Life-course acculturation trajectories and dementia in a multi-ethnic cohort of older adults: The MESA Acculturation and dementia Study

PROJECT SUMMARY/ABSTRACT
There has been increasing emphasis on understanding the social-contextual factors that contribute to risk of
Alzheimer’s Disease and related dementias (ADRD). Although immigrants represent a growing, and aging, share
of the US population, the state of the science on dementia among immigrants is limited. The few studies
published show immigrant status and lower levels of acculturation (a process of adaptation to US social and
behavioral norms) to be associated with a higher prevalence of dementia and more cognitive decline. These
findings are intriguing as they appear to be at odds with the much larger body of evidence that shows immigrant
status and less acculturation to be associated with better health outcomes for obesity, hypertension, diabetes,
and cardiovascular disease (CVD), clinical precursors of dementia. However the measurement of acculturation
has been limited by the use of simplistic, cross-sectional, and individual-level proxy measures to characterize
what is an otherwise complicated process that evolves over the life-course, and is influenced by both individual-
level and contextual factors. The proposed study addresses this challenge by adapting a segmented assimilation
framework, and applying a life-course approach, to consider how immigrants' trajectories of integration can differ,
and are influenced by the interplay of multi-level factors to influence biological aging. We propose to leverage
comprehensive, longitudinal data from the Multi-Ethnic Study of Atherosclerosis (MESA), and its associated
ancillary studies, MESA Neighborhood and MESA MIND, to identify unique life-course acculturation patterns,
based on individual- and neighborhood-level longitudinal data, and evaluate associations with cognition,
AD/ADRD biomarkers, and dementia in a population-based sample of diverse, older adults. We hypothesize that
individuals with acculturation trajectories characterized by factors such as improvements in socioeconomic status
over time, older age at migration, increasing English proficiency, and residence in supportive neighborhoods
(e.g. high walkability, high social cohesion), which remain stable or improve over time, will experience less
cognitive decline and dementia. With over 20 years of follow-up and extensive cognitive measures (including
fMRI), MESA is the ideal cohort to address major gaps in research on immigrants and dementia. We will attain
our main objective by characterizing longitudinal, life-course acculturation trajectories (Aim 1); and examining
associations of life-course acculturation trajectories with cognition and clinically-relevant ADRD outcomes (Aim
2). The proposed work brings together two large and powerful datasets (MESA Neighborhood and MESA MIND),
and lays the foundation for future projects to investigate the social, behavioral, and clinical mechanisms
underlying the patterns we observe. Through this, our goal is to contextualize the experience of immigrants to
promote supportive policies and environments for stemming cognitive decline and dementia.

Grant Number: 1R21AG089014-01
NIH Institute/Center: NIH
Principal Investigator: Sandra Albrecht