Vemuri P, Wiste HJ, Knopman DS, Lowe V, Weiner M, Petersen RC, Jack Jr CR.
Effect of APOE on rate of change of PIB retention across the cognitive continuum.
Human Amyloid Imaging 2011 Meeting Abstracts. 2011 Jan 15;
Objective: To study the effect of APOE ε4 status on the annual change in brain As amyloid load as measured by
PIB-PET in cognitively normal (CN), amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD).
Methods: We included all 147 subjects (67 CN, 59 aMCI, 21 AD) from the Alzheimer's disease Neuroimaging
Initiative and the Mayo Clinic Study of Aging with a baseline PIB scan and at least one follow-up PIB scan. We
used linear mixed-effects models with a random subject-specific intercept and slope to estimate the longitudinal
change in mean PIB ratio. We fit two models, the first with years since baseline PIB scan, clinical diagnosis, and
their interaction. The second model additionally included APOE genotype and all interactions.
Results: We found that the annual change in PIB ratio significantly increased in CN and MCI (p Discussion: In this study we found evidence that the annual change in PIB ratio does not differ by clinical group
but may differ by APOE ε4 status especially in aMCIs. Additionally, APOE ε4 aMCIs tended to be younger that
non-carriers aMCIs at the same level of cognitive performance suggesting that APOE ε4 status not only lowers the
onset of AD but also increases the rate of disease progression in aMCIs.