APOE effect on Alzheimer's disease biomarkers in older adults with significant memory concern.

ABSTRACT: INTRODUCTION:This study assessed apolipoprotein E (APOE) ?4 carrier status effects on Alzheimer's disease imaging and cerebrospinal fluid (CSF) biomarkers in cognitively normal older adults with significant memory concerns (SMC). METHODS:Cognitively normal, SMC, and early mild cognitive impairment participants from Alzheimer's Disease Neuroimaging Initiative were divided by APOE ?4 carrier status. Diagnostic and APOE effects were evaluated with emphasis on SMC. Additional analyses in SMC evaluated the effect of the interaction between APOE and [(18)F]Florbetapir amyloid positivity on CSF biomarkers. RESULTS:SMC ?4+ showed greater amyloid deposition than SMC ?4-, but no hypometabolism or medial temporal lobe (MTL) atrophy. SMC ?4+ showed lower amyloid beta 1-42 and higher tau/p-tau than ?4-, which was most abnormal in APOE ?4+ and cerebral amyloid positive SMC. DISCUSSION:SMC APOE ?4+ show abnormal changes in amyloid and tau biomarkers, but no hypometabolism or MTL neurodegeneration, reflecting the at-risk nature of the SMC group and the importance of APOE in mediating this risk.

SUBMITTER: Risacher SL 

PROVIDER: S-EPMC4637003 | biostudies-literature | 2015 Dec

REPOSITORIES: biostudies-literature