title: Variables associated with hippocampal atrophy rate in normal aging and mild cognitive impairment.
abstract: The goal of this study was to identify factors contributing to hippocampal atrophy rate (HAR) in clinically normal older adults (NC) and participants with mild cognitive impairment (MCI). Longitudinal HAR was measured on T1-weighted magnetic resonance imaging, and the contribution of age, gender, apolipoprotein E (ApoE) ε4 status, intracranial volume, white matter lesions, and β-amyloid (Aβ) levels to HAR was determined using linear regression. Age-related effects of HAR were compared in Aβ positive (Aβ+) and Aβ negative (Aβ-) participants. Age and Aβ levels had independent effects on HAR in NC, whereas gender, ApoE ε4 status, and Aβ levels were associated with HAR in MCI. In multivariable models, Aβ levels were associated with HAR in NC; ApoE ε4 and Aβ levels were associated with HAR in MCI. In MCI, age was a stronger predictor of HAR in Aβ- versus Aβ+ participants. HAR was higher in Aβ+ participants, but most of the HAR was because of factors other than Aβ status. Age-related effects on HAR did not differ between NC versus MCI participants with the same Aβ status. Therefore, we conclude that even when accounting for other covariates, Aβ status, and not age, is a significant predictor of HAR; and that most of the HAR is not accounted for by Aβ status in either NC or MCI.
authors.affiliation: Department of Veterans Affairs Medical Center, Center for Imaging of Neurodegenerative Diseases, San Francisco, CA, USA. Electronic address: rachel.nosheny@ucsf.edu.
authors.forename: Rachel L
authors.initials: RL
authors.lastname: Nosheny
authors.affiliation: Department of Veterans Affairs Medical Center, Center for Imaging of Neurodegenerative Diseases, San Francisco, CA, USA.
authors.forename: Philip S
authors.initials: PS
authors.lastname: Insel
authors.affiliation: Department of Veterans Affairs Medical Center, Center for Imaging of Neurodegenerative Diseases, San Francisco, CA, USA.
authors.forename: Diana
authors.initials: D
authors.lastname: Truran
authors.affiliation: Department of Veterans Affairs Medical Center, Center for Imaging of Neurodegenerative Diseases, San Francisco, CA, USA.
authors.forename: Norbert
authors.initials: N
authors.lastname: Schuff
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Clifford R
authors.initials: CR
authors.lastname: Jack
authors.affiliation: Department of Neurosciences, University of California San Diego School of Medicine, La Jolla, CA, USA.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Aisen
authors.affiliation: Department of Pathology & Laboratory Medicine, Institute on Aging, Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Leslie M
authors.initials: LM
authors.lastname: Shaw
authors.affiliation: Department of Pathology & Laboratory Medicine, Institute on Aging, Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: John Q
authors.initials: JQ
authors.lastname: Trojanowski
authors.affiliation: Department of Veterans Affairs Medical Center, Center for Imaging of Neurodegenerative Diseases, San Francisco, CA, USA; Department of Radiology and Biomedical Imaging, University of California, CA, USA.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Weiner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D016229:Amyloid beta-Peptides / Q000378:metabolism; D053327:Apolipoprotein E4; D001284:Atrophy; D060825:Cognitive Dysfunction / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D016014:Linear Models; D008297:Male; D009929:Organ Size
chemical_list: D016229:Amyloid beta-Peptides; D053327:Apolipoprotein E4
keywords: Alzheimer's disease; Hippocampal atrophy rate; Longitudinal study; Normal aging; β-amyloid