Alzheimer's Disease and Related Dementias (ADRD) prevalence in American Samoa

ABSTRACT Alzheimer’s disease and related dementias (ADRD) affects over 5.7 million Americans and over 35 million people worldwide. Indigenous populations including American Indians, Alaskan Natives, Native Hawaiians and Pacific Islanders are increasingly concerned about ADRD and its prodromal state, mild cognitive impairment (MCI), as

these conditions increasingly exert a major impact on their communities. Although these populations are culturally diverse and geographically dispersed, they share in common a high prevalence of well-established ADRD risk factors. Life expectancies in indigenous populations have increased over the past 5 decades resulting in a 3-fold

increase in people over the age of 65. These changing demographics have made ADRD potentially more visible to communities, however the healthcare systems that serve these populations are unprepared for the patient, caregiver, social, and economic burdens associated with ADRD. Unfortunately, these same communities have low

health literacy and limited research readiness needed to address the growing problem of ADRD. Situated in the heart of the South Pacific, American Samoa is the only U.S. territory located south of the equator. The 2020 U.S. Census recorded 49,710 residents, with 11,025 (4.1%) of the population over age 50. Currently, there are no known

studies that document ADRD prevalence within the Samoan population. Our overarching OBJECTIVE is to build upon our prior work, test novel approaches to increase ADRD literacy and research readiness, improve detection of ADRD, and build upon a nascent research infrastructure to conduct important phenotypic and genotypic

characterization of ADRD in American Samoa. Our SPECIFIC AIMS are: (1) Test ADRD knowledge, health literacy, research readiness and determine ADRD resilience and vulnerability factors, and cognitive status in a probability sample of 981 Samoans age 50+ using culturally adapted instruments in our probability sample, (2)

Conduct Gold Standard evaluations in our probability sample using the Uniform Data Set (UDSv3.0) from the NIA Alzheimer’s Disease Research Center program to determine a population-based prevalence of MCI and ADRD for harmonization, data sharing, and comparison to other groups, and (3) Cross-validate Gold Standard dementia

evaluations with genetic (i.e., ApoE) and plasma Amyloid-Tau-Neuronal Injury/Neurodegeneration (ATN) framework (e.g., A 40, A42, p-tau, NFL, GFAP) biomarkers in our probability sample and compare to information available for other racial/ethnic groups. The dearth of relevant clinical and programmatic knowledge hamstrings efforts by clinicians, scientists,

policymakers, and communities to reduce ADRD disparities in American Samoa. Our short-term goal is to determine ADRD prevalence and study resilience and vulnerability factors contributing to ADRD in American Samoa and share resources with other investigators. Our long-term goal is foster future research efforts to

increase accurate and early diagnosis, expand access to care, and improve health outcomes in American Samoa.