Ongoing Pilot Studies
The following information below represents the Ongoing Research our current RCMAR Scientists are conducting for the Alzheimer's Disease Center at this time. As new RCMAR Scientists are selected, updates will be made to show a brief overview of the different proposals each individual is currently working on.
Cohort 1 (2018-2019)
Designing an environmental enrichment intervention to improve quality of life of caretakers of persons with dementia
Annelyn Torres-Reveron, PhDEnvironmental interventions to improve quality of life and increase resilience in response to stressful life events are highly desirable due to the high benefit to risk ratio. Caretakers/caregivers of people with dementia experience elevated levels of stress and low quality of life caused by physical, emotional and financial burdens. Most caretakers are women related to the affected individual, who in many cases lack formal training to cope with the increased physical and psychological demands.
Our long term goal is to provide effective non-pharmacological interventions to improve psychological resilience to caretaking burden. The main goal of this project is to design and refine a multi-modal intervention using environmental enrichment for caretakers of individuals with dementia from the lower Rio Grande Valley, TX.
We hypothesize that a multi-modal intervention based on the Obesity-Related Behavioral Intervention Trials (ORBIT) model for the development of behavioral treatments for chronic diseases, and designed to translate the environment enrichment model to human application can be effectively adapted and refined to meet the needs of Hispanic caretakers.
Role of AVPR1A gene in psychosocial stress, cognitive performance, and health outcomes in older Hispanics/Latinos
Mario Gil, PhDAlzheimer's Disease (AD), a leading cause of dementia, affects millions of people across the globe; and it is estimated that 40 million people have dementia worldwide, a figure that is expected to double every 20 years, until the year 2050. Disruption of cognitive function that is associated with AD and related dementias (ADRD) has a devastating effect on an individual's daily life activities. The burden of ADRD care and management is particularly problematic for underserved minority groups, such as Hispanic/Latinos that are underrepresented in clinical trials, which compounds the problem and leads to a severe lack of information about the relationship between psychosocial stress, ADRD, and minority health outcomes. Thus, a major priority of this proposal is to conduct translational research that focuses on Hispanic/Latino health.
Our research group has studied the neurobiology of social behavior and social stressors extensively, and we have identified arginine-vasopressin (AVP) and its main receptor, the V1A receptor (AVPR1A), as comprising a hormone pathway in the midbrain that is sensitive to and appear to regulate responses to psychosocial stressors.
There is growing evidence that psychosocial stressors increase heart disease risk, and exploring the relationship between these stressors and ADRD warrants further investigation.
VAscular DEmentia Research (VADER) Pilot Project at Rio Grande Valley
Juan Carlos Lopez-Alvarenga, M.D., D.Sc.Twelve percent of older adults in the Latino/Hispanic population suffer from Alzheimer's Disease (AD), the highest proportion among different ethnic groups in the US. Texas ranks fourth in the number of AD cases and second in the number of AD deaths among US states. The Rio Grande Valley of Texas (RGV) has a high prevalence of AD and vascular dementia (VD) as found in Latin-American countries. The lower RGV has a majority Latino/Hispanic population that is medically underserved and has pressing health and social vulnerabilities, including a high proportion of uninsured persons, high poverty rates, and high rates of migration.
The main goal of this VADER Pilot Project is to analyze such relationship in two well-characterized samples of Hispanics with a high risk of metabolic syndrome. We hypothesize that diabetes medicated changes in subcortical structures are predictive of cognitive decline and risk of dementia and that their effects are modulated by socioeconomic status, education, and physical activity.
Cohort 2 (2019-2020)
Search for novel endophenotypes predicting risk of dementia in Mexican Americans
Marcio A. Almeida, Ph.D.This study is designed to identify novel-invasive endophenotypes, biomarkers that index genetic risk for a disorder but which are not dependent on disease state. It will use extensive, available whole genome sequence, transcriptomic, and neurocognitive assessment data from 2000 members of large Mexican American families, living in San Antonio, Texas who were recruited as part of the Genetics of Brain Structure (GOBS) project, itself a component of the larger 35-year old San Antonio Family Study. Seventy of these individuals exhibit dementia, as diagnosed by clinical assessments and/or death certificate data. Extensive data also are available on socioeconomic status, educational history, physical activity, dietary behavior, acculturation, and variable related to the place of residence.
Patterns of relatedness in these large extended pedigrees can be exploited to detect and characterize genetic contributions to variation in complex traits like ADRD risk; and, in fact, a large proportion of variation in ADRD risk in these families already is known to be due to the effects of genes. This will facilitate the selection of endophenotypes based on their genetic correlations with ADRD risk.
Like the disease state, the selected endophenotypes are expected to have important environmental determinants, and their genetic components are likely to interact with environmental factors. Therefore, the identification of informative endophenotypes will be followed by a systematic search for evidence of genotype-by-environment (GxE) interaction. The GxE interaction analyses will utilize the existing measures of socioeconomic, socio-behavioral, and socio-environmental domains as environmental indicators. An Endophenotype Ranking Value procedure, developed by study mentors [Drs. Blangero and Glahn], will be used to identify relevant transcriptomic endophenotypes. Formal tests for genotype-by-environment interactions will be done using variance component modeling approaches that include covariance kernels reflecting overall socio-environmental similarity between pairs of individuals.
Characteristics of Mexican American Alzheimer’s Caregivers within the South Texas-Mexico Border Region
Romeo Luis Escobar, Ph.D.There is a growing evidence that Latinos have the highest percentage of family caregivers than most other ethnic groups including Caucasians. Mexican-Americans families tend to take care of their own because of strong ties to family. This study proposes to focus on Mexican American caregivers of family members along the Rio Grande Valley and Mexico border with patients that have Alzheimer's disease and/or dementia to determine what factors may contribute to caregiving of their loved ones in the home setting. The study will emphasize determining the challenges and predictors that contribute to caregiving. The pilot study will address three specific aims.
The first aim is to determine the practitioner’s perception of dementia family caregivers' knowledge of caring for family members with Alzheimer's disease and/or dementia. Focus groups will be held with professional staff that provides direct and indirect services to caregivers of individuals with Alzheimer's disease and/or dementia.
The second aim is to identify specific reasons leading people from Mexican American ethnicity to make decisions regarding caregiving decisions for elderly family members with Alzheimer's disease and/or dementia. Focus groups made up of caregivers of patients with Alzheimer's disease and/or dementia will be held in Cameron, Hidalgo, and Webb Counties to identify predictors of caregiver burden, challenges, and stressors that impact caregiving on Mexican American families with family members with Alzheimer's disease and/or dementia and contribute to their caregiving decisions
The last aim is to address the following question: what specific determinants of psychological burden (cultural traits vs. personality traits) contribute to caregiver's decisions to determine the location of care for elderly relatives with Alzheimer's disease and/or dementia? Individual interviews with caregivers will be held to explore more extensively the specific reasons contributing to individuals’ decisions to care for a family member with Alzheimer's disease and/or dementia in the home. For example, to what extent is the location of caregiving due to strong attachment and loyalty or to a sense of responsibility or obligation?
Epigenetic influences on Alzheimer’s disease risk
Ana Cristina Leandro, Ph.D.Age is considered one of the greatest risk factors for the development of Alzheimer’s disease (AD), with the likelihood of developing AD increasing exponentially with age, doubling every 5 years after age 65. While the reason for this is still unknown, the etiology of AD and its relationship with age are both likely the result of an intricate interplay between genetic, epigenetic, and environmental factors. Differential methylation of sites across the genome has been implicated as a contributor to variation in risk, severity, and progression of AD. In addition to being affected by both genetic and environmental factors, variation in global DNA methylation levels has been shown to have a complex relationship with aging. Indeed, epigenetic changes have been shown to be one of the hallmarks of aging.
A number of studies of the relationship between DNA methylation and AD risk are ongoing but there currently are no published reports of the phenomenon in Hispanic populations. This pilot study is a first step toward addressing that gap in knowledge.
To do this the investigator will take advantage of existing biomaterials and data from the Maracaibo Aging Study (MAS), directed by Dr. Gladys Maestre. More than 800,000 genome-wide methylation sites will be evaluated at single-nucleotide resolution in existing white blood cell samples from 24 AD cases and 24 unaffected sex and age matched controls. There are two specific aims. The first aim is to identify quantitative methylation profiles that distinguish the AD cases from the unaffected controls. The second is to identify methylated sites that show the greatest differences between the two groups, generate epigenetic clock-based ages, and compare AD cases and controls.
This project’s ultimate objective is to generate novel data that will serve as valuable preliminary results in a subsequent application for extramural funding of a more extensive and intensive study of epigenetic influences on the relationships between age and AD risk, severity, and progression in a Hispanic population. Because DNA methylation is to a degree responsive to other environmental stressors the results of this pilot study can also serve as preliminary data for investigations of the interplay between age, epigenetics and socioeconomic, socio-behavioral, and socio-environmental factors in AD.
Cohort 3 (2020-2021)
The Genetic Basis of Alzheimer's Disease (AD) in Hispanic Americans affected by Type-2 Diabetes (T2D)
Upal Roy, Ph.D.
Alzheimer’s disease (AD) is characterized by progressive neurodegeneration that ultimately leads to brain-related disorders characterized by cognitive dysfunction. Of the estimated 5.8 million Americans of all ages living with AD in 2019, Hispanics, the fastest-growing populations in the USA, also are showing increasing prevalence of the disorder when compared to other ethnic groups in the country. The pathology of AD becomes more complicated when it is associated with other comorbidities like Type -2 Diabetes (T2D). Hispanics are also at a significantly higher risk of T2D compared to the national average among other non-Hispanic populations. Considering the increased risk of AD and T2D among Hispanics, it is increasingly important to identify these diseases early on to develop a proper treatment strategy.
Several studies have identified microRNA (miRNA) as a key indicator of AD and/or T2D pathology. However, none of the studies have identified any molecular marker that can identify AD early on in a co-morbid condition such as T2D. Considering the higher risk of AD and T2D in the Rio Grande Valley population, this study may help us identify the onset of AD in the T2D affected population and perhaps lead to research designed to develop a more effective treatment strategy for these patients.
Association between the gut microbiome and dementia
Bernard Fongang, Ph.D.
Although a substantial proportion of the variability in risk, severity, and progression of Alzheimer’s disease and related dementias (ADRD) can be captured by genetics, efforts are needed to identify additional factors that could not only stratify the population at risk, but also help reverse the course of the diseases. These efforts include identification of modifiable risk factors.
Differences in the prevalence of ADRD among ethnic groups have been reported. It is estimated that non-Hispanic blacks have roughly double and Hispanics about 50% greater prevalence of ADRD compared to non-Hispanic whites. Of these three groups, Hispanic Americans and non-Hispanic Blacks are expected to undergo significantly larger increases in population size by 2060, approximately 114% and 42%, respectively, as opposed to -8% in non-Hispanic Whites. However, their causes have been understudied and, consequently, are poorly understood. Therefore, there is an urgent need to identify and characterize early “modifiable signals” indicating the presence of ADRD in these two ethnic groups for whom traditional biomarkers may be inefficient. The gut microbiome is an excellent modifiable risk factor that could help prevent ADRD and has recently been found to be associated with dementia through the bi-directional brain-gut axis.
In this proposal, we aim to study the association between the gut microbiome, neurocognitive tests, and genetic predisposition to dementia. Identifying distinct microbiome profiles associated with neuropsychological tests and genetic risk factors could enable earlier identification of individuals at increased risk of cognitive decline and dementia. Moreover, it could open the door to medical intervention with the possibility to modify the course of disease with the use of pre/probiotics or fecal microbial transplantation. Overall, we believe understanding how specific microbial taxa and functional pathways are related to neurological endophenotypes may ultimately lead to novel therapies that modulate microbial function or host-microbe functional interactions and will ultimately benefit understudied population for whom traditional biomarkers may be inefficient. We expect the project to be completed in 12 months with the publication of at least one manuscript and the generation of preliminary data for a NIA R01 grant targeting a larger population.
Cohort 4 (2021-2022)
Examining the contribution of persistent organic pollutant exposures on mild cognitive impairment in Mexican Americans
Candace Robledo, Ph.D., MPH
Studies of the etiology of mild cognitive impairment (MCI) and Alzheimer’s disease (AD) among Mexican Americans is warranted given this rapidly growing and aging segment of the US Hispanic population. Sixty-five percent of US Hispanics are Mexican American and 12% of all older Hispanics will develop AD, more than any other racial/ethnic group in the US. The neurotoxic effects of environmental chemical exposures on the developing and aging brain have been demonstrated, indicating that exposure to environmental chemicals across the lifespan may be an important contributor to the risk of MCI in Mexican Americans. A matched case-control study will be undertaken to examine the role that persistent organic pollutant exposures have on the development of MCI in Mexican Americans.
The specific aims of this project will be to leverage banked serum samples from the San Antonio Mexican American Family study to 1) Characterize and compare levels of 55 persistent organic pollutants among 50 Mexican Americans with MCI and 50 controls matched on age and gender; 2) Use innovative statistical techniques to account for multiple comparisons and to control for genetic effects to comprehensively assess and better detect associations between persistent organic pollutants and MCI in Mexican Americans; and 3) Estimate the population attributable risk or the percent of MCI cases among Mexican Americans that might have been prevented if exposure to persistent organic pollutants were lower. The results of this pilot project will inform the design of subsequent studies to further explore the contributions of environmental chemical exposure on mild cognitive impairment, an important precursor to Alzheimer’s disease in Mexican Americans.
Lipidomic correlates of mild cognitive impairment
Mikko Kuokkanen, Ph.D.
Alzheimer’s disease (AD) is a progressive heterogeneous neurodegenerative disease with a major healthcare burden and the most common cause of dementia. Mild cognitive impairment (MCI) is an intermediate state between normal aging and dementia, mainly caused by AD. About 80% of MCI cases progress to AD in 6 years and changes in the brain caused by AD pathogenesis may happen earlier than the first detected MCI symptoms. Annual rates of MCI conversion to dementia are from 5% to 20%.Hispanic populations have a 1.5 times increased risk of developing AD or other dementias, relative to non-Hispanic whites. Given that Hispanics are the largest minority group and one of the fastest growing population groups in the United States, additional studies predicting development of AD in this population are crucial.
AD is a multifactorial disease with both genetic and environmental factors affecting its development and progression. There are a few biomarkers that can reveal the progress of AD, two examples of which, tau protein and beta amyloid (Aβ) peptides, can be measured from cerebrospinal fluid. Amyloid and tau pathology can be detected by positron emission tomography imaging technology in the brain. Unfortunately, they both are extremely invasive procedures and far from general practice. In view of this, less invasive blood-based biomarkers would be a big step forward. Lipidome characteristics can represent a key to understanding AD development and disease prediction. Additionally, the lipidome can guide us to which metabolic pathways are crucial for drug development.
Here we propose a novel research design for disentangling the contribution of biological and environmental factors to MCI/AD risk. We will systematically evaluate genetic correlation of the endophenotypic potential of our lipidomic phenotypes and rank their value for predicting MCI risk using the endophenotype ranking value (ERV) statistic. Further, we will utilize a statistical genetic method to maximize the detection of spatially patterned environmental signal in AD risk. Finally, we will actively incorporate genetic factors to search for genotype × spatial interactions using a simple extension of the linear mixed models.
Decreasing social isolation among Mexican American informal caregivers of persons with Alzheimer's disease during the COVID-19 era: The utilization of technology
Lin Jiang, Ph.D.
Mexican Americans with Alzheimer’s disease and related dementias (ADRD) rely heavily on unpaid informal care. Dementia caregiving is demanding and takes an emotional, financial, and physical toll on caregivers. The South Texas-Mexico border is one of the areas hardest-hit by COVID-19 and caregiving challenges have been exacerbated during the pandemic. Social distancing and business closures are much needed to control the outbreak but have also increased social isolation, limited caregiver support services, and created additional layers of caregiver burden. Supporting Mexican American informal caregivers during and after the pandemic is an urgent public health need.
The purpose of this study is to examine the utilization of Information communication technology (ICT) to reduce social isolation among Mexican American informal caregivers of patients with ADRD in the context of cultural, religious, pandemic, and ethnic factors. The long-term goal is to design a culturally grounded ICT-based intervention to reduce Hispanic American ADRD caregivers’ social isolation and improve their mental health. The overall objective is to help caregivers mitigate the impact of current pandemic and future disaster-like conditions and even support them in coping with social isolation during “normal” times. The central research questions are: (1) what is the relationship between ICT use (e.g., type of ICT use, frequency, and intent of use) and social isolation; (2) what are ADRD caregivers’ experiences of using ICT to reduce social isolation before, during, and post- COVID-19; and (3) how do culture and religion affect the utilization of ICT as a coping strategy to reduce social isolation?
Using a mixed-methods design, we will collect data via online and mailed surveys from Mexican American informal caregivers of patients with ADRD living in Cameron, Hidalgo, and Webb counties. We will then select a group of participants to be interviewed by phone or web-based video teleconferencing (e.g., Zoom), using semi-structured interviews. Our pilot study will pursue three specific aims: (1) explore the relationship between use of ICT (e.g., type of ICT use, frequency, and intent of use) and social isolation in Mexican American informal caregivers; (2) document the experiences of caregivers using ICT to reduce social isolation before, during, and post- COVID-19; and (3) assess the role of culture and spirituality on the use of ICT as a coping strategy. Descriptive and inferential statistical approaches will be used (e.g., regressions with covariates and control variables) will be used, and qualitative thematic analyses will be conducted.
Cohort 5 (2022-2023)
Promoting Transcendence for Hispanics with Alzheimer’s Through Music Playlists
Kim Nguyen-Finn, PhD, LPC
The Hispanic population in the South Texas is unique in that has rich musical tradition that fosters emotional expression and social interaction. Providing music therapy to Hispanics that they enjoy listening to and/or from their culture may help them feel that the counselor is sensitive to their needs, thereby building rapport and improving client outcomes. The proposed study explores how using listening to personalized music playlists may help Hispanics with early-onset Alzheimer’s disease (AD) have improved mood, psychosocial adaptation, and quality of life, as opposed to listening to researcher-selected, universal playlists. Effects of adaptation and quality of life on caregivers of those individuals with AD will also be studied.
Socioenvironmental support systems and brain health among Latinos
Mayra Estrella, PhD
Latinos, one of the fastest growing minority populations in the US, are 1.5 times more likely to develop Alzheimer’s disease than non-Latino whites. Unfortunately, research on protective factors that may serve as targets for promoting brain health among Latinos in the US is scant. Social factors such as an individual’s socioenvironmental support system, which refers to interpersonal relationships that promote a social connection to others and provide different forms of social support such as functional, emotional, and structural, may contribute to health disparities in brain aging and Alzheimer’s dementia in Latinos. While many of these socioenvironmental support system factors (such as loneliness and social isolation) are individually associated with an increased risk of cognitive decline, less work has examined brain-MRI outcomes. Moreover, to date, most studies have examined socioenvironmental exposures in isolation, as opposed to considering the larger concept of socioenvironmental support system and the many factors that it encompasses. In this pilot project, we will use latent profile analysis (LPA) to examine phenotypes of the socioenvironmental support system in middle-aged and older Latinos (Aim 1). LPA is a methodological approach that will allow us to capture probabilistic subgroups (phenotypes) underlying the multidimensional array of socioenvironmental support system factors (i.e., functional social support, structural social support, and family cohesion measures). This pilot project would also achieve the Aim of examining whether LPA-derived aspects (phenotypes) of the socioenvironmental support system are differentially associated with brain health (specifically, composite scores of Alzheimer’s disease signature regions and cerebrovascular brain health as well as hippocampal volume) in middle-aged and older Latino adults (Aim 2). Finally, we will also investigate the psychological mechanisms (including chronic stress and depressive symptoms) that are potentially underlying the associations of socioenvironmental support systems and brain health (Aim 3). To do so, we will incorporate advanced statistical techniques, recently available neuroimaging data, and well-characterized individual measures of the social environment. We will also leverage the infrastructure of the largest cohort study of the health of Latinos in the US, the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Visit 2 and its NIA-funded SOL-Investigation of Neurocognitive Aging MRI Ancillary Study into this pilot project.
Social engagement and cognitive function among Latino older adults of Mexican descent: An exploratory study of social engagement as a target for cognitive decline interventions.
Liza Talavera-Garza, PhD
The proposed study aims to examine the strength of the association between social engagement and cognitive function among older Latino/Hispanic residents of the Rio Grande Valley (RGV), above and beyond that of other social and cultural factors that are known to be protective against cognitive decline, such as social support and social network embeddedness, and bilingualism and familism. In addition, the study proposes to explore patterns of gray matter microstructural integrity in socially relevant brain regions of interest in selected participants to determine whether there are neurological differences in those with high compared to low levels of social engagement. The proposed study is necessary as a first step to determine whether social engagement is viable as a factor that could be targeted in interventions for Alzheimer’s disease and related dementias (ADRD) for Latinos in the RGV. The ultimate purpose of the study is to generate the foundational knowledge necessary to apply for external research funding to develop and test a culturally relevant community-based intervention for older Latinos in the RGV focused on reducing the risk of developing Alzheimer’s disease and associated dementias (ADRD), or slowing cognitive decline in those with ADRD, through the promotion of social engagement.
Cohort 6 (2023-2025)
Occupational Determinants and Alzheimer’s disease and related dementia
Xi Mao Ph.D.
This project aims to unravel the occupational determinants of cognitive impairment among a medically underserved and understudied minority population in their later stages of life, Hispanic Americans in the Rio Grande Valley of south Texas. These occupational determinants include working seniority, leadership responsibilities, workload intensity, and task complexity. The goal is to set the stage for further, larger-scale studies, incorporating genetic and other components with implications for the value of incorporating providing health-oriented career guidance to families with family histories or concerns related to AD/ADRD.
This will be a study of four occupational determinants. They are 1) accumulation of working seniority: i.e., the decision of late-life discontinuation of work; 2) impact of leadership experience during one's career journey: i.e., the number of individuals directly managed in a professional context; 3) level of workload experienced throughout a career and its potential connection to cognitive well-being; and 4) complexity of tasks undertaken in a professional capacity. My hypothesis, supported by work in other populations, is that these four factors, separately or in combination, contribute to shaping the cognitive trajectory in late life. The pilot study utilizes newly collected data from one-time phone surveys of participants recruited through both the RGV Alzheimer's Disease-Resource Center for Minority Aging Research (AD-RCMAR; University of Texas Rio Grande Valley) and the South Texas Alzheimer’s Research Education Center (STAC; UT Health San Antonio) and their existing cognitive function data.
This project aims to unravel the occupational determinants of cognitive impairment among a medically underserved and understudied minority population in their later stages of life, Hispanic Americans in the Rio Grande Valley of south Texas. These occupational determinants include working seniority, leadership responsibilities, workload intensity, and task complexity. The goal is to set the stage for further, larger-scale studies, incorporating genetic and other components with implications for the value of incorporating providing health-oriented career guidance to families with family histories or concerns related to AD/ADRD.
The Relationship Between Baseline Intake of Pulses and Markers of Cardiovascular and Cognitive Health in an Aging Venezuelan Population
Lisa Salinas, Ph.D., RDN, LD
This is an investigation of the relationships between patterns of consumption of pulses (the dried, edible seeds of specific leguminous plants; i.e., beans, peas, and lentils) and cardiometabolic risk factors and measures of cognitive dysfunction in a well-characterized and studied Latin American population in Venezuela will have implications for the development of dietary interventions to lower the risk and possibly severity of AD/ADRD disease and other neurological disorders in a U.S. Hispanic population with a high prevalence of those disorders. To our knowledge, no research has examined the relationship between pulses and markers of cognitive dysfunction in an aging Hispanic/Latino population. The main objective of this application is to establish the prevalence of pulse intake in an aging Latin American population from Venezuela and assess the interaction between pulse intake and cognitive function tests, genetic markers of cognitive dysfunction, and Alzheimer’s disease and markers of cardiovascular disease. The long-term research goal is to promote pulse intake as a potential strategy to improve health and wellness in various populations, especially those who lack financial and/or food security and are at risk for chronic disease.
The overarching hypothesis is that pulse consumption at or above recommended levels has beneficial effects on risk factors for cardiometabolic disease and measures of cognitive function and risk for AD/ADRD. This is the central hypothesis motivating this pilot study: i.e., increased pulse intake, which will be generally low in this aging Latin American population serving as a model for future studies in the U.S. Hispanic population of south Texas, will show a protective effect against cardiometabolic disease, cognitive decline, and ADRD. Specific Aim 1: To test the hypothesis that pulse consumption in an aging Venezuelan population will be lower than the recommended intake. I will quantify pulse intake among an aging Venezuelan population, I will use information from the Maracaibo Aging Study which collected baseline nutrition data in a ≥ 55-year-old population residing in the Santa Lucia neighborhood of Maracaibo, Venezuela. Furthermore, I will stratify the data to examine the influence of sex and age on pulse intake. Specific Aim 2: To test the hypothesis that higher pulse intake will also be shown to be protective against cognitive disease such as Alzheimer’s disease and cardiovascular disease. Baseline pulse intake will be associated with higher performance on baseline and follow-up cognitive assessments. I will complete this specific aim using already collected baseline nutrition data on diet, from which pulse intake will be quantified, measurements of performance on cognitive function tests, genetic markers for dementia risk, and data on known biomarkers of risk for cardiometabolic disease.
Influences of Limited Access to Health Care on MRI AD-Relevant Brain Measures
Jesus David Melgarejo Arias, MD, PhD
Current scientific efforts aim to underline the biological mechanisms by which adverse social determinants of health (SDOH) exert their effects on ADRD among underrepresented groups. To do so, SDOH are often collected as single time-point data that reflects recent, or current situations individuals are exposed. This approach omits retrospective information, which can be captured as accumulated and interindividual variability events that may provide a deeper understanding of the correlation between adverse SDOH and ADRD. Moreover, retrospective SDOH may result in stronger correlations with ADRD, which will facilitate the identification of biological mechanisms connecting the two. This remains poorly explored. To fill these gaps, the present project aims to test the overall hypothesis that retrospective information on SDOH provides stronger correlations with ADRD, which provides better opportunities to underly biological mechanisms connecting the two. Our aims will be: Specific Aim 1: by selecting one SDOH as the test event, we will compare the correlation of LAHC captured as a single time-point and as retrospective events with MRI AD-relevant brain measures. We hypothesize that retrospective LAHC events will have a stronger correlation with MRI AD-relevant brain measures. Specific Aim 2: by selecting a variable biological trait, we will determine how much of the correlation between LAHC and MRI measures is due to 24-hour blood pressure dysregulation. As we are studying SDOH as accumulated and variable events, we selected a method that also captures accumulated and variable information of a biological system as it is 24-hour blood pressure data. Another reason to select blood pressure was that poor blood pressure control strongly associates with LACH and ADRD. We hypothesize that part of the correlation between LACH and MRI AD-relevant brain measures is due to 24-hour blood pressure dysregulation. Impact: This project could enhance the understanding of how adverse SDOH effects on brain aging by examining variations in SDOH and biological mechanisms, particularly in underrepresented populations. The findings could inform the development of targeted interventions to mitigate the impact of adverse SDOH on ADRD.