Publications by authors named "Walter K Kremers"

Background: Plasma biomarkers for Alzheimer's disease and neurodegeneration have shown accurate prediction of underlying neuropathology. However, chronic cardiovascular risk factors such as diabetes and hypertension are associated with plasma biomarker levels and can influence the accurate prediction of underlying neuropathologic changes.

Objective: To understand the interaction between plasma biomarkers of Alzheimer's disease and neurodegeneration with cardiovascular risk factors in relation to neuropathologic change in a heterogenous population to ascertain a more accurate utilization of these biomarkers.

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Background: Previous case reports raised concerns about the cardiovascular effects of metal particles and ions produced by mechanical wear and corrosion of total joint arthroplasty (TJA) implants. We compared the long-term risk of heart failure in a cohort of individuals who had TJA and in a general population comparison cohort.

Methods: This was a population-based, retrospective cohort study of 7,182 TJA subjects who first had total hip arthroplasty (THA) or total knee arthroplasty surgeries between 1990 and 2020 and 7,407 age-, sex-, and calendar year-matched non-TJA subjects.

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Objective: The authors of this prospective cohort study sought to examine associations between mid- and late-life physical activities and incident clinical depression and anxiety among community-dwelling older adults.

Methods: The sample included 2,630 adults to examine the outcome of clinical depression (median follow-up length=5.4 years) and 2,444 to examine clinical anxiety (median follow-up length=5.

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Introduction: Alzheimer's disease and related dementias are public health and social care challenges. This study used the National Institute on Aging Health Disparities Research Framework to organize potential cognitive impairment risk factors. It aimed to examine patterns of environmental, sociocultural, behavioral, and biological factors and identify key components that predict mild cognitive impairment risk.

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Few normative data for unsupervised, remotely-administered computerized cognitive measures are available. We examined variables to include in normative models for Mayo Test Drive (MTD, a multi-device remote cognitive assessment platform) measures, developed normative data, and validated the norms. 1240 Cognitively Unimpaired (CU) adults ages 32-100 years (96% White) from the Mayo Clinic Study of Aging and Mayo Alzheimer's Disease Research Center with Clinical Dementia Rating of 0 were included.

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Background: Pharmacological treatments for fibrocalcific aortic valve stenosis (FCAVS) have been elusive for >50 years. Here, we tested the hypothesis that reactivation of oxidized sGC (soluble guanylate cyclase), the primary receptor for nitric oxide, with ataciguat is a safe and efficacious strategy to slow progression of FCAVS.

Methods: We used quantitative real-time reverse transcription polymerase chain reaction, Western blotting, and immunohistochemistry to characterize sGC signaling and the biological effects of ataciguat on signaling cascades related to nitric oxide, calcification, and fibrosis in excised human aortic valve tissue, aortic valve interstitial cells, and mouse aortic valves.

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Background: Mayo Test Drive (MTD): Mayo Test Development through Rapid Iteration, Validation and Expansion, is a web-based remote cognitive assessment platform for self-administered neuropsychological measures with previously demonstrated validity and reliability. We examined the usability of MTD and hypothesized that completion rates would be greater than 90%. We explored whether completion and participation rates differed by cognitive status and demographic factors.

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The study aimed to assess eligibility for donanemab phase 3 trial in participants of the Mayo Clinic Study of Aging with mild cognitive impairment (MCI) or mild dementia consistent with Alzheimer's disease (AD) clinical syndrome, positive brain amyloid burden, and available tau PET. There were 817 study participants, 60-85 years old, with MCI or dementia consistent with AD clinical syndrome. Applying the Mini-Mental State Examination criteria (20 to 28) and excluding participants with imaging contraindications reduced the sample to 769; 275 participants had amyloid PET available, of whom 130 had also tau PET at the same visit; 56 participants were amyloid positive, had tau PET available at the same visit, and of those, 27 had evidence of tau pathology measured by 18F-flortaucipir PET imaging.

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We examined whether total joint arthroplasty (TJA) is associated with increased metal accumulation in the brain and histopathologic changes of Alzheimer's disease. We measured ultra-trace metal concentrations (aluminum, chromium, cobalt, manganese, molybdenum, nickel, titanium, and vanadium) on postmortem frozen tissues of the occipital lobe of 177 subjects (89 non-TJA and 88 TJA) using a triple-quadrupole inductively coupled plasma mass spectrometry and correlated elemental concentrations to the degree of Alzheimer's disease neuropathic change (ADNC). To effectively assess the relationship between TJA and brain metal concentrations, subjects with and without TJA were matched for baseline clinical characteristics and showed no difference in postmortem Alzheimer's disease neuropathic change.

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Background: Declining gait performance is seen in aging individuals, due to neural and systemic factors. Plasma biomarkers provide an accessible way to assess evolving brain changes; non-specific neurodegeneration (NfL, GFAP) or evolving Alzheimer's disease (Aβ 42/40 ratio, P-Tau181).

Methods: In a population-based cohort of older adults, we evaluate the hypothesis that plasma biomarkers of neurodegeneration and Alzheimer's Disease pathology are associated with worse gait performance.

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Importance: Although 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a well-established cross-sectional biomarker of brain metabolism in dementia with Lewy bodies (DLB), the longitudinal change in FDG-PET has not been characterized.

Objective: To investigate longitudinal FDG-PET in prodromal DLB and DLB, including a subsample with autopsy data, and report estimated sample sizes for a hypothetical clinical trial in DLB.

Design, Setting, And Participants: Longitudinal case-control study with mean (SD) follow-up of 3.

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Cellular senescence is a biological mechanism of aging and age-related diseases. The aim of this study was to examine whether senescence biomarkers are associated with frailty and physical function trajectories in patients undergoing kidney transplantation (KT). We also discussed the relationship between senescence biomarkers and KT function.

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Article Synopsis
  • Physical activity (PA) in older adults is linked to improvements in gait speed and a reduced risk of falls, highlighting its importance for maintaining mobility.
  • A study followed over 4,000 individuals aged 50 and above for about four years, assessing their PA levels and various gait measures using advanced technology.
  • Results showed that higher PA, especially moderate-vigorous activity, correlated with better gait performance and significantly lowered fall risks over time.
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Background: Periprosthetic joint infection (PJI) is an uncommon, but serious complication in total joint arthroplasty. Personalized risk prediction and risk factor management may allow better preoperative assessment and improved outcomes. We evaluated different data-driven approaches to develop surgery-specific PJI prediction models using large-scale data from the electronic health records (EHRs).

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Objective: Few normative data for unsupervised, remotely-administered computerized cognitive measures are available. We examined variables to include in normative models for Mayo Test Drive (a multi-device remote cognitive assessment platform) measures, developed normative data, and validated the norms.

Method: 1240 Cognitively Unimpaired (CU) adults ages 32-100-years (96% white) from the Mayo Clinic Study of Aging and Mayo Alzheimer's Disease Research Center with Clinical Dementia Rating of 0 were included.

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Performance-based measures of frailty are associated with healthcare utilization after kidney transplantation (KT) but require in-person assessment. A promising alternative is self-reported frailty. The goal of this study was to examine the ability of performance-based and self-reported frailty measures to predict 30-day rehospitalizations after KT.

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Background: Studies that assess cognition prospectively and study in detail anxiety history in the participants' medical records within the context of brain aging and Alzheimer's disease are limited.

Objective: To examine the associations of anxiety and unspecified emotional distress (UED) acquired throughout a person's life with prospectively collected cognitive outcomes.

Methods: Mayo Clinic Study of Aging participants who were cognitively unimpaired at baseline were included.

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Background: Conventional normative samples include individuals with undetected Alzheimer's disease neuropathology, lowering test sensitivity for cognitive impairment.

Objective: We developed Mayo Normative Studies (MNS) norms limited to individuals without elevated amyloid or neurodegeneration (A-N-) for Rey's Auditory Verbal Learning Test (AVLT). We compared these MNS A-N- norms in female, male, and total samples to conventional MNS norms with varying levels of demographic adjustments.

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Objective: To evaluate the performance of Alzheimer disease (AD) cerebrospinal fluid (CSF) biomarkers in a tertiary neurology clinic setting with high frequency of non-AD cases, including normal pressure hydrocephalus (NPH).

Methods: There were 534 patients who underwent AD CSF biomarkers (Roche Elecsys Aβ42, p-Tau181, total-Tau) from April 1, 2020, through April 23, 2021. A behavioral neurologist blinded to CSF results assigned a clinical diagnosis retrospectively on the basis of consensus criteria, and a neuroradiologist blinded to the diagnosis and CSF studies graded brain magnetic resonance images for indicators of CSF dynamics disorders.

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In a previous study, we observed decreased 1,25-dihydroxyvitamin D levels, secondary hyperparathyroidism, and increased bone turnover markers in living kidney donors (LKDs) at 3 months and 36 months after kidney donation. In our recent survey-based study, we found no increased risk of fractures of all types but observed significantly more vertebral fractures in LKDs compared with matched controls. To elucidate the long-term effects of kidney donation on bone health, we recruited 139 LKDs and 139 age and sex matched controls from the survey-based participants for further mechanistic analyses.

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Background: Primary progressive aphasia (PPA) defines a group of neurodegenerative disorders characterised by language decline. Three PPA variants correlate with distinct underlying pathologies: semantic variant PPA (svPPA) with transactive response DNA-binding protein of 43 kD (TDP-43) proteinopathy, agrammatic variant PPA (agPPA) with tau deposition and logopenic variant PPA (lvPPA) with Alzheimer's disease (AD). Our objectives were to differentiate PPA variants using clinical and neuroimaging features, assess progression and evaluate structural MRI and a novel 18-F fluorodeoxyglucose positron emission tomography (FDG-PET) image decomposition machine learning algorithm for neuropathology prediction.

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Importance: Living kidney donors may have an increased risk of fractures due to reductions in kidney mass, lower concentrations of serum 1,25-dihydroxyvitamin D, and secondary increases in serum parathyroid hormone.

Objective: To compare the overall and site-specific risk of fractures among living kidney donors with strictly matched controls from the general population who would have been eligible to donate a kidney but did not do so.

Design, Setting, And Participants: This survey study was conducted between December 1, 2021, and July 31, 2023.

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Article Synopsis
  • The study analyzed 1,738 participants aged 50 and older from the Mayo Clinic Study of Aging, focusing on the relationship between cerebrovascular imaging markers and mental health indicators.
  • It found that a high burden of white matter hyperintensities (WMH) was significantly linked to increased depression and anxiety scores among participants.
  • Additionally, both cerebrovascular biomarkers and mental health issues were independently associated with an increased likelihood of mild cognitive impairment (MCI).
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Objective: Normative neuropsychological data are essential for interpretation of test performance in the context of demographic factors. The Mayo Normative Studies (MNS) aim to provide updated normative data for neuropsychological measures administered in the Mayo Clinic Study of Aging (MCSA), a population-based study of aging that randomly samples residents of Olmsted County, Minnesota, from age- and sex-stratified groups. We examined demographic effects on neuropsychological measures and validated the regression-based norms in comparison to existing normative data developed in a similar sample.

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