Objective: The relationship between the epsilon 4 allele of the apolipoprotein E gene (APOE-epsilon4) located on chromosome 19 and Alzheimer's disease is well documented among Caucasian populations. However, the findings of research addressing the link between APOE polymorphism and neurocognitive functioning in populations of African origin from around the world have been equivocal. Therefore, the current study explored the relation of APOE-epsilon4 with cognitive impairment in a sample of community-dwelling English-speaking elderly blacks.
Methods: All participants (N = 57) were recruited consecutively from a community memory-screening program at a University affiliated Memory Disorders Clinic and evaluated using standardized assessment procedures. Cognitive impairment was classified according to an age and education adjusted Mini-Mental State Exam score of less than 24 as well as poorer functioning on a measure of delayed verbal memory.
Results: Increased risk for global cognitive dysfunction (OR = 9.5, 95 percent CI = 2.3-55.3, p = .004) and poorer verbal recall performance (beta = -.36, p = .006) were linked with the APOE epsilon4 allele after controlling for the potentially confounding effects of age, education, and gender.
Conclusions: This investigation supports the role of APOE polymorphism in determining neurocognitive impairment among black elders residing in the community.