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BACKGROUND: Despite tremendous advancements in the field, our understanding of mild cognitive impairment (MCI) and Alzheimer's disease (AD) among Mexican Americans remains limited. OBJECTIVE: The aim of this study was to characterize MCI and dementia among Mexican Americans and non-Hispanic whites. METHODS: Baseline data were analyzed from nâ=â1,705 (nâ=â890 Mexican American; nâ=â815 non-Hispanic white) participants enrolled in the Health and Aging Brain Study-Health Disparities (HABS-HD). RESULTS: Among Mexican Americans, age (ORâ=â1.07), depression (ORâ=â1.09), and MRI-based neurodegeneration (ORâ=â0.01) were associated with dementia, but none of these factors were associated with MCI. Among non-Hispanic whites, male gender (ORâ=â0.33), neighborhood deprivation (ORâ=â1.34), depression (ORâ=â1.09), and MRI-based neurodegeneration (ORâ=â0.03) were associated with MCI, while depression (ORâ=â1.09) and APOEÉ4 genotype (ORâ=â4.38) were associated with dementia. CONCLUSION: Findings from this study revealed that the demographic, clinical, sociocultural and biomarker characteristics of MCI and dementia are different among Mexican Americans as compared to non-Hispanic whites.
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Doença de Alzheimer , Disfunção Cognitiva , Masculino , Humanos , Americanos Mexicanos/psicologia , Vida Independente , População Branca , Fatores de Risco , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/genéticaRESUMO
INTRODUCTION: Among vascular risk factors we hypothesized that an increased prevalence of diabetes in Hispanics would be associated with greater white matter hyperintensity (WMH) volume, which may contribute to cognitive decline. METHODS: A total of 1318 participants (60% female; 49% Hispanic, 51% non-Hispanic White; age 66.2 ± 8.9 years) underwent clinical evaluation and brain magnetic resonance imaging (MRI). WMH volume associations were assessed with age, sex, and ethnicity and then with vascular risk factors in a selective regression model. RESULTS: WMH volume was greater with older age (P < .0001), Hispanic ethnicity (P = .02), and female sex (P = .049). WMH volume was best predicted by age, diastolic blood pressure, hypertension history, hemoglobin A1c (HbA1c), white blood cell count, and hematocrit (P < .01 for all). Elevated HbA1c was associated with greater WMH volume among Hispanics (parameter estimate 0.08 ± 0.02, P < .0001) but not non-Hispanic Whites (parameter estimate 0.02 ± 0.04, P = .5). DISCUSSION: WMH volume was greater in Hispanics, which may be partly explained by increased WMH volume related to elevated HbA1c among Hispanics but not non-Hispanic Whites.
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BACKGROUND: Hispanics are expected to experience the largest increase in Alzheimer's disease (AD) and AD related dementias over the next several decades. However, few studies have examined biomarkers of AD among Mexican Americans, the largest segment of the U.S. Hispanic population. OBJECTIVE: We sought to examine proteomic profiles of an MRI-based marker of neurodegeneration from the AT(N) framework among a multi-ethnic, community-dwelling cohort. METHODS: Community-dwelling Mexican Americans and non-Hispanic white adults and elders were recruited. All participants underwent comprehensive assessments including an interview, functional exam, clinical labs, informant interview, neuropsychological testing, and 3T MRI of the brain. A neurodegeneration MRI meta-ROI biomarker for the AT(N) framework was calculated. RESULTS: Data was examined from nâ=â1,291 participants. Proteomic profiles were highly accurate for detecting neurodegeneration (i.e., N+) among both Mexican Americans (AUCâ=â1.0) and non-Hispanic whites (AUCâ=â0.98). The proteomic profile of Nâ+âwas different between ethnic groups. Further analyses revealed that the proteomic profiles of Nâ+âvaried by diagnostic status (control, MCI, dementia) and ethnicity (Mexican American versus non-Hispanic whites) though diagnostic accuracy was high for all classifications. CONCLUSION: A proteomic profile of neurodegeneration has tremendous value and point towards novel diagnostic and intervention opportunities. The current findings demonstrate that the underlying biological factors associated with neurodegeneration are different between Mexican Americans versus non-Hispanic whites as well as at different levels of disease progression.
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Doença de Alzheimer , Disfunção Cognitiva , Idoso , Doença de Alzheimer/diagnóstico , Biomarcadores , Disfunção Cognitiva/diagnóstico , Humanos , Americanos Mexicanos , Testes Neuropsicológicos , ProteômicaRESUMO
INTRODUCTION: We sought to examine a magnetic resonance imaging (MRI)-based marker of neurodegeneration from the AT(N) (amyloid/tau/neurodegeneration) framework among a multi-ethnic, community-dwelling cohort. METHODS: Community-dwelling Mexican Americans and non-Hispanic White adults and elders were recruited. All participants underwent comprehensive assessments including an interview, functional exam, clinical labs, informant interview, neuropsychological testing and 3T MRI of the brain. A neurodegeneration MRI meta-region of interest (ROI) biomarker for the AT(N) framework was calculated. RESULTS: Data were examined from n = 1305 participants. Mexican Americans experienced N at significantly younger ages. The N biomarker was significantly associated with cognitive outcomes. N was significantly impacted by cardiovascular factors (e.g., total cholesterol, low-density lipoprotein) among non-Hispanic Whites whereas diabetes (glucose, HbA1c, duration of diabetes) and sociocultural (household income, acculturation) factors were strongly associated with N among Mexican Americans. DISCUSSION: The prevalence, progression, timing, and sequence of the AT(N) biomarkers must be examined across diverse populations.
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INTRODUCTION: The APOEε4 allele is the single strongest genetic risk for late-onset Alzheimer's disease (AD). Prior work demonstrates that not only the APOEε4 allele varies by race/ethnicity but also the risk for AD and cognitive impairment conveyed by the APOEε4 allele varies by the racial/ethnic group as well as genetic ancestry. Here, we sought to examine the link between the APOEε4 and neuropsychological functioning among Mexican Americans (MAs). METHODS: Data were examined from 1,633 (852 MAs and 781 non-Hispanic Whites [NHWs]) participants of the Health & Aging Brain Study - Health Disparities (HABS-HD) and were enrolled with all requisite data to be included into the current analyses. RESULTS: The frequency of both ε4 and ε2 alleles was significantly lower among MAs as compared to NHWs. Among MAs, APOEε4 allele presence was associated specifically with poorer immediate and delayed memory (Wechsler Memory Scale - Third Edition [WMS-III] Logical Memory and Spanish-English Verbal Learning Test [SEVLT]). Among NHWs, APOEε4 allele presence was associated with poorer immediate and delayed memory as well as worse executive functioning (Trials B) and verbal fluency (Animal naming). DISCUSSION/CONCLUSION: The APOEε4 allele was associated with poorer cognition across multiple domains among NHWs; however, allele presence was specifically associated with poorer memory performance among MAs. When combined with prior work, the current findings demonstrate that the risk factors associated with cognitive dysfunction differ among MAs as compared to NHWs and require additional investigation.
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Doença de Alzheimer , Apolipoproteína E4 , Envelhecimento/genética , Doença de Alzheimer/genética , Doença de Alzheimer/psicologia , Apolipoproteína E4/genética , Encéfalo , Etnicidade , Humanos , Americanos Mexicanos/genética , Testes NeuropsicológicosRESUMO
INTRODUCTION: Representation of Mexican Americans in Alzheimer's disease (AD) clinical research has been extremely poor. METHODS: Data were examined from the ongoing community-based, multi-ethnic Health & Aging Brain among Latino Elders (HABLE) study. Participants underwent functional exams, clinical labs, neuropsychological testing, and 3T magnetic resonance imaging of the brain. Fasting proteomic markers were examined for predicting mild cognitive impairment (MCI) and AD using support vector machine models. RESULTS: Data were examined from n = 1649 participants (Mexican American n = 866; non-Hispanic White n = 783). Proteomic profiles were highly accurate in detecting MCI (area under the curve [AUC] = 0.91) and dementia (AUC = 0.95). The proteomic profiles varied significantly between ethnic groups and disease state. Negative predictive value was excellent for ruling out MCI and dementia across ethnic groups. DISCUSSION: A blood-based screening tool can serve as a method for increasing access to state-of-the-art AD clinical research by bridging between community-based and clinic-based settings.
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Doença de Alzheimer/sangue , Doença de Alzheimer/diagnóstico , Disfunção Cognitiva/diagnóstico , Vida Independente , Programas de Rastreamento , Americanos Mexicanos/estatística & dados numéricos , População Branca/estatística & dados numéricos , Idoso , Doença de Alzheimer/etnologia , Biomarcadores/sangue , Disfunção Cognitiva/sangue , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Seleção de Pacientes , ProteômicaRESUMO
BACKGROUND: The current project sought to evaluate the impact that white matter hyperintensities (WMH) have on executive function in cognitively normal Mexican Americans, an underserved population with onset and more rapid progression of dementia. METHODS: Data from 515 participants (360 female) enrolled in the Health and Aging Brain Study: Health Disparities project were analyzed. Participants underwent clinical evaluation, cognitive testing, and a brain MRI. Linear regression was used to predict the effect of total WMH volume on cognitive test scores. Age, sex, and education were entered as covariates. RESULTS: Regression analysis showed that WMH volume significantly predicted executive function. WMH also predicted global cognition and attention scores, although not significantly after adjusting for age. CONCLUSION: In this sample of cognitively normal Mexican Americans, we found that WMH volume was associated with lower scores in a measure of executive function, after accounting for age, sex, and education.
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INTRODUCTION: Alzheimer's disease (AD) is the most frequently occurring neurodegenerative disease; however, little work has been conducted examining biomarkers of AD among Mexican Americans. Here, we examined diffusion tensor MRI marker profiles for detecting mild cognitive impairment (MCI) and dementia in a multi-ethnic cohort. METHODS: 3T MRI measures of fractional anisotropy (FA) were examined among 1,636 participants of the ongoing community-based Health & Aging Brain among Latino Elders (HABLE) community-based study (Mexican American n = 851; non-Hispanic white n = 785). RESULTS: The FA profile was highly accurate in detecting both MCI (area under the receiver operating characteristic curve [AUC] = 0.99) and dementia (AUC = 0.98). However, the FA profile varied significantly not only between diagnostic groups but also between Mexican Americans and non-Hispanic whites. CONCLUSION: Findings suggest that diffusion tensor imaging markers may have a role in the neurodiagnostic process for detecting MCI and dementia among diverse populations.