Biomarkers.

Background: Tau PET tracers are employed to measure the accumulation of tau in vivo in the brain. Each tau tracer possesses unique characteristics, including binding affinity, sensitivity, and specificity to tau aggregates. This study leverages the HEAD study dataset, which is currently performing baseline tau PET tracers and conducting multiple clinical and cognitive assessments.

Biomarkers.

Background: Autosomal Dominant Alzheimer's Disease (ADAD) is a rare and early-onset form of Alzheimer's disease with a familial pattern of inheritance. While the pathological features of ADAD, such as amyloid plaques and neurofibrillary tangles, have been extensively studied, the involvement of white matter (WM) neuroinflammation is not well-explored. In sporadic AD, the hindered ratio (HR) derived from diffusion basis spectrum imaging (DBSI) has been used to study neuroinflammation in WM.

Biomarkers.

Background: Utilizing PET amyloid-beta (Aβ) and tau for staging Alzheimer's Disease (AD) has demonstrated potential in identifying individuals with varying degrees of disease severity, applicable to both clinical trials and practice. However, the diverse binding characteristics of tau tracers pose challenges to the application of this staging across different ligands. In this study, we evaluate a novel staging framework proposed by the AA working group, employing Aβ PET and either [F]MK6240 or [F]Flortaucipir in individuals participating in a head-to-head study of tau PET tracers.

Biomarkers.

Background: Brains affected by Alzheimer's disease (AD) exhibit senile plaques containing amyloid beta (Aβ) peptides and neurofibrillary tangles, formed when tau becomes hyperphosphorylated and disengages from microtubules (MTs). Early instability in MTs is observed in the AD process, emphasizing its significance in connecting the hallmark pathologies of Aβ/tau-based degenerative events. While current Aβ and tau PET approaches can characterize disease lesions, they fall short in capturing earlier molecular events.

Biomarkers.

Background: Tau PET provides continuous measurements of tau tangle pathology in the human brain. However, establishing cutoffs is crucial for selecting individuals for treatment in clinical trials or practice. In the absence of postmortem data, PET cutoffs must be established using statistical methods based on what is considered normal tracer uptake.

Biomarkers.

Background: Gaussian smoothing to a common image resolution is frequently employed to harmonize Aβ PET in multisite studies. However, spatial smoothing of PET can increase spill-over contamination between neighboring regions. Geometric transfer matrix partial volume correction (PVC) has been applied, in turn, to correct for such contamination.

Biomarkers.

Background: The HEAD study focuses on collecting an extensive dataset from various tau-PET tracers, aiming to establish robust anchor values, which are essential for harmonizing tau-PET measurements. Here, we aim to showcase the capability of converting 3D tau-PET images into a common scale using the Universal Tau-PET Scale, Uniτ (tau), and to use these 3D images to subsequently obtain ROIs as needed.

Methods: We assessed 185 individuals across the aging and AD spectrum from the HEAD study, with [F]Flortaucipir and [F]MK-6240 tau-PET tracers.

Biomarkers.

Background: Sarcopenia has been linked to brain atrophy and there is lack of information on specific muscle groups that may contribute to this link. The psoas muscles are sensitive to sarcopenia and thus may sensitively relate to brain aging and Alzheimer disease risk.

Method: This study utilized 7,149 healthy individuals across four sites (Mean age 53.

Biomarkers.

Background: Comparative information on how whole-body organs are linked with age and the brain is lacking.

Method: Overall, 7,149 healthy participants from four sites (Mean age 53.06 ± 12.

Biomarkers.

Background: Obesity in midlife, body mass index (BMI) of 30 kg/m or higher, is recognized as a contributor to Alzheimer disease (AD) later in life. Adiposity in visceral tissues such as liver is associated with increased systemic inflammation and impaired cognition. In this study, we aimed to investigate the relationship between MRI-derived Positron Density Fat Fraction (PDFF) and brain histology and neuroinflammation using Diffusion Basis Spectrum Imaging (DBSI) in cognitively normal midlife individuals.

Biomarkers.

Background: Tau PET imaging has become pivotal in understanding the pathophysiological processes underlying Alzheimer disease (AD). In individuals without amyloid pathology, there is evidence tau levels are elevated with increase age and that females show greater levels of binding. An unknown question is how consistent these effects are, and whether they are susceptible to methodological choices impacting PET quantification.

Biomarkers.

Background: Blood-based biomarkers able to detect atypical neuropathology could serve as a cost-effective and noninvasive screening to include participants with Down syndrome (DS) in anti-amyloid clinical trials. Accurately placing these novel biomarkers on the AD pathological cascade as proposed by the AT(N) framework informs relative disease progression of individuals. This work examines associations between plasma pTau217 accumulation, PET amyloid positivity, and cognitive status in adults with Down syndrome.

Biomarkers.

Background: Obesity in midlife is a risk factor for developing Alzheimer disease later in life. However, the metabolic and inflammatory effects of body fat varies based on its anatomical localization. In this study, we aimed to investigate the association of MRI-derived abdominal visceral and subcutaneous adipose tissue (VAT and SAT), liver proton-density fat fraction (PDFF), thigh fat-to-muscle ratio (FMR), and insulin resistance with whole-brain amyloid burden in cognitively normal midlife individuals.

Public Health.

Background: Estimates of the prevalence of preclinical amyloid positivity in the US general population are of great interest to the field, but difficult to measure and thus unavailable in representative studies. A statistical approach from causal inference, 'transport', may allow for improved generalizability of findings from a sample of persons from one population to another. We aimed to explore the feasibility and validity of extending results from a deeply-phenotyped convenience sample, the Alzheimer's Disease Neuroimaging Initiative (ADNI), to a representative target sample, the Atherosclerosis Risk in Communities Study PET Amyloid Imaging Study (ARIC-PET) - with "proof of concept" defined by the performance of the transport estimator in recovering the observed prevalence of amyloid positivity in ARIC-PET.

Public Health.

Background: With the rapid aging of the US population, the prevalence of dementia is projected to double. The enactment of the Affordable Care Act and Medicaid expansion could create opportunities for detection and classification of dementia. There are trends of increasing dementia mortality, however, it is unknown whether Medicaid expansion increased the reporting of dementia as the underlying cause of death (UCOD) or as a multiple cause of death (MCOD) among the elderly.

Public Health.

Background: Calculating an individual's risk for preclinical and symptomatic Alzheimer disease (AD) involves considering their experiences across the lifespan. This includes assessment of childhood experiences as risk factors for dementing disorders in later life.

Method: The Knight Alzheimer Disease Research Center (ADRC) examined the relationship of well-established AD biomarkers with childhood experiences as reported by research participants.

Public Health.

Background: While two-thirds of the 57 million people with dementia worldwide live in low- and middle-income countries, research to inform dementia-related policy in these regions remains scarce. We aimed to increase early dementia diagnosis and the use of standardized cognitive assessment by PCP in primary care settings in Cuba METHOD: We selected 16 Primary care clinics, with an estimated 160-200 providers. Clinics were carefully paired based on a number of providers, population demographics, and baseline rates of cognitive impairment diagnosis before being randomized into two groups: one to receive a targeted intervention and the other to continue with usual care practices.

Public Health.

Background: Although most individuals experiencing cognitive impairment reside with another, as many as one third may live alone. Such individuals may have difficulty managing their health and wellbeing. Further, they may be more isolated from healthcare and social services.

Public Health.

Background: Weight loss has been associated with Alzheimer's Disease (AD), suggesting the possibility that overweight may be protective against AD. Mendelian Randomization (MR) is a common method of revealing causal relationships in observational studies. Our recent MR analysis using the Health and Retirement Study (HRS) data found that overweight has a causal protective effect on late-onset-AD.

Public Health.

Background: Accumulating evidence indicates exercise may delay or prevent the onset of Alzheimer's disease (AD). To our knowledge, no study has investigated the longitudinal impact of exercise on AD-related biomarkers in individuals with Autosomal dominant Alzheimer's disease (ADAD) mutations who are destined to develop AD. This study examined longitudinal associations between self-reported exercise levels and AD-related biomarkers in a cohort of ADAD mutation carriers and investigated whether observed associations depended upon disease stage.

Public Health.

Background: Cross-national comparisons of dementia prevalence are essential for identifying unique determinants and cultural-specific risk factors, but methodological differences in dementia ascertainment across countries hinder global comparisons. This study maps the 10/66 Dementia Research Group algorithm for dementia ascertainment, widely used and validated in lower- and middle-income countries, to the U.S.

Public Health.

Background: The survival outcomes following an Alzheimer's disease (AD) diagnosis hold significant importance for health management, caregivers, patients, and their families. Hawaii is known as the most diverse ethnic population in the United States and there exist significant racial health disparities. This study investigates racial/ethnic disparities in survival among AD patients in Hawaii and develops Machine Learning models for overall survival prediction, utilizing Hawaii Medicare data.

Public Health.

Background: As disease-modifying treatments for Alzheimer's disease (AD) are becoming available in the US, concerns have been raised that an unprepared healthcare system will be unable to cope with the expected influx of patients. Individuals dually eligible for Medicare and Medicaid might be disproportionately affected by wait times for three reasons. They have higher burden of disease; many practices do not accept Medicaid at all and those who do might limit the number of Medicaid patients because of lower payment rates under the so-called lesser-of policy.

Public Health.

Background: Dramatically varying estimates of survival time following an initial diagnosis of Alzheimer's disease and other dementias have been reported across different studies. The prevalence of dementia increases with age while survival time decreases with increasing age at diagnosis. This study aimed to investigate how survival time after a diagnosis of dementia varies by sex, race/ethnicity, and age at time of diagnosis.

Public Health.

Background: Cholecystectomy is considered the definitive treatment option for cholecystitis, and patients living with Alzheimer's Disease and Related Dementias (PLWDs) are at risk for increased mortality, complications, and delirium. However, the effect of different treatment options for cholecystitis among PLWDs has not been elucidated; therefore, this study compares outcomes following cholecystectomy, cholecystostomy tube, and medical management of cholecystitis among this high-risk group.

Method: We conducted a retrospective analysis of Medicare claims data from 1/1/2016-12/31/2020.