COVID-19 and dementia: Analyses of risk, disparity, and outcomes from electronic health records in the US

The Worst of Times: Depressive Symptoms Among Racialized Groups Living With Dementia and Cognitive Impairment During the COVID-19 Pandemic

Objective: To explore differences in depressive symptoms for older adults (Black, Latinx, and White) by cognitive status during the 2020 COVID-19 pandemic. Methods: Data from the Health and Retirement Study identified older adults as cognitively normal, cognitively impaired without dementia (CIND), and persons living with dementia (PLWD). Multiple linear regression analyses examined associations between cognitive status and depressive symptoms among these racialized groups. Results: Compared to the cognitively normal older adults racialized as Black, those with CIND reported higher depressive symptoms during the pandemic (overall and somatic) and PLWD had higher somatic symptoms (p < .01). Older adults racialized as White with CIND reported higher somatic (p < .01) symptoms compared to cognitively normal older adults racialized as White. Discussion: The COVID-19 pandemic was a challenging event among older adults racialized as Black with CIND and PLWD. Future studies should examine if these depressive symptoms persist over time.

Digital epidemiology: harnessing big data for early detection and monitoring of viral outbreaks

Digital epidemiology is the process of investigating the dynamics of disease-related patterns, both social and clinical, as well as the causes of these trends in epidemiology. Digital epidemiology, utilising big data from a variety of digital sources, has emerged as a viable method for early detection and monitoring of viral outbreaks. The present review gives an overview of digital epidemiology, emphasising its importance in the timely detection of infectious disease outbreaks. Researchers may discover and track outbreaks in real time using digital data sources such as search engine queries, social media trends, and digital health records. However, data quality, concerns about privacy, and data interoperability must be addressed to maximise the effectiveness of digital epidemiology. As the global landscape of infectious diseases evolves, integrating digital epidemiology becomes critical to improving pandemic preparedness and response efforts. Integrating digital epidemiology into routine monitoring systems has the potential to improve global health outcomes and save lives in the event of viral outbreaks.

Disentangling the relationship between cancer mortality and COVID-19 in the US

Cancer is considered a risk factor for COVID-19 mortality, yet several countries have reported that deaths with a primary code of cancer remained within historic levels during the COVID-19 pandemic. Here, we further elucidate the relationship between cancer mortality and COVID-19 on a population level in the US. We compared pandemic-related mortality patterns from underlying and multiple cause (MC) death data for six types of cancer, diabetes, and Alzheimer's. Any pandemic-related changes in coding practices should be eliminated by study of MC data. Nationally in 2020, MC cancer mortality rose by only 3% over a pre-pandemic baseline, corresponding to ~13,600 excess deaths. Mortality elevation was measurably higher for less deadly cancers (breast, colorectal, and hematological, 2-7%) than cancers with a poor survival rate (lung and pancreatic, 0-1%). In comparison, there was substantial elevation in MC deaths from diabetes (37%) and Alzheimer's (19%). To understand these differences, we simulated the expected excess mortality for each condition using COVID-19 attack rates, life expectancy, population size, and mean age of individuals living with each condition. We find that the observed mortality differences are primarily explained by differences in life expectancy, with the risk of death from deadly cancers outcompeting the risk of death from COVID-19.

Recent advances in Alzheimer's disease: Mechanisms, clinical trials and new drug development strategies

Alzheimer's disease (AD) stands as the predominant form of dementia, presenting significant and escalating global challenges. Its etiology is intricate and diverse, stemming from a combination of factors such as aging, genetics, and environment. Our current understanding of AD pathologies involves various hypotheses, such as the cholinergic, amyloid, tau protein, inflammatory, oxidative stress, metal ion, glutamate excitotoxicity, microbiota-gut-brain axis, and abnormal autophagy. Nonetheless, unraveling the interplay among these pathological aspects and pinpointing the primary initiators of AD require further elucidation and validation. In the past decades, most clinical drugs have been discontinued due to limited effectiveness or adverse effects. Presently, available drugs primarily offer symptomatic relief and often accompanied by undesirable side effects. However, recent approvals of aducanumab (1) and lecanemab (2) by the Food and Drug Administration (FDA) present the potential in disrease-modifying effects. Nevertheless, the long-term efficacy and safety of these drugs need further validation. Consequently, the quest for safer and more effective AD drugs persists as a formidable and pressing task. This review discusses the current understanding of AD pathogenesis, advances in diagnostic biomarkers, the latest updates of clinical trials, and emerging technologies for AD drug development. We highlight recent progress in the discovery of selective inhibitors, dual-target inhibitors, allosteric modulators, covalent inhibitors, proteolysis-targeting chimeras (PROTACs), and protein-protein interaction (PPI) modulators. Our goal is to provide insights into the prospective development and clinical application of novel AD drugs.

The risk of cognitive decline and dementia in older adults diagnosed with COVID-19: A systematic review and meta-analysis

BACKGROUND

Cognitive impairment can be caused by infections with various pathogens, including SARS-CoV-2. Research has yet to determine the true incidence and course of cognitive impairment in older adults following COVID-19. Furthermore, research has theorised that COVID-19 is associated with dementia progression and diagnosis but this association has yet to be fully described.

METHODS

A systematic review was registered in Prospero and conducted on the databases PubMed, Embase, Ovid, CENTRAL and Cochrane Library. Studies reporting cognitive impairment and dementia outcomes in post-acute and post-COVID-19 patients aged ≥65 years, and which included control data, were included in this review.

RESULTS

15,124 articles were identified by the search strategy. After eliminating duplicate titles and completing title, abstracts and full-text review, 18 studies were included comprising of 412,957 patients with COVID-19 (46.63% male) and 411,929 patients without COVID-19 (46.59% male). The overall mean Montreal Cognitive Assessment (MoCA) score in COVID-19 patients was 23.34 out of 30 (95% CI [22.24, 24.43]). indicating cognitive impairment. The overall proportion of patients identified as having new onset cognitive impairment was 65% (95% CI [44, 81]). Subgroup analyses indicated that time since infection significantly improves overall MoCA score and reduces proportion of patients with cognitive impairment.

CONCLUSION

This study indicates that cognitive impairment may be an important sequela of COVID-19. Further research with adequate sample sizes is warranted regarding COVID-19's association with new-onset dementia and dementia progression, and the effect of repeat infections. There is a need for development of diagnostic and management protocols for COVID-19 patients with cognitive impairment.

Psychotherapy Engagement Before and After a Rapid Transition to Telehealth During COVID-19 for Older Adults With Dementia

Objective: To understand the impact of the transition to telehealth during COVID-19 on psychotherapy visits for patients with dementia. Method: Retrospective study of older adults with dementia who had at least one psychotherapy visit in the 9 months before and after the onset of COVID-19 at 3 U.S. health systems. Care disruptions were gaps of 45+ days. Descriptive statistics and logistic mixed-effects models examined factors associated with care disruption. Results: 4953 patients with dementia made 19,902 psychotherapy visits. Gaps in psychotherapy were less frequent during COVID-19 (29.4%) than before (48.9%), with the odds of a patient experiencing a care disruption during COVID-19 0.54 times the odds prior to COVID-19 (95% CI: 0.50-0.59). Almost all patient subgroups had lower adjusted odds of care disruption during COVID-19. Discussion: There were fewer disruptions in psychotherapy care following the rapid shift to virtual care. Telehealth may be a viable option for patients with dementia.

Factors Associated With Psychological Wellbeing in Home Care Older Adults With Alzheimer's Disease: A Longitudinal Analysis

The long-term symptoms associated with Alzheimer's disease pose significant challenges to the psychological wellbeing of patients. This longitudinal study aims to analyze the effects of socioeconomic factors and physical health factors on the psychological wellbeing of older patients diagnosed with Alzheimer's disease (AD) receiving home care, as well as the moderating role of aging and care support in influencing their psychological wellbeing. Data from the Health and Retirement Study (N = 628 older Alzheimer's patients) were analyzed using pooled ordinary least squares fixed-effects models. Findings suggest that Alzheimer's patients' psychological wellbeing was significantly affected by factors including cohabitation, gender, assistance frequency, age, education, and daily activity challenges, with assistance and increasing age mitigating some daily difficulties. The findings underline the multifactorial nature of psychological wellbeing among older Alzheimer's patients in home care and the critical role of social and physical health determinants in shaping these outcomes.

COVID-19 outcomes among patients with dementia and age-matched controls who were hospitalized in 21 US health-care systems

INTRODUCTION

COVID-19 had devastating impacts worldwide. However, most research examining the impact of dementia on COVID-19 outcomes has been conducted in Europe and Asia and has not examined dementia subtypes.

METHODS

A retrospective analysis of electronic health record data from 21 US health-care systems examined relationships of all-cause dementia, Alzheimer's disease (AD), and vascular dementia with in-hospital mortality, intensive care unit (ICU) admission, and hospital stay duration.

RESULTS

All-cause dementia, but not AD or vascular dementia independently, was associated with increased mortality risk, the inclusion of discharge to hospice as a mortality equivalent increased risk for mortality for all-cause dementia, and AD and vascular dementia. Patients with all-cause dementia and AD were less likely to be admitted to the ICU than patients without. Patients with any form of dementia had longer hospital stays than patients without.

DISCUSSION

Dementia was associated with increased mortality or hospice discharge, decreased ICU admissions, and longer hospital stays.

HIGHLIGHTS

Only all-cause dementia was associated with increased mortality risk. This risk was lower than what has been published in previous research. Combining mortality and hospice discharge increased risk for all dementia subtypes. All-cause and Alzheimer's disease (AD) dementia were associated with decreased intensive care unit admissions. All-cause, vascular, and AD dementia were associated with longer hospital stays.

Shared genetics and causal association between plasma levels of SARS-CoV-2 entry receptor ACE2 and Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is the highest risk of COVID-19 infection, hospitalization, and mortality. However, it remains largely unclear about the link between AD and COVID-19 outcomes. ACE2 is an entry receptor for SARS-CoV-2. Circulating ACE2 is a novel biomarker of death and associated with COVID-19 outcomes.

METHODS

Here, we explored the shared genetics and causal association between AD and plasma ACE2 levels using large-scale genome-wide association study, gene expression, expression quantitative trait loci, and high-throughput plasma proteomic profiling datasets.

RESULTS

We found a significant causal effect of genetically increased circulating ACE2 on increased risk of AD. Cross-trait association analysis identified 19 shared genetic variants, and three variants rs3104412, rs2395166, and rs3135344 at chromosome 6p21.32 were associated with COVID-19 infection, hospitalization, and severity. We mapped 19 variants to 117 genes, which were significantly upregulated in lung, spleen, and small intestine, downregulated in brain tissues, and involved in immune system, immune disease, and infectious disease pathways. The plasma proteins corresponding to LST1, AGER, TNXB, and APOC1 were predominantly associated with COVID-19 infection, ventilation, and death.

CONCLUSION

Together, our findings suggest the shared genetics and causal association between AD and plasma ACE2 levels, which may partially explain the link between AD and COVID-19.

Identifying X (Formerly Twitter) Posts Relevant to Dementia and COVID-19: Machine Learning Approach

BACKGROUND

During the pandemic, patients with dementia were identified as a vulnerable population. X (formerly Twitter) became an important source of information for people seeking updates on COVID-19, and, therefore, identifying posts (formerly tweets) relevant to dementia can be an important support for patients with dementia and their caregivers. However, mining and coding relevant posts can be daunting due to the sheer volume and high percentage of irrelevant posts.

OBJECTIVE

The objective of this study was to automate the identification of posts relevant to dementia and COVID-19 using natural language processing and machine learning (ML) algorithms.

METHODS

We used a combination of natural language processing and ML algorithms with manually annotated posts to identify posts relevant to dementia and COVID-19. We used 3 data sets containing more than 100,000 posts and assessed the capability of various algorithms in correctly identifying relevant posts.

RESULTS

Our results showed that (pretrained) transfer learning algorithms outperformed traditional ML algorithms in identifying posts relevant to dementia and COVID-19. Among the algorithms tested, the transfer learning algorithm A Lite Bidirectional Encoder Representations from Transformers (ALBERT) achieved an accuracy of 82.92% and an area under the curve of 83.53%. ALBERT substantially outperformed the other algorithms tested, further emphasizing the superior performance of transfer learning algorithms in the classification of posts.

CONCLUSIONS

Transfer learning algorithms such as ALBERT are highly effective in identifying topic-specific posts, even when trained with limited or adjacent data, highlighting their superiority over other ML algorithms and applicability to other studies involving analysis of social media posts. Such an automated approach reduces the workload of manual coding of posts and facilitates their analysis for researchers and policy makers to support patients with dementia and their caregivers and other vulnerable populations.

Characteristics of patients who died in the hospital emergency service during the SARS-CoV-2 pandemic: a retrospective cohort study in a tertiary hospital in Spain

The objective of this study is to analyze the characteristics of patients who died in the Hospital Emergency Department (HED) of a Spanish third-level hospital, with a special focus on those who died due to SARS-CoV-2. A retrospective cohort study was conducted, including all patients over 18 years old who died in the Hospital Emergency Department (HED) of a Spanish third-level hospital located in Badalona, Spain, from Jun 2019 to Dec 2020. Various sociodemographic, clinical, and diagnostic variables of the patients were analyzed to identify potential risk factors associated with mortality. During the first wave of the COVID-19 pandemic, a total of 72 patients died in the HED, representing a 42% increase compared to the pre-pandemic period. Of the deceased patients, 11% were attributed to SARS-CoV-2. Furthermore, it was found that patients who died from SARS-CoV-2 during the first wave were significantly younger than those in the second wave, with an average age of 78.6 ± 3.1 years in the first wave and 91.8 ± 4.8 years in the second wave. No significant differences were found regarding gender or associated comorbidities. Overall, the mortality rate at the HED in relation to COVID-19 was low, and infected patients died at younger ages during the first wave compared to the second wave.

The impact of the COVID-19 pandemic on non-COVID-associated mortality: A descriptive longitudinal study of UK data

Background

It has been previously reported in the literature that the COVID-19 pandemic resulted in overall excess deaths and an increase in non-COVID deaths during the pandemic period.Specifically, our research elucidates the impact of the COVID-19 pandemic on non-COVID associated mortality.

Study aim

To compare mortality rates in non-COVID conditions before and after the onset of the COVID-19 pandemic in England and Wales.

Study design

Annual mortality data for the years 2011-2019 (pre-pandemic) and 2020 (pandemic) in England and Wales were retrieved from the Office for National Statistics (ONS). These data were filtered by ICD-10 codes for nine conditions with high associated mortality. We calculated mortality numbers - overall and age stratified (20-64 and 65+ years) and rates per 100 000, using annual mid-year population estimates.

Methods

Interrupted time series analyses were conducted using segmented quasi-Poisson regression to identify whether there was a statistically significant change (p < 0.05) in condition-specific death rates following the pandemic onset.

Results

Eight of the nine conditions investigated in this study had significant changes in mortality rate during the pandemic period (2020). All-age mortality rate was significantly increased in: 'Symptoms Signs and Ill-defined conditions', 'Cirrhosis and Other Diseases of the Liver', and 'Malignant Neoplasm of the Breast', whereas 'Chronic Lower Respiratory Disorders' saw a significant decrease. Age-stratified analyses also revealed significant increases in the 20-64 age-group in: 'Cerebrovascular Disorders', 'Dementia and Alzheimer's Disease', and 'Ischaemic Heart Diseases'.

Conclusion

Trends in non-COVID condition-specific mortality rates from 2011 to 2020 revealed that some non-COVID conditions were disproportionately affected during the pandemic. This may be due to the direct impact COVID-19 had on these conditions or the effect the public health response had on non-COVID risk factor development and condition-related management. Further work is required to understand the reasons behind these disproportionate changes.

Neuropathological lesions in intravenous BCG-stimulated K18-hACE2 mice challenged with SARS-CoV-2

In the wake of the COVID-19 pandemic caused by SARS-CoV-2, questions emerged about the potential effects of Bacillus Calmette-Guérin (BCG) vaccine on the immune response to SARS-CoV-2 infection, including the neurodegenerative diseases it may contribute to. To explore this, an experimental study was carried out in BCG-stimulated and non-stimulated k18-hACE2 mice challenged with SARS-CoV-2. Viral loads in tissues determined by RT-qPCR, histopathology in brain and lungs, immunohistochemical study in brain (IHC) as well as mortality rates, clinical signs and plasma inflammatory and coagulation biomarkers were assessed. Our results showed BCG-SARS-CoV-2 challenged mice presented higher viral loads in the brain and an increased frequency of neuroinvasion, with the greatest differences observed between groups at 3-4 days post-infection (dpi). Histopathological examination showed a higher severity of brain lesions in BCG-SARS-CoV-2 challenged mice, mainly consisting of neuroinflammation, increased glial cell population and neuronal degeneration, from 5 dpi onwards. This group also presented higher interstitial pneumonia and vascular thrombosis in lungs (3-4 dpi), BCG-SARS-CoV-2 mice showed higher values for TNF-α and D-dimer values, while iNOS values were higher in SARS-CoV-2 mice at 3-4 dpi. Results presented in this study indicate that BCG stimulation could have intensified the inflammatory and neurodegenerative lesions promoting virus neuroinvasion and dissemination in this experimental model. Although k18-hACE2 mice show higher hACE2 expression and neurodissemination, this study suggests that, although the benefits of BCG on enhancing heterologous protection against pathogens and tumour cells have been broadly demonstrated, potential adverse outcomes due to the non-specific effects of BCG should be considered.

Characteristics of Older Adults with Alzheimer's Disease Who Were Hospitalized during the COVID-19 Pandemic: A Secondary Data Analysis

We aim to investigate the relationships between the population characteristics of patients with Alzheimer's Disease (AD) and their Healthcare Utilization (HU) during the COVID-19 pandemic. Electronic health records (EHRs) were utilized. The study sample comprised those with ICD-10 codes G30.0, G30.1, G30.8, and G30.9 between 1 January 2020 and 31 December 2021. Pearson's correlation and multiple regression were used. The analysis utilized 1537 patient records with an average age of 82.20 years (SD = 7.71); 62.3% were female. Patients had an average of 1.64 hospitalizations (SD = 1.18) with an average length of stay (ALOS) of 7.45 days (SD = 9.13). Discharge dispositions were primarily home (55.1%) and nursing facilities (32.4%). Among patients with multiple hospitalizations, a negative correlation was observed between age and both ALOS (r = -0.1264, p = 0.0030) and number of hospitalizations (r = -0.1499, p = 0.0004). Predictors of longer ALOS included male gender (p = 0.0227), divorced or widowed (p = 0.0056), and the use of Medicare Advantage and other private insurance (p = 0.0178). Male gender (p = 0.0050) and Black race (p = 0.0069) were associated with a higher hospitalization frequency. We recommend future studies including the co-morbidities of AD patients, larger samples, and longitudinal data.

Modeling mortality prediction in older adults with dementia receiving COVID-19 vaccination

OBJECTIVE

This study compared COVID-19 outcomes between vaccinated and unvaccinated older adults with and without cognitive impairment.

METHOD

Electronic health records from Israel from March 2020-February 2022 were analyzed for a large cohort (N = 85,288) aged 65 + . Machine learning constructed models to predict mortality risk from patient factors. Outcomes examined were COVID-19 mortality and hospitalization post-vaccination.

RESULTS

Our study highlights the significant reduction in mortality risk among older adults with cognitive disorders following COVID-19 vaccination, showcasing a survival rate improvement to 93%. Utilizing machine learning for mortality prediction, we found the XGBoost model, enhanced with inverse probability of treatment weighting, to be the most effective, achieving an AUC-PR value of 0.89. This underscores the importance of predictive analytics in identifying high-risk individuals, emphasizing the critical role of vaccination in mitigating mortality and supporting targeted healthcare interventions.

CONCLUSIONS

COVID-19 vaccination strongly reduced poor outcomes in older adults with cognitive impairment. Predictive analytics can help identify highest-risk cases requiring targeted interventions.

2024 Alzheimer's disease facts and figures

This article describes the public health impact of Alzheimer's disease (AD), including prevalence and incidence, mortality and morbidity, use and costs of care and the ramifications of AD for family caregivers, the dementia workforce and society. The Special Report discusses the larger health care system for older adults with cognitive issues, focusing on the role of caregivers and non-physician health care professionals. An estimated 6.9 million Americans age 65 and older are living with Alzheimer's dementia today. This number could grow to 13.8 million by 2060, barring the development of medical breakthroughs to prevent or cure AD. Official AD death certificates recorded 119,399 deaths from AD in 2021. In 2020 and 2021, when COVID-19 entered the ranks of the top ten causes of death, Alzheimer's was the seventh-leading cause of death in the United States. Official counts for more recent years are still being compiled. Alzheimer's remains the fifth-leading cause of death among Americans age 65 and older. Between 2000 and 2021, deaths from stroke, heart disease and HIV decreased, whereas reported deaths from AD increased more than 140%. More than 11 million family members and other unpaid caregivers provided an estimated 18.4 billion hours of care to people with Alzheimer's or other dementias in 2023. These figures reflect a decline in the number of caregivers compared with a decade earlier, as well as an increase in the amount of care provided by each remaining caregiver. Unpaid dementia caregiving was valued at $346.6 billion in 2023. Its costs, however, extend to unpaid caregivers' increased risk for emotional distress and negative mental and physical health outcomes. Members of the paid health care and broader community-based workforce are involved in diagnosing, treating and caring for people with dementia. However, the United States faces growing shortages across different segments of the dementia care workforce due to a combination of factors, including the absolute increase in the number of people living with dementia. Therefore, targeted programs and care delivery models will be needed to attract, better train and effectively deploy health care and community-based workers to provide dementia care. Average per-person Medicare payments for services to beneficiaries age 65 and older with AD or other dementias are almost three times as great as payments for beneficiaries without these conditions, and Medicaid payments are more than 22 times as great. Total payments in 2024 for health care, long-term care and hospice services for people age 65 and older with dementia are estimated to be $360 billion. The Special Report investigates how caregivers of older adults with cognitive issues interact with the health care system and examines the role non-physician health care professionals play in facilitating clinical care and access to community-based services and supports. It includes surveys of caregivers and health care workers, focusing on their experiences, challenges, awareness and perceptions of dementia care navigation.

Effects of COVID-19 Status on Hip Fracture Surgical Outcomes: An ACS NSQIP Study

BACKGROUND

Studies have indicated that patients infected with the SARS-CoV-2 virus fare worse clinically after a traumatic injury, especially those who are older and have other comorbidities.

OBJECTIVE

This study aims to understand the effects of Corona Virus Disease 19 (COVID-19) diagnosis on patients undergoing surgery for hip fractures.

METHODS

This is a retrospective review of the 2021 American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) Targeted Hip Fracture database for patients who underwent surgery. Two cohorts were formed based on patients' preoperative COVID-19 status, as tested within 14 days prior to the operation. Several clinical factors were compared.

RESULTS

The COVID-positive cohort consisted of 184 patients, all of whom had a laboratory-confirmed or clinically suspected SARS-CoV-2 infection, while the COVID-negative cohort consisted of 12,211 patients with no infection. A lower proportion of COVID-positive patients had an emergent operation compared to the COVID-negative cohort (58.70% vs. 73.09%, p < .001). Preoperatively, the COVID-positive cohort showed higher rates of coagulopathy/bleeding disorders (22.83% vs. 14.12%), congestive heart failure (16.30% vs. 9.84%), diabetes mellitus (28.26% vs. 19.24%), and dementia (42.39% vs. 28.07%), with p ≤ .005 for all. Postoperatively, a higher proportion of COVID-positive patients died (9.78% vs. 5.40%) or had pneumonia (8.70% vs. 3.65%), hospital readmission within 30 days (10.87% vs. 6.76%), and pressure sores (8.15% vs. 4.55%), with p ≤ .033 for all.

CONCLUSION

The diagnosis of COVID-19 in hip fracture patients was associated with higher rates of postoperative complications, including mortality, when compared to COVID-negative patients, indicating the severity of the viral infection.

Mapping racial and ethnic healthcare disparities for persons living with dementia: A scoping review

INTRODUCTION

We set out to map evidence of disparities in Alzheimer's disease and Alzheimer's disease related dementias healthcare, including issues of access, quality, and outcomes for racial/ethnic minoritized persons living with dementia (PLWD) and family caregivers.

METHODS

We conducted a scoping review of the literature published from 2000 to 2022 in PubMed, PsycINFO, and CINAHL. The inclusion criteria were: (1) focused on PLWD and/or family caregivers, (2) examined disparities or differences in healthcare, (3) were conducted in the United States, (4) compared two or more racial/ethnic groups, and (5) reported quantitative or qualitative findings.

RESULTS

Key findings include accumulating evidence that minoritized populations are less likely to receive an accurate and timely diagnosis, be prescribed anti-dementia medications, and use hospice care, and more likely to have a higher risk of hospitalization and receive more aggressive life-sustaining treatment at the end-of-life.

DISCUSSION

Future studies need to examine underlying processes and develop interventions to reduce disparities while also being more broadly inclusive of diverse populations.

Interaction effect of race-ethnicity and dementia on COVID-19 diagnosis among a national US older adult sample

Older racial and ethnic minorities and older adults with dementia have an elevated COVID-19 risk, warranting research into the intersection between these two high-risk groups. We examined whether race-ethnicity moderates the association between dementia and COVID-19 diagnosis. Data were retrieved for 3189 respondents from a nationally representative prospective cohort sample of US older adults aged 65+ years. We analysed the effects of the interaction between race-ethnicity and dementia on COVID-19 diagnosis, after adjusting for sociodemographic factors, health and COVID-19 mitigation behaviours. The odds of COVID-19 diagnosis were significantly lower for Black older adults with dementia (adjusted odds ratio [aOR] = 0.07, 95% CI = 0.01-0.78, P = 0.03). In addition, dementia increased the odds of COVID-19 diagnosis among Hispanic older adults (aOR = 1.59, 95% CI = 0.12-21.29, P = 0.72), although this increase was not statistically significant. The interaction between race-ethnicity and dementia should be considered when assessing COVID-19 risk among older adults. Future research is needed to examine pathways through which dementia may interact with race and ethnicity to influence COVID-19 risk.

COVID-19 and Alzheimer's disease: Impact of lockdown and other restrictive measures during the COVID-19 pandemic

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection initially results in respiratory distress symptoms but can also lead to central nervous system (CNS) and neurological manifestations, significantly impacting coronavirus disease 2019 (COVID-19) patients with neurodegenerative diseases. Additionally, strict lockdown measures introduced to curtail the spread of COVID-19 have raised concerns over the wellbeing of patients with dementia and/or Alzheimer's disease. The aim of this review was to discuss the overlapping molecular pathologies and the potential bidirectional relationship between COVID-19 and Alzheimer's dementia, as well as the impact of lockdown/restriction measures on the neuropsychiatric symptoms (NPS) of patients with Alzheimer's dementia. Furthermore, we aimed to assess the impact of lockdown measures on the NPS of caregivers, exploring its potential effects on the quality and extent of care they provide to dementia patients.We utilized the PubMed and Google Scholar databases to search for articles on COVID-19, dementia, Alzheimer's disease, lockdown, and caregivers. Our review highlights that patients with Alzheimer's disease face an increased risk of COVID-19 infection and complications. Additionally, these patients are likely to experience greater cognitive decline. It appears that these issues are primarily caused by the SARS-CoV-2 infection and appear to be further exacerbated by restrictive/lockdown measures. Moreover, lockdown measures introduced during the pandemic have negatively impacted both the NPSs of caregivers and their perception of the wellbeing of their Alzheimer's patients. Thus, additional safeguard measures, along with pharmacological and non-pharmacological approaches, are needed to protect the wellbeing of dementia patients and their caregivers in light of this and possible future pandemics.

The bidirectional links between coronavirus disease 2019 and Alzheimer's disease

Coronavirus disease 2019 (COVID-19) can be a critical disease, particularly in the elderly and those with comorbidities. Patients with Alzheimer's disease are more vulnerable to COVID-19 consequences. The latest results have indicated some common risk factors for both diseases. An understanding of the pathological link between COVID-19 and Alzheimer's disease will help develop timely strategies to treat both diseases. This review explores the bidirectional links between COVID-19 and Alzheimer's disease.

The impact of the 2022 spring COVID-19 booster vaccination programme on hospital occupancy in England: An interrupted time series analysis

Regular booster vaccination programmes help protect the most vulnerable from COVID-19 and limit pressure on health systems. Existing studies find booster doses to be effective in preventing hospital admissions and deaths but focus on individual effects, failing to consider the population impact of incomplete vaccination coverage and seasonal patterns in disease transmission. We estimated the effectiveness of the 2022 spring booster vaccination programme, available for those aged 75 years and older, residents in care homes, and adults with weakened immune systems, on COVID-19 hospital bed occupancy in England. Booster vaccine coverage in the eligible population increased rapidly in the months after rollout (from 21st March 2022), flattening out just below 80% by July 2022. We used interrupted time series analysis to estimate a 23.7% overall reduction in the rate of hospital occupancy for COVID-19 following the programme, with a statistically significant benefit in the 6-12 weeks following rollout. In the absence of the programme, we calculate that a total of 380,104 additional hospital bed-days would have been occupied by patients with COVID-19 from 4th April to 31st August 2022 (95% CI: -122,842 to 1,034,590). The programme delayed and shortened the duration of the peak while not reducing its magnitude. In sensitivity analyses adjusting the start of the post-intervention period or removing the rate of COVID-19 infection in the over 60s from the model, the effect of the spring booster programme on hospital bed occupancy remained similar. Our findings suggest that timing is a critical consideration in the implementation of COVID-19 booster programmes and that policymakers cannot rely on intermittent booster vaccination of high-risk groups alone to mitigate anticipated peaks in hospital pressure due to COVID-19 epidemics.

Extracellular Vesicles: The Invisible Heroes and Villains of COVID-19 Central Neuropathology

Acknowledging the neurological symptoms of COVID-19 and the long-lasting neurological damage even after the epidemic ends are common, necessitating ongoing vigilance. Initial investigations suggest that extracellular vesicles (EVs), which assist in the evasion of the host's immune response and achieve immune evasion in SARS-CoV-2 systemic spreading, contribute to the virus's attack on the central nervous system (CNS). The pro-inflammatory, pro-coagulant, and immunomodulatory properties of EVs contents may directly drive neuroinflammation and cerebral thrombosis in COVID-19. Additionally, EVs have attracted attention as potential candidates for targeted therapy in COVID-19 due to their innate homing properties, low immunogenicity, and ability to cross the blood-brain barrier (BBB) freely. Mesenchymal stromal/stem cell (MSCs) secreted EVs are widely applied and evaluated in patients with COVID-19 for their therapeutic effect, considering the limited antiviral treatment. This review summarizes the involvement of EVs in COVID-19 neuropathology as carriers of SARS-CoV-2 or other pathogenic contents, as predictors of COVID-19 neuropathology by transporting brain-derived substances, and as therapeutic agents by delivering biotherapeutic substances or drugs. Understanding the diverse roles of EVs in the neuropathological aspects of COVID-19 provides a comprehensive framework for developing, treating, and preventing central neuropathology and the severe consequences associated with the disease.

The SNP rs6859 in NECTIN2 gene is associated with underlying heterogeneous trajectories of cognitive changes in older adults

BACKGROUND

Functional decline associated with dementia, including in Alzheimer's disease (AD), is not uniform across individuals, and respective heterogeneity is not yet fully explained. Such heterogeneity may in part be related to genetic variability among individuals. In this study, we investigated whether the SNP rs6859 in nectin cell adhesion molecule 2 (NECTIN2) gene (a major risk factor for AD) influences trajectories of cognitive decline in older participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI).

METHODS

We retrospectively analyzed records on 1310 participants from the ADNI database for the multivariate analysis. We used longitudinal measures of Mini-Mental State Examination (MMSE) scores in participants, who were cognitively normal, or having AD, or other cognitive deficits to investigate the trajectories of cognitive changes. Multiple linear regression, linear mixed models and latent class analyses were conducted to investigate the association of the SNP rs6859 with MMSE.

RESULTS

The regression coefficient per one allele dose of the SNP rs6859 was independently associated with MMSE in both cross-sectional (-2.23, p < 0.01) and linear mixed models (-2.26, p < 0.01) analyses. The latent class model with three distinct subgroups (class 1: stable and gradual decline, class 2: intermediate and late decline, and class 3: lowest and irregular) performed best in the posterior classification, 42.67% (n = 559), 21.45% (n = 281), 35.88% (n = 470) were classified as class 1, class 2, and class 3. In the heterogeneous linear mixed model, the regression coefficient per one allele dose of rs6859 - A risk allele was significantly associated with MMSE class 1 and class 2 memberships and related decline; Class 1 (-2.28, 95% CI: -4.05, -0.50, p < 0.05), Class 2 (-5.56, 95% CI: -9.61, -1.51, p < 0.01) and Class 3 (-0.37, 95% CI: -1.62, 0.87, p = 0.55).

CONCLUSIONS

This study found statistical evidence supporting the classification of three latent subclass groups representing complex MMSE trajectories in the ADNI cohort. The SNP rs6859 can be suggested as a candidate genetic predictor of variation in modeling MMSE trajectory, as well as for identifying latent classes with higher baseline MMSE. Functional studies may help further elucidate this relationship.

Changes in Place of Death among Patients with Dementia during the COVID-19 Pandemic in Japan: A Time Series Analysis

BACKGROUND

A key measure of the effectiveness of end-of-life care is the place of death. The COVID-19 pandemic affected end-of-life care and the circumstances of patients with dementia.

METHODS

This observational, retrospective cohort study used Japanese national data to examine the numbers and locations of reported deaths among patients with dementia older than 65 years during the COVID-19 pandemic. Locations were grouped as medical institutions, nursing facilities, homes, or all the above. The quasi-Poisson regression model known as the Farrington algorithm was employed.

RESULTS

Between December 30, 2019, and January 29, 2023, 279,703 patients who died of causes related to dementia were reported in Japan. A decline was seen in early 2020, followed by increased numbers of deaths in homes, medical facilities, and nursing homes beginning in October 2020, December 2020, and March 2021, respectively. In 2021, the percentage of excess deaths at home peaked at 35.2%, while in 2022, those in medical facilities and nursing homes peaked at 18.8% and 16.6%, respectively. In 2022, the percentage of excess deaths in nursing homes exceeded that of other locations.

CONCLUSIONS

The results suggest a change in the preferred place of death, along with pandemic-related visitation restrictions among healthcare facilities. Excess deaths also suggest strained medical resources and limited access to care. Methodological limitations include data from a limited period (2017 onwards) and post-2020 data used to estimate data after 2021, albeit with weighting. Considering these findings, physicians should reconfirm preferred places of death among older patients with dementia.

What can multiple causes of death tell about cardiovascular mortality during COVID-19 pandemic in the United States?

BACKGROUND

The COVID-19 pandemic may have caused an underestimation of cardiovascular disease (CVD) mortality, as COVID-19 was predominantly recorded as the underlying cause of death. This study investigates CVD-related excess mortality and recording of CVD on the death certificates during 2020-2021, considering underlying (underlying causes of death (UCD)), immediate and contributory causes.

METHODS

We utilize US Multiple-Cause-of-Death Mortality Data. Excess deaths are assessed by comparing actual 2020-2021 deaths with Seasonal Autoregressive Integrated Moving Average model predictions. To understand changes in cause-of-death recording, we use the standardized ratio of multiple to underlying causes (SRMU).

RESULTS

Excess CVD mortality is most prominent in contributory causes, including hypertensive disease, essential hypertension, and acute myocardial infarction. While excess of contributory CVDs generally decreased in 2021, acute myocardial infarction, pulmonary heart diseases and other circulatory diseases showed a continual increase. Changes in SRMU from 2020 to 2021, compared to 2010-2019, reveal shifts in coding practices, particularly for pulmonary heart, cerebrovascular diseases, non-rheumatic valve disorders and heart failure.

CONCLUSIONS

The COVID-19 pandemic has significantly increased CVD-related mortality, which is not fully captured in conventional analyses based solely on the UCD. The trend of coding CVDs as non-underlying causes of death accelerated during 2020-2021. Multiple-causes-of-death should be employed to evaluate mortality when new leading cause of death emerges.

Patterns of psychotropic drug prescriptions and general practice consultations among community-dwelling older people with dementia during the first two years of the COVID-19 pandemic

BACKGROUND

The COVID-19 pandemic and subsequent lockdown measures had serious implications for community-dwelling older people with dementia. While the short-term impacts of the pandemic on this population have been well studied, there is limited research on its long-term impacts. Quantifying the long-term impacts may provide insights into whether healthcare adaptations are needed after the acute phase of the pandemic to balance infection prevention measures with healthcare provision. This study aims to examine patterns of psychotropic drug prescriptions and general practice consultations in community-dwelling older people with dementia during the first two years of the pandemic.

METHODS

We utilised routine electronic health records from three Dutch academic general practice research networks located in the North, East, and South, between 2019 and 2021. We (1) compared the weekly prescription rates of five groups of psychotropic drugs and two groups of tracer drugs, and weekly general practice consultation rates per 1000 participants, between the first two years of the pandemic and the pre-pandemic phase, (2) calculated changes in these rates during three lockdowns and two relaxation phases relative to the corresponding weeks in 2019, and (3) employed interrupted time series analyses for the prescription rates. Analyses were performed for each region separately.

RESULTS

The study population sizes in the North, East, and South between 2019 and 2021 were 1726 to 1916, 93 to 117, and 904 to 960, respectively. Data from the East was excluded from the statistical analyses due to the limited sample size. During the first two years of the pandemic, the prescription rates of psychotropic drugs were either lower or similar to those in the pre-pandemic phase, with differences varying from -2.6‰ to -10.2‰. In contrast, consultation rates during the pandemic were higher than in the pre-pandemic phase, increasing by around 38‰.

CONCLUSIONS

This study demonstrates a decrease in psychotropic drug prescriptions, but an increase in general practice consultations among community-dwelling older people with dementia during the first two years of the pandemic. However, reasons for the decrease in psychotropic drug prescriptions are unclear due to limited information on the presence of neuropsychiatric symptoms and the appropriateness of prescribing.

Investigating the Potential Shared Molecular Mechanisms between COVID-19 and Alzheimer's Disease via Transcriptomic Analysis

SARS-CoV-2 caused the COVID-19 pandemic. COVID-19 may elevate the risk of cognitive impairment and even cause dementia in infected individuals; it may accelerate cognitive decline in elderly patients with dementia, possibly in Alzheimer's disease (AD) patients. However, the mechanisms underlying the interplay between AD and COVID-19 are still unclear. To investigate the underlying mechanisms and associations between AD progression and SARS-CoV-2 infection, we conducted a series of bioinformatics research into SARS-CoV-2-infected cells, COVID-19 patients, AD patients, and SARS-CoV-2-infected AD patients. We identified the common differentially expressed genes (DEGs) in COVID-19 patients, AD patients, and SARS-CoV-2-infected cells, and these DEGs are enriched in certain pathways, such as immune responses and cytokine storms. We constructed the gene interaction network with the signaling transduction module in the center and identified IRF7, STAT1, STAT2, and OAS1 as the hub genes. We also checked the correlations between several key transcription factors and the SARS-CoV-2 and COVID-19 pathway-related genes. We observed that ACE2 expression is positively correlated with IRF7 expression in AD and coronavirus infections, and interestingly, IRF7 is significantly upregulated in response to different RNA virus infections. Further snRNA-seq analysis indicates that NRGN neurons or endothelial cells may be responsible for the increase in ACE2 and IRF7 expression after SARS-CoV-2 infection. The positive correlation between ACE2 and IRF7 expressions is confirmed in the hippocampal formation (HF) of SARS-CoV-2-infected AD patients. Our findings could contribute to the investigation of the molecular mechanisms underlying the interplay between AD and COVID-19 and to the development of effective therapeutic strategies for AD patients with COVID-19.

Associations between cohort derived dementia and COVID-19 serological diagnosis among older Black adults in rural South Africa

Objectives

This study investigates the association between cohort derived dementia and serologically confirmed SARS-CoV-2 infection, an underexplored phenomena in low-and middle-income countries. Examining this relationship in a rural South African community setting offers insights applicable to broader healthcare contexts.

Methods

Data were collected from Black South Africans in the Mpumalanga province who participated in the Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa. Cohort derived dementia was developed using a predictive model for consensus-based dementia diagnosis. Multinomial logistic regression models estimated the association between predicted dementia probability in 2018 and SARS-CoV-2 infection risk in 2021, controlling for demographics, socioeconomic status, and comorbidities.

Results

Fifty-two percent of the tested participants had serologically confirmed SARS-CoV-2 infections. In the fully adjusted model, cohort derived dementia was significantly associated with over twice the risk of serological diagnosis of COVID-19 (RRR = 2.12, p = 0.045).

Conclusion

Complying with COVID-19 prevention recommendations may be difficult for individuals with impaired cognitive functioning due to their symptoms. Results can inform community-based public health initiatives to reduce COVID-19 transmission among South Africa's rapidly aging population.

MPTN: A message-passing transformer network for drug repurposing from knowledge graph

Drug repurposing (DR) based on knowledge graphs (KGs) is challenging, which uses knowledge graph reasoning models to predict new therapeutic pathways for existing drugs. With the rapid development of computing technology and the growing availability of validated biomedical data, various knowledge graph-based methods have been widely used to analyze and process complex and novel data to discover new indications for given drugs. However, existing methods need to be improved in extracting semantic information from contextual triples of biomedical entities. In this study, we propose a message-passing transformer network named MPTN based on knowledge graph for drug repurposing. Firstly, CompGCN is used as precoder to jointly aggregate entity and relation embeddings. Then, to fully capture the semantic information of entity context triples, the message propagating transformer module is designed. The module integrates the transformer into the message passing mechanism and incorporates the attention weight information of computing entity context triples into the entity embedding to update the entity embedding. Next, the residual connection is introduced to retain information as much as possible and improve prediction accuracy. Finally, MPTN utilizes the InteractE module as the decoder to obtain heterogeneous feature interactions in entity and relation representations and predict new pathways for drug treatment. Experiments on two datasets show that the model is superior to the existing knowledge graph embedding (KGE) learning methods.

Preventable Emergency Department Visits of Patients with Alzheimer's Disease and Related Dementias During the COVID-19 Pandemic by Hospital-Based Health Information Exchange

Background: This study examined the relationship between hospital-based electronic health information exchange (HIE) and the likelihood of having a preventable emergency department (ED) visit during the COVID-19 pandemic for US patients with Alzheimer's Disease and Related Dementias (ADRD). Methods: We used multi-level data from six states. The linked data sets included the 2020 State Emergency Department Databases (SEDD), the Area Health Resources File, the American Hospital Association (AHA) Annual Survey, and the AHA Information Technology Supplement to study 85,261 hospital discharges from patients with ADRD. Logistic regression models were produced to determine the odds of having a preventable ED visit among patients with ADRD. Results: Our final sample included 85,261 hospital discharges from patients with ADRD. Patients treated in hospitals that received more types of clinical information for treating patients with COVID-19 from outside providers (OR = 0.961, p < .05) and/or hospitals that received COVID-19 test results from more outside entities were significantly less likely to encounter preventable EDs (OR = 0.964, p < .05), especially among patients who also had multiple chronic conditions (MCC) (OR = 0.89, p = .001; OR = 0.856, p < .001). Conclusion: Our results suggest that electronic HIE may be useful for reducing preventable ED visits during the COVID-19 pandemic for people with ADRD and ADRD alongside MCC.

Impact of COVID-19 pandemic on mortality rate in memory clinic patients

INTRODUCTION

We investigated whether mortality in memory clinic patients changed due to coronavirus disease 2019 (COVID-19) pandemic.

METHODS

We included patients from the Amsterdam Dementia Cohort: (1) n = 923 pandemic patients (baseline visit: 2017-2018, follow-up: until 2021), and (2) n = 830 historical control patients (baseline visit: 2015-2016, follow-up: until 2019). Groups were well-balanced. We compared mortality during pandemic with historical control patients using Cox regression. Differences in cause of death between groups were explored using Fisher's exact test.

RESULTS

Pandemic patients had a higher risk of mortality than historical control patients (hazard ratio [HR] [95% confidence interval {CI}] = 1.34 [1.05-1.70]). Stratified for syndrome diagnosis, the effect remained significant in dementia patients (HR [95% CI] = 1.35 [1.03-1.78]). Excluding patients who died of COVID-19-infection, the higher mortality risk in pandemic patients attenuated (HR [95% CI] = 1.24 [0.97-1.58]). Only the difference in cause of death between pandemic patients and historical control patients for death to COVID-19-infection (p = 0.001) was observed.

CONCLUSION

Memory clinic patients had increased mortality risk during COVID-19 compared to historical control patients, attributable to dementia patients.

Highlights

We investigated if mortality rates in memory clinic patients changed due to COVID-19 pandemic.We included patients along the cognitive continuum, including SCD, MCI, and dementia.We used a well-balanced historical control group.Memory clinic patients had higher risk for mortality during COVID-19 lockdown.Our results indicate that excess mortality is mainly caused by death to COVID-19 infection.

Effects of COVID-19 on cognition and brain health

COVID-19 is associated with a range of neurological, cognitive, and mental health symptoms both acutely and chronically that can persist for many months after infection in people with long-COVID syndrome. Investigations of cognitive function and neuroimaging have begun to elucidate the nature of some of these symptoms. They reveal that, although cognitive deficits may be related to brain imaging abnormalities in some people, symptoms can also occur in the absence of objective cognitive deficits or neuroimaging changes. Furthermore, cognitive impairment may be detected even in asymptomatic individuals. We consider the evidence regarding symptoms, cognitive deficits, and neuroimaging, as well as their possible underlying mechanisms.

COVID-19 and the impact on Alzheimer's disease pathology

Coronavirus disease 2019 (COVID-19) has rapidly escalated into a global pandemic that primarily affects older and immunocompromised individuals due to underlying clinical conditions and suppressed immune responses. Furthermore, COVID-19 patients exhibit a spectrum of neurological symptoms, indicating that COVID-19 can affect the brain in a variety of manners. Many studies, past and recent, suggest a connection between viral infections and an increased risk of neurodegeneration, raising concerns about the neurological effects of COVID-19 and the possibility that it may contribute to Alzheimer's disease (AD) onset or worsen already existing AD pathology through inflammatory processes given that both COVID-19 and AD share pathological features and risk factors. This leads us to question whether COVID-19 is a risk factor for AD and how these two conditions might influence each other. Considering the extensive reach of the COVID-19 pandemic and the devastating impact of the ongoing AD pandemic, their combined effects could have significant public health consequences worldwide.

Exploratory study of risk factors related to SARS-CoV-2 prevalence in nursing homes in Flanders (Belgium) during the first wave of the COVID-19 pandemic

In a previous study in Belgian nursing homes (NH) during the first wave of the COVID-19 pandemic, we found a SARS-CoV-2 seroprevalence of 17% with a large variability (0-45%) between NH. The current exploratory study aimed to identify nursing home-specific risk factors for high SARS-CoV-2 seroprevalence. Between October 19th, 2020 and November 13th, 2020, during the second COVID-19 wave in Belgium, capillary blood was collected on dried blood spots from 60 residents and staff in each of the 20 participating NH in Flanders and Brussels. The presence of SARS-CoV-2-specific IgG antibodies was assessed by ELISA. Risk factors were evaluated using a questionnaire, filled in by the director or manager of the NH. Assessed risk factors comprised community-related factors, resident-related factors, management and performance features as well as building-related aspects. The relation between risk factors and seroprevalence was assessed by applying random forest modelling, generalized linear models and Bayesian linear regression. The present analyses showed that the prevalence of residents with dementia, the scarcity of personal protective equipment (surgical masks, FFP2 masks, glasses and face shields), and inadequate PCR test capacity were related to a higher seroprevalence. Generally, our study put forward that the various aspects of infection prevention in NH require more attention and investment. This exploratory study suggests that the ratio of residents with dementia, the availability of test capacity and personal protective equipment may have played a role in the SARS-CoV-2 seroprevalence of NH, after the first wave. It underscores the importance of the availability of PPE and education in infection prevention. Moreover, investments may also yield benefits in the prevention of other respiratory infections (such as influenza).

Higher angiotensin-converting enzyme 2 (ACE2) levels in the brain of individuals with Alzheimer's disease

Cognitive decline due to Alzheimer's disease (AD) is frequent in the geriatric population, which has been disproportionately affected by the COVID-19 pandemic. In this study, we investigated the levels of angiotensin-converting enzyme 2 (ACE2), a regulator of the renin-angiotensin system and the main entry receptor of SARS-CoV-2 in host cells, in postmortem parietal cortex samples from two independent AD cohorts, totalling 142 persons. Higher concentrations of ACE2 protein (p < 0.01) and mRNA (p < 0.01) were found in individuals with a neuropathological diagnosis of AD compared to age-matched healthy control subjects. Brain levels of soluble ACE2 were inversely associated with cognitive scores (p = 0.02) and markers of pericytes (PDGFRβ, p = 0.02 and ANPEP, p = 0.007), but positively correlated with concentrations of soluble amyloid-β peptides (Aβ) (p = 0.01) and insoluble phospho-tau (S396/404, p = 0.002). However, no significant differences in ACE2 were observed in the 3xTg-AD mouse model of tau and Aβ neuropathology. Results from immunofluorescence and Western blots showed that ACE2 protein is predominantly localized in microvessels in the mouse brain whereas it is more frequently found in neurons in the human brain. The present data suggest that higher levels of soluble ACE2 in the human brain may contribute to AD, but their role in CNS infection by SARS-CoV-2 remains unclear.

Association between COVID-19 vaccination and critical outcomes among older adults with dementia: a comparative cohort study

Background

As COVID-19 vaccines became available, understanding their potential benefits in vulnerable populations has gained significance. This study explored the advantages of COVID-19 vaccination in individuals with cognitive disorders by analyzing health-related variables and outcomes.

Methods

A prospective cohort study analyzed electronic medical records of 25,733 older adults with cognitive disorders and 65,544 older adults without cognitive disorders from March 2020 to February 2022. COVID-19 vaccination status was the primary exposure variable, categorized as fully vaccinated or unvaccinated. The primary outcomes measured were all-cause mortality and hospitalization rates within 14 and 400 days post-vaccination. Data on vaccination status, demographics, comorbidities, testing history, and clinical outcomes were collected from electronic health records. The study was ethically approved by the relevant medical facility's Institutional Review Board (0075-22-MHS).

Results

Vaccinated individuals had significantly lower mortality rates in both groups. In the research group, the mortality rate was 52% (n = 1852) for unvaccinated individuals and 7% (n = 1,241) for vaccinated individuals (p < 0.001). Similarly, in the control group, the mortality rate was 13.58% (n = 1,508) for unvaccinated individuals and 1.85% (n = 936) for vaccinated individuals (p < 0.001), despite higher COVID-19 positivity rates. In the research group, 30.26% (n = 1,072) of unvaccinated individuals tested positive for COVID-19, compared to 37.16% (n = 6,492) of vaccinated individuals (p < 0.001). In the control group, 17.31% (n = 1922) of unvaccinated individuals were COVID-19 positive, while 37.25% (n = 18,873) of vaccinated individuals tested positive (p < 0.001). Vaccination also showed potential benefits in mental health support. The usage of antipsychotic drugs was lower in vaccinated individuals (28.43%, n = 4,967) compared to unvaccinated individuals (37.48%, n = 1,328; 95% CI [0.92-1.28], p < 0.001). Moreover, vaccinated individuals had lower antipsychotic drug prescription rates (23.88%, n = 4,171) compared to unvaccinated individuals (27.83%, n = 968; 95% CI [-1.02 to -0.63], p < 0.001). Vaccination appeared to have a positive impact on managing conditions like diabetes, with 38.63% (n = 6,748) of vaccinated individuals having diabetes compared to 41.55% (n = 1,472) of unvaccinated individuals (95% CI [0.24, 0.48], p < 0.001).

Discussion

The findings highlight the importance of vaccination in safeguarding vulnerable populations during the pandemic and call for further research to optimize healthcare strategies for individuals with cognitive disorders.

Caregiver Experience of Tele-dementia Care for Older Veterans

BACKGROUND

For the 5 million persons living with dementia (PLWD) in the USA, telemedicine may improve access to specialty care from their homes.

OBJECTIVE

To elicit informal caregiver perceptions of tele-dementia care provided during COVID-19.

DESIGN

Qualitative, observational study using grounded theory.

PARTICIPANTS

Informal caregivers aged 18 + who cared for an older adult who received tele-dementia services at two major VA healthcare systems participated in 30-60-min semi-structured telephone interviews.

INTERVENTIONS

Interviews were designed using Fortney's Access to Care model.

MAIN MEASURES

Thirty caregivers (mean age = 67, SD = 12, 87% women) were interviewed.

KEY RESULTS

Five major themes were (1) Tele-dementia care avoids routine disruption and pre-visit stress; (2) Transportation barriers to in-person visits include not only travel logistics but navigating the sequelae of dementia and comorbid medical conditions. These include cognitive, behavioral, physical, and emotional challenges such as balance issues, incontinence, and agitation in traffic; (3) Tele-dementia care saves time and money and improves access to specialists; (4) Tele-dementia facilitated communication between caregiver and provider without hindering communication between PLWD and provider; and (5) Caregivers described ideal future dementia care as a combination of virtual and in-person modalities with in-home help, financial and medical support, and dementia-sensitive caregiver access. Caregivers interviewed saved 2.6 h ± 1.5 h (range: 0.5 to 6 h) of travel time. Multiple caregivers described disruption of routines as difficult in PLWD and appreciated the limited preparation and immediate return to routine post telemedicine visit as positives.

CONCLUSIONS

Caregivers found tele-dementia care convenient, comfortable, stress reducing, timesaving, and highly satisfactory. Caregivers would prefer a combination of in-person and telemedicine visits, with an opportunity to communicate with providers privately. This intervention prioritizes care for older Veterans with dementia who have high care needs and are at higher risk for hospitalization than their same age counterparts without 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.

High content screening miniaturization and single cell imaging of mature human feeder layer-free iPSC-derived neurons

Human induced pluripotent stem cell (iPSC)-derived neurons are being increasingly used for high content imaging and screening. However, iPSC-derived neuronal differentiation and maturation is time-intensive, often requiring >8 weeks. Unfortunately, the differentiating and maturing iPSC-derived neuronal cultures also tend to migrate and coalesce into ganglion-like clusters making single-cell analysis challenging, especially in miniaturized formats. Using our defined extracellular matrix and low oxygen culturing conditions for the differentiation and maturation of human cortical neurons, we further modified neuronal progenitor cell seeding densities and feeder layer-free culturing conditions in miniaturized formats (i.e., 96 well) to decrease neuronal clustering, enhance single-cell identification and reduce edge effects usually observed after extended neuronal cell culture. Subsequent algorithm development refined capabilities to distinguish and identify single mature neurons, as identified by NeuN expression, from large cellular aggregates, which were excluded from image analysis. Incorporation of astrocyte conditioned medium during differentiation and maturation periods significantly increased the percentage (i.e., ∼10% to ∼30%) of mature neurons (i.e., NeuN+) detected at 4-weeks post-differentiation. Pilot, proof of concept studies using this optimized assay system yielded negligible edge effects and robust Z-factors in population-based as well as image-based neurotoxicity assay formats. Moreover, moxidectin, an FDA-approved drug with documented neurotoxic adverse effects, was identified as a hit using both screening formats. This miniaturized, feeder layer-free format and image analysis algorithm provides a foundational imaging and screening platform, which enables quantitative single-cell analysis of differentiated human neurons.

Dignity as a Central Issue in Treating Patients with Dementia Associated with COVID-19 Infection

COVID-19 was initially considered a primary respiratory disorder associated with various short- and long-term complications, affecting many patients and imposing a significant burden. Patients who have dementia are especially vulnerable to the SARS-CoV2 infection, which is associated with an increased risk for neuropsychiatric complications. These patients need a unique approach to managing ethical issues related to the COVID-19 pandemic, including autonomy, veracity, non-maleficence, justice, compassion, and dignity. The latter is one of the most elusive and misunderstood concepts in medical ethics and is extremely important in debates surrounding the proper management of patients with dementia. However, it is often left out of ethical analysis, as most clinicians, when debating issues associated with clinical practice, often evaluate only the "classical" principles of biomedical ethics. In this article, we aim to assess the unique features of dignity in treating this group of patients during the COVID-19 pandemic. We will briefly analyze dignity as a bioethical concept. We will further explore its principal axes, namely compassion, creating a humane and purposeful environment, employing persuasion to meet the person's essential needs, exerting a certain degree of mild restraint to meet the person's critical needs, minimizing harm in terminal care, and justice, through the lens of people who had dementia during the COVID-19 pandemic. Applying this principle in clinical practice requires significant commitment from all healthcare workers. New approaches to the analysis of dignity, such as through the Ring Theory of Personhood, may facilitate its understanding by practitioners and aid its implementation in populations with multiple vulnerabilities, such as dementia patients, during an infectious outbreak that generates significant social and medical changes.

Cognitive concerns are a risk factor for mortality in people with HIV and coronavirus disease 2019

BACKGROUND

Data supporting dementia as a risk factor for coronavirus disease 2019 (COVID-19) mortality relied on ICD-10 codes, yet nearly 40% of individuals with probable dementia lack a formal diagnosis. Dementia coding is not well established for people with HIV (PWH), and its reliance may affect risk assessment.

METHODS

This retrospective cohort analysis of PWH with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) PCR positivity includes comparisons to people without HIV (PWoH), matched by age, sex, race, and zipcode. Primary exposures were dementia diagnosis, by International Classification of Diseases (ICD)-10 codes, and cognitive concerns, defined as possible cognitive impairment up to 12 months before COVID-19 diagnosis after clinical review of notes from the electronic health record. Logistic regression models assessed the effect of dementia and cognitive concerns on odds of death [odds ratio (OR); 95% CI (95% confidence interval)]; models adjusted for VACS Index 2.0.

RESULTS

Sixty-four PWH were identified out of 14 129 patients with SARS-CoV-2 infection and matched to 463 PWoH. Compared with PWoH, PWH had a higher prevalence of dementia (15.6% vs. 6%, P  = 0.01) and cognitive concerns (21.9% vs. 15.8%, P  = 0.04). Death was more frequent in PWH ( P  < 0.01). Adjusted for VACS Index 2.0, dementia [2.4 (1.0-5.8), P  = 0.05] and cognitive concerns [2.4 (1.1-5.3), P  = 0.03] were associated with increased odds of death. In PWH, the association between cognitive concern and death trended towards statistical significance [3.92 (0.81-20.19), P  = 0.09]; there was no association with dementia.

CONCLUSION

Cognitive status assessments are important for care in COVID-19, especially among PWH. Larger studies should validate findings and determine long-term COVID-19 consequences in PWH with preexisting cognitive deficits.

Role of toll-like receptors in the pathogenesis of COVID-19: Current and future perspectives

The coronavirus disease 2019 (COVID-19) pandemic underlines a persistent threat of respiratory tract infectious diseases and warrants preparedness for a rapid response. At present, COVID-19 has had a serious social impact and imposed a heavy global burden on public health. The exact pathogenesis of COVID-19 has not been fully elucidated. Since the outbreak of COVID-19, a renewed attention has been brought to Toll-like receptors (TLRs). Available data and new findings have demonstrated that the interaction of human TLRs and SARS-CoV-2 is a vital mediator of COVID-19 immunopathogenesis. TLRs such as TLR2, 4, 7 and 8 are potentially important in viral combat and activation of immunity in patients with COVID-19. Therapeutics targeting TLRs are currently considered promising options against the pandemic. A number of TLR-targeting immunotherapeutics are now being investigated in preclinical studies and different phases of clinical trials. In addition, innovative vaccines based on TLRs under development could be a promising approach for building a new generation of vaccines to solve the current challenges. In this review, we summarize recent progress in the role of TLRs in COVID-19, focusing the new candidate drugs targeting TLRs, the current technology and potential paths forward for employing TLR agonists as vaccine adjuvants.

Global trends in COVID-19 Alzheimer's related research: a bibliometric analysis

Background

The COVID-19 pandemic has significantly impacted public health, putting people with Alzheimer's disease at significant risk. This study used bibliometric analysis method to conduct in-depth research on the relationship between COVID-19 and Alzheimer's disease, as well as to predict its development trends.

Methods

The Web of Science Core Collection was searched for relevant literature on Alzheimer's and Coronavirus-19 during 2019-2023. We used a search query string in our advanced search. Using Microsoft Excel 2021 and VOSviewer software, a statistical analysis of primary high-yield authors, research institutions, countries, and journals was performed. Knowledge networks, collaboration maps, hotspots, and regional trends were analyzed using VOSviewer and CiteSpace.

Results

During 2020-2023, 866 academic studies were published in international journals. United States, Italy, and the United Kingdom rank top three in the survey; in terms of productivity, the top three schools were Harvard Medical School, the University of Padua, and the University of Oxford; Bonanni, Laura, from Gabriele d'Annunzio University (Italy), Tedeschi, Gioacchino from the University of Campania Luigi Vanvitelli (Italy), Vanacore, Nicola from Natl Ctr Dis Prevent and Health Promot (Italy), Reddy, P. Hemachandra from Texas Tech University (USA), and El Haj, Mohamad from University of Nantes (France) were the authors who published the most articles; The Journal of Alzheimer's Disease is the journals with the most published articles; "COVID-19," "Alzheimer's disease," "neurodegenerative diseases," "cognitive impairment," "neuroinflammation," "quality of life," and "neurological complications" have been the focus of attention in the last 3 years.

Conclusion

The disease caused by the COVID-19 virus infection related to Alzheimer's disease has attracted significant attention worldwide. The major hot topics in 2020 were: "Alzheimer' disease," COVID-19," risk factors," care," and "Parkinson's disease." During the 2 years 2021 and 2022, researchers were also interested in "neurodegenerative diseases," "cognitive impairment," and "quality of life," which require further investigation.

Racial/Ethnic Differences in Risk Factors Associated With Severe COVID-19 Among Older Adults With ADRD

OBJECTIVE

To examine racial/ethnic differences in risk factors, and their associations with COVID-19-related outcomes among older adults with Alzheimer's disease and related dementias (ADRD).

DESIGN

Observational study.

SETTING AND PARTICIPANTS

National Medicare claims data and the Minimum Data Set 3.0 from April 1, 2020, to December 31, 2020, were linked in this study. We included community-dwelling fee-for-service Medicare beneficiaries with ADRD, diagnosed with COVID-19 between April 1, 2020, and December 1, 2020 (N = 138,533).

METHODS

Two outcome variables were defined: hospitalization within 14 days and death within 30 days of COVID-19 diagnosis. We obtained information on individual sociodemographic characteristics, chronic conditions, and prior health care utilization based on the Medicare claims and the Minimum Dataset. Machine learning methods, including lasso regression and discriminative pattern mining, were used to identify risk factors in racial/ethnic subgroups (ie, White, Black, and Hispanic individuals). The associations between identified risk factors and outcomes were evaluated using logistic regression and compared across racial/ethnic subgroups using the coefficient comparison approach.

RESULTS

We found higher risks of COVID-19-related outcomes among Black and Hispanic individuals. The areas under the curve of the models with identified risk factors were 0.65 to 0.68 for mortality and 0.61 to 0.62 for hospitalization across racial/ethnic subgroups. Although some identified risk factors (eg, age, gender) for COVID-19-related outcomes were common among all racial/ethnic subgroups, other risk factors (eg, hypertension, obesity) varied by racial/ethnic subgroups. Furthermore, the associations between some common risk factors and COVID-19-related outcomes also varied by race/ethnicity. Being male was related to 138.2% (95% CI: 1.996-2.841), 64.7% (95% CI: 1.546-1.755), and 37.1% (95% CI: 1.192-1.578) increased odds of death among Hispanic, White, and Black individuals, respectively. In addition, the racial/ethnic disparity in COVID-19-related outcomes could not be completely explained by the identified risk factors.

CONCLUSIONS AND IMPLICATIONS

Racial/ethnic differences were detected in the likelihood of having COVID-19-related outcomes, specific risk factors, and relationships between specific risk factors and COVID-19-related outcomes. Future research is needed to elucidate the reasons for these differences.

The functional and structural changes in the hippocampus of COVID-19 patients

Since the hippocampus is predominantly susceptible to injuries caused by COVID-19, there are increasing data indicating the likelihood of post-infection memory loss and quickening neurodegenerative disorders, such as Alzheimer's disease. This is due to the fact that the hippocampus has imperative functions in spatial and episodic memory as well as learning. COVID-19 activates microglia in the hippocampus and induces a CNS cytokine storm, leading to loss of hippocampal neurogenesis. The functional and structural changes in the hippocampus of COVID-19 patients can explain neuronal degeneration and reduced neurogenesis in the human hippocampus. This will open a window to explain memory and cognitive dysfunctions in "long COVID" through the resultant loss of hippocampal neurogenesis.

SARS-CoV-2 susceptibility and COVID-19 illness course and outcome in people with pre-existing neurodegenerative disorders: systematic review with frequentist and Bayesian meta-analyses

BACKGROUND

People with neurodegenerative disease and mild cognitive impairment (MCI) may have an elevated risk of acquiring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and may be disproportionally affected by coronavirus disease 2019 (COVID-19) once infected.

AIMS

To review all eligible studies and quantify the strength of associations between various pre-existing neurodegenerative disorders and both SARS-CoV-2 susceptibility and COVID-19 illness course and outcome.

METHOD

Pre-registered systematic review with frequentist and Bayesian meta-analyses. Systematic searches were executed in PubMed, Web of Science and preprint servers. The final search date was 9 January 2023. Odds ratios (ORs) were used as measures of effect.

RESULTS

In total, 136 primary studies (total sample size n = 97 643 494), reporting on 268 effect-size estimates, met the inclusion criteria. The odds for a positive SARS-CoV-2 test result were increased for people with pre-existing dementia (OR = 1.83, 95% CI 1.16-2.87), Alzheimer's disease (OR = 2.86, 95% CI 1.44-5.66) and Parkinson's disease (OR = 1.65, 95% CI 1.34-2.04). People with pre-existing dementia were more likely to experience a relatively severe COVID-19 course, once infected (OR = 1.43, 95% CI 1.00-2.03). People with pre-existing dementia or Alzheimer's disease were at increased risk for COVID-19-related hospital admission (pooled OR range: 1.60-3.72). Intensive care unit admission rates were relatively low for people with dementia (OR = 0.54, 95% CI 0.40-0.74). All neurodegenerative disorders, including MCI, were at higher risk for COVID-19-related mortality (pooled OR range: 1.56-2.27).

CONCLUSIONS

Our findings confirm that, in general, people with neurodegenerative disease and MCI are at a disproportionally high risk of contracting COVID-19 and have a poor outcome once infected.

Anti-Viral Surfaces in the Fight against the Spread of Coronaviruses

This review is conducted against the background of nanotechnology, which provides us with a chance to effectively combat the spread of coronaviruses, and which primarily concerns polyelectrolytes and their usability for obtaining protective function against viruses and as carriers for anti-viral agents, vaccine adjuvants, and, in particular, direct anti-viral activity. This review covers nanomembranes in the form of nano-coatings or nanoparticles built of natural or synthetic polyelectrolytes--either alone or else as nanocomposites for creating an interface with viruses. There are not a wide variety of polyelectrolytes with direct activity against SARS-CoV-2, but materials that are effective in virucidal evaluations against HIV, SARS-CoV, and MERS-CoV are taken into account as potentially active against SARS-CoV-2. Developing new approaches to materials as interfaces with viruses will continue to be relevant in the future.

Risk of Adverse Events and Delirium After COVID-19 Vaccination in Patients Living With Dementia

OBJECTIVES

The aim of this study was to compare incidences of adverse events of special interest (AESI) and delirium in 3 cohorts: after COVID-19 vaccination, prepandemic, and SARS-CoV-2 polymerase chain reaction (PCR) test positive.

DESIGN

This is a population-based cohort study using electronic medical records linked with vaccination records in Hong Kong.

SETTING AND PARTICIPANTS

A total of 17,449 older people with dementia received at least 1 dose of CoronaVac (n = 14,719) or BNT162b2 (n = 2730) between February 23, 2021, and March 31, 2022. Moreover, 43,396 prepandemic and 3592 SARS-CoV-2 test positive patients were also included in this study.

METHODS

The incidences of AESI and delirium up to 28 days after vaccination in the vaccinated dementia cohort were compared with the prepandemic and SARS-CoV-2 test positive dementia cohorts by calculating incidence rate ratios (IRRs). Patients who received multiple doses were followed up separately for each dose, up to the third dose.

RESULTS

We did not detect an increased risk of delirium and most AESI following vaccination compared to the prepandemic period and those tested positive for SARS-CoV-2. No AESI group nor delirium incidence exceeded 10 per 1000 person-days in vaccinated individuals.

CONCLUSIONS AND IMPLICATIONS

The findings provide evidence for the safe use of COVID-19 vaccines in older patients with dementia. In the short run, benefit appears to outweigh the harm due to vaccine; however, longer follow-up should be continued to identify remote adverse events.

The Two-Way Route between Delirium Disorder and Dementia: Insights from COVID-19

BACKGROUND

Delirium disorder is a frequent neurological complication of SARS-CoV-2 infection and associated with increased disease severity and mortality. Cognitive impairment is a major risk factor for developing delirium disorder during COVID-19, which, in turn, increases the risk of subsequent neurological complications and cognitive decline.

SUMMARY

The bidirectional connection between delirium disorder and dementia likely resides at multiple levels, and its pathophysiological mechanisms during COVID-19 include endothelial damage, blood-brain barrier dysfunction, and local inflammation, with activation of microglia and astrocytes. Here, we describe the putative pathogenic pathways underlying delirium disorder during COVID-19 and highlight how they cross with the ones leading to neurodegenerative dementia.

KEY MESSAGES

The analysis of the two-sided link can offer useful insights for confronting with long-term neurological consequences of COVID-19 and framing future prevention and early treatment strategies.