Is ApoE ε4 Associated with Cognitive Functioning in African Americans Diagnosed with Alzheimer Disease? An Exploratory Study

Objective: The effect of the apolipoprotein epsilon 4 allele (ApoE epsilon 4) on cognitive performance in patients with probable Alzheimer disease (AD) has been studied in primarily Caucasian samples. The aim of this exploratory study was to examine whether the presence of ApoE epsilon 4 is associated with cognitive performance in African American AD patients. Methods: A cross-sectional, retrospective design was used to address the study objective. Data were extracted from the records of 65 African American patients who participated in the National Institutes of Health-National Institute on Aging (NIH-NIA) Emory University Alzheimer Disease Center Registry. Inclusion criteria were a clinical diagnosis of probable AD, cognitive testing using the Mattis Dementia Rating Scale and the Consortium to Establish a Registry for Alzheimer Disease (CERAD) neuropsychological battery, and ApoE genotyping. Results: Seventy percent of the patients were ApoE epsilon 4 positive. Multiple regression analyses indicated that ApoE epsilon 4 was significantly associated with poorer design copying (CERAD Constructional Praxis subtest), but other significant relationships were not observed between Positive epsilon 4 status and cognitive performance. Conclusions: These preliminary findings suggest that the ApoE epsilon 4 allele is not strongly associated with a particular pattern of cognitive functioning in African Americans once they are diagnosed with AD. However, these findings require replication in a large prospectively recruited and population-based sample of African American AD patients before firm conclusions can be reached.