Shayne S-H Lin, Alicia Milam, Andrew M Kiselica, Stephen L Aita, Mubarick Saeed, Troy Webber, Steven Paul Woods, Nicholas C Borgogna, Keenan A Walker, Vidyulata Kamath, Kristina Visscher, Charles F Murchison, David S Geldmacher, Erik D Roberson, Benjamin D Hill, Victor A Del Bene
Increased AD biomarker burden was associated with increased IICV among cognitively impaired individuals (correlational strength ranging from 0.149 to 0.460) but not among the cognitively intact group.
INTRODUCTION: This study aimed to assess intra-individual cognitive variability (IICV) in relation to Alzheimer's disease (AD) biomarkers.
METHODS: The National Alzheimer's Coordinating Center sample (n = 879), aged 50+ with a complete neuropsychological evaluation and AD biomarker data available (64% cognitively intact; 36% cognitively impaired). Moderated regression models using AD biomarkers, neurocognitive status, and interaction effects predicted IICV. AD biomarkers included cerebrospinal fluid (CSF) measures of Aβ1-42, phosphorylated tau 181 (p-Tau181), total tau (t-Tau), and amyloid positron emission tomography.
RESULTS: Increased AD biomarker burden was associated with increased IICV among cognitively impaired individuals (correlational strength ranging from 0.149 to 0.460) but not among the cognitively intact group.
DISCUSSION: Increases in measures of amyloid, soluble tau, and neurodegeneration are associated with increased IICV among cognitively impaired older adults. The findings underscore the potential of IICV as a sensitive outcome measure. Future studies should replicate findings longitudinally and in more diverse samples.