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.