.627322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 02/01/2021] [Indexed: 12/01/2022] Open
Abstract
Hispanics/Latinos are at an equal or a greater risk for Alzheimer's disease (AD), yet risk factors remain more poorly characterized as compared to non-Hispanic/Latino Whites. Among non-Hispanic/Latino White cohorts, the apolipoprotein E (APOE) ε4 allele is one of the strongest risk factors for AD with subtle declines in episodic memory and brain volumes detectable in the preclinical stages. We examined whether the APOE ε4 status had a differential impact on cognition and brain volumes among cognitively healthy and mild cognitively impaired Hispanics/Latinos (n = 86; ε4 n = 23) compared to a well-matched group of non-Hispanic/Latino Whites (n = 92; ε4 n = 29). Neither the APOE ε4 status nor the interaction between the ε4 status and ethnicity was associated with cognitive performance. The APOE ε4 status was associated with white matter and not with gray matter volumes. APOE ε4 carriers had a significantly smaller total brain white matter volumes, as well as smaller right middle temporal and left superior temporal volumes. The Hispanics/Latinos had significantly smaller left middle frontal gray matter volumes, yet marginally larger overall white matter volumes, than the non-Hispanic/Latino Whites. Exploratory analysis within the Hispanic/Latino sample found that those people whose primary language was Spanish had larger total brain white matter volumes compared primarily to the English speakers. Importantly, primary language differences only held for Hispanic/Latino ε4 carriers and did not differentiate Hispanic/Latino non-carriers, underscoring the need for further investigation into the impacts of language and acculturation on cognitive aging among the fastest growing ethnic minority group in the United States.
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Affiliation(s)
- Ariana M. Stickel
- Department of Psychology, University of Arizona, Tucson, AZ, United States
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, United States
| | - Andrew C. McKinnon
- Department of Psychology, University of Arizona, Tucson, AZ, United States
- Brain and Mind Centre, University of Sydney, Camperdown, NSW, Australia
| | | | - Matthew D. Grilli
- Department of Psychology, University of Arizona, Tucson, AZ, United States
| | - John Ruiz
- Department of Psychology, University of Arizona, Tucson, AZ, United States
| | - Lee Ryan
- Department of Psychology, University of Arizona, Tucson, AZ, United States
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Fockler J, Kwang W, Ashford MT, Flenniken D, Hwang J, Truran D, Mackin RS, Jin C, O'Hara R, Hallmayer JF, Yesavage JA, Weiner MW, Nosheny RL. Brain health registry GenePool study: A novel approach to online genetics research. ALZHEIMERS & DEMENTIA-TRANSLATIONAL RESEARCH & CLINICAL INTERVENTIONS 2021; 7:e12118. [PMID: 33614891 PMCID: PMC7882536 DOI: 10.1002/trc2.12118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 10/07/2020] [Accepted: 11/04/2020] [Indexed: 12/29/2022]
Abstract
Introduction Remote data collection, including the establishment of online registries, is a novel approach to efficiently identify risk for cognitive decline and Alzheimer's disease (AD) in older adults, with growing evidence for feasibility and validity. Addition of genetic data to online registries has the potential to facilitate identification of older adults at risk and to advance the understanding of genetic contributions to AD. Methods 573 older adult participants with longitudinal online Brain Health Registry (BHR) data underwent apolipoprotein E (APOE) genotyping using remotely collected saliva samples and a novel, automated Biofluid Collection Management Portal. We evaluated acceptability of genetic sample collection and estimated associations between (1) sociodemographic variables and willingness to participate in genetics research and (2) APOE results and online cognitive and functional assessments. We also assessed acceptance of hypothetical genetics research participation by surveying a larger sample of 25,888 BHR participants. Results 51% of invited participants enrolled in the BHR genetics study, BHR‐GenePool Study (BHR‐GPS); 27% of participants had at least one APOE ε4 allele. Older participants and those with higher educational attainment were more likely to participate. In the remotely administered Cogstate Brief Battery, APOE ε4/ε4 homozygotes (HM) had worse online learning scores, and greater decline in processing speed and attention, compared to ε3/ε4 heterozygotes (HT) and ε4 non‐carriers (NC). Discussion APOE genotyping of more than 500 older adults enrolled in BHR supports the feasibility and validity of a novel, remote biofluids collection approach from a large cohort of older adults, with data linkage to longitudinal online cognitive data. This approach can be expanded for efficient collection of genetic data and other information from biofluids in the future.
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Affiliation(s)
- Juliet Fockler
- VA Advanced Imaging Research Center San Francisco Veteran's Administration Medical Center San Francisco California USA.,San Francisco Department of Radiology and Biomedical Imaging University of California, San Francisco San Francisco California USA
| | - Winnie Kwang
- VA Advanced Imaging Research Center San Francisco Veteran's Administration Medical Center San Francisco California USA.,San Francisco Department of Radiology and Biomedical Imaging University of California, San Francisco San Francisco California USA
| | - Miriam T Ashford
- VA Advanced Imaging Research Center San Francisco Veteran's Administration Medical Center San Francisco California USA.,San Francisco Department of Radiology and Biomedical Imaging University of California, San Francisco San Francisco California USA
| | - Derek Flenniken
- VA Advanced Imaging Research Center San Francisco Veteran's Administration Medical Center San Francisco California USA.,San Francisco Department of Radiology and Biomedical Imaging University of California, San Francisco San Francisco California USA
| | - Joshua Hwang
- VA Advanced Imaging Research Center San Francisco Veteran's Administration Medical Center San Francisco California USA.,San Francisco Department of Radiology and Biomedical Imaging University of California, San Francisco San Francisco California USA
| | - Diana Truran
- VA Advanced Imaging Research Center San Francisco Veteran's Administration Medical Center San Francisco California USA.,San Francisco Department of Radiology and Biomedical Imaging University of California, San Francisco San Francisco California USA
| | - R Scott Mackin
- VA Advanced Imaging Research Center San Francisco Veteran's Administration Medical Center San Francisco California USA.,San Francisco Department of Psychiatry University of California, San Francisco San Francisco California USA
| | - Chengshi Jin
- San Francisco Department of Biostatistics and Epidemiology University of California, San Francisco San Francisco California USA
| | - Ruth O'Hara
- Department of Psychiatry and Behavioral Sciences Stanford University Stanford California USA
| | - Joachim F Hallmayer
- Department of Psychiatry and Behavioral Sciences Stanford University Stanford California USA
| | - Jerome A Yesavage
- Department of Psychiatry and Behavioral Sciences Stanford University Stanford California USA
| | - Michael W Weiner
- VA Advanced Imaging Research Center San Francisco Veteran's Administration Medical Center San Francisco California USA.,San Francisco Department of Radiology and Biomedical Imaging University of California, San Francisco San Francisco California USA
| | - Rachel L Nosheny
- VA Advanced Imaging Research Center San Francisco Veteran's Administration Medical Center San Francisco California USA.,San Francisco Department of Psychiatry University of California, San Francisco San Francisco California USA
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Abstract
OBJECTIVES Low educational attainment is a risk factor for more rapid cognitive aging, but there is substantial variability in cognitive trajectories within educational groups. The aim of this study was to determine the factors that confer resilience to memory decline within educational strata. METHODS We selected 2573 initially nondemented White, African American, and Hispanic participants from the longitudinal community-based Washington Heights/Inwood Columbia Aging Project who had at least two visits. We estimated initial memory (intercept) and the rate of memory decline (slope) using up to five occasions of measurement. We classified groups according to the educational attainment groups as low (≤5 years), medium (6-11 years), and high (≥12 years). We used a multiple-group latent growth model to identify the baseline predictors of initial memory performance and rate of memory decline across groups. The model specification considered the influence of demographic, socioeconomic, biomedical, and cognitive variables on the intercept and the slope of memory trajectory. RESULTS Our results indicated that the three educational groups do not benefit from the same factors. When allowed to differ across groups, the predictors were related to cognitive outcomes in the highly educated group, but we found no unique predictor of cognition for the low educated older adults. CONCLUSIONS These findings highlight that memory-protective factors may differ across older adults with distinct educational backgrounds, and the need to evaluate a broader range of potential resilience factors for older adults with few years of school.
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Williams OA, An Y, Armstrong NM, Shafer AT, Helphrey J, Kitner-Triolo M, Ferrucci L, Resnick SM. Apolipoprotein E ε4 allele effects on longitudinal cognitive trajectories are sex and age dependent. Alzheimers Dement 2019; 15:1558-1567. [PMID: 31561966 DOI: 10.1016/j.jalz.2019.07.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 07/08/2019] [Accepted: 07/14/2019] [Indexed: 10/26/2022]
Abstract
INTRODUCTION Questions remain about whether apolipoprotein E (APOE)-ε4 effects on cognitive decline are similar in men and women and how APOE-ε4 and age interact to influence decline in different cognitive domains. METHODS In sex-stratified analyses, baseline age-dependent associations between APOE-ε4 status and longitudinal cognitive trajectories were examined in cognitively normal Caucasian older adults (631 men, 561 women, baseline age range: 50-93, 6733 assessments). RESULTS In men, older baseline age was associated with greater effects of APOE-ε4 on longitudinal decline in memory and executive function, detectible from baseline age of 64 and 68, respectively. In women, older baseline age was associated with greater APOE-ε4 effects on longitudinal decline in attention, detectible at baseline age of 66. No significant APOE-ε4 effects were found for language, visual-spatial ability, or processing speed. DISCUSSION Results highlight the importance of considering sex and age when assessing APOE-ε4-associated vulnerability to cognitive decline.
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Affiliation(s)
- Owen A Williams
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, MD, USA
| | - Yang An
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, MD, USA
| | - Nicole M Armstrong
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, MD, USA
| | - Andrea T Shafer
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, MD, USA
| | - Jessica Helphrey
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, MD, USA
| | - Melissa Kitner-Triolo
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, MD, USA
| | - Luigi Ferrucci
- Longitudinal Studies Section, Translational Gerontology Branch, National Institute on Aging, Baltimore, MD, USA
| | - Susan M Resnick
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, MD, USA.
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The Contribution of Genetic Factors to Cognitive Impairment and Dementia: Apolipoprotein E Gene, Gene Interactions, and Polygenic Risk. Int J Mol Sci 2019; 20:ijms20051177. [PMID: 30866553 PMCID: PMC6429136 DOI: 10.3390/ijms20051177] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 02/26/2019] [Indexed: 12/19/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease. Although it has been studied for years, the pathogenesis of AD is still controversial. Genetic factors may play an important role in pathogenesis, with the apolipoprotein E (APOE) gene among the greatest risk factors for AD. In this review, we focus on the influence of genetic factors, including the APOE gene, the interaction between APOE and other genes, and the polygenic risk factors for cognitive function and dementia. The presence of the APOE ε4 allele is associated with increased AD risk and reduced age of AD onset. Accelerated cognitive decline and abnormal internal environment, structure, and function of the brain were also found in ε4 carriers. The effect of the APOE promoter on cognition and the brain was confirmed by some studies, but further investigation is still needed. We also describe the effects of the associations between APOE and other genetic risk factors on cognition and the brain that exhibit a complex gene⁻gene interaction, and we consider the importance of using a polygenic risk score to investigate the association between genetic variance and phenotype.
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Reas ET, Laughlin GA, Bergstrom J, Kritz-Silverstein D, Barrett-Connor E, McEvoy LK. Effects of APOE on cognitive aging in community-dwelling older adults. Neuropsychology 2019; 33:406-416. [PMID: 30730162 DOI: 10.1037/neu0000501] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE The apolipoprotein E (APOE) gene is an established risk factor for sporadic Alzheimer's disease, with elevated risk for ε4-carriers and reduced risk for ε2-carriers. However, it is unclear whether APOE modifies risk for cognitive decline in normal aging. The objective of this study was to determine whether ε2 and ε4 are associated with rates of normal cognitive aging, and whether associations of ε4 with cognitive decline are modified by sex, education or health behaviors (exercise, alcohol consumption, smoking). METHOD A community-based sample of 1,393 older adults were genotyped for APOE and underwent cognitive assessment up to seven times over a maximum of period of 27 years. RESULTS ε2-carriers showed slower executive function decline with age relative to ε3 homozygotes or ε4-carriers, whereas ε4-carriers demonstrated more rapid executive function and verbal fluency decline. Accelerated executive function decline was particularly pronounced in ε4-carriers with lower education. After excluding individuals with cognitive impairment, faster executive function decline was still apparent in ε4-carriers, and the effect of ε4 on episodic memory interacted with alcohol consumption, such that only ε4-carriers who did not drink showed more rapid memory decline than ε4 noncarriers. The influence of ε4 on cognitive aging did not differ by sex, nor was it modified by smoking or exercise. CONCLUSIONS These findings indicate that the ε2 and ε4 alleles have differential effects on cognitive aging, and that negative effects of ε4 may be partly mitigated by behavioral choices. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
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López ME, Turrero A, Delgado ML, Rodríguez-Rojo IC, Arrazola J, Barabash A, Maestú F, Fernández A. APOE ε4 Genotype and Cognitive Reserve Effects on the Cognitive Functioning of Healthy Elders. Dement Geriatr Cogn Disord 2018; 44:328-342. [PMID: 29414814 DOI: 10.1159/000481852] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 09/28/2017] [Indexed: 01/21/2023] Open
Abstract
AIM To test the association between cognitive performance and APOE genotype, and to assess potential modifications of this association by sociodemographic and neuroanatomical factors in a sample of 74 healthy elders. METHODS Firstly, we explored the isolated role of the APOE ɛ4 genotype (i.e., APOE4) in different neuropsychological tests, and then the effects of its interaction with sociodemographic (i.e., age, gender, and educational level) and neuroanatomical (i.e., hippocampal volumes) variables. Subsequently, we performed the same analyses after dividing the sample into two subgroups according to their Mini-Mental State Examination scores (control-high group ≥29 and control-low group < 29). RESULTS In the whole group, APOE4 carriers exhibited a significantly poorer execution in several cognitive domains including global cognitive functioning, episodic memory, verbal fluency, and naming. This effect was more noticeable in older and less educated subjects. The separated analyses revealed that APOE4 carriers in the control-low group exhibited lower scores in global cognitive functioning and episodic memory, while no effects were observed in the control-high group. Neither gender nor hippocampal volumes showed a significant interaction effect with APOE genotype. CONCLUSIONS Current results point out that APOE4 genotype influences healthy aged cognition, although factors such age or educational attainment seem to modulate its effects.
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Affiliation(s)
- María Eugenia López
- Laboratory of Neuropsychology, Universitat de les Illes Balears, Palma de Mallorca, Spain.,Institute of Sanitary Investigation (IdISSC), San Carlos University Hospital, Madrid, Spain.,Laboratory of Cognitive and Computational Neuroscience (UCM-UPM), Centre for Biomedical Technology (CTB), Madrid, Spain
| | - Agustín Turrero
- Institute of Sanitary Investigation (IdISSC), San Carlos University Hospital, Madrid, Spain.,Department of Biostatistics and Operational Investigation, Complutense University of Madrid, Madrid, Spain
| | - María Luisa Delgado
- Seniors Center of the District of Chamartín, Madrid, Spain.,Department of Basic Psychology II, Complutense University of Madrid, Madrid, Spain
| | - Inmaculada Concepción Rodríguez-Rojo
- Laboratory of Cognitive and Computational Neuroscience (UCM-UPM), Centre for Biomedical Technology (CTB), Madrid, Spain.,Department of Basic Psychology II, Complutense University of Madrid, Madrid, Spain
| | - Juan Arrazola
- Institute of Sanitary Investigation (IdISSC), San Carlos University Hospital, Madrid, Spain.,Radiology Department, San Carlos University Hospital, Madrid, Spain
| | - Ana Barabash
- Institute of Sanitary Investigation (IdISSC), San Carlos University Hospital, Madrid, Spain.,Laboratory of Psychoneuroendocrinology and Molecular Genetics, Biomedical Research Foundation, San Carlos University Hospital, Madrid, Spain
| | - Fernando Maestú
- Institute of Sanitary Investigation (IdISSC), San Carlos University Hospital, Madrid, Spain.,Laboratory of Cognitive and Computational Neuroscience (UCM-UPM), Centre for Biomedical Technology (CTB), Madrid, Spain.,Department of Basic Psychology II, Complutense University of Madrid, Madrid, Spain
| | - Alberto Fernández
- Institute of Sanitary Investigation (IdISSC), San Carlos University Hospital, Madrid, Spain.,Laboratory of Cognitive and Computational Neuroscience (UCM-UPM), Centre for Biomedical Technology (CTB), Madrid, Spain.,Department of Psychiatry, Complutense University of Madrid, Madrid, Spain
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O'Donoghue MC, Murphy SE, Zamboni G, Nobre AC, Mackay CE. APOE genotype and cognition in healthy individuals at risk of Alzheimer's disease: A review. Cortex 2018; 104:103-123. [DOI: 10.1016/j.cortex.2018.03.025] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 02/02/2018] [Accepted: 03/19/2018] [Indexed: 01/22/2023]
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12
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Prieto del Val L, Cantero JL, Baena D, Atienza M. Damage of the temporal lobe and APOE status determine neural compensation in mild cognitive impairment. Cortex 2018; 101:136-153. [DOI: 10.1016/j.cortex.2018.01.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 12/31/2017] [Accepted: 01/17/2018] [Indexed: 11/16/2022]
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Martins RN, Villemagne V, Sohrabi HR, Chatterjee P, Shah TM, Verdile G, Fraser P, Taddei K, Gupta VB, Rainey-Smith SR, Hone E, Pedrini S, Lim WL, Martins I, Frost S, Gupta S, O’Bryant S, Rembach A, Ames D, Ellis K, Fuller SJ, Brown B, Gardener SL, Fernando B, Bharadwaj P, Burnham S, Laws SM, Barron AM, Goozee K, Wahjoepramono EJ, Asih PR, Doecke JD, Salvado O, Bush AI, Rowe CC, Gandy SE, Masters CL. Alzheimer's Disease: A Journey from Amyloid Peptides and Oxidative Stress, to Biomarker Technologies and Disease Prevention Strategies-Gains from AIBL and DIAN Cohort Studies. J Alzheimers Dis 2018; 62:965-992. [PMID: 29562546 PMCID: PMC5870031 DOI: 10.3233/jad-171145] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Worldwide there are over 46 million people living with dementia, and this number is expected to double every 20 years reaching about 131 million by 2050. The cost to the community and government health systems, as well as the stress on families and carers is incalculable. Over three decades of research into this disease have been undertaken by several research groups in Australia, including work by our original research group in Western Australia which was involved in the discovery and sequencing of the amyloid-β peptide (also known as Aβ or A4 peptide) extracted from cerebral amyloid plaques. This review discusses the journey from the discovery of the Aβ peptide in Alzheimer's disease (AD) brain to the establishment of pre-clinical AD using PET amyloid tracers, a method now serving as the gold standard for developing peripheral diagnostic approaches in the blood and the eye. The latter developments for early diagnosis have been largely achieved through the establishment of the Australian Imaging Biomarker and Lifestyle research group that has followed 1,100 Australians for 11 years. AIBL has also been instrumental in providing insight into the role of the major genetic risk factor apolipoprotein E ɛ4, as well as better understanding the role of lifestyle factors particularly diet, physical activity and sleep to cognitive decline and the accumulation of cerebral Aβ.
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Affiliation(s)
- Ralph N. Martins
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Australian Alzheimer’s Research Foundation, Ralph and Patricia Sarich Neuroscience Research Institute, Nedlands, WA, Australia
- Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
- School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth WA, Australia
- KaRa Institute of Neurological Diseases, Sydney NSW, Australia
| | - Victor Villemagne
- Department of Nuclear Medicine and Centre for PET, Austin Health, Heidelberg, Australia
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
| | - Hamid R. Sohrabi
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Australian Alzheimer’s Research Foundation, Ralph and Patricia Sarich Neuroscience Research Institute, Nedlands, WA, Australia
- Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
- School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth WA, Australia
- KaRa Institute of Neurological Diseases, Sydney NSW, Australia
- Cooperative Research Centre for Mental Health, Carlton, VIC, Australia
| | - Pratishtha Chatterjee
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
- KaRa Institute of Neurological Diseases, Sydney NSW, Australia
| | - Tejal M. Shah
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Australian Alzheimer’s Research Foundation, Ralph and Patricia Sarich Neuroscience Research Institute, Nedlands, WA, Australia
- Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
| | - Giuseppe Verdile
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Australian Alzheimer’s Research Foundation, Ralph and Patricia Sarich Neuroscience Research Institute, Nedlands, WA, Australia
- School of Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University of Technology, Bentley, WA, Australia
| | - Paul Fraser
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, ON, Canada
| | - Kevin Taddei
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Australian Alzheimer’s Research Foundation, Ralph and Patricia Sarich Neuroscience Research Institute, Nedlands, WA, Australia
- Cooperative Research Centre for Mental Health, Carlton, VIC, Australia
| | - Veer B. Gupta
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Cooperative Research Centre for Mental Health, Carlton, VIC, Australia
| | - Stephanie R. Rainey-Smith
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Australian Alzheimer’s Research Foundation, Ralph and Patricia Sarich Neuroscience Research Institute, Nedlands, WA, Australia
| | - Eugene Hone
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Cooperative Research Centre for Mental Health, Carlton, VIC, Australia
| | - Steve Pedrini
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Cooperative Research Centre for Mental Health, Carlton, VIC, Australia
| | - Wei Ling Lim
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Ian Martins
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Shaun Frost
- CSIRO Australian e-Health Research Centre/Health and Biosecurity, Perth, WA, Australia
| | - Sunil Gupta
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Australian Alzheimer’s Research Foundation, Ralph and Patricia Sarich Neuroscience Research Institute, Nedlands, WA, Australia
- Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
- KaRa Institute of Neurological Diseases, Sydney NSW, Australia
| | - Sid O’Bryant
- University of North Texas Health Science Centre, Fort Worth, TX, USA
| | - Alan Rembach
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
| | - David Ames
- National Ageing Research Institute, Parkville, VIC, Australia
- University of Melbourne Academic Unit for Psychiatry of Old Age, St George’s Hospital, Kew, VIC, Australia
| | - Kathryn Ellis
- Department of Psychiatry, The University of Melbourne, Parkville, VIC, Australia
| | - Stephanie J. Fuller
- Australian Alzheimer’s Research Foundation, Ralph and Patricia Sarich Neuroscience Research Institute, Nedlands, WA, Australia
| | - Belinda Brown
- Australian Alzheimer’s Research Foundation, Ralph and Patricia Sarich Neuroscience Research Institute, Nedlands, WA, Australia
- School of Psychology and Exercise Science, Murdoch University, Perth, WA, Australia
| | - Samantha L. Gardener
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Australian Alzheimer’s Research Foundation, Ralph and Patricia Sarich Neuroscience Research Institute, Nedlands, WA, Australia
| | - Binosha Fernando
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Prashant Bharadwaj
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Samantha Burnham
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- eHealth, CSIRO Health and Biosecurity, Parkville, VIC, Australia
| | - Simon M. Laws
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Cooperative Research Centre for Mental Health, Carlton, VIC, Australia
- Collaborative Genomics Group, Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Anna M. Barron
- School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth WA, Australia
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Kathryn Goozee
- Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
- School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth WA, Australia
- KaRa Institute of Neurological Diseases, Sydney NSW, Australia
- Anglicare, Sydney, NSW, Australia
- Cooperative Research Centre for Mental Health, Carlton, VIC, Australia
| | - Eka J. Wahjoepramono
- Centre of Excellence for Alzheimer’s Disease Research and Care, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Prita R. Asih
- KaRa Institute of Neurological Diseases, Sydney NSW, Australia
- School of Medical Sciences, University of New South Wales, Kensington, NSW, Australia
| | - James D. Doecke
- CSIRO Health and Biosecurity, Australian E-Health Research Centre, Brisbane, Australia
| | - Olivier Salvado
- CSIRO Health and Biosecurity, Australian E-Health Research Centre, Brisbane, Australia
- Cooperative Research Centre for Mental Health, Carlton, VIC, Australia
| | - Ashley I. Bush
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Cooperative Research Centre for Mental Health, Carlton, VIC, Australia
| | - Christopher C. Rowe
- Department of Nuclear Medicine and Centre for PET, Austin Health, Heidelberg, Australia
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
| | - Samuel E. Gandy
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Colin L. Masters
- Cooperative Research Centre for Mental Health, Carlton, VIC, Australia
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14
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Abstract
PURPOSE OF REVIEW The apolipoprotein ε4 (APOE ε4) allele has been recognized as a risk factor for the late-onset Alzheimer's disease. It may modulate cognitive performance in nondemented younger and older ε4 carriers. Does APOE ε4 genotype affect cognition in mid-aged population as well? In this review, a summary of current evidence concerning the effect of this genotype on cognition in middle-aged individuals will be presented. RECENT FINDINGS Recent findings did not provide a clear cognitive signature of APOE ε4 genotype in mid-life. A positive, negative, and null effect on cognitive functions has been observed, especially on memory performance. SUMMARY The discrepancy of the results may be because of several limitations. Future studies should be focused on a narrower participants' age range and a wider level of education range. Moreover, cognition should be explored by means of more sensitive tasks. Finally, interaction between genotype and additional risk factors and other allelic variants should be taken into account to fully understand the APOE genotype effect on brain and cognition.
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Ashford JW. Treatment of Alzheimer's Disease: The Legacy of the Cholinergic Hypothesis, Neuroplasticity, and Future Directions. J Alzheimers Dis 2016; 47:149-56. [PMID: 26402763 DOI: 10.3233/jad-150381] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In this issue, an article by Waring et al. provides a meta-analysis of the effects of apo-lipo-protein E (APOE) genotype on the beneficial effect of acetyl-cholinesterase inhibitors (AChEIs) in patients with Alzheimer's disease (AD). There was no significant effect found. As of 2015, AChEI medications are the mainstay of AD treatment, and APOE genotype is the most significant factor associated with AD causation. This lack of a significant effect of APOE is analyzed with respect to the "Cholinergic Hypothesis" of AD, dating from 1976, through the recognition that cholinergic neurons are not the sole target of AD, but rather that AD attacks all levels of neuroplasticity in the brain, an idea originated by Ashford and Jarvik in 1985 and which still provides the clearest explanation for AD dementia. The "Amyloid Hypothesis" is dissected back to the alpha/beta pathway switching mechanism affecting the nexin-amyloid pre-protein (NAPP switch). The NAPP switch may be the critical neuroplasticity component of all learning involving synapse remodeling and subserve all learning mechanisms. The gamma-secretase cleavage is discussed, and its normal complementary products, beta-amyloid and the NAPP intracellular domain (NAICD), appear to be involved in natural synapse removal, but the link to AD dementia may involve the NAICD rather than beta-amyloid. Understanding neuroplasticity and the critical pathways to AD dementia are needed to determine therapies and preventive strategies for AD. In particular, the effect of APOE on AD predisposition needs to be established and a means found to adjust its effect to prevent AD.
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Abstract
Genetic characterization of individuals at risk of Alzheimer's disease (AD), i.e. people having amyloid deposits in the brain without symptoms, people suffering from subjective cognitive decline (SCD) or mild cognitive impairment (MCI), has spurred the interests of researchers. However, their pre-dementia genetic profile remains mostly unexplored. In this study, we reviewed the loci related to phenotypes of AD, MCI and SCD from literature and performed the first meta-analyses evaluating the role of apolipoprotein E (APOE) in the risk of conversion from a healthy status to MCI and SCD. For AD dementia risk, an increased number of loci have been identified; to date, 28 genes have been associated with Late Onset AD. In MCI syndrome, APOE is confirmed as a pheno-conversion factor leading from MCI to AD, and clusterin is a promising candidate. Additionally, our meta-analyses revealed APOE as genetic risk factor to convert from a healthy status to MCI [OR = 1.849 (1.587-2.153); P = 2.80 × 10-15] and to a lesser extent from healthy status to SCD [OR = 1.151 (1.015-1.304); P = 0.028]. Thus, we believe that genetic studies in longitudinal SCD and MCI series may provide new therapeutic targets and improve the existing knowledge of AD. This type of studies must be completed on healthy subjects to better understand the natural disease resistance to brain insults and neurodegeneration.
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17
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Albrecht MA, Masters CL, Ames D, Foster JK. Impact of Mild Head Injury on Neuropsychological Performance in Healthy Older Adults: Longitudinal Assessment in the AIBL Cohort. Front Aging Neurosci 2016; 8:105. [PMID: 27242516 PMCID: PMC4863889 DOI: 10.3389/fnagi.2016.00105] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 04/25/2016] [Indexed: 11/13/2022] Open
Abstract
Traumatic brain injury (TBI) is suggested to be a significant risk factor for dementia. However, little research has been conducted into long-term neuropsychological outcomes after head trauma. Participants from the Australian Imaging, Biomarkers and Lifestyle Study of Ageing (AIBL) who had recovered after sustaining a mild TBI involving loss of consciousness more than 5 years previously were compared with matched controls across a 3-year period. Bayesian nested-domain modeling was used to estimate the effect of TBI on neuropsychological performance. There was no evidence for a chronic effect of mild TBI on any neuropsychological domain compared to controls. Within the TBI group, there was some evidence suggesting that the age that the head trauma occurred and the duration of unconsciousness were modulators of episodic memory. However, these findings were not robust. Taken together, these findings indicate that adults who have sustained a TBI resulting in loss of consciousness, but who recover to a healthy level of cognitive functioning, do not experience frank deficits in cognitive ability.
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Affiliation(s)
- Matthew A Albrecht
- School of Public Health, Curtin UniversityPerth, WA, Australia; Curtin Health Innovation Research Institute - BiosciencesPerth, WA, Australia; Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of MedicineBaltimore, MD, USA
| | - Colin L Masters
- Mental Health Research Institute, The University of Melbourne Parkville, VIC, Australia
| | - David Ames
- Department of Psychiatry, Academic Unit for Psychiatry of Old Age, The University of Melbourne, St. Vincent's Aged Psychiatry Service, St. George's HospitalParkville, VIC, Australia; National Ageing Research Institute, Royal Melbourne HospitalParkville, VIC, Australia
| | - Jonathan K Foster
- School of Psychology and Speech Pathology, Curtin UniversityPerth, WA, Australia; Health Department of WA, Neurosciences UnitPerth, WA, Australia
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18
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Albrecht MA, Szoeke C, Maruff P, Savage G, Lautenschlager NT, Ellis KA, Taddei K, Martins R, Masters CL, Ames D, Foster JK. Longitudinal cognitive decline in the AIBL cohort: The role of APOE ε4 status. Neuropsychologia 2015; 75:411-9. [PMID: 26102189 DOI: 10.1016/j.neuropsychologia.2015.06.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 06/01/2015] [Accepted: 06/06/2015] [Indexed: 11/16/2022]
Abstract
The ε4 polymorphism of the APOE gene confers a substantially increased risk of developing Alzheimer's disease. However, the influence of the ε4 allele on age-related cognitive functioning is more contentious. Previously, we demonstrated relatively little evidence for a role of the ε4 allele on baseline cognitive performance in older adults in the Australian Imaging, Biomarkers and Lifestyle (AIBL) Study of Ageing (Foster et al., 2013). We here investigated whether the APOE ε4 allele influenced cognitive status over time when the AIBL cohort was studied longitudinally over a 3-year period. The AIBL neuropsychological test battery was administered at baseline, after 18 months and again after 36 months. Participants comprised 764 Healthy Controls and 131 Mild Cognitively Impaired individuals enrolled in the AIBL Study of Ageing. We compared individuals within each group with and without an ε4 allele. Healthy Controls with an ε4 allele manifested a modest acceleration in cognitive decline over 36 months on measures of verbal episodic memory. By contrast, Mild Cognitively Impaired individuals with an ε4 allele showed increased cognitive decline across a range of cognitive tasks, putatively reflecting early cognitive signs of Alzheimer's disease. Given the long prodromal period that has been noted in late onset Alzheimer's disease, we suggest that these findings are consistent with a prodromal account rather than a phenotypic account of ε4-related cognitive ageing.
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Affiliation(s)
- Matthew A Albrecht
- School of Psychology and Speech Pathology, Curtin University, Perth, Western Australia, Australia; School of Public Health, Curtin University, Perth, Western Australia, Australia; Maryland Psychiatric Research Center, School of Medicine, University of Maryland, MD, United States
| | - Cassandra Szoeke
- National Ageing Research Institute, Royal Melbourne Hospital, Victoria, Australia; CSIRO, Parkville, Victoria, Australia
| | - Paul Maruff
- Cogstate Ltd, Melbourne, Victoria, Australia
| | - Greg Savage
- Department of Psychology and ARC Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, Australia
| | - Nicola T Lautenschlager
- Academic Unit for Psychiatry of Old Age, Department of Psychiatry, The University of Melbourne, St. Vincent's Aged Psychiatry Service, St George's Hospital, Victoria, Australia; School of Psychiatry and Clinical Neurosciences and Western Australia Centre for Health and Ageing, University of Western Australia, Perth, Western Australia, Australia
| | - Kathryn A Ellis
- National Ageing Research Institute, Royal Melbourne Hospital, Victoria, Australia; Academic Unit for Psychiatry of Old Age, Department of Psychiatry, The University of Melbourne, St. Vincent's Aged Psychiatry Service, St George's Hospital, Victoria, Australia; Mental Health Research Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Kevin Taddei
- Centre of Excellence for Alzheimer's Disease Research and Care, School of Medical Sciences, Edith Cowan University, Joondalup, Western Australia, Australia; Sir James McCusker Alzheimer's Research Unit, Hollywood Private Hospital, Perth, Western Australia, Australia
| | - Ralph Martins
- Centre of Excellence for Alzheimer's Disease Research and Care, School of Medical Sciences, Edith Cowan University, Joondalup, Western Australia, Australia; Sir James McCusker Alzheimer's Research Unit, Hollywood Private Hospital, Perth, Western Australia, Australia
| | - Colin L Masters
- Mental Health Research Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - David Ames
- National Ageing Research Institute, Royal Melbourne Hospital, Victoria, Australia; Academic Unit for Psychiatry of Old Age, Department of Psychiatry, The University of Melbourne, St. Vincent's Aged Psychiatry Service, St George's Hospital, Victoria, Australia
| | - Jonathan K Foster
- School of Psychology and Speech Pathology, Curtin University, Perth, Western Australia, Australia; Neurosciences Unit, Health Department of WA, Perth, Western Australia, Australia.
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19
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The BDNF Val66Met polymorphism moderates the relationship between cognitive reserve and executive function. Transl Psychiatry 2015; 5:e590. [PMID: 26125153 PMCID: PMC4490292 DOI: 10.1038/tp.2015.82] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/25/2015] [Accepted: 05/21/2015] [Indexed: 01/01/2023] Open
Abstract
The concept of cognitive reserve (CR) has been proposed to account for observed discrepancies between pathology and its clinical manifestation due to underlying differences in brain structure and function. In 433 healthy older adults participating in the Tasmanian Healthy Brain Project, we investigated whether common polymorphic variations in apolipoprotein E (APOE) or brain-derived neurotrophic factor (BDNF) influenced the association between CR contributors and cognitive function in older adults. We show that BDNF Val66Met moderates the association between CR and executive function. CR accounted for 8.5% of the variance in executive function in BDNF Val homozygotes, but CR was a nonsignificant predictor in BDNF Met carriers. APOE polymorphisms were not linked to the influence of CR on cognitive function. This result implicates BDNF in having an important role in capacity for building or accessing CR.
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20
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Prieto del Val L, Cantero JL, Atienza M. APOE ɛ4 constrains engagement of encoding-related compensatory networks in amnestic mild cognitive impairment. Hippocampus 2015; 25:993-1007. [PMID: 25616215 DOI: 10.1002/hipo.22422] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2015] [Indexed: 12/27/2022]
Abstract
People with amnestic mild cognitive impairment (aMCI), compared to healthy older adults (HO), benefit less from semantic congruent cues during episodic encoding. The presence of the apolipoprotein E (APOE) ɛ4 makes this congruency benefit smaller, but the neural correlates of this deficit are unknown. Here, we estimated the source generators of EEG oscillatory activity associated with successful encoding of face-location associations preceded by semantically congruent and incongruent cues in HO (N = 26) and aMCI subjects (N = 34), 16 of which were ɛ4 carriers (ɛ4(+) ) and 18 ɛ4 noncarriers (ɛ4(-) ). Source estimation was performed in those spectrotemporal windows where the power of low-alpha, high-alpha, and beta oscillatory activity differed either between congruent and incongruent faces or between groups. Differences in high-alpha and beta-oscillatory dynamics indicated that aMCI ɛ4(+) are unable to activate lateral regions of the temporal lobe involved in associative memory and congruency benefit in HO. Interestingly, and regardless of APOE genotype, aMCI activated additional regions relative to HO, through alpha oscillations. However, only activation in a distributed fronto-temporo-parietal network in ɛ4 noncarriers was paralleled by enhanced memory. On the contrary, the redundant prefrontal activation shown by aMCI ɛ4(+) did not prevent performance from decreasing. These results indicate that the effect of aMCI-related degeneracy on functional networks is constrained by the presence of APOE ɛ4. Whereas individuals with aMCI ɛ4(-) activate attentional, perceptual and semantic compensatory networks, aMCI ɛ4(+) show reduced processing efficiency and capacity.
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Affiliation(s)
- Laura Prieto del Val
- Laboratory of Functional Neuroscience, Spanish Network of Excellence for Research on Neurodegenerative Diseases (CIBERNED), Pablo de Olavide University, Seville, Spain
| | - Jose L Cantero
- Laboratory of Functional Neuroscience, Spanish Network of Excellence for Research on Neurodegenerative Diseases (CIBERNED), Pablo de Olavide University, Seville, Spain
| | - Mercedes Atienza
- Laboratory of Functional Neuroscience, Spanish Network of Excellence for Research on Neurodegenerative Diseases (CIBERNED), Pablo de Olavide University, Seville, Spain
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21
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The backup is active in Alzheimer's disease: a hypothesis from problem theory. Med Hypotheses 2015; 84:241-8. [PMID: 25632793 DOI: 10.1016/j.mehy.2015.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 12/23/2014] [Accepted: 01/06/2015] [Indexed: 10/24/2022]
Abstract
Problem theory distinguishes between six general problems of everyday life, which people work through in turn during childhood, learning to switch between them. One of them requires the protection of a cut-out and an override. People who develop Alzheimer's disease (AD), and apolipoprotein allele epsilon 4 carriers, are preoccupied with this problem, or readily switch back to it. It is the freedom problem, of raising hope or confidence of freedom or power to control. Here people try to raise hope of success with any task on which attention happens to rest. This indiscriminateness means that there is no basis for giving up on a task, or for avoiding dangerous environments. Thus the cut-out is needed when someone becomes stuck on a mental task and the override is needed so as to help in avoiding danger. Activity relevant to the freedom problem is confined to the left hemisphere and the right hemisphere operates the cut-out and override. In providing these two forms of protection the right hemisphere can be said to act as a backup. Accordingly EEG, metabolism, and atrophy findings indicate that both cut-out and override are active in mild clinical impairment, especially among patients who later develop AD. The pattern of atrophy of AD matches what would be expected from disuse caused by an overactive cut-out followed by an overactive override. A parallel loss of testosterone might contribute to the weakening of resistance to infections leading to autoimmune effects.
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22
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Abstract
BACKGROUND dementia is a highly prevalent acquired cognitive disorder that interferes with activities of daily living, relationships and quality of life. Recognition and effective management strategies are necessary to provide comprehensive care for these patients and their families. High-quality clinical practice guidelines can improve the quality and consistency of care in all aspects of dementia diagnosis and management by clarifying interventions supported by sound evidence and by alerting clinicians to interventions without proven benefit. OBJECTIVE we aimed to offer a synthesis of existing practice recommendations for the diagnosis and management of dementia, based upon moderate-to-high quality dementia guidelines. METHODS we performed a systematic search in EMBASE and MEDLINE as well as the grey literature for guidelines produced between 2008 and 2013. RESULTS thirty-nine retrieved practice guidelines were included for quality appraisal by the Appraisal of Guidelines Research and Evaluation II (AGREE-II) tool, performed by two independent reviewers. From the 12 moderate-to-high quality guidelines included, specific practice recommendations for the diagnosis and/or management of any aspect of dementia were extracted for comparison based upon the level of evidence and strength of recommendation. CONCLUSION there was a general agreement between guidelines for many practice recommendations. However, direct comparisons between guidelines were challenging due to variations in grading schemes.
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Affiliation(s)
- Jennifer Ngo
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada
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23
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Ward DD, Summers MJ, Saunders NL, Janssen P, Stuart KE, Vickers JC. APOE and BDNF Val66Met polymorphisms combine to influence episodic memory function in older adults. Behav Brain Res 2014; 271:309-15. [PMID: 24946073 DOI: 10.1016/j.bbr.2014.06.022] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Revised: 06/09/2014] [Accepted: 06/10/2014] [Indexed: 01/09/2023]
Abstract
Genetic polymorphisms of apolipoprotein E (APOE) and brain-derived neurotrophic factor (BDNF) have shown inconsistent associations with healthy adult cognitive functions. Recent investigations have suggested that APOE polymorphisms do not contribute to non-pathological cognitive function and that any effect is likely due to prodromal Alzheimer's disease (AD). Similarly, although BDNF Val66Met polymorphisms affect hippocampal morphology and function, associations with learning and/or memory have not always been found. This study sought to determine whether APOE and BDNF polymorphisms were associated, either independently or in combination, with adult cognition. Comprehensive neuropsychological assessments were conducted on 433 older adults, aged 50-79 years (M=62.16, SD=6.81), which yielded measures of episodic memory, working memory, executive function, and language processing. Participants underwent comprehensive neuropsychological assessment to ensure that only cognitively intact individuals comprised the sample. APOE and BDNF polymorphic data were used as predictors in general linear models that assessed composite cognitive domain variables, while covarying for education and age. Although no main effects for APOE or BDNF were found, the analysis identified a significant APOE×BDNF interaction that predicted episodic memory performance (p=.02, η(2)=.02). Post-hoc analyses demonstrated that in BDNF Val homozygotes, the cognitive consequences of APOE polymorphisms were minimal. However, in BDNF Met carriers, the hypothesized beneficial/detrimental effects of APOE polymorphisms were found. Our data show that concurrent consideration of both APOE and BDNF polymorphisms are required in order to witness a cognitive effect in healthy older adults.
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Affiliation(s)
- David D Ward
- School of Medicine, University of Tasmania, Australia; Wicking Dementia Research & Education Centre, University of Tasmania, Australia
| | - Mathew J Summers
- School of Medicine, University of Tasmania, Australia; Wicking Dementia Research & Education Centre, University of Tasmania, Australia.
| | - Nichole L Saunders
- Wicking Dementia Research & Education Centre, University of Tasmania, Australia
| | - Pierce Janssen
- Wicking Dementia Research & Education Centre, University of Tasmania, Australia
| | - Kimberley E Stuart
- School of Medicine, University of Tasmania, Australia; Wicking Dementia Research & Education Centre, University of Tasmania, Australia
| | - James C Vickers
- School of Medicine, University of Tasmania, Australia; Wicking Dementia Research & Education Centre, University of Tasmania, Australia
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24
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Toledo JB, Da X, Weiner MW, Wolk DA, Xie SX, Arnold SE, Davatzikos C, Shaw LM, Trojanowski JQ. CSF Apo-E levels associate with cognitive decline and MRI changes. Acta Neuropathol 2014; 127:621-32. [PMID: 24385135 DOI: 10.1007/s00401-013-1236-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 12/16/2013] [Accepted: 12/17/2013] [Indexed: 12/31/2022]
Abstract
Apolipoprotein E (APOE) ε4 allele is the most important genetic risk factor for Alzheimer's disease (AD) and it is thought to do so by modulating levels of its product, apolipoprotein E (Apo-E), and regulating amyloid-β (Aβ) clearance. However, information on clinical and biomarker correlates of Apo-E proteins is scarce. We examined the relationship of cerebrospinal fluid (CSF) and plasma Apo-E protein levels, and APOE genotype to cognition and AD biomarker changes in 311 AD neuroimaging initiative subjects with CSF Apo-E measurements and 565 subjects with plasma Apo-E measurements. At baseline, higher CSF Apo-E levels were associated with higher total and phosphorylated CSF tau levels. CSF Apo-E levels were associated with longitudinal cognitive decline, MCI conversion to dementia, and gray matter atrophy rate in total tau/Aβ1-42 ratio and APOE genotype-adjusted analyses. In analyses stratified by APOE genotype, our results were only significant in the group without the ε4 allele. Baseline CSF Apo-E levels did not predict longitudinal CSF Aβ or tau changes. Plasma Apo-E levels show a mild correlation with CSF Apo-E levels, but were not associated with longitudinal cognitive and MRI changes. Based on our analyses, we speculate that increased CSF Apo-E2 or -E3 levels might represent a protective response to injury in AD and may have neuroprotective effects by decreasing neuronal damage independent of tau and amyloid deposition in addition to its effects on amyloid clearance.
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Affiliation(s)
- Jon B Toledo
- Department of Pathology and Laboratory Medicine, Institute on Aging, Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, HUP, Maloney 3rd, 36th and Spruce Streets, Philadelphia, PA, 19104-4283, USA
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25
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Da X, Toledo JB, Zee J, Wolk DA, Xie SX, Ou Y, Shacklett A, Parmpi P, Shaw L, Trojanowski JQ, Davatzikos C. Integration and relative value of biomarkers for prediction of MCI to AD progression: spatial patterns of brain atrophy, cognitive scores, APOE genotype and CSF biomarkers. Neuroimage Clin 2013; 4:164-73. [PMID: 24371799 PMCID: PMC3871290 DOI: 10.1016/j.nicl.2013.11.010] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 11/20/2013] [Accepted: 11/22/2013] [Indexed: 01/18/2023]
Abstract
This study evaluates the individual, as well as relative and joint value of indices obtained from magnetic resonance imaging (MRI) patterns of brain atrophy (quantified by the SPARE-AD index), cerebrospinal fluid (CSF) biomarkers, APOE genotype, and cognitive performance (ADAS-Cog) in progression from mild cognitive impairment (MCI) to Alzheimer's disease (AD) within a variable follow-up period up to 6 years, using data from the Alzheimer's Disease Neuroimaging Initiative-1 (ADNI-1). SPARE-AD was first established as a highly sensitive and specific MRI-marker of AD vs. cognitively normal (CN) subjects (AUC = 0.98). Baseline predictive values of all aforementioned indices were then compared using survival analysis on 381 MCI subjects. SPARE-AD and ADAS-Cog were found to have similar predictive value, and their combination was significantly better than their individual performance. APOE genotype did not significantly improve prediction, although the combination of SPARE-AD, ADAS-Cog and APOE ε4 provided the highest hazard ratio estimates of 17.8 (last vs. first quartile). In a subset of 192 MCI patients who also had CSF biomarkers, the addition of Aβ1-42, t-tau, and p-tau181p to the previous model did not improve predictive value significantly over SPARE-AD and ADAS-Cog combined. Importantly, in amyloid-negative patients with MCI, SPARE-AD had high predictive power of clinical progression. Our findings suggest that SPARE-AD and ADAS-Cog in combination offer the highest predictive power of conversion from MCI to AD, which is improved, albeit not significantly, by APOE genotype. The finding that SPARE-AD in amyloid-negative MCI patients was predictive of clinical progression is not expected under the amyloid hypothesis and merits further investigation.
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Affiliation(s)
- Xiao Da
- Section of Biomedical Image Analysis, Department of Radiology, and Center for Biomedical Image Computing and Analytics, University of Pennsylvania, Philadelphia, PA, USA
| | - Jon B. Toledo
- Department of Pathology & Laboratory Medicine, Institute on Aging, Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Jarcy Zee
- Department of Biostatistics and Epidemiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - David A. Wolk
- Section of Biomedical Image Analysis, Department of Radiology, and Center for Biomedical Image Computing and Analytics, University of Pennsylvania, Philadelphia, PA, USA
- Memory Center, University of Pennsylvania, Philadelphia, PA, USA
| | - Sharon X. Xie
- Department of Biostatistics and Epidemiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Yangming Ou
- Section of Biomedical Image Analysis, Department of Radiology, and Center for Biomedical Image Computing and Analytics, University of Pennsylvania, Philadelphia, PA, USA
| | - Amanda Shacklett
- Section of Biomedical Image Analysis, Department of Radiology, and Center for Biomedical Image Computing and Analytics, University of Pennsylvania, Philadelphia, PA, USA
| | - Paraskevi Parmpi
- Section of Biomedical Image Analysis, Department of Radiology, and Center for Biomedical Image Computing and Analytics, University of Pennsylvania, Philadelphia, PA, USA
| | - Leslie Shaw
- Department of Pathology & Laboratory Medicine, Institute on Aging, Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - John Q. Trojanowski
- Department of Pathology & Laboratory Medicine, Institute on Aging, Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Christos Davatzikos
- Section of Biomedical Image Analysis, Department of Radiology, and Center for Biomedical Image Computing and Analytics, University of Pennsylvania, Philadelphia, PA, USA
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