LAUSR

Apolipoprotein (ApoE)-e4 is well established as a genetic risk factor for Alzheimer’s disease (AD) as well as a predictor for the rate of cognitive decline in AD. Among older adults without dementia, some research has found that e4 carriers have worse episodic memory compared to e4 non-carriers, whereas others have not found this association. The present study examined differences in cognitive performance between ApoE-e4 carriers and non-carriers. 91 non-demented individuals (age range: 55–87) were genotyped for ApoE (41 e4 carriers, 49 e4 non-carriers) and completed neuropsychological testing as a part of a longitudinal study at the Center for Neurodegeneration and Translational Neuroscience. Cognitively normal (CN) and mild cognitive impairment (MCI) participants were included (41 CN, 49 MCI). Group differences between e4 carriers and non-carriers were compared across cognitive measures after controlling for age, gender, and education. In the total sample, e4 carriers performed significantly worse across measures of verbal and nonverbal memory, as well as on the Boston Naming Test and Symbol Digit Modalities Test (all p’s < .05). No significant group differences were observed across visuospatial or executive function tasks. When diagnostic subgroups were examined, e4 carriers had worse verbal memory than non-carriers in the MCI group, but there was no effect of e4 status on cognition among CN participants. These findings support that ApoE-e4 positivity is associated with worse cognitive performance, especially on tasks related to medial temporal lobe function, among non-demented older adults. In MCI, worse verbal memory in e4 carriers likely reflects increased progression of underlying AD pathology.