Contribution of Alzheimer disease to mortality in the United States

Natural Products in the Treatment of Neuroinflammation at Microglia: Recent Trend and Features

Natural products (NPs) are considered to be the oldest medicine in human history and numerous NPs have been investigated to search for therapeutic agents in various diseases. Neurodegenerative diseases such as dementia, Parkinson's, Alzheimer's, and Huntington's disease have been increasing following the extension of human lifespans. Neuroinflammation is a key factor in the genesis of several neurodegenerative diseases; therefore, many studies have been focused on finding therapeutics for the reduction in neuroinflammation. Microglia cells are found in the central nervous system (CNS) and these play a crucial role in the regulation of neuroinflammation; thus, the importance of microglia research has been recognized. This review focuses on recent research trends in finding neuroinflammatory regulators in microglia by using NPs.

Using a standardized assessment tool to identify patients for referral to discuss and understand their goals of care

INTRODUCTION

Dementia, a terminal illness, deteriorates the physical and mental health as it advances. Discussing goals of care (GOC) is important in these patients but there is no standard way to identify these patients.

PURPOSE

Identify patients that can be referred for GOC discussion based on their quality of life (QOL) by utilizing dementia quality of life (DEMQOL) or DEMQOL carer tools.

METHODS

The study was conducted in a nursing home in long-term care patients diagnosed with dementia. Patients who scored less than 90 in assessment tools were referred for GOC discussion.

RESULTS

20 patients and family participated in the study. Unit A had total of 62.5% referral rate, unit B had 66.7%, and unit C had 66.7%. Total referrals showed increased number of patients that were referred for goals of care discussion.

CONCLUSION

Utilization of QOL assessment tools is feasible in nursing home. DEMQOL/DEMQOL carer, an assessment tool helped identify patients for GOC discussion.

Sleep Timing, Sleep Timing Regularity, and Cognitive Performance in Women Entering Late Adulthood: The Study of Women's Health Across the Nation (SWAN)

STUDY OBJECTIVES

This study examined whether sleep timing and its regularity are associated with cognitive performance in older women and whether associations vary based on cardiometabolic risk factors.

METHODS

The cross-sectional analysis included 1,177 community-dwelling females (mean age 65 years) from the observational Study of Women's Health Across the Nation (SWAN) annual visit 15. Sleep timing (mean midpoint from sleep onset to wake-up) and its regularity (standard deviation of midpoint ) were assessed using actigraphy. Cognitive measures included immediate and delayed verbal memory, working memory, and processing speed. Cardiometabolic risk measures included central obesity, hypertension, diabetes, and the Atherosclerotic Cardiovascular Disease (ASCVD) risk score. Linear regression models, adjusted for covariates, tested associations between sleep and cognitive measures.

RESULTS

After covariate adjustment, early sleep timing was associated with worse delayed verbal memory (β = -0.37; p = 0.047) and late sleep timing was associated with worse processing speed (β = -1.80; p = 0.008). Irregular sleep timing was associated with worse immediate (β = -0.29; p = 0.020) and delayed verbal memory (β = -0.36; p= 0.006), and better working memory (β = 0.50; p = 0.004). Associations between early sleep timing and delayed verbal memory strengthened as ASCVD risk increased (interaction β=-8.83, p=.026), and tsleep timing irregularity's effect on-working memory was stronger among women with hypertension (interaction β = -3.35, p = .039).

CONCLUSIONS

Sleep timing and its regularity are concurrently associated with cognitive performance in older women. Cardiovascular disease risk may modify some of these associations. Future longitudinal studies are needed to clarify these relationships.

The effect of a students led caregiving support program on depression, sleep quality and quality of life of the caregivers and patients with stroke

PURPOSE

We aimed to provide care support to stroke patients and their caregivers and investigate this support's impact on the psychosocial characteristics of patients', caregivers', and volunteer students' depression, quality of life, and sleep quality.

MATERIAL/METHODS

Volunteer students received caregiving training and provided support to caregivers at patients' homes. Caregivers received care support through the project for four sessions, once a week. Depression levels were assessed using the Beck Depression Scale, quality of life with RAND-36, sleep quality with the Pittsburgh Sleep Quality Index.

RESULTS

The study included 15 patients after stroke, 15 caregivers, and a total of 30 students participated in delivering the intervention. We observed that physical function (d = 0.52) and social function (d = 0.67) showed significant improvements with moderate effect sizes in caregivers. In patients, Energy/Vitality (d = 0.86) showed a significant and large effect size, and pain reduction (d = 0.78) demonstrated a significant, moderate effect size. For students, Emotional Role Difficulty had a significant improvement with a moderate effect size.

CONCLUSIONS

Overall, the findings suggest that the project led to meaningful benefits for all involved, particularly in enhancing quality of life parameters. It was found that all participants were extremely satisfied with the study and thought that it should be expanded.

Impaired insulin signaling and diet-induced type 3 diabetes pathophysiology increase amyloid β expression in the Drosophila model of Alzheimer's disease

Compelling evidence has strongly linked unregulated sugar levels to developing Alzheimer's disease, suggesting Alzheimer's to be 'diabetes of the brain or 'type 3 diabetes. Insulin resistance contributes to the pathogenesis of Alzheimer's disease due to uncontrolled and unchecked blood glucose, though the interrelatedness between Alzheimer's disease and type 2 diabetes is debatable. Here we describe the consequences of inducing type 3 diabetes by feeding Drosophila on a high sucrose diet, which effectively mimics the pathophysiology of diabetes. A high sucrose diet increases glycogen and lipid accumulation. Inducing type 3 diabetes worsened neurodegeneration and accelerated disease progression in Drosophila expressing the Alzheimer's Familial Arctic mutation. High sucrose milieu also negatively affected locomotor ability and reduced the lifespan in the Alzheimer's disease model of Drosophila. The results showed that creating diabetic conditions by using insulin receptor (InR) knockdown in the eyes of Drosophila led to a degenerative phenotype, indicating a genetic interaction between the insulin signaling pathway and Alzheimer's disease. The expression of PERK reflects disruption in the endoplasmic reticulum homeostasis due to amyloid-β (Aβ) under a high sucrose diet. These observations demonstrated an association between type 3 diabetes and Alzheimer's disease, and that a high sucrose environment has a degenerating effect on Alzheimer's disease condition.

The impact of cardiovascular and cerebrovascular disease on the risk of dementia in rheumatoid arthritis: A mediation analysis

OBJECTIVE

To examine the role of cardiovascular disease (CVD) as a mediator in the pathway between rheumatoid arthritis (RA) and Alzheimer's disease and related dementias (ADRD).

METHODS

This retrospective population-based study included patients over 50 years of age with incident RA, who met the 1987 ACR criteria in 1980-2014. This cohort was matched 1:1 on age, sex and index year to comparators without RA. Information on CVD events was manually extracted from electronic health records. The relationships between RA, CVD and ADRD were examined using Cox proportional hazard models. Time dependent mediation analysis was used to examine the role of CVD as a mediator between RA and ADRD.

RESULTS

1754 individuals were included (877 persons with RA and 877 comparators without RA). During follow-up, 105 patients with RA and 102 individuals without RA developed ADRD; 444 patients with RA and 375 individuals without RA developed CVD. There was a non-significant association between RA and ADRD both without (aHR 1.27, 95 % CI 0.96, 1.69) and with (aHR 1.27, 95 % CI 0.95,1.68) CVD as a time dependent mediator. The mediation effect of any CVD on ADRD risk was not significant (p = 0.84). We found a significant interaction between RA and CVD on the risk of ADRD (aHR 1.95, 95 % CI 1.11, 3.42; p = 0.021).

CONCLUSIONS

The risk of ADRD in RA appears to be increased mainly in the presence of CVD. CVD was not a significant mediator on the risk of ADRD in RA. There was a significant synergistic effect of RA and CVD on ADRD risk.

Evaluating the Regional and Demographic Variations in Dementia-Related Mortality Trends in the United States: 1999 to 2020

INTRODUCTION

Dementia, a term for a range of cognitive impairments impacting memory, thinking, and social abilities, represents a formidable challenge to healthcare systems worldwide. Analysing the temporal trends in dementia-related mortality among individuals, identifying the populations at high risk, and guiding the implementation of tailored interventions to address the escalating effects of dementia on public health.

METHODS

Data from CDC WONDER database was examined from 1999 to 2020 for the four causes of dementia mortality: unspecified dementia (F03), Alzheimer's disease (G30), vascular dementia (F01), and other degenerative diseases of nervous system not elsewhere classified (G31). Age-adjusted mortality rates (AAMRs) per 100,000 persons and annual percent change (APC) were calculated and stratified by geographic region, year, age groups, sex, and race/ethnicity.

RESULTS

A total of 4,077,973 reported deaths were related to dementia from 1999 to 2020 in the United States. The greatest proportion of deaths was associated with Alzheimer's disease (45.9%), followed by unspecified dementia (43.8%). Very low proportion of deaths were associated with vascular dementia (4.9%) or other neurodegenerative diseases (5.3%). The AAMR increased in two distinct periods: a steep incline from 1999 to 2010 (APC: 6.95, 95% CI: 6.00-7.90), followed by a modest incline till 2020 (APC: 1.41, 95% CI: 0.80-2.04). Overall, females had a higher AAMR than males. AAMRs were highest among NH Whites patients and lowest in NH Asians or Pacific Islanders. A significant geographical difference was also observed among different US census regions. Nearly equal AAMRs were seen in non-metropolitan areas and metropolitan areas. States with AAMRs in the top 90th percentile included South Carolina, North Carolina, Maine, Tennessee, Georgia, and Alabama while states with AAMRs in the bottom 10th percentile included South Dakota, Florida, Hawaii, New Jersey, District of Columbia, and New York (33.1). Individuals aged above 85 had the highest AAMRs. Most deaths occurred in nursing homes and least in hospice facilities.

CONCLUSION

The dementia related deaths are continuously increasing. Highest AAMRs were observed among the NH White people, females, and in the southern areas of the United States. People aged 85+ were most affected. To stop the rising death rates, targeted interventions and awareness are required for both prevention and treatment of dementia.

A systematic review of clinical efficacy and safety of cell-based therapies in Alzheimer's disease

There is presently no disease-modifying therapy for Alzheimer's Disease (AD), which is the most prevalent cause of dementia.

Objective

This study aspires to estimate the efficacy and safety of cell-based treatments in AD.

Methods

Observing the Joanna Briggs Institute (JBI) methods and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, a systematic search was accomplished in PubMed, Medical Literature Analysis and Retrieval System Online (Medline, via Ovid), Embase; Cochrane, and Cumulative Index of Nursing and Allied Health Literature - CINAHL (via EBSCO) databases up to June 2023. The relevant clinical studies in which cell-based therapies were utilized to manage AD were included. The risk of bias was evaluated using the JBI checklists, based on the study designs.

Results

Out of 1,014 screened records, a total of five studies with 70 individuals (including 59 patients receiving stem cells and 11 placebo controls) were included. In all these studies, despite the discrepancy in the origin of stem cells, cell density, and transplant site, safety goals were obtained. The intracerebroventricular injection of adipose-derived stromal vascular fraction (ADSVF) and umbilical cord-derived mesenchymal stem cells (UC-MSCs), the intravenous injection of Lomecel-B, and the bilateral hippocampi and right precuneus injection of UC-MSCs are not linked to any significant safety concerns, according to the five included studies. Studies also revealed improvements in biomarkers and clinical outcomes as a secondary outcome. Three studies had no control groups and there are concerns regarding the similarity of the groups in others. Also, there is considerable risk of bias regarding the outcome assessment scales.

Conclusion

Cell-based therapies are well tolerated by AD patients, which emphasizes the need for further, carefully planned randomized studies to reach evidence-based clinical recommendations in this respect.

Case Definition for Diagnosed Alzheimer Disease and Related Dementias in Medicare

Importance

Lack of a US dementia surveillance system hinders efforts to support and address disparities among persons living with Alzheimer disease and related dementias (ADRD).

Objective

To review diagnosis and prescription drug code ADRD identification algorithms to develop and implement case definitions for national surveillance.

Design, Setting, and Participants

In this cross-sectional study, a systematic literature review was conducted to identify unique International Statistical Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) and prescription drug codes used by researchers to identify ADRD in administrative records. Code frequency of use, characteristics of beneficiaries identified by codes, and expert and author consensus around code definitions informed code placement into categories indicating highly likely, likely, and possible ADRD. These definitions were applied cross-sectionally to 2017 to 2019 Medicare fee-for-service (FFS) claims and Medicare Advantage (MA) encounter data to classify January 2019 Medicare enrollees. Data analysis was conducted from September 2022 to March 2024.

Exposures

ICD-10-CM and national drug codes in FFS claims or MA encounters.

Main Outcomes and Measures

The primary outcome was counts and rates of beneficiaries meeting each case definition. Category-specific age, sex, race and ethnicity, MA enrollment, dual-eligibility, long-term care utilization, mortality, and rural residence distributions, as well as frailty scores and FFS monthly expenditures were also analyzed. Beneficiary characteristics were compared across categories, and age-standardized to minimize confounding by age.

Results

Of the 60 000 869 beneficiaries included (50 853 806 aged 65 years or older [84.8%]; 32 567 891 female [54.3%]; 5 555 571 Hispanic [9.3%]; 6 318 194 non-Hispanic Black [10.5%]; 44 384 980 non-Hispanic White [74.0%]), there were 4 312 496 (7.2%) with highly likely ADRD, 1 124 080 (1.9%) with likely ADRD, and 2 572 176 (4.3%) with possible ADRD, totaling more than 8.0 million with diagnostic evidence of at least possible ADRD. These beneficiaries were older, more frail, more likely to be female, more likely to be dual-eligible, more likely to use long-term care, and more likely to die in 2019 compared with beneficiaries with no evidence of ADRD. These differences became larger when moving from the possible ADRD group to the highly likely ADRD group. Mean (SD) FFS monthly spending was $2966 ($4921) among beneficiaries with highly likely ADRD compared with $936 ($2952) for beneficiaries with no evidence of ADRD. Differences persisted after age standardization.

Conclusions and Relevance

This cross-sectional study of 2019 Medicare beneficiaries identified more than 5.4 million Medicare beneficiaries with evidence of at least likely ADRD in 2019 using the diagnostic case definition. Pending validation against clinical and other methods of ascertainment, this approach can be adopted provisionally for national surveillance.

Exploring the therapeutic potential of steroidal alkaloids in managing Alzheimer's disease

Steroidal alkaloids are secondary metabolites that are often found in plants, fungi and sponges. These compounds are considered as a source of bioactive compounds for the treatment of chronic diseases, such as neurological disorder like Alzheimer's disease (AD). Some examples of alkaloid derivatives currently used to treat AD symptoms include galantamine, huperzine A, and other alkaloids. AD is a multifactorial disease caused by multiple factors such as inflammation, oxidative stress, and protein aggregation. Based on the various important neuroprotective activities and different pharmacological effects of steroidal alkaloids with polypharmacological modulatory effects, they can lead to the development of new drugs for the treatment of AD. There are limited studies on the involvement of steroidal alkaloids in AD. Therefore, the mechanisms and neuroprotective abilities of these compounds are still poorly understood. The purpose of this review article is to provide an overview of the mechanism, toxicity and neuroprotective benefits of steroidal alkaloids and to discuss future possibilities to improve the application of steroidal alkaloids as anti-AD agents. The therapeutic value and limitations of the steroidal alkaloid are investigated to provide new perspectives for future clinical development studies.

Pretransplant Cognitive Function and Kidney Transplant Outcomes: A Prospective Cohort Study

Background & Hypothesis

Cognitive impairment is common in patients being evaluated for a kidney transplant (KT). The association between pretransplant cognitive function and posttransplant outcomes is unclear.

Study Design

We performed a prospective cohort study to assess the association between pretransplant cognitive function and clinically relevant posttransplant outcomes.

Setting and Population

In this single center study, participants from the transplant clinic were evaluated during their pretransplant clinic visits and followed prospectively.

Outcomes

Our primary outcome measure was allograft function. Secondary outcomes were length of hospitalization for KT, hospital readmission within 30 and 90 days, graft loss, graft rejection within 90 days and 1 year, and mortality.

Analytic Approach

We measured cognitive function with the Montreal Cognitive Assessment (MoCA) test. We assessed the association of pretransplant MoCA score with posttransplant outcomes; we used linear mixed effects models to assess the association with the change in estimated glomerular filtration rate, Poisson regression for length of hospitalization, Cox proportional hazard model for graft loss and mortality, and a logistic regression model for readmission and rejection.

Results

We followed 501 participants for 2.7 ± 1.5 years. The mean age of the patients was 53 ± 14 years and the mean pretransplant MoCA score was 25 ± 3. Lower pretransplant MoCA scores did not adversely affect the primary outcome of allograft function or the secondary outcomes. Although higher MoCA scores predicted a higher decline in graft function (β = -0.28, 95% CI: -0.55 to -0.01, P = 0.04), the effect was small and not clinically significant. Older age was associated with longer hospitalization, lower likelihood of rejection, and higher mortality. Deceased donor KT (vs living donor KT) was associated with longer hospitalization but better graft function. Longer time receiving dialysis before KT was associated with longer hospitalization. A history of diabetes mellitus was associated with higher mortality.

Limitations

Single center study limiting generalizability.

Conclusions

Pretransplant MoCA scores were not associated with the primary outcome of allograft function or the secondary outcomes.

Depressive symptoms-Not a predictor for five-year mortality in patients with subjective cognitive decline, non-amnestic and amnestic mild cognitive impairment

The main aim of the present study is to evaluate the influence of depressive symptoms on mortality in patients with SCD (subjective cognitive decline), naMCI (non-amnestic mild cognitive impairment), and aMCI (amnestic mild cognitive impairment). Additional factors (age, sex, years of school attendance, and neuropsychological performance) were considered to determine the impact on survival probability. A monocentric retrospective data analysis based on adjusted patient protocols (n = 1221) from the observation period 1998-2021, using the Cox Proportional Hazards model, assessed whether depressivity had an explanatory value for survival, considering SCD as the reference level in relation to naMCI and aMCI. Covariates were included blockwise. Cox regression revealed that depressiveness (Beck Depression Inventory, Geriatric Depression Scale) did not make a significant contribution as a risk factor for mortality in all five model blocks, BDI-II with HR 0.997 [0.978; 1.02] and GDS-15 with HR 1.03 [0.98; 1.08]. Increasing age with HR 1.09 [1.07; 1.11] and male sex with HR (inverted) 1.53 [1.17; 2.00] appeared as risk factors for increased mortality across all five model blocks. aMCI (vs. SCD) with HR 1.91 [1.33; 2.76] showed a significant explanatory value only up to the fourth model block. By adding the six dimensions of the Neuropsychological Test Battery Vienna in the fifth model block, the domains attention and perceptual speed with HR 1.34 [1.18; 1.53], and executive functions with HR 1.24 [1.11; 1.39], showed substantial explanatory values for survival. Accordingly, no tendency can be attributed to depressiveness as a risk factor on the probability of survival, whereas the influence of certain cognitive dimensions, especially attention and perceptual speed, and executive functions, can be seen as protective for survival.

Associations of cognitive impairment and functional limitation with all-cause mortality risk in older adults: A population-based study from the National Health and Nutrition Examination Survey

Cognitive impairment and functional limitation are commonly observed in older adults. They have a complex correlation, and both are risk factors for mortality. This prospective cohort study aimed to explore the independent and joint impact of cognitive impairment and functional limitations on all-cause mortality in older adults. A total of 3,759 participants aged ≥ 60 years who had available information on mortality data, cognitive function, physical function, and covariates were enrolled. Cox proportional hazards regression models were employed to assess the independent and joint impacts of cognitive impairment and functional limitation on all-cause mortality. Smoothing curve fitting was used to show the nonlinear relationship between the Digit Symbol Coding (DSC) score and all-cause mortality. An interaction between cognitive impairment and functional limitation was identified when examining their associations with all-cause mortality. Cognitive impairment and functional limitation independently correlated with all-cause mortality risk even after adjusting for covariates and performing mutual adjustments (HR for cognitive impairment: 1.34, 95% CI 1.15-1.56; HR for functional limitation: 1.50, 95% CI 1.32-1.70). When the DSC score was > 18, as the score increased, the risk of death significantly decreased (HR 0.99, 95% CI 0.98-0.99). Participants with both cognitive impairment and functional limitation had the highest hazard ratio for all-cause mortality (HR 1.98, 95%CI 1.63-2.40). In summary, cognitive impairment and functional limitation independently correlated with increased all-cause mortality risk. A higher DSC score was a protective factor reducing the premature mortality risk. Older adults with cognitive impairment and functional limitation demonstrated the highest all-cause mortality risk.

Detection of mild cognitive impairment based on attention mechanism and parallel dilated convolution

Mild cognitive impairment (MCI) is a precursor to neurodegenerative diseases such as Alzheimer's disease, and an early diagnosis and intervention can delay its progression. However, the brain MRI images of MCI patients have small changes and blurry shapes. At the same time, MRI contains a large amount of redundant information, which leads to the poor performance of current MCI detection methods based on deep learning. This article proposes an MCI detection method that integrates the attention mechanism and parallel dilated convolution. By introducing an attention mechanism, it highlights the relevant information of the lesion area in the image, suppresses irrelevant areas, eliminates redundant information in MRI images, and improves the ability to mine detailed information. Parallel dilated convolution is used to obtain a larger receptive field without downsampling, thereby enhancing the ability to acquire contextual information and improving the accuracy of small target classification while maintaining detailed information on large-scale feature maps. Experimental results on the public dataset ADNI show that the detection accuracy of the method on MCI reaches 81.63%, which is approximately 6.8% higher than the basic model. The method is expected to be used in clinical practice in the future to provide earlier intervention and treatment for MCI patients, thereby improving their quality of life.

Novel Biomarkers for Alzheimer's Disease: Plasma Neurofilament Light and Cerebrospinal Fluid

Neurodegenerative disorders such as Alzheimer's disease (AD) represent an increasingly significant public health concern. As clinical diagnosis faces challenges, biomarkers are becoming increasingly important in research, trials, and patient assessments. While biomarkers like amyloid-β peptide, tau proteins, CSF levels (Aβ, tau, and p-tau), and neuroimaging techniques are commonly used in AD diagnosis, they are often limited and invasive in monitoring and diagnosis. For this reason, blood-based biomarkers are the optimal choice for detecting neurodegeneration in brain diseases due to their noninvasiveness, affordability, reliability, and consistency. This literature review focuses on plasma neurofilament light (NfL) and CSF NfL as blood-based biomarkers used in recent AD diagnosis. The findings revealed that the core CSF biomarkers of neurodegeneration (T-tau, P-tau, and Aβ42), CSF NFL, and plasma T-tau were strongly associated with Alzheimer's disease, and the core biomarkers were strongly associated with mild cognitive impairment due to Alzheimer's disease. Elevated levels of plasma and cerebrospinal fluid NfL were linked to decreased [18F]FDG uptake in corresponding brain areas. In participants with Aβ positivity (Aβ+), NfL correlated with reduced metabolism in regions susceptible to Alzheimer's disease. In addition, CSF NfL levels correlate with brain atrophy and predict cognitive changes, while plasma total tau does not. Plasma P-tau, especially in combination with Aβ42/Aβ40, is promising for symptomatic AD stages. Though not AD-exclusive, blood NfL holds promise for neurodegeneration detection and assessing treatment efficacy. Given the consistent levels of T-tau, P-tau, Aβ42, and NFL in CSF, their incorporation into both clinical practice and research is highly recommended.

Trends in cause-specific mortality among persons with Alzheimer's disease in South Carolina: 2014 to 2019

Introduction

Inconsistencies of reports contributes to the underreporting of Alzheimer's disease (AD) on death certificates. Whether underreporting exists within South Carolina has not been studied.

Methods

We conducted a prospective, population-based study on a cohort of persons (N = 78,534) previously diagnosed with AD and died between 2014-2019. We linked vital records with the South Carolina Alzheimer's Disease and Related Dementias Registry to investigate their cause of death and survival rates. Descriptive analyses calculated frequencies of demographic and health-related characteristics. Turnbull's method estimated the survival probabilities for different subgroups of patients. Hazard ratios were computed from the Cox proportional hazards model, adjusting for the following confounding variables of age at diagnosis, education level, gender, and race.

Results

The top immediate cause of death was Alzheimer's disease among all racial groups, except for Native American/American Indian. More females (60.3%) were affected by AD compared to males (39.7%). There is a 25% probability of survival, beyond 5 years, after AD diagnosis. Black/African American AD patients have the smallest risk of all-cause mortality across all racial/ethnic groups (HR 0.87; 95% CI, 0.85-0.89). Individuals with lower education had a lower likelihood of mortality.

Conclusion

Although AD was not underreported in the state of South Carolina further research is needed to develop protocols around classification of deaths among those diagnosed with dementia and comorbidities, including cardiovascular disease, to ensure dementia is properly reported as we move to prevent and treat Alzheimer's disease by 2025 and beyond.

Clinical Characterization of Veterans With Alzheimer Disease by Disease Severity in the United States

PURPOSE

We aimed to examine the clinical characteristics of US veterans who underwent neurocognitive test score-based assessments of Alzheimer disease (AD) stage in the Veterans Affairs Healthcare System (VAHS).

METHODS

Test dates for specific stages of AD were referenced as index dates to study behavioral and psychological symptoms of dementia (BPSD) and other patient characteristics related to utilization/work-up and time to death.

PATIENTS

We identified veterans with AD and neurocognitive evaluations using the VAHS Electronic Health Record (EHR).

RESULTS

Anxiety and sleep disorders/disturbances were the most documented BPSDs across all AD severity stages. Magnetic resonance imaging, neurology and psychiatry consultations, and neuropsychiatric evaluations were slightly higher in veterans with mild AD than in those at later stages. The overall average time to death from the first AD severity record was 5 years for mild and 4 years for moderate/severe AD.

CONCLUSION

We found differences in clinical symptoms, healthcare utilization, and survival among the mild, moderate, and severe stages of AD. These differences are limited by the low documentation of BPSDs among veterans with test score-based AD stages. These data support the hypothesis that our cohorts represent coherent subgroups of patients with AD based on disease severity.

Olfactory identification, cognition, depressive symptoms, and 5-year mortality in patients with subjective cognitive decline, mild cognitive impairment, and Alzheimer's disease

OBJECTIVE

An association between odor and cognitive impairment has been shown in many studies. The objective of the present hospital-based, single-center retrospective study was to assess the impact of odor impairment on the mortality of patients with Alzheimer's disease (AD), subjective cognitive decline (SCD), and mild cognitive impairment (MCI).

METHODS

Odor function was measured by Sniffin Sticks (Burghart Messtechnik, Holm, Germany) and the assessment of self-reported olfactory functioning and olfaction-related quality of life (ASOF) test. Cognitive performance was assessed by an extensive neuropsychological test battery, symptoms of depression were diagnosed with the Geriatric Depressive Scale (GDS). The influence of demographic factors such as gender, age, and education were examined.

RESULTS

Although the univariate analyses and pairwise post hoc comparison showed significant differences for some of the olfactory performance tests/subtests, the multivariate models showed no association between olfactory test performance and mortality among patients with cognitive impairment. "Attention," a domain of the Neuropsychological Test Battery Vienna (NTBV), as well as depressive symptoms, gender, and age, showed a significant influence on the mortality of the patient group.

CONCLUSION

Lower olfactory performance showed no impact on mortality. However, decreased cognitive function of "Attention" can be considered as an influential predictor for mortality.

The Role of Vitamin K in the Development of Neurodegenerative Diseases

Neurodegenerative diseases are a growing global health problem with enormous consequences for individuals and society. The most common neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases, can be caused by both genetic factors (mutations) and epigenetic changes caused by the environment, in particular, oxidative stress. One of the factors contributing to the development of oxidative stress that has an important effect on the nervous system is vitamin K, which is involved in redox processes. However, its role in cells is ambiguous: accumulation of high concentrations of vitamin K increases the content of reactive oxygen species increases, while small amounts of vitamin K have a protective effect and activate the antioxidant defense systems. The main function of vitamin K is its involvement in the gamma carboxylation of the so-called Gla proteins. Some Gla proteins are expressed in the nervous system and participate in its development. Vitamin K deficiency can lead to a decrease or loss of function of Gla proteins in the nervous system. It is assumed that the level of vitamin K in the body is associated with specific changes involved in the development of dementia and cognitive abilities. Vitamin K also influences the sphingolipid profile in the brain, which also affects cognitive function. The role of vitamin K in the regulation of biochemical processes at the cellular and whole-organism levels has been studied insufficiently. Further research can lead to the discovery of new targets for vitamin K and development of personalized diets and therapies.

Moderate and vigorous leisure time physical activity in older adults and Alzheimer's disease-related mortality in the USA: a dose-response, population-based study

BACKGROUND

Data for the dose-response associations of moderate physical activity (MPA) and vigorous physical activity (VPA) with Alzheimer's disease-related mortality are scarce. We aimed to examine the prospective associations of such activity with Alzheimer's disease-related mortality.

METHODS

In this dose-response, population-based study, we pooled data from 22 consecutive waves of the US National Health Interview Survey (from 1997 to 2018). Participants aged 68 years or older were included in the study if they had full data for physical or muscle-strengthening activity, chronic conditions, functional limitations, marital status, education level, alcohol consumption, smoking status, and BMI, and follow-up time after study entry. Participants were linked to the National Death Index until Dec 31, 2019. We defined Alzheimer's disease-related mortality as a leading cause by using the G-30 code of the International Statistical Classification of Diseases and Related Health Problems tenth revision. Information on MPA and VPA was self-reported, with participants asked to answer four questions on the frequency and duration of both types of physical activity. We calculated hazard ratios (HRs) and used restricted cubic splines models to assess dose-response associations, and we estimated the annual number of Alzheimer's disease-related deaths that could be prevented through physical activity using adjusted population attributable fractions.

FINDINGS

After excluding 21 377 participants, 91 298 adults were included in the analysis. The weighted mean participant age was 75·8 years (SE 0·0); 55 658 (56·7%) were female and 76 796 (87·6%) were White (weighted percentages). The median follow-up was 6·5 years (IQR 3·6-10·7), corresponding to 703 393 person-years. 2176 (2·4%) participants died due to Alzheimer's disease as the leading cause. For MPA, we did not find a significant dose-response association with Alzheimer's disease-related mortality, whereas for VPA, we observed a significant L-shaped association between 20 weekly min and 190 weekly min. For VPA, we identified a minimal amount (ie, 50% of the optimal amount) at 40 min/week (HR 0·91, 95% CI 0·84-0·95) and an optimal amount (ie, the nadir of the curve) at 140 min/week (0·79, 0·66-0·95) for reducing Alzheimer's disease-related mortality. For the USA, we estimated that 40 weekly min of VPA would prevent 12 238 deaths per year (95% CI 89-23 172) and 140 weekly min of VPA would prevent 37 710 deaths per year (311-63 567), compared with a scenario in which US adults did not do any VPA.

INTERPRETATION

These findings might inform future guidelines for preventing Alzheimer's disease-related mortality by emphasising the importance of VPA over MPA and providing specific VPA targets.

FUNDING

None.

Alzheimer Disease: A Life-Limiting Disease With a Burden of a Terminal Illness

Purpose of Review

An estimated 6.5 million Americans live with Alzheimer dementia. Better understanding of advanced stages of Alzheimer disease (AD) and timely monitoring of its preventable complications would translate to improved survival and quality of life in this population.

Recent Findings

In this perspective review, we proposed shifting the narrative to recognizing AD as a chronic life-limiting illness instead of a terminal disease. In support of this view, we discussed the following: (1) the biochemical, cellular (preclinical), and clinical phases of AD; (2) survival after AD; (3) AD therapeutics and potential implications for the population with AD in the advanced stages.

Summary

On the bases of the prolonged preclinical phase in AD, promising advances in AD therapeutics and the varying survival after AD, we proposed a new classification for AD and more broadly neurodegenerative disorders to be recognized as chronic life-limiting illnesses rather than terminal diseases with important implications for patients with AD in the advanced stages given the challenges that are specific to this population.

Vascular determinants of hippocampal viscoelastic properties in healthy adults across the lifespan

Arterial stiffness and cerebrovascular pulsatility are non-traditional risk factors of Alzheimer's disease. However, there is a gap in understanding the earliest mechanisms that link these vascular determinants to brain aging. Changes to mechanical tissue properties of the hippocampus (HC), a brain structure essential for memory encoding, may reflect the impact of vascular dysfunction on brain aging. We tested the hypothesis that arterial stiffness and cerebrovascular pulsatility are related to HC tissue properties in healthy adults across the lifespan. Twenty-five adults underwent measurements of brachial blood pressure (BP), large elastic artery stiffness, middle cerebral artery pulsatility index (MCAv PI), and magnetic resonance elastography (MRE), a sensitive measure of HC viscoelasticity. Individuals with higher carotid pulse pressure (PP) exhibited lower HC stiffness (β = -0.39, r = -0.41, p = 0.05), independent of age and sex. Collectively, carotid PP and MCAv PI significantly explained a large portion of the total variance in HC stiffness (adjusted R2 = 0.41, p = 0.005) in the absence of associations with HC volumes. These cross-sectional findings suggest that the earliest reductions in HC tissue properties are associated with alterations in vascular function.

Inflammasome assembly in neurodegenerative diseases

Neurodegenerative disorders are characterized by the progressive dysfunction and death of selectively vulnerable neuronal populations, often associated with the accumulation of aggregated host proteins. Sustained brain inflammation and hyperactivation of inflammasome complexes have been increasingly demonstrated to contribute to neurodegenerative disease progression. Here, we review molecular mechanisms leading to inflammasome assembly in neurodegeneration. We focus primarily on four degenerative brain disorders in which inflammasome hyperactivation has been well documented: Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), and the spectrum of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). We discuss shared and divergent principles of inflammasome assembly across these disorders, and underscore the differences between neurodegeneration-associated inflammasome activation pathways and their peripheral-immune counterparts. We examine how aberrant assembly of inflammasome complexes may amplify pathology in neurodegeneration, including misfolded protein aggregation, and highlight prospects for neurotherapeutic interventions based on targeting inflammasome pathways.

The effect of herpes zoster vaccination on the occurrence of deaths due to dementia in England and Wales

Background

The United Kingdom (UK) has used date of birth-based eligibility rules for live-attenuated herpes zoster (HZ) vaccination that have led to large differences in HZ vaccination coverage between individuals who differed in their age by merely a few days. Using this unique natural randomization, we have recently provided evidence from Welsh electronic health record data that HZ vaccination caused a reduction in new dementia diagnoses over a seven-year period. Based on this, we hypothesized that HZ vaccination may have slowed the dementia disease process more generally and, thus, already reduced deaths with dementia as their underlying cause even though the UK's HZ vaccination program commenced as recently as September 2013. Using country-wide death certificate data for England and Wales, this study, therefore, aimed to determine whether eligibility for HZ vaccination caused a reduction in deaths due to dementia over a nine-year follow-up period.

Methods

Adults who had their 80th birthday shortly before September 1 2013 were ineligible for HZ vaccination in the UK's National Health Service and remained ineligible for life, whereas those who had their 80th birthday shortly after September 1 2013 (i.e., born on or after September 2 1933) were eligible for one year. Akin to a randomized trial, this date-of-birth threshold generated birth cohorts who are likely exchangeable in observed and unobserved characteristics except for a small difference in age and a large difference in HZ vaccination uptake. We used country-wide data from death certificates in England and Wales on underlying causes of death from September 1 2004 to August 31 2022 by ICD-10 code and month of birth. Our analysis compared the percentage of the population with a death due to dementia among the month-of-birth cohorts around the September 2 1933 eligibility threshold using a regression discontinuity design. The primary analyses used the maximal available follow-up period of nine years.

Results

The study population included 5,077,426 adults born between September 1 1925 and August 31 1941 who were alive at the start of the HZ vaccination program. The month-of-birth cohorts around the September 2 1933 eligibility cutoff were well balanced in their occurrence of all-cause and cause-specific deaths (including deaths due to dementia) prior to the start of the vaccination program. We estimated that over a nine-year follow-up period, eligibility for HZ vaccination reduced the percentage of the population with a death due to dementia by 0.38 (95% CI: 0.08 to 0.68, p=0.012) percentage points, corresponding to a relative reduction of 4.8%. As in our prior analysis, this effect was stronger among women (-0.62 [95% CI: -1.06 to -0.19] percentage points, p=0.004) than among men (-0.11 [95% CI: -0.51 to 0.28] percentage points, p=0.574). The reduction in deaths due to dementia likely resulted in an increase in remaining life expectancy because we found that HZ vaccination eligibility reduced all-cause mortality but had no effect on deaths not due to dementia. An effect on deaths due to dementia at the September 2 date-of-birth eligibility threshold existed only since the year in which the HZ vaccination program was implemented.

Conclusions

Our findings indicate that HZ vaccination improved cognitive function at a fairly advanced stage of the dementia disease process because most individuals whose underlying cause of death was dementia during our nine-year follow-up period were likely already living with dementia at the start of the HZ vaccination program. By using a different population, type of data, and outcome than our prior study in Welsh electronic health record data, this analysis adds to the evidence base that HZ vaccination slows, or potentially even prevents, the natural history of dementia.

Excess Mortality With Alzheimer Disease and Related Dementias as an Underlying or Contributing Cause During the COVID-19 Pandemic in the US

Importance

Adults with Alzheimer disease and related dementias (ADRD) are particularly vulnerable to the direct and indirect effects of the COVID-19 pandemic. Deaths associated with ADRD increased substantially in pandemic year 1. It is unclear whether mortality associated with ADRD declined when better prevention strategies, testing, and vaccines became widely available in year 2.

Objective

To compare pandemic-era excess deaths associated with ADRD between year 1 and year 2 overall and by age, sex, race and ethnicity, and place of death.

Design, Setting, and Participants

This time series analysis used all death certificates of US decedents 65 years and older with ADRD as an underlying or contributing cause of death from January 2014 through February 2022.

Exposure

COVID-19 pandemic era.

Main Outcomes and Measures

Pandemic-era excess deaths associated with ADRD were defined as the difference between deaths with ADRD as an underlying or contributing cause observed from March 2020 to February 2021 (year 1) and March 2021 to February 2022 (year 2) compared with expected deaths during this period. Expected deaths were estimated using data from January 2014 to February 2020 fitted with autoregressive integrated moving average models.

Results

Overall, 2 334 101 death certificates were analyzed. A total of 94 688 (95% prediction interval [PI], 84 192-104 890) pandemic-era excess deaths with ADRD were estimated in year 1 and 21 586 (95% PI, 10 631-32 450) in year 2. Declines in ADRD-related deaths in year 2 were substantial for every age, sex, and racial and ethnic group evaluated. Pandemic-era ADRD-related excess deaths declined among nursing home/long-term care residents (from 34 259 [95% PI, 25 819-42 677] in year 1 to -22 050 [95% PI, -30 765 to -13 273] in year 2), but excess deaths at home remained high (from 34 487 [95% PI, 32 815-36 142] in year 1 to 28 804 [95% PI, 27 067-30 571] in year 2).

Conclusions and Relevance

This study found that large increases in mortality with ADRD as an underlying or contributing cause of death occurred in COVID-19 pandemic year 1 but were largely mitigated in pandemic year 2. The most pronounced declines were observed for deaths in nursing home/long-term care settings. Conversely, excess deaths at home and in medical facilities remained high in year 2.

Protein aggregation and neurodegenerative disease: Structural outlook for the novel therapeutics

Before the controversial approval of humanized monoclonal antibody lecanemab, which binds to the soluble amyloid-β protofibrils, all the treatments available earlier, for Alzheimer's disease (AD) were symptomatic. The researchers are still struggling to find a breakthrough in AD therapeutic medicine, which is partially attributable to lack in understanding of the structural information associated with the intrinsically disordered proteins and amyloids. One of the major challenges in this area of research is to understand the structural diversity of intrinsically disordered proteins under in vitro conditions. Therefore, in this review, we have summarized the in vitro applications of biophysical methods, which are aimed to shed some light on the heterogeneity, pathogenicity, structures and mechanisms of the intrinsically disordered protein aggregates associated with proteinopathies including AD. This review will also rationalize some of the strategies in modulating disease-relevant pathogenic protein entities by small molecules using structural biology approaches and biophysical characterization. We have also highlighted tools and techniques to simulate the in vivo conditions for native and cytotoxic tau/amyloids assemblies, urge new chemical approaches to replicate tau/amyloids assemblies similar to those in vivo conditions, in addition to designing novel potential drugs.

Handling missing values in healthcare data: A systematic review of deep learning-based imputation techniques

OBJECTIVE

The proper handling of missing values is critical to delivering reliable estimates and decisions, especially in high-stakes fields such as clinical research. In response to the increasing diversity and complexity of data, many researchers have developed deep learning (DL)-based imputation techniques. We conducted a systematic review to evaluate the use of these techniques, with a particular focus on the types of data, intending to assist healthcare researchers from various disciplines in dealing with missing data.

MATERIALS AND METHODS

We searched five databases (MEDLINE, Web of Science, Embase, CINAHL, and Scopus) for articles published prior to February 8, 2023 that described the use of DL-based models for imputation. We examined selected articles from four perspectives: data types, model backbones (i.e., main architectures), imputation strategies, and comparisons with non-DL-based methods. Based on data types, we created an evidence map to illustrate the adoption of DL models.

RESULTS

Out of 1822 articles, a total of 111 were included, of which tabular static data (29%, 32/111) and temporal data (40%, 44/111) were the most frequently investigated. Our findings revealed a discernible pattern in the choice of model backbones and data types, for example, the dominance of autoencoder and recurrent neural networks for tabular temporal data. The discrepancy in imputation strategy usage among data types was also observed. The "integrated" imputation strategy, which solves the imputation task simultaneously with downstream tasks, was most popular for tabular temporal data (52%, 23/44) and multi-modal data (56%, 5/9). Moreover, DL-based imputation methods yielded a higher level of imputation accuracy than non-DL methods in most studies.

CONCLUSION

The DL-based imputation models are a family of techniques, with diverse network structures. Their designation in healthcare is usually tailored to data types with different characteristics. Although DL-based imputation models may not be superior to conventional approaches across all datasets, it is highly possible for them to achieve satisfactory results for a particular data type or dataset. There are, however, still issues with regard to portability, interpretability, and fairness associated with current DL-based imputation models.

Cognition and Mortality Risk Among Midlife and Older Americans

BACKGROUND

Cognitive impairment is associated with increased mortality rates in late life, but it is unclear whether worse cognition predicts working-age mortality.

METHODS

The data come from a U.S. national survey (N = 3 973 aged 32-84 at cognitive testing in 2004-06, mean age 56.6, 56.3% female; N = 3 055 retested in 2013-18 at ages 42-94, mean age 64.6, 56.6% female; mortality follow-up through 2019). We use Cox hazard models to investigate whether cognition is associated with mortality below age 65, how the magnitude of this risk compares with the risk in later life, and whether the association persists after adjusting for potential confounders.

RESULTS

Worse cognition is associated with mortality, but the demographic-adjusted hazard ratio (HR) diminishes with age from 2.0 per standard deviation (SD; 95% confidence interval [CI], 1.7-2.4) at age 55-1.4 (95% CI, 1.3-1.6) at age 85. In the fully adjusted model, the corresponding HRs are 1.4 (95% CI, 1.2-1.7) and 1.3 (95% CI, 1.1-1.4), respectively. The absolute differences in mortality by level of cognition, however, are larger at older ages because mortality is rare at younger ages. The fully adjusted model implies a 2.7 percentage point differential in the estimated percentage dying between ages 55 and 65 for those with low cognition (1 SD below the overall mean, 5.7%) versus high cognition (1 SD above the mean, 3.0%). The corresponding differential between ages 75 and 85 is 8.4 percentage points (24.6% vs 16.2%, respectively).

CONCLUSIONS

Cognitive function may be a valuable early warning sign of premature mortality, even at working ages, when dementia is rare.

Dementia and electronic health record phenotypes: a scoping review of available phenotypes and opportunities for future research

OBJECTIVE

We performed a scoping review of algorithms using electronic health record (EHR) data to identify patients with Alzheimer's disease and related dementias (ADRD), to advance their use in research and clinical care.

MATERIALS AND METHODS

Starting with a previous scoping review of EHR phenotypes, we performed a cumulative update (April 2020 through March 1, 2023) using Pubmed, PheKB, and expert review with exclusive focus on ADRD identification. We included algorithms using EHR data alone or in combination with non-EHR data and characterized whether they identified patients at high risk of or with a current diagnosis of ADRD.

RESULTS

For our cumulative focused update, we reviewed 271 titles meeting our search criteria, 49 abstracts, and 26 full text papers. We identified 8 articles from the original systematic review, 8 from our new search, and 4 recommended by an expert. We identified 20 papers describing 19 unique EHR phenotypes for ADRD: 7 algorithms identifying patients with diagnosed dementia and 12 algorithms identifying patients at high risk of dementia that prioritize sensitivity over specificity. Reference standards range from only using other EHR data to in-person cognitive screening.

CONCLUSION

A variety of EHR-based phenotypes are available for use in identifying populations with or at high-risk of developing ADRD. This review provides comparative detail to aid in choosing the best algorithm for research, clinical care, and population health projects based on the use case and available data. Future research may further improve the design and use of algorithms by considering EHR data provenance.

Ultrasound-mediated blood-brain barrier opening uncovers an intracerebral perivenous fluid network in persons with Alzheimer's disease

BACKGROUND

Focused ultrasound (FUS)-mediated blood-brain barrier (BBB) opening is under investigation as a therapeutic modality for neurodegeneration, yet its effects in humans are incompletely understood. Here, we assessed physiologic responses to FUS administered in multifocal brain sites of persons with Alzheimer's disease (AD).

METHODS

At a tertiary neuroscience institute, eight participants with AD (mean age 65, 38% F) enrolled in a phase 2 clinical trial underwent three successive targeted BBB opening procedures at 2 week intervals using a 220 kHz FUS transducer in combination with systemically administered microbubbles. In all, 77 treatment sites were evaluated and encompassed hippocampal, frontal, and parietal brain regions. Post-FUS imaging changes, including susceptibility effects and spatiotemporal gadolinium-based contrast agent enhancement patterns, were analyzed using serial 3.0-Tesla MRI.

RESULTS

Post-FUS MRI revealed expected intraparenchymal contrast extravasation due to BBB opening at all targeted brain sites. Immediately upon BBB opening, hyperconcentration of intravenously-administered contrast tracer was consistently observed around intracerebral veins. Following BBB closure, within 24-48 h of FUS intervention, permeabilization of intraparenchymal veins was observed and persisted for up to one week. Notably, extraparenchymal meningeal venous permeabilization and associated CSF effusions were also elicited and persisted up to 11 days post FUS treatment, prior to complete spontaneous resolution in all participants. Mild susceptibility effects were detected, however no overt intracranial hemorrhage or other serious adverse effects occurred in any participant.

CONCLUSIONS

FUS-mediated BBB opening is safely and reproducibly achieved in multifocal brain regions of persons with AD. Post-FUS tracer enhancement phenomena suggest the existence of a brain-wide perivenous fluid efflux pathway in humans and demonstrate reactive physiological changes involving these conduit spaces in the delayed, subacute phase following BBB disruption. The delayed reactive venous and perivenous changes are consistent with a dynamic, zonal exudative response to upstream capillary manipulation. Further preclinical and clinical investigations of these FUS-related imaging phenomena and of intracerebral perivenous compartment changes are needed to elucidate physiology of this pathway as well as biological effects of FUS administered with and without adjuvant neurotherapeutics.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03671889, registered 9/14/2018.

Reappraising the public health benefits conferred by environmental policy: Considerations for an aging society

Although addressing environmental pollution and unprecedented societal aging are concurrent public health challenges, rarely is the relationship between the two considered. Current approaches to valuing the public health benefits conferred by environmental policy may be ill-suited to aging populations. We describe the limitations of the age-invariant approach used by the United States Environmental Protection Agency to estimate the public health benefits corresponding to environmental regulation. These include the poor age-representativeness of the samples informing the valuation of mortality risk reduction, the exclusion of age-related outcomes from valuation, and the omission of age-related third-party expenditures. We offer an empirical framework that could address these limitations. Our recommendations could improve the calibration of environmental regulatory analysis to the changing age distribution of the United States population.

Infections among individuals with multiple sclerosis, Alzheimer's disease and Parkinson's disease

A link between neurodegenerative diseases and infections has been previously reported. However, it is not clear to what extent such link is caused by confounding factors or to what extent it is intimately connected with the underlying conditions. Further, studies on the impact of infections on mortality risk following neurodegenerative diseases are rare. We analysed two data sets with different characteristics: (i) a community-based cohort from the UK Biobank with 2023 patients with multiple sclerosis, 2200 patients with Alzheimer's disease, 3050 patients with Parkinson's disease diagnosed before 1 March 2020 and 5 controls per case who were randomly selected and individually matched to the case; (ii) a Swedish Twin Registry cohort with 230 patients with multiple sclerosis, 885 patients with Alzheimer's disease and 626 patients with Parkinson's disease diagnosed before 31 December 2016 and their disease-free co-twins. The relative risk of infections after a diagnosis of neurodegenerative disease was estimated using stratified Cox models, with adjustment for differences in baseline characteristics. Causal mediation analyses of survival outcomes based on Cox models were performed to assess the impact of infections on mortality. Compared with matched controls or unaffected co-twins, we observed an elevated infection risk after diagnosis of neurodegenerative diseases, with a fully adjusted hazard ratio (95% confidence interval) of 2.45 (2.24-2.69) for multiple sclerosis, 5.06 (4.58-5.59) for Alzheimer's disease and 3.72 (3.44-4.01) for Parkinson's disease in the UK Biobank cohort, and 1.78 (1.21-2.62) for multiple sclerosis, 1.50 (1.19-1.88) for Alzheimer's disease and 2.30 (1.79-2.95) for Parkinson's disease in the twin cohort. Similar risk increases were observed when we analysed infections during the 5 years before diagnosis of the respective disease. Occurrence of infections after diagnosis had, however, relatively little impact on mortality, as mediation of infections on mortality (95% confidence interval) was estimated as 31.89% (26.83-37.11%) for multiple sclerosis, 13.38% (11.49-15.29%) for Alzheimer's disease and 18.85% (16.95-20.97%) for Parkinson's disease in the UK Biobank cohort, whereas it was 6.56% (-3.59 to 16.88%) for multiple sclerosis, -2.21% (-0.21 to 4.65%) for Parkinson's disease and -3.89% (-7.27 to -0.51%) for Alzheimer's disease in the twin cohort. Individuals with studied neurodegenerative diseases display an increased risk of infections independently of genetic and familial environment factors. A similar magnitude of risk increase is present prior to confirmed diagnosis, which may indicate a modulating effect of the studied neurological conditions on immune defences.

COVID-19 and Frailty

Older age is a major risk factor for adverse outcomes of COVID-19, potentially due to immunosenescence and chronic low-grade inflammation, both characteristics of older adults which synergistically contribute to their vulnerability. Furthermore, older age is also associated with decreased kidney function and is consequently associated with an increased risk of cardiovascular disease. All of this in the course of COVID-19 infection can worsen and promote the progression of chronic kidney damage and all its sequelae. Frailty is a condition characterized by the decline in function of several homeostatic systems, leading to increased vulnerability to stressors and risk of adverse health outcomes. Thus, it is very likely that frailty, together with comorbidities, may have contributed to the high vulnerability to severe clinical manifestations and deaths from COVID-19 among older people. The combination of viral infection and chronic inflammation in the elderly could cause multiple unforeseen harmful consequences, affecting overall disability and mortality rates. In post-COVID-19 patients, inflammation has been implicated in sarcopenia progression, functional activity decline, and dementia. After the pandemic, it is imperative to shine a spotlight on these sequelae so that we can be prepared for the future outcomes of the ongoing pandemic. Here, we discuss the potential long-term consequences of SARS-CoV-2 infection and its possibility of causing permanent damage to the precarious balance existing in the frail elderly with multiple pathologies.

Associations Between Objectively Measured Sleep and Cognition: Main Effects and Interactions With Race in Adults Aged ≥50 Years

BACKGROUND

This study examined associations of actigraphy-estimated sleep parameters with concurrent and future cognitive performance in adults aged ≥ 50 years and explored interactions with race.

METHODS

Participants were 435 cognitively normal adults in the Baltimore Longitudinal Study of Aging who completed wrist actigraphy at baseline (mean = 6.6 nights) and underwent longitudinal testing of memory, attention, executive function, language, and visuospatial ability. On average, participants with follow-up data were followed for 3.1 years. Primary predictors were baseline mean total sleep time, sleep onset latency, sleep efficiency (SE), and wake after sleep onset (WASO). Fully adjusted linear mixed-effects models included demographics, baseline health-related characteristics, smoking status, sleep medication use, APOE e4 carrier status, and interactions of each covariate with time.

RESULTS

In adjusted models, higher SE (per 10%; B = 0.11, p = .012) and lower WASO (per 30 minutes; B = -0.12, p = .007) were associated with better memory cross-sectionally. In contrast, higher SE was associated with greater visuospatial ability decline longitudinally (B = -0.02, p = .004). Greater WASO was associated with poorer visuospatial ability cross-sectionally (B = -0.09, p = .019) but slower declines in visuospatial abilities longitudinally (B = 0.02, p = .002). Several sleep-cognition cross-sectional and longitudinal associations were stronger in, or limited to, Black participants (compared to White participants).

CONCLUSIONS

This study suggests cross-sectional sleep-cognition associations differ across distinct objective sleep parameters and cognitive domains. This study also provides preliminary evidence for racial differences across some sleep-cognition relationships. Unexpected directions of associations between baseline sleep and cognitive performance over time may be attributable to the significant proportion of participants without follow-up data and require further investigation.

Well-Being and Cognitive Resilience to Dementia-Related Neuropathology

Not all older adults with dementia-related neuropathology in their brains experience cognitive decline or impairment. Instead, some people maintain relatively normal cognitive functioning despite neuropathologic burden, a phenomenon called cognitive resilience. Using a longitudinal, epidemiological, clinical-pathologic cohort study of older adults in the United States (N = 348), the present research investigated associations between well-being and cognitive resilience. Consistent with preregistered hypotheses, results showed that higher eudaimonic well-being (measured via the Ryff Psychological Well-Being Scale) and higher hedonic well-being (measured via the Satisfaction with Life Scale) were associated with better-than-expected cognitive functioning relative to one's neuropathological burden (i.e., beta-amyloid, neurofibrillary tangles, Lewy bodies, vascular pathologies, hippocampal sclerosis, and TDP-43). The association of eudaimonic well-being in particular was present above and beyond known cognitive resilience factors (i.e., socioeconomic status, education, cognitive activity, low neuroticism, low depression) and dementia risk factors (i.e., apolipoprotein E [ApoE] genotype, medical comorbidities). This research highlights the importance of considering eudaimonic well-being in efforts to prevent dementia.

Reporting Down syndrome on the death certificate for Alzheimer disease/unspecified dementia deaths

BACKGROUND

Death certificates are crucial for understanding population health trends including the burden of disease mortality. Accurate reporting of causes of death on these records is necessary in order to implement adequate public health policies and fund disease research. While there is evidence that Alzheimer disease and unspecified dementia are prevalent among people with Down syndrome, a 2014 Centers for Disease Control and Prevention (CDC) rule change instructing that Down syndrome should be reported as the underlying cause of death in instances when death occurred from Alzheimer disease or unspecified dementia threatens the accuracy and the utility of death certificates for this population.

METHODS

This study used 15 years (2005-2019) of US death certificate data for adults with and without Down syndrome. We compare the mortality burden due to Alzheimer disease and unspecified dementia prior to and after amending death certificates that report Down syndrome as the underlying cause of death.

RESULTS

When analyzing death certificates without addressing the reporting of Down syndrome as the underlying cause of death, rates of death due to Alzheimer disease and dementia ranked as the third leading cause of death for both adults with and without Down syndrome. After amending death certificates that reported Down syndrome as the underlying cause of death, Alzheimer disease and dementia were the leading cause of death among those with Down syndrome, occurring 2.7 times more in adults with compared to without Down syndrome.

CONCLUSION

The findings of this study highlight the importance of accurate mortality data for studying and addressing population health trends. The current practice of reporting Down syndrome as the underlying cause of death rather than the disease responsible for death needs to be reconsidered and modified. If not, people with Down syndrome may be further marginalized within dementia related support and research.

Thwarting Alzheimer's Disease through Healthy Lifestyle Habits: Hope for the Future

Alzheimer's disease (AD) is a neurodegenerative disorder that slowly disintegrates memory and thinking skills. Age is known to be the major risk factor in AD, but there are several nonmodifiable and modifiable causes. The nonmodifiable risk factors such as family history, high cholesterol, head injuries, gender, pollution, and genetic aberrations are reported to expediate disease progression. The modifiable risk factors of AD that may help prevent or delay the onset of AD in liable people, which this review focuses on, includes lifestyle, diet, substance use, lack of physical and mental activity, social life, sleep, among other causes. We also discuss how mitigating underlying conditions such as hearing loss and cardiovascular complications could be beneficial in preventing cognitive decline. As the current medications can only treat the manifestations of AD and not the underlying process, healthy lifestyle choices associated with modifiable factors is the best alternative strategy to combat the disease.

Rationale for a Multi-Factorial Approach for the Reversal of Cognitive Decline in Alzheimer's Disease and MCI: A Review

Alzheimer's disease (AD) is a multifactorial, progressive, neurodegenerative disease typically characterized by memory loss, personality changes, and a decline in overall cognitive function. Usually manifesting in individuals over the age of 60, this is the most prevalent type of dementia and remains the fifth leading cause of death among Americans aged 65 and older. While the development of effective treatment and prevention for AD is a major healthcare goal, unfortunately, therapeutic approaches to date have yet to find a treatment plan that produces long-term cognitive improvement. Drugs that may be able to slow down the progression rate of AD are being introduced to the market; however, there has been no previous solution for preventing or reversing the disease-associated cognitive decline. Recent studies have identified several factors that contribute to the progression and severity of the disease: diet, lifestyle, stress, sleep, nutrient deficiencies, mental health, socialization, and toxins. Thus, increasing evidence supports dietary and other lifestyle changes as potentially effective ways to prevent, slow, or reverse AD progression. Studies also have demonstrated that a personalized, multi-therapeutic approach is needed to improve metabolic abnormalities and AD-associated cognitive decline. These studies suggest the effects of abnormalities, such as insulin resistance, chronic inflammation, hypovitaminosis D, hormonal deficiencies, and hyperhomocysteinemia, in the AD process. Therefore a personalized, multi-therapeutic program based on an individual's genetics and biochemistry may be preferable over a single-drug/mono-therapeutic approach. This article reviews these multi-therapeutic strategies that identify and attenuate all the risk factors specific to each affected individual. This article systematically reviews studies that have incorporated multiple strategies that target numerous factors simultaneously to reverse or treat cognitive decline. We included high-quality clinical trials and observational studies that focused on the cognitive effects of programs comprising lifestyle, physical, and mental activity, as well as nutritional aspects. Articles from PubMed Central, Scopus, and Google Scholar databases were collected, and abstracts were reviewed for relevance to the subject matter. Epidemiological, pathological, toxicological, genetic, and biochemical studies have all concluded that AD represents a complex network insufficiency. The research studies explored in this manuscript confirm the need for a multifactorial approach to target the various risk factors of AD. A single-drug approach may delay the progression of memory loss but, to date, has not prevented or reversed it. Diet, physical activity, sleep, stress, and environment all contribute to the progression of the disease, and, therefore, a multi-factorial optimization of network support and function offers a rational therapeutic strategy. Thus, a multi-therapeutic program that simultaneously targets multiple factors underlying the AD network may be more effective than a mono-therapeutic approach.

Precision Medicine Approach to Alzheimer's Disease: Rationale and Implications

The neurodegenerative disease field has enjoyed extremely limited success in the development of effective therapeutics. One potential reason is the lack of disease models that yield accurate predictions and optimal therapeutic targets. Standard clinical trials have pre-determined a single treatment modality, which may be unrelated to the primary drivers of neurodegeneration. Recent proof-of-concept clinical trials using a precision medicine approach suggest a new model of Alzheimer's disease (AD) as a chronic innate encephalitis that creates a network insufficiency. Identifying and addressing the multiple potential contributors to cognitive decline for each patient may represent a more effective strategy. Here we review the rationale for a precision medicine approach in prevention and treatment of cognitive decline associated with AD. Results and implications from recent proof-of-concept clinical trials are presented. Randomized controlled trials, with much larger patient numbers, are likely to be significant to establishing precision medicine protocols as a standard of care for prevention and treatment of cognitive decline. Furthermore, combining this approach with the pharmaceutical approach offers the potential for enhanced outcomes. However, incorporating precision medicine approaches into everyday evaluation and care, as well as future clinical trials, would require fundamental changes in trial design, IRB considerations, funding considerations, laboratory evaluation, personalized treatment plans, treatment teams, and ultimately in reimbursement guidelines. Nonetheless, precision medicine approaches to AD, based on a novel model of AD pathophysiology, offer promise that has not been realized to date with monotherapeutic approaches.

Early Chronic Stress Induced Changes within the Locus Coeruleus in Sporadic Alzheimer's Disease

Chronic exposure to stress throughout the lifespan has been the focus of many studies on Alzheimer's disease (AD) because of the similarities between the biological mechanisms involved in chronic stress and the pathophysiology of AD. In fact, the earliest abnormality associated with the disease is the presence of phosphorylated tau protein in locus coeruleus neurons, a brain structure highly responsive to stress and perceived threat. Here, we introduce allostatic load as a useful concept for understanding many of the complex, interacting neuropathological changes involved in the AD degenerative process. In response to chronic stress, aberrant tau proteins that begin to accumulate within the locus coeruleus decades prior to symptom onset appear to represent a primary pathological event in the AD cascade, triggering a wide range of interacting brain changes involving neuronal excitotoxicity, endocrine alterations, inflammation, oxidative stress, and amyloid plaque exacerbation. While it is acknowledged that stress will not necessarily be the major precipitating factor in all cases, early tau-induced changes within the locus coeruleus-norepinephrine pathway suggests that a therapeutic window might exist for preventative measures aimed at managing stress and restoring balance within the HPA axis.

Health economic modeling for Alzheimer's disease: Expert perspectives

The successful development of an economic model for the evaluation of future Alzheimer's disease (AD) interventions is critical to accurately inform policy makers and payers. As our understanding of AD expands, this becomes an increasingly complex and challenging goal. Advances in diagnostic techniques for AD and the prospect of disease-modifying treatments raise an urgent need to define specifications for future economic models and to ensure that the necessary data to populate them are available. This Perspective article provides expert opinions from health economists and governmental agency representatives on how future economic models for AD might be structured, validated, and reported. We aim to stimulate much-needed discussion about the detailed specification of future health economic models for AD.

Trends in prevalence of self-reports of Alzheimer’s disease/dementia among non-institutionalized individuals 45+ in Canada, 1994–2014

Background:

Alzheimer’s disease/dementia (AD) prevalence is of concern globally and in Canada owing to the rapidly aging population and increase in life expectancy. This study explored: (1) trends in the overall prevalence of self-reported AD/dementia by sex, age groups, educational levels, and geographic areas in Canada from 1994 to 2014, and (2) assessed what the observed trends mean in the context of the aging Canadian population and the health care system.

Design and methods:

This cross-sectional study used Canadian national survey data. Data for this study were from two Canadian national health surveys (National Population Health Survey and the Canadian Community Health Survey), between 1994 and 2014. After age-sex standardization, trends in the prevalence of self-reported Alzheimer’s disease/dementia were tracked over time. The two cross-sectional surveys used similar diagnostic criteria over the years.

Results:

The overall prevalence of Alzheimer’s disease/dementia increased from 0.14 in 1994 to 0.80 in 2014 representing a 0.66-point increase over the 20 years. Alzheimer’s disease/dementia prevalence increased with age across all years but was more pronounced after age 80. Men 65+ years, those with lower education, and Canadians living in Central Canada had an increased prevalence.

Conclusions:

The overall prevalence of Alzheimer’s disease/dementia in the community increased over time. This study highlights the importance of establishing effective community-based prevention strategies that focus on minimizing risk and optimizing protection as well as health system capacity strengthening and preparation for long-term care including increased demand for neurologists’ services, increased associated disability, psychosocial difficulties, rising costs, and caregiver burden.

Tensorizing GAN With High-Order Pooling for Alzheimer's Disease Assessment

It is of great significance to apply deep learning for the early diagnosis of Alzheimer's disease (AD). In this work, a novel tensorizing GAN with high-order pooling is proposed to assess mild cognitive impairment (MCI) and AD. By tensorizing a three-player cooperative game-based framework, the proposed model can benefit from the structural information of the brain. By incorporating the high-order pooling scheme into the classifier, the proposed model can make full use of the second-order statistics of holistic magnetic resonance imaging (MRI). To the best of our knowledge, the proposed Tensor-train, High-order pooling and Semisupervised learning-based GAN (THS-GAN) is the first work to deal with classification on MR images for AD diagnosis. Extensive experimental results on Alzheimer's disease neuroimaging initiative (ADNI) data set are reported to demonstrate that the proposed THS-GAN achieves superior performance compared with existing methods, and to show that both tensor-train and high-order pooling can enhance classification performance. The visualization of generated samples also shows that the proposed model can generate plausible samples for semisupervised learning purpose.

Mood disorders increase mortality mainly through dementia: A community-based prospective cohort study

OBJECTIVE

The effects of mood disorders on mortality may be mediated by their effects on the risk of dementia, and interventions to reduce the occurrence of dementia may reduce their overall mortality. This study aimed to investigate the direct effects of depressive and bipolar disorders on the 6-year risk of mortality and also their indirect effects on mortality due to their effect on the risk of dementia.

METHODS

A total of 5101 Koreans were selected from a community-based prospective cohort study, and 6-year risks of mortality and dementia in participants with depressive and bipolar disorders were estimated by Cox proportional hazard analysis. The direct and indirect effects of depressive and bipolar disorders on the risk of mortality were estimated using structural equation modeling.

RESULTS

The depressive and bipolar disorder groups showed 51% and 85% higher 6-year mortality, and 82% and 127% higher risk of dementia, respectively, compared to euthymic controls. The effects of depressive and bipolar disorders on mortality were mainly mediated by their effects on the risk of dementia in a structural equation model. The direct effects of each mood disorder on mortality were not significant.

CONCLUSION

Both depressive and bipolar disorders increased the risks of mortality and dementia, and the effects of mood disorders on mortality were mainly mediated through dementia. As dementia occurs later in life than mood disorders, measures to prevent it may effectively reduce mortality in individuals with a history of mood disorders, as well as being more feasible than attempting to control other causes of death.

Patterns of Healthcare Use and Mortality After Alzheimer's Disease or Related Dementia Diagnosis Among Alaska Native Patients: Results of a Cluster Analysis in a Tribal Healthcare Setting

Background

Alaska Native and American Indian (AN/AI) people represent a rapidly aging population with disproportionate burdens of Alzheimer's disease and related dementias (ADRD) risk factors.

Objective

To characterize healthcare service use patterns and mortality in the years following ADRD diagnosis for patients in an Alaska Native Tribal health system.

Methods

The study sample included all AN/AI patients aged 55 or older with an ADRD diagnosis who were seen between 2012-2018 (n = 407). We used cluster analysis to identify distinct patterns of healthcare use for primary care, emergency and urgent care, inpatient hospital stays, and selected specialty care. We compared demographic and clinical factors between clusters and used regression to compare mortality.

Results

We identified five clusters of healthcare service use patterns after ADRD diagnosis: 1) people who use a low amount of all services (n = 107), 2) people who use a high amount of all services (n = 60), 3) people who use a high amount of primary and specialty care (n = 105), 4) people who use a high amount of specialty care (n = 65), and 5) people who use a high amount of emergency and urgent care (n = 70). The cluster with the highest use had the greatest proportion of comorbidities and had a 2.3-fold increased risk of mortality compared to the cluster with the lowest healthcare service use.

Conclusion

Results indicate that those receiving the most services had the greatest healthcare-related needs and increased mortality. Future research could isolate factors that predict service use following ADRD diagnosis and identify other differential health risks.

Precision Medicine Approach to Alzheimer’s Disease: Successful Pilot Project

Background:

Effective therapeutics for Alzheimer’s disease are needed. However, previous clinical trials have pre-determined a single treatment modality, such as a drug candidate or therapeutic procedure, which may be unrelated to the primary drivers of the neurodegenerative process. Therefore, increasing data set size to include the potential contributors to cognitive decline for each patient, and addressing the identified potential contributors, may represent a more effective strategy.

Objective:

To determine whether a precision medicine approach to Alzheimer’s disease and mild cognitive impairment is effective enough in a proof-of-concept trial to warrant a larger, randomized, controlled clinical trial.

Methods:

Twenty-five patients with dementia or mild cognitive impairment, with Montreal Cognitive Assessment (MoCA) scores of 19 or higher, were evaluated for markers of inflammation, chronic infection, dysbiosis, insulin resistance, protein glycation, vascular disease, nocturnal hypoxemia, hormone insufficiency or dysregulation, nutrient deficiency, toxin or toxicant exposure, and other biochemical parameters associated with cognitive decline. Brain magnetic resonance imaging with volumetrics was performed at baseline and study conclusion. Patients were treated for nine months with a personalized, precision medicine protocol, and cognition was assessed at t = 0, 3, 6, and 9 months.

Results:

All outcome measures revealed improvement: statistically significant improvement in MoCA scores, CNS Vital Signs Neurocognitive Index, and Alzheimer’s Questionnaire Change score were documented. No serious adverse events were recorded. MRI volumetrics also improved.

Conclusion:

Based on the cognitive improvements observed in this study, a larger, randomized, controlled trial of the precision medicine therapeutic approach described herein is warranted.

Is the Rise in Reported Dementia Mortality Real? Analysis of Multiple-Cause-of-Death Data for Australia and the United States

Official statistics in Australia and the United States show large recent increases in dementia mortality rates. In this study, we assessed whether these trends are biased by an increasing tendency of medical certifiers (predominantly physicians) to report on the death certificate that dementia was a direct cause of death. Regression models of multiple-cause-of-death data in Australia (2006-2016) and the United States (2006-2017) were constructed to adjust dementia mortality rates for changes in death certification practices. Compared with official statistics, the recent increase in adjusted age-standardized dementia death rates was less than half as large in Australia and about two-thirds as large in the United States. Further adjustment for changes in reporting of dementia anywhere on the death certificate implied even lower increases in dementia mortality. Declines in reporting of cardiovascular diseases as comorbid conditions also contributed to rises in dementia mortality rates. The increasing likelihood of dementia's being reported as directly leading to death largely explains recent increases in dementia mortality rates in both countries. However, studies have found that reported dementia on death certificates remains low compared with clinical evaluations of its prevalence. Improved guidance and training for certifiers in reporting of dementia on death certificates will help standardize mortality statistics within and between countries.

Multimodal deep learning for Alzheimer's disease dementia assessment

Worldwide, there are nearly 10 million new cases of dementia annually, of which Alzheimer's disease (AD) is the most common. New measures are needed to improve the diagnosis of individuals with cognitive impairment due to various etiologies. Here, we report a deep learning framework that accomplishes multiple diagnostic steps in successive fashion to identify persons with normal cognition (NC), mild cognitive impairment (MCI), AD, and non-AD dementias (nADD). We demonstrate a range of models capable of accepting flexible combinations of routinely collected clinical information, including demographics, medical history, neuropsychological testing, neuroimaging, and functional assessments. We then show that these frameworks compare favorably with the diagnostic accuracy of practicing neurologists and neuroradiologists. Lastly, we apply interpretability methods in computer vision to show that disease-specific patterns detected by our models track distinct patterns of degenerative changes throughout the brain and correspond closely with the presence of neuropathological lesions on autopsy. Our work demonstrates methodologies for validating computational predictions with established standards of medical diagnosis.

Insulin and Its Key Role for Mitochondrial Function/Dysfunction and Quality Control: A Shared Link between Dysmetabolism and Neurodegeneration

Insulin was discovered and isolated from the beta cells of pancreatic islets of dogs and is associated with the regulation of peripheral glucose homeostasis. Insulin produced in the brain is related to synaptic plasticity and memory. Defective insulin signaling plays a role in brain dysfunction, such as neurodegenerative disease. Growing evidence suggests a link between metabolic disorders, such as diabetes and obesity, and neurodegenerative diseases, especially Alzheimer's disease (AD). This association is due to a common state of insulin resistance (IR) and mitochondrial dysfunction. This review takes a journey into the past to summarize what was known about the physiological and pathological role of insulin in peripheral tissues and the brain. Then, it will land in the present to analyze the insulin role on mitochondrial health and the effects on insulin resistance and neurodegenerative diseases that are IR-dependent. Specifically, we will focus our attention on the quality control of mitochondria (MQC), such as mitochondrial dynamics, mitochondrial biogenesis, and selective autophagy (mitophagy), in healthy and altered cases. Finally, this review will be projected toward the future by examining the most promising treatments that target the mitochondria to cure neurodegenerative diseases associated with metabolic disorders.