Publication Type	Academic Article
Authors	Osorio R, Pirraglia E, Gumb T, Mantua J, Ayappa I, Williams S, Mosconi L, Glodzik L, de Leon M
Journal	Neurodegener Dis
Volume	13
Issue	2-3
Pagination	163-5
Date Published	10/02/2013
ISSN	1660-2862
Keywords	Alzheimer Disease, Biomarkers
Abstract	BACKGROUND: The pathophysiological process of Alzheimer's disease (AD) begins many years before the emergence of clinical symptoms (preclinical AD). A hypothetical biomarker progression in the pathogenesis of AD has been suggested, beginning with the deposition of amyloid-β (Aβ) and followed by increases in neurofibrillary tangles, synaptic loss, hippocampal atrophy, and lastly, cognitive impairment. OBJECTIVE: We explored the effect of several risk factors for AD on the pattern of AD biomarker expression in normal subjects. METHODS: AD biomarker evidence was examined at baseline in 96 cognitively normal elderly subjects with none or at least one of the following: ApoE4+ allele, a maternal history of AD (mFHx), sleep-disordered breathing (SDB), and longitudinal evidence of decline to mild cognitive impairment or AD (decliners) at follow-up. RESULTS: Decliners and ApoE4+ subjects presented with expected reduced cerebrospinal fluid Aβ42, elevated P-tau and T-tau. In addition, decliners had fluorodeoxyglucose positron emission tomography hypometabolism in the medial temporal lobe. Individuals with mFHx demonstrated no Aβ42 effect, but had elevations in P-tau and T-tau. SDB was found to be associated with elevated Aβ42, P-tau and T-tau, as well as with reduced medial temporal lobe glucose metabolic rates. CONCLUSION: Our results indicate a heterogeneous biomarker expression, suggesting diversity of AD pathways in at-risk presymptomatic subjects.
DOI	10.1159/000355063
PubMed ID	24107601
PubMed Central ID	PMC4022141