Authors: Michelle E. Farrell, Kathryn V. Papp, Heidi I.L. Jacobs, Rachel F. Buckley, Michael J. Properzi, Aaron P. Schultz, Bernard Hanseeuw, Dorene M. Rentz, Keith A. Johnson, Reisa A. Sperling
Published: 2020-12-07
DOI: 10.1002/alz.046075
Source: Full article
AbstractBackgroundWe sought to assess the preclinical contributions of longitudinal Aβ and tau accumulation at different baseline Aβ levels to decline across multiple cognitive domains.Method124 clinically normal older adults from the Harvard Aging Brain Study with longitudinal Aβ (PIB), tau (FTP) and cognition (PACC) were included (median follow‐up=8.0±1.0 years). The following linear mixed models examined neocortical PIB and inferior temporal (IT) FTP change effects on PACC and its component tasks and included age, sex, APOE and education as covariates: 1) Time*PIB level t0*PIB change t0‐3 on cognition t0‐8, with post‐hoc regional analyses. 2) Time*PIB level t3*FTP change t3‐8 on cognition t3‐8, because FTP was introduced at t3. Mediation analyses assessed whether the effect of PIB change t0‐3 on subsequent cognitive decline t3‐8 was mediated by IT‐FTP at t3.