The Social Environment, APOE-e4, and Dementia: The Social Environment as a Moderating Factor Among Individuals Genetically Predisposed to Develop Dementia

Many studies have shown a relationship between the APOE-e4 allele and dementia, as well as a relationship between the social environment and dementia. However, relatively little investigation into the potential moderating effect of the social environment on the relationship between the APOE-e4 allele and cognitive well-being has been reported. Further, studies that did examine these relationships typically have employed clinical populations, along with regional and non-U.S. samples. This study contributed to the research literature, in part, by using the first U.S. nationally representative sample of older adults that included clinical diagnosis of cognition and dementia (Aging, Demographics, and Memory Study from the Health and Retirement Study). A combination of descriptive analyses and multinomial logistic regression models were used to investigate these relationships. Overall, the prevalence of unique APOE genotypic combinations was similar in the ADAMS sample as compared to samples taken from other developed nations. Descriptive results also showed that respondents with and without the APOE-e4 allele were only found to differ on race and ethnic status. Regression results indicated that the APOE-e4 allele was associated with a higher risk of cognitive difficulty, and that being more socially engaged and more socially connected to others was associated with a lower risk of cognitive difficulty and dementia. All aspects of the social environment, except social engagement, were found to moderate the relationship of the APOE-e4 allele to cognitive diagnosis. The relationship of the social environment to dementia, as well as its moderating influence, indicated a need for further investigation into the unique contributions of the social environment for cognitive well-being in later life