Authors: Edwards, Melissa | Hall, James | Williams, Benjamin | Johnson, Leigh | O’Bryant, Sid
Article Type: Research Article
Abstract: Background: Mexican Americans face a significant health disparity when it comes to Alzheimer’s disease (AD) as they present with higher rates of the disease and develop AD at an earlier age compared to other ethnic groups. Recent work identified a proteomic profile of AD among this population; however, no work to date has sought to examine the biological profile of pre-AD among Mexican Americans. Objective: This study aims to identify an amnestic mild cognitive impairment (aMCI) proteomic profile among Mexican Americans. Methods: Data were analyzed from 284 Mexican American participants (aMCI, n = 73; normal controls, n = 211) from the Health …& Aging Brain among Latino Elders study. Fasting serum samples were analyzed using a multi-plex biomarker assay platform. A biomarker profile was generated using random forest analyses. Results: Among aMCI cases, the biomarker profile was found to be largely inflammatory with the top three markers shown to include TNFα , IL10, and TARC. The overall diagnostic accuracy of the biomarkers in detecting aMCI was 96% (sensitivity = 0.82; specificity = 0.97). Inclusion of clinical variables with the selected biomarkers did not impact the overall detection accuracy (area under the curve = 0.96) but led to a slight improvement in specificity (specificity = 0.99) and decrease in sensitivity (sensitivity = 0.74). Conclusion: The biomarker profile of aMCI was shown to be different from our previously generated AD profile among Mexican Americans, which was largely metabolic in nature. The findings implicate a possible interplay between inflammatory and metabolic processes and additional work is needed to further examine this. Show more
Keywords: Amnestic, biomarker, Mexican American, mild cognitive impairment
DOI: 10.3233/JAD-150553
Citation: Journal of Alzheimer's Disease, vol. 49, no. 1, pp. 221-228, 2016
Authors: O'Bryant, Sid E. | Johnson, Leigh | Balldin, Valerie | Edwards, Melissa | Barber, Robert | Williams, Benjamin | Devous, Michael | Cushings, Blair | Knebl, Janice | Hall, James
Article Type: Research Article
Abstract: The purpose of the study was to provide characterization of Mexican Americans who meet criteria for Alzheimer's disease (AD) and mild cognitive impairment (MCI). For the study, 1,069 participants ages 40 and above who self-identified as either non-Hispanic white (n = 633) or Mexican American (n = 436) were recruited using a community-based participatory research approach. Global cognition was assessed via the Mini-Mental State Examination (MMSE), dementia severity by the Clinical Dementia Rating Scale, and depression via the Geriatric Depression Scale 30-item version. Age, gender, education, ApoE ε4 allele frequency, and diabetic diagnoses were also analyzed. The findings showed that …Mexican Americans (normal controls, MCI, and AD) were younger, less highly educated, performed more poorly on the MMSE, endorsed more symptoms of depression, were more likely to be diagnosed with diabetes, and possessed the ApoE ε4 allele less frequently. Age was the only significant risk factor for cognitive dysfunction (AD/MCI) among Mexican Americans (OR = 1.06, 95% CI = 1.03–1.09). Age (B = 0.07, std = 0.02, p < 0.001) and ApoE ε4 presence (B = 0.9, std = 0.4, p = 0.02) were significantly related to increased disease severity. Given the rapidly growing and aging Mexican American population, there is a substantial need for research into cognitive aging, MCI, and AD among this ethnic group. The current findings hold important implications for both clinic and research settings and point to additional research needs. Show more
Keywords: Alzheimer's disease, cognition, depression, diabetes, Hispanic, Mexican American, mild cognitive impairment
DOI: 10.3233/JAD-2012-121420
Citation: Journal of Alzheimer's Disease, vol. 33, no. 2, pp. 373-379, 2013
Authors: Duran, Tugce | Gaussoin, Sarah A. | Latham, Lauren A. | Rundle, Melissa M. | Espeland, Mark A. | Williams, Benjamin J. | Hughes, Timothy M. | Craft, Suzanne | Sachs, Bonnie C. | Bateman, James R. | Lockhart, Samuel N.
Article Type: Research Article
Abstract: Background: The preclinical Alzheimer’s cognitive composite (PACC) was developed for in-person administration to capture subtle cognitive decline. At the outset of the COVID-19 pandemic, cognitive testing was increasingly performed remotely by telephone or video administration. It is desirable to have a harmonized composite measurement derived from both in-person and remote assessments for identifying cognitive changes and to examine its relationship with common neuroimaging biomarkers. Objective: We defined a telehealth compatible PACC (tPACC) and examined its relationship with neuroimaging biomarkers related to neurodegeneration, brain function and perfusion, white matter integrity, and amyloid-β. Methods: We examined 648 participants’ neuroimaging and in-person and …remote cognitive testing data from the Wake Forest Alzheimer’s Disease Research Center’s Clinical Core cohort (observational study) to calculate a modified PACC (PACC5-RAVLT) score and tPACC scores (in-person and remote). We performed Spearman/intraclass correlation coefficient (ICC) analyses for reliability of tPACC scores and linear regression models to evaluate associations between tPACC and neuroimaging. Bland-Altman plots for agreement were constructed across cognitively normal and impaired (mild cognitive impairment and dementia) participants. Results: There was a significant positive relationship between tPACCin - person and PACC5-RAVLT (Overall group: r2 = 0.94, N = 648), and tPACCin - person and tPACCremote (validation subgroup: ICC = 0.82, n = 53). Overall, tPACC showed significant associations with brain thickness/volume, gray matter perfusion, white matter free water, and amyloid-β deposition. Conclusions: There is a good agreement between tPACCand PACC5-RAVLTfor cognitively normal and impaired individuals. The tPACC is associated with common neuroimaging markers of Alzheimer’s disease. Show more
Keywords: Alzheimer’s disease, amyloid-beta, cognitive composite, cognitive decline, MRI, PET, reliability, telehealth testing
DOI: 10.3233/JAD-231435
Citation: Journal of Alzheimer's Disease, vol. 99, no. 2, pp. 679-691, 2024
Authors: Hughes, Timothy M. | Lockhart, Samuel N. | Suerken, Cynthia K. | Jung, Youngkyoo | Whitlow, Christopher T. | Bateman, James R. | Williams, Benjamin J. | Espeland, Mark A. | Sachs, Bonnie C. | Williamson, Jeff | Cleveland, Maryjo | Yang, Mia | Rogers, Samantha | Hayden, Kathleen M. | Baker, Laura D. | Craft, Suzanne
Article Type: Research Article
Abstract: Background: Cardiometabolic disorders (hypertension, diabetes) are key modifiable risk factors for Alzheimer’s disease and related disorders. They often co-occur; yet, the extent to which they independently affect brain structure and function is unclear. Objective: We hypothesized their combined effect is greater in associations with cognitive function and neuroimaging biomarkers of white matter (WM) health and cerebral perfusion in a diverse older adult cohort. Methods: Participants aged 50-85 years received: clinical evaluation, oral glucose tolerance testing, neuroimaging, cognitive testing, and adjudication. Neuroimaging included: T1 (gray [GM]/WM segmentation, regional volumes/thicknesses); FLAIR (WM hyperintensity volume [WMHv]; arterial spin labeling (cerebral blood flow); diffusion …tensor imaging (fractional anisotropy [FA]); and neurite orientation dispersion and density imaging (Free Water). Hypertension (HTN) and impaired glucose tolerance (IGT) were staged and cardiometabolic status was categorized (HTN only, IGT only, IGT+HTN, neither). Multivariable linear regression modeled associations with cognitive and neuroimaging measures (covariates: age, gender, race). Results: MRI was available for 478 participants (35% mild cognitive impairment, 10% dementia) with mean age 70±8 years, 74% with HTN, 61% with IGT, and 15% self-identified as Black/African-American. IGT+HTN was significantly associated with cognitive impairment, higher WM Free Water and WMHv, lower FA, and lower GM perfusion compared to neither factor. HTN alone was associated with poorer cognition and lower GM perfusion. Cardiometabolic factors were not associated with GM macrostructure (volumes, temporal lobe cortical thickness) or cognitive status. Conclusion: HTN and its co-occurrence with IGT (HTN+IGT) were associated with lower global cognitive performance and reduced GM perfusion and impaired WM microstructure. Show more
Keywords: Brain, cognition, hyperglycemia, hypertension
DOI: 10.3233/JAD-220646
Citation: Journal of Alzheimer's Disease, vol. 90, no. 4, pp. 1589-1599, 2022