Aging and Brain Health in American Indians: Understanding Cognitive Variability, Diabetes, and Dementia Risk
Overview
American Indians are at a higher risk for Alzheimer’s disease and Alzheimer’s disease–related dementias (AD/ADRD) than the general population, yet dementia onset and progression in this group remain understudied. American Indians also face a disproportionate burden of type 2 diabetes and vascular brain injury, which are known to accelerate Alzheimer’s-related brain changes and contribute to mixed forms of dementia.
This NIH-funded study uses existing data from two landmark longitudinal studies – the Strong Heart Study (SHS) and the Cerebrovascular Disease and its Consequences in American Indians (CDCAI) – to better understand how diabetes and brain health interact over time in aging American Indians.
What We’re Studying
Our research focuses on within person cognitive variability- a measure of how much a person’s performance varies across different cognitive tests at a single time point. Growing evidence suggests that higher variability may be an early, low-cost, noninvasive marker of neurodegeneration and dementia risk.
We are exploring how IICV relates to:
- Brain imaging markers of Alzheimer’s disease and related conditions, including changes in hippocampal, entorhinal, and whole-brain atrophy.
- Vascular brain injury, including progression of white matter hyperintensities (WMH).
- Cognitive decline and dementia diagnosis over time.
We will also examine how diabetes influences these relationships, given its known impact on both vascular and neurodegenerative pathways. This rich, long-term dataset allows us to examine both the early and late-life impacts of diabetes on brain structure, cognition, and dementia risk.
Why This Study Matters
- Addresses a critical gap in Alzheimer’s research by focusing on an underserved and underrepresented population.
- Identifies new, accessible biomarkers for early detection of dementia risk.
- Improves understanding of how diabetes contributes to brain aging and dementia in American Indians.
- Provides essential groundwork for future research and prevention efforts focused on culturally informed, equitable brain health strategies.
By validating IICV as a potential early marker of Alzheimer’s disease and related dementias, this study aims to:
- Enable earlier, noninvasive identification of individuals at risk.
- Inform targeted prevention strategies that address both metabolic and neurological health.
- Serve as preliminary data for a future large-scale study dedicated to understanding cognitive aging and resilience in aging American Indians and other minority populations.
If you are interested in learning more about this project, please contact the Principal Investigator, Dr. Luciana Mascarenhas Fonseca, at luciana.fonseca@rutgers.edu