Clinical outcomes of COVID-19 infection among patients with Alzheimer's disease or mild cognitive impairment

Comparing COVID-19 vaccination coverage, adverse reactions and impact of social determinants of health on vaccine hesitancy in ADRD/MCI and non-ADRD/MCI population: protocol for a retrospective cross-sectional study

INTRODUCTION

COVID-19 vaccination is crucial for vulnerable people with underlying chronic conditions such as Alzheimer's disease and related dementias (ADRD) and mild cognitive impairment (MCI). These individuals face unique challenges, including higher risk of COVID-19, difficulties in adopting preventive behaviours and vaccine hesitancy due to concerns about adverse reactions. Therefore, efforts to promote vaccination, including boosters tailored to the currently circulating virus, are essential for people with ADRD/MCI.

OBJECTIVE

The primary purpose of this study protocol is to conduct a comprehensive analysis of COVID-19 vaccination coverage and adverse reactions among individuals with ADRD/MCI in comparison to those without ADRD/MCI. Additionally, the proposed study aims to investigate the impact of social determinants of health on COVID-19 vaccination and vaccine hesitancy in individuals with ADRD/MCI.

METHODS AND ANALYSIS

A retrospective cross-sectional study will be conducted utilising data from the All of Us (AoU) Researcher Workbench. Relevant data fields are extracted from sources including demographic information, COVID-19 Vaccine Survey, Basic Survey, Health Access & Utilization, Social Determinants of Health, and Electronic Health Record (EHR) data. Data on vaccination, adverse reactions and vaccine hesitancy will be collected through COVID-19 vaccine survey questionnaires. Propensity score matching and binary logistic regression will be applied to assess the vaccination rates and vaccine hesitancy, while controlling for demographic characteristics and social determinants of health factors.

ETHICS AND DISSEMINATION

This study protocol received approval from the Institutional Review Board at Florida State University (STUDY00004571). Results will be disseminated through publication in peer-reviewed journals and presented at scientific conferences.

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.

SARS-CoV-2 and the Angiotensin-Converting Enzyme 2 Receptor: Angiotensin-Converting Enzyme Inhibitor/Angiotensin 2 Receptor Blocker Utilization and a Shift Towards the Renin-Angiotensin-Aldosterone System Classical Pathway

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the coronavirus disease 2019 (COVID-19) pandemic, uses the surface angiotensin-converting enzyme 2 (ACE2) receptor as the site of entry into host cardiac, respiratory, intestinal, renal, and nervous system cells. Predisposing risk factors such as cardiovascular disease increase the risk of developing severe disease. Hypertension is characterized by the stimulation of the renin-angiotensin-aldosterone system (RAAS). Angiotensin-converting enzyme inhibitors (ACEis) and angiotensin 2 receptor blockers (ARBs), medications used to treat hypertension, inhibit RAAS and its downstream effects; however, they have also been shown to upregulate ACE2 receptors. In this review, we aim to evaluate the effectiveness of ACEi/ARBs as an adjunct therapy in patients with SARS-CoV-2 as well as examine the possible protective effects and impact on infection rate and disease severity. A PubMed literature search excluding sources outside the United States and duplicates was performed using the following search criteria: "COVID-19 AND cardiovascular disease AND ACEi AND ARB", "SARS-COVID-19 OR COVID-19, AND ACEi AND ARB AND Infection rate", "COVID-19 AND ACEi and ARB", "Omicron BA.1 and BA.2 AND ACE2 OR ARBs", "Omicron AND ACEi AND ARBs". This resulted in 33 final sources. The review concluded that ACEi/ARB therapy may continue to improve COVID-19 survival as previous treatment is associated with positive clinical outcomes. Patients taking ACEis or ARBs were found to have a decreased risk of hospitalization, reduced severity of COVID-19 pneumonia, a lesser need for mechanical ventilation, and an overall reduction in mortality rate. No statistically significant association between ACEi/ARB use and enhanced COVID-19 infectivity was found. The Omicron variant is theoretically more infectious and was associated with increased negative clinical outcomes in those undertreated with ACEis/ARBs. The majority of the literature supports the current guidelines from the American College of Cardiology (ACC), American Heart Association (AHA), European Society of Cardiology (ESC), and Heart Failure Society of America (HFSA), which state that ACEi and ARB medications should not be withdrawn from or initiated on patients with cardiovascular disease who are infected with SARS-CoV-2. More research needs to be conducted on the association between the emerging COVID-19 variants and ACEis/ARBs to give clinicians confidence when treating patients within this subgroup of the population.

Cognitive Aspects of COVID-19

PURPOSE OF REVIEW

Since the beginning of the coronavirus disease 2019 pandemic, many lasting neurological sequelae including cognitive impairment have been recognized as part of the so-called long COVID syndrome. This narrative review summarizes the cognitive aspects of COVID-19.

RECENT FINDINGS

Studies have consistently identified attention, memory, and executive functions as the cognitive domains most often affected by COVID-19 infection. Many studies have also reported neuroimaging, biofluid, and neurophysiological abnormalities that could potentially reflect the pathophysiological aspects of post-COVID cognitive impairment. While patients suffering from dementia have an elevated risk of COVID-19 infection, increasing evidence has also indicated that COVID-19 infection may increase the risks of Alzheimer's disease, suggesting bidirectional relationships. Post-COVID cognitive dysfunction is a pervasive and multifaceted problem and we are surely in our infancy of understanding. Future elucidation into the long-term effects, mechanisms, and therapies will depend on a concerted effort from clinicians, researchers, patients, and policy-makers alike.

The Comparative Effectiveness of Monotherapy and Combination Therapies: Impact of Angiotensin Receptor Blockers on the Onset of Alzheimer's Disease

Background

The criteria for use of Alzheimer's disease (AD) drug Leqembi recommended by the Department of Veterans Affairs (VA) include patients aged 65 years or older with mild cognitive impairment (MCI) or mild AD. Comorbidities that include hypertension, hyperlipidemia, and diabetes are common among these patients.

Objectives

Our objective is to investigate the comparative effectiveness of the administration of one, two, or three medications belonging to the categories of angiotensin receptor blockers (ARBs), angiotensin-converting enzyme inhibitors (ACEIs), Beta Blockers, Statins, and Metformin, for their potential to delay the clinical onset of AD and provide a window of opportunity for therapeutic intervention.

Design

Retrospective matched case-control study.

Setting

Data from the Department of Veterans Affairs national corporate data warehouse.

Participants

We conducted an analysis of 122,351 participants (13,611 with AD and 108,740 without AD), aged 65-89, who began at least one of the prescribed medication classes under investigation between October 1998 and April 2018.

Measurements

We utilized Cox proportional hazard regressions, both with and without propensity score weighting, to estimate hazard ratios (HR) associated with the use of different medication combinations for the pre-symptomatic survival time of AD onset. Additionally, we employed a supervised machine learning algorithm (random forest) to assess the relative importance of various therapies in predicting the occurrence of AD.

Result

Adding Metformin to the combination of ACEI+Beta Blocker (HR = 0.56, 95% CI (0.41, 0.77)) reduced the risk of AD onset compared to ACEI monotherapy alone (HR = 0.91, (0.85, 0.98)), Beta Blocker monotherapy (HR = 0.86, 95% CI (0.80, 0.92)), or combined ACEI+Beta Blocker (HR=0.85, 95%CI (0.77, 0.94)), when statin prescribers were used as a reference. Prescriptions of ARB alone or the combination of ARB with Beta Blocker showed an association with a lower risk of AD onset.

Conclusion

Selected medications for the treatment of multiple chronic conditions among elderly individuals with hypertension, hyperlipidemia, and diabetes as monotherapy or combination therapies lengthen the pre-symptomatic period before the onset of AD.

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.

Links between COVID-19 and Parkinson's disease/Alzheimer's disease: reciprocal impacts, medical care strategies and underlying mechanisms

The impact of coronavirus disease 2019 (COVID-19) pandemic on patients with neurodegenerative diseases and the specific neurological manifestations of COVID-19 have aroused great interest. However, there are still many issues of concern to be clarified. Therefore, we review the current literature on the complex relationship between COVID-19 and neurodegenerative diseases with an emphasis on Parkinson's disease (PD) and Alzheimer's disease (AD). We summarize the impact of COVID-19 infection on symptom severity, disease progression, and mortality rate of PD and AD, and discuss whether COVID-19 infection could trigger PD and AD. In addition, the susceptibility to and the prognosis of COVID-19 in PD patients and AD patients are also included. In order to achieve better management of PD and AD patients, modifications of care strategies, specific drug therapies, and vaccines during the pandemic are also listed. At last, mechanisms underlying the link of COVID-19 with PD and AD are reviewed.

Examining the immediate and ongoing impact of the COVID-19 pandemic on population-based estimates of dementia: a population-based time series analysis in Ontario, Canada

OBJECTIVES

Population-based chronic disease surveillance systems were likely disrupted by the COVID-19 pandemic. The objective of this study was to examine the immediate and ongoing impact of the COVID-19 pandemic on the claims-based incidence of dementia.

METHODS

We conducted a population-based time series analysis from January 2015 to December 2021 in Ontario, Canada. We calculated the monthly claims-based incidence of dementia using a validated case ascertainment algorithm drawing from routinely collected health administrative data. We used autoregressive linear models to compare the claims-based incidence of dementia during the COVID-19 period (2020-2021) to the expected incidence had the pandemic not occurred, controlling for seasonality and secular trends. We examined incidence by source of ascertainment and across strata of sex, age, community size and number of health conditions.

RESULTS

The monthly claims-based incidence of dementia dropped from a 2019 average of 11.9 per 10 000 to 8.5 per 10 000 in April 2020 (32.6% lower than expected). The incidence returned to expected levels by late 2020. Across the COVID-19 period there were a cumulative 2990 (95% CI 2109 to 3704) fewer cases of dementia observed than expected, equivalent to 1.05 months of new cases. Despite the overall recovery, ascertainment rates continued to be lower than expected among individuals aged 65-74 years and in large urban areas. Ascertainment rates were higher than expected in hospital and among individuals with 11 or more health conditions.

CONCLUSIONS

The claims-based incidence of dementia recovered to expected levels by late 2020, suggesting minimal long-term changes to population-based dementia surveillance. Continued monitoring of claims-based incidence is necessary to determine whether the lower than expected incidence among individuals aged 65-74 and in large urban areas, and higher than expected incidence among individuals with 11 or more health conditions, is transitory.

Risk Factors of Severe COVID-19: A Review of Host, Viral and Environmental Factors

The clinical course and outcome of COVID-19 are highly variable, ranging from asymptomatic infections to severe disease and death. Understanding the risk factors of severe COVID-19 is relevant both in the clinical setting and at the epidemiological level. Here, we provide an overview of host, viral and environmental factors that have been shown or (in some cases) hypothesized to be associated with severe clinical outcomes. The factors considered in detail include the age and frailty, genetic polymorphisms, biological sex (and pregnancy), co- and superinfections, non-communicable comorbidities, immunological history, microbiota, and lifestyle of the patient; viral genetic variation and infecting dose; socioeconomic factors; and air pollution. For each category, we compile (sometimes conflicting) evidence for the association of the factor with COVID-19 outcomes (including the strength of the effect) and outline possible action mechanisms. We also discuss the complex interactions between the various risk factors.

Mortality and survival in nonagenarians during the COVID-19 pandemic: Unstable equilibrium of aging

Introduction

Aging puts the human body under an immense stress and makes it extremely susceptible to many diseases, often leading to poor outcomes and even death. Long-living individuals represent a unique group of people who withstood the stress of time and offer an abundance of information on the body's ability to endure the pressure of aging. In this study, we sought to identify predictors of overall one-year mortality in 1641 long-living individuals. Additionally, we analyzed risk factors for COVID-19-related morality, since statistics demonstrated an extreme vulnerability of older adults.

Methods

We conducted a two-stage evaluation, including a comprehensive geriatric assessment for major aging-associated: frailty, cognitive impairment, frontal lobe dysfunction, chronic pain, anxiety, risk of falls, sensory deficit, depression, sarcopenia, risk of malnutrition, fecal and urinary incontinence, dependence in Activities of Daily Living, dependence in Instrumental Activities of Daily Living, polypragmasia, and orthostatic hypotension; extensive blood testing, a survey, and a one-year follow-up interview.

Results

The most reliable predictors of overall mortality were cognitive impairment, malnutrition, frailty, aging-associated diseases and blood markers indicating malnutrition-induced metabolic dysfunctions (decreased levels of protein fractions, iron, 25-hydroxyvitamin D, and HDL), and aging biomarkers, such as IGF-1 and N-terminal pro b-type natriuretic peptide. In post-COVID 19 participants, the most significant mortality predictors among geriatric syndromes were depression, frontal lobe dysfunction and frailty, and similar to overall mortality blood biomarkers - 25-hydroxyvitamin D, IGF-1, HDL as well as high white blood cell, neutrophils counts and proinflammatory markers. Based on the results, we built a predictive model of overall mortality in the long-living individuals with f-score=0.76.

Conclusion

The most sensitive and reliable predictors of mortality were modifiable. This is another evidence of the critical importance of proper geriatric care and support for individuals in their "golden years". These results could facilitate geriatric institutions in their pursuit for providing improved care and could aid physicians in detecting early signs of potentially deadly outcomes. Additionally, our findings could be used in developing day-to-day care guidelines, which would greatly improve prevention statistics.

Positive Effect of Cognitive Training in Older Adults with Different APOE Genotypes and COVID-19 History: A 1-Year Follow-Up Cohort Study

(1) Background: Older people suffer from cognitive decline; several risk factors contribute to greater cognitive decline. We used acquired (COVID-19 infection) and non-modifiable (presence of APOE rs429358 and rs7412 polymorphisms) factors to study the progression of subjective cognitive impairment while observing patients for one year. Cognitive training was used as a protective factor. (2) Methods: Two groups of subjects over the age of 65 participated in the study: group with subjective cognitive decline receiving cognitive training and individuals who did not complain of cognitive decline without receiving cognitive training (comparison group). On the first visit, the concentration of antibodies to COVID-19 and APOE genotype was measured. At the first and last point (1 year later) the Mini-Mental State Examination scale and the Hospital Anxiety and Depression Scale were performed. (3) Results: COVID-19 infection did not affect cognitive function. A significant role of cognitive training in improving cognitive functions was revealed. Older adults with APOE-ε4 genotype showed no positive effect of cognitive training. (4) Conclusions: Future research should focus on cognitive dysfunction after COVID-19 in long-term follow-up. Attention to the factors discussed in our article, but not limited to them, are useful for a personalized approach to maintaining the cognitive health of older adults.

The COVID-19 pandemic and Alzheimer’s disease: mutual risks and mechanisms

Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a life-threatening disease, especially in elderly individuals and those with comorbidities. The predominant clinical manifestation of COVID-19 is respiratory dysfunction, while neurological presentations are increasingly being recognized. SARS-CoV-2 invades host cells primarily via attachment of the spike protein to the angiotensin-converting enzyme 2 (ACE2) receptor expressed on cell membranes. Patients with Alzheimer’s disease (AD) are more susceptible to SARS-CoV-2 infection and prone to severe clinical outcomes. Recent studies have revealed some common risk factors for AD and COVID-19. An understanding of the association between COVID-19 and AD and the potential related mechanisms may lead to the development of novel approaches to treating both diseases. In the present review, we first summarize the mechanisms by which SARS-CoV-2 invades the central nervous system (CNS) and then discuss the associations and potential shared key factors between COVID-19 and AD, with a focus on the ACE2 receptor, apolipoprotein E (APOE) genotype, age, and neuroinflammation.

microRNA, the Innate-Immune System and SARS-CoV-2

The single-stranded viral RNA (ssvRNA) known as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes COVID-19 can be effectively inactivated by a number of natural ribonucleic acid-based host cell defenses. One of the most important of these defenses includes the actions of a class of small non-coding RNAs (sncRNAs) known as microRNAs (miRNAs). Via base-pair complementarity miRNAs are capable of specifically targeting ssvRNA sequences such as SARS-CoV-2 promoting its inactivation and neutralization. RNA-sequencing and bioinformatics analysis indicate that multiple naturally-occurring human miRNAs have extensive complementarity to the SARS-CoV-2 ssvRNA genome. Since miRNA abundance, speciation, and complexity vary significantly amongst human individuals, this may in part explain the variability in the innate-immune and pathophysiological response of different individuals to SARS-CoV-2 and overall susceptibility to ssvRNA-mediated viral infection.