Alzheimer's Disease and Related Dementia in Indigenous Populations: A Systematic Review of Risk Factors

Background: There remains a lack of information and understanding of the prevalence and incidence of Alzheimer's disease and related dementia in Indigenous populations. Little evidence available suggests that Indigenous peoples may have disproportionately high rates of Alzheimer's disease and related dementia (ADRD). Objective: Given this information, this study systematically explores what risk factors may be associated with ADRD in Indigenous populations. Methods: A search of all published literature was conducted in October 2016, March 2018, and July 2019 using Medline, Embase, and PsychINFO. Subject headings explored were inclusive of all terms related to Indigenous persons, dementia, and risk. All relevant words, phrases, and combinations were used. To be included in this systematic review, articles had to display an association of a risk factor and ADRD. Only studies that reported a quantifiable measure of risk, involved human subjects, and were published in English were included. Results: Of 237 articles originally identified through database searches, 45 were duplicates and 179 did not meet a priori inclusion criteria, resulting in 13 studies eligible for inclusion in this systematic review. Conclusion: The large number of potentially modifiable risk factors reported relative to non-modifiable risk factors illustrates the importance of socioeconomic context in the pathogenesis of ADRD in Indigenous populations. The tendency to prioritize genetic over social explanations when encountering disproportionately high disease rates in Indigenous populations can distract from modifiable proximal, intermediate, and distal determinants of health.