Estimates of Current Capacity for Diagnosing Alzheimer's Disease in Sweden and the Need to Expand Specialist Numbers.

BACKGROUND: The emergence of disease-modifying Alzheimer's (AD) treatments provides new hope to patients and families but concerns have been raised about the preparedness of healthcare systems to provide timely access to such treatments because of a combination of a complex diagnostic process and a large prevalent pool. OBJECTIVES: We assess the preparedness of Sweden, a high-income country known for its dementia-friendly policies, to diagnose AD patients eligible for treatment within a six-month window, given current capacity for specialist evaluations and biomarker testing. We calculate the investment requirements for Sweden to achieve this target over a timeframe of 20 years. DESIGN: Desk research to identify data for population, mortality, disease burden, cost of services and current capacity, expert consultation to inform assumptions about patient journey, and use of a Markov model to predict waiting times. The model simulates the patients' journey through different evaluation stages: initial evaluation by a primary care specialist, neurocognitive testing by an AD specialist, and confirmatory biomarker testing with PET scanning or cerebrospinal fluid (CSF) testing. The model assumes specialist appointments and PET scans are capacity constrained, and patients progress from cognitively normal to MCI and from MCI to dementia in the resulting waiting times. MEASUREMENTS: Projected waiting times for diagnosis of eligibility for disease-modifying Alzheimer's treatment from 2023 to 2042 assuming current capacity, assuming 20% of Swedish residents aged 60 years and above would seek an evaluation for cognitive decline. Investments required to scale capacity up to reach target of providing diagnosis within six months on average. RESULTS: Initial average waiting times for AD specialist appointments would be around 21 months in 2023 and remain around 55 months through 2042, as demand would continue to outstrip supply throughout the 20-year model horizon. Waiting times for biomarker testing would be stable at less than four weeks, as patients would be held up in the queue for their first specialist consultations, and use of CSF testing is widely accepted in Sweden. An additional 25% of AD specialists would have to be added above the current growth trend to reduce waiting times to less than 6 months at an average annual cost of approximately 805 million SEK. The increased cost of volume of biomarker testing would amount to about 106 million SEK per year. CONCLUSIONS: At current capacity, the Swedish healthcare system is unable to provide timely diagnosis of patients eligible for disease-modifying AD treatment. Although future diagnostic technologies, such as digital cognitive assessments and blood tests for the AD pathology, might decrease demand for capacity-constrained services, substantial investments will be required to meet a target of less than six months of waiting time for a diagnosis.

Body mass index and Mini Nutritional Assessment-Short Form as predictors of in-geriatric hospital mortality in older adults with COVID-19.

BACKGROUND & AIMS: Overweight and obesity have been consistently reported to carry an increased risk for poorer outcomes in coronavirus disease 2019 (COVID-19) in adults. Existing reports mainly focus on in-hospital and intensive care unit mortality in patient cohorts usually not representative of the population with the highest mortality, i.e. the very old and frail patients. Accordingly, little is known about the risk patterns related to body mass and nutrition in very old patients. Our aim was to assess the relationship between body mass index (BMI), nutritional status and in-geriatric hospital mortality among geriatric patients treated for COVID-19. As a reference, the analyses were performed also in patients treated for other diagnoses than COVID-19. METHODS: We analyzed up to 10,031 geriatric patients with a median age of 83 years of which 1409 (14%) were hospitalized for COVID-19 and 8622 (86%) for other diagnoses in seven geriatric hospitals in the Stockholm region, Sweden during March 2020-January 2021. Data were available in electronic hospital records. The associations between 1) BMI and 2) nutritional status, assessed using the Mini-Nutritional Assessment - Short Form (MNA-SF) scale, and short-term in-geriatric hospital mortality were analyzed using logistic regression. RESULTS: After adjusting for age, sex, comorbidity, polypharmacy, frailty and the wave of the pandemic (first vs. second), underweight defined as BMI<18.5 increased the risk of in-hospital mortality in COVID-19 patients (odds ratio [OR] = 2.30; confidence interval [CI] = 1.17-4.31). Overweight and obesity were not associated with in-hospital mortality. Malnutrition; i.e. MNA-SF 0-7 points, increased the risk of in-hospital mortality in patients treated for COVID-19 (OR = 2.03; CI = 1.16-3.68) and other causes (OR = 6.01; CI = 2.73-15.91). CONCLUSIONS: Our results indicate that obesity is not a risk factor for very old patients with COVID-19, but emphasize the role of underweight and malnutrition for in-hospital mortality in geriatric patients with COVID-19.

Calcium channel blockers, survival and ischaemic stroke in patients with dementia: a Swedish registry study.

BACKGROUND: The effect of calcium channel blockers (CCB) on mortality and ischaemic stroke risk in dementia patients is understudied. OBJECTIVES: To calculate the risk of death and ischaemic stroke in dementia patients treated with CCBs, considering individual agents and dose response. METHODS: Longitudinal cohort study with 18 906 hypertensive dementia patients from the Swedish Dementia Registry (SveDem), 2008-2014. Other Swedish national registries contributed information on comorbidities, dispensed medication and outcomes. Individual CCB agents and cumulative defined daily doses (cDDD) were considered. RESULTS: In patients with hypertension and dementia, nifedipine was associated with increased mortality risk (aHR 1.32; CI 1.01-1.73; P < 0.05) compared to non-CCB users. Patients diagnosed with Alzheimer's dementia (AD) or dementia with Lewy bodies/Parkinson's disease dementia (DLB-PDD) taking amlodipine had lower mortality risk (aHR, 0.89; CI, 0.80-0.98; P < 0.05 and aHR 0.58; CI, 0.38-0.86; P < 0.01, respectively), than those taking other CCBs. Amlodipine was associated with lower stroke risk in patients with Alzheimer's dementia compared to other CCBs (aHR 0.63; CI, 0.44-0.89; P < 0.05). Sensitivity analyses with propensity score-matched cohorts repeated the results for nifedipine (aHR 1.35; 95% CI, 1.02-1.78; P < 0.05) and amlodipine in AD (aHR, 0.87; CI, 0.78-0.97; P < 0.05) and DLB-PDD (aHR, 0.56, 95%CI, 0.37-0.85; P < 0.05). CONCLUSION: Amlodipine was associated with reduced mortality risk in dementia patients diagnosed with AD and DLB-PDD. AD patients using amlodipine had a lower risk of ischaemic stroke compared to other CCB users.

Multimorbidity and functional impairment-bidirectional interplay, synergistic effects and common pathways.

This review discusses the interplay between multimorbidity (i.e. co-occurrence of more than one chronic health condition in an individual) and functional impairment (i.e. limitations in mobility, strength or cognition that may eventually hamper a person's ability to perform everyday tasks). On the one hand, diseases belonging to common patterns of multimorbidity may interact, curtailing compensatory mechanisms and resulting in physical and cognitive decline. On the other hand, physical and cognitive impairment impact the severity and burden of multimorbidity, contributing to the establishment of a vicious circle. The circle may be further exacerbated by people's reduced ability to cope with treatment and care burden and physicians' fragmented view of health problems, which cause suboptimal use of health services and reduced quality of life and survival. Thus, the synergistic effects of medical diagnoses and functional status in adults, particularly older adults, emerge as central to assessing their health and care needs. Furthermore, common pathways seem to underlie multimorbidity, functional impairment and their interplay. For example, older age, obesity, involuntary weight loss and sedentarism can accelerate damage accumulation in organs and physiological systems by fostering inflammatory status. Inappropriate use or overuse of specific medications and drug-drug and drug-disease interactions also contribute to the bidirectional association between multimorbidity and functional impairment. Additionally, psychosocial factors such as low socioeconomic status and the direct or indirect effects of negative life events, weak social networks and an external locus of control may underlie the complex interactions between multimorbidity, functional decline and negative outcomes. Identifying modifiable risk factors and pathways common to multimorbidity and functional impairment could aid in the design of interventions to delay, prevent or alleviate age-related health deterioration; this review provides an overview of knowledge gaps and future directions.

Connecting the brain cholesterol and renin-angiotensin systems: potential role of statins and RAS-modifying medications in dementia.

Millions of people worldwide receive agents targeting the renin-angiotensin system (RAS) to treat hypertension or statins to lower cholesterol. The RAS and cholesterol metabolic pathways in the brain are autonomous from their systemic counterparts and are interrelated through the cholesterol metabolite 27-hydroxycholesterol (27-OHC). These systems contribute to memory and dementia pathogenesis through interference in the amyloid-beta cascade, vascular mechanisms, glucose metabolism, apoptosis, neuroinflammation and oxidative stress. Previous studies examining the relationship between these treatments and cognition and dementia risk have produced inconsistent results. Defining the blood-brain barrier penetration of these medications has been challenging, and the mechanisms of action on cognition are not clearly established. Potential biases are apparent in epidemiological and clinical studies, such as reverse epidemiology, indication bias, problems defining medication exposure, uncertain and changing doses, and inappropriate grouping of outcomes and medications. This review summarizes current knowledge of the brain cholesterol and RAS metabolism and the mechanisms by which these pathways affect neurodegeneration. The putative mechanisms of action of statins and medications inhibiting the RAS will be examined, together with prior clinical and animal studies on their effects on cognition. We review prior epidemiological studies, analysing their strengths and biases, and identify areas for future research. Understanding the pathophysiology of the brain cholesterol system and RAS and their links to neurodegeneration has enormous potential. In future, well-designed epidemiological studies could identify potential treatments for Alzheimer's disease (AD) amongst medications that are already in use for other indications.

Targeting Alzheimer's disease with gene and cell therapies.

Alzheimer's disease (AD) causes dementia in both young and old people affecting more than 40 million people worldwide. The two neuropathological hallmarks of the disease, amyloid beta (Aß) plaques and neurofibrillary tangles consisting of protein tau are considered the major contributors to the disease. However, a more complete picture reveals significant neurodegeneration and decreased cell survival, neuroinflammation, changes in protein and energy homeostasis and alterations in lipid and cholesterol metabolism. In addition, gene and cell therapies for severe neurodegenerative disorders have recently improved technically in terms of safety and efficiency and have translated to the clinic showing encouraging results. Here, we review broadly current data within the field for potential targets that could modify AD through gene and cell therapy strategies. We envision that not only Aß will be targeted in a disease-modifying treatment strategy but rather that a combination of treatments, possibly at different intervention times may prove beneficial in curing this devastating disease. These include decreased tau pathology, neuronal growth factors to support neurons and modulation of neuroinflammation for an appropriate immune response. Furthermore, cell based therapies may represent potential strategies in the future.

Management of acute ischaemic stroke in patients with dementia.

An estimated 10% of stroke patients have an underlying dementia. As a consequence, health professionals often face the challenge of managing patients with dementia presenting with an acute stroke. Patients with dementia are less likely to receive thrombolysis (0.56-10% vs. 1-16% thrombolysis rates in the general population), be admitted to a stroke unit or receive some types of care. Anticoagulation for secondary stroke prevention is sometimes withheld, despite dementia not being listed as an exclusion criterion in current guidelines. Studies in this population are scarce, and results have been contradictory. Three observational studies have examined intravenous thrombolysis for treatment of acute ischaemic stroke in patients with dementia. In the two largest matched case-control studies, there were no significant differences between patients with and without dementia in the risks of intracerebral haemorrhage or mortality. The risk of intracerebral haemorrhage ranged between 14% and 19% for patients with dementia. Studies of other interventions for stroke are lacking for this population. Patients with dementia are less likely to be discharged home compared with controls (19% vs. 41%) and more likely to be disabled (64% vs. 59%) or die during hospitalization (22% vs. 11%). The aim of this review was to summarize current knowledge about the management of ischaemic stroke in patients with pre-existing dementia, including organizational aspects of stroke care, intravenous thrombolysis, access to stroke unit care and use of supportive treatment. Evidence to support anticoagulation for secondary prevention of stroke in patients with atrial fibrillation and antiplatelet therapy in nonembolic stroke will be discussed, as well as rehabilitation and how these factors influence patient outcomes. Finally, ethical issues, knowledge gaps and pathways for future research will be considered.

Quejas cognitivas subjetivas: hacia una identificación precoz de la enfermedad de Alzheimer / Subjective cognitive impairment: Towards early identification of Alzheimer disease

Introducción: La neurodegeneración en enfermedad de Alzheimer (EA) empieza décadas antes que la demencia y algunos pacientes con deterioro cognitivo leve presentan una importante carga lesional. La ausencia de información sobre la fisiopatología temprana de la enfermedad dificulta la búsqueda de estrategias terapéuticas. La queja cognitiva subjetiva (QCS) agrupa a sujetos con quejas mnésicas sin déficits significativos en test neuropsicológicos. Es un síndrome heterogéneo sobre el que no existe consenso, pero algunos de estos pacientes podrían representar el estadio más precoz de EA. Método: Realizamos una revisión bibliográfica para resumir el estado del conocimiento actual sobre quejas cognitivas subjetivas. Resultados: Aunque a nivel individual no presenten enfermedad objetivable, a nivel de grupo los pacientes con QCS rinden peor en test neuropsicológicos que la población general y tienen mayor incidencia de declive cognitivo futuro. La depresión y la comorbilidad psiquiátrica desempeñan un papel pero no son la única causa de quejas cognitivas. Estudios con resonancia magnética muestran un patrón de atrofia hipocampal similar al del deterioro cognitivo leve amnésico y en resonancia funcional hay aumento de activación en tareas cognitivas que podrían representar una compensación ante pérdida de función. Los pacientes con QCS presentan un patrón tipo EA de marcadores betaamiloide (A 42) y tau con mayor frecuencia que la población general. Conclusiones: Las quejas mnésicas son un síntoma relevante y podrían predecir EA. La heterogeneidad de los pacientes y de los ensayos clínicos ha dificultado la definición del síndrome. En el futuro, una definición estandarizada y estudios longitudinales con un seguimiento suficiente, y centrados en variables cuantificables, podrían clarificar aspectos tempranos de la EA

Introduction: Neurodegeneration in Alzheimer disease (AD) begins decades before dementia and patients with mild cognitive impairment (MCI) already demonstrate significant lesion loads. Lack of information about the early pathophysiology in AD complicates the search for therapeutic strategies. Subjective cognitive impairment is the description given to subjects who have memory-related complaints without pathological results on neuropsychological tests. There is no consensus regarding this heterogeneous syndrome, but at least some of these patients may represent the earliest stage in AD. Method: We reviewed available literature in order to summarise current knowledge on subjective cognitive impairment. Results: Although they may not present detectable signs of disease, SCI patients as a group score lower on neuropsychological tests than the general population does, and they also have a higher incidence of future cognitive decline. Depression and psychiatric co-morbidity play a role but cannot account for all cognitive complaints. Magnetic resonance imaging studies in these patients reveal a pattern of hippocampal atrophy similar to that of amnestic mild cognitive impairment and functional MRI shows increased activation during cognitive tasks which might indicate compensation for loss of function. Prevalence of an AD-like pattern of beta-amyloid (A 42) and tau proteins in cerebrospinal fluid is higher in SCI patients than in the general population. Conclusions: Memory complaints are relevant symptoms and may predict AD. Interpatient variability and methodological differences between clinical studies make it difficult to assign a definition to this syndrome. In the future, having a standard definition and longitudinal studies with sufficient follow-up times and an emphasis on quantifiable variables may clarify aspects of early AD

Antidepressants and mortality risk in a dementia cohort: data from SveDem, the Swedish Dementia Registry.

BACKGROUND: The association between mortality risk and use of antidepressants in people with dementia is unknown. OBJECTIVE: To describe the use of antidepressants in people with different dementia diagnoses and to explore mortality risk associated with use of antidepressants 3 years before a dementia diagnosis. METHODS: Study population included 20 050 memory clinic patients from the Swedish Dementia Registry (SveDem) diagnosed with incident dementia. Data on antidepressants dispensed at the time of dementia diagnosis and during 3-year period before dementia diagnosis were obtained from the Swedish Prescribed Drug Register. Cox regression models were used. RESULTS: During a median follow-up of 2 years from dementia diagnosis, 25.8% of dementia patients died. A quarter (25.0%) of patients were on antidepressants at the time of dementia diagnosis, while 21.6% used antidepressants at some point during a 3-year period before a dementia diagnosis. Use of antidepressant treatment for 3 consecutive years before a dementia diagnosis was associated with a lower mortality risk for all dementia disorders and in Alzheimer's disease. CONCLUSION: Antidepressant treatment is common among patients with dementia. Use of antidepressants during prodromal stages may reduce mortality in dementia and specifically in Alzheimer's disease.

Subjective cognitive impairment: Towards early identification of Alzheimer disease. / Quejas cognitivas subjetivas: hacia una identificación precoz de la enfermedad de Alzheimer.

INTRODUCTION: Neurodegeneration in Alzheimer disease (AD) begins decades before dementia and patients with mild cognitive impairment (MCI) already demonstrate significant lesion loads. Lack of information about the early pathophysiology in AD complicates the search for therapeutic strategies.Subjective cognitive impairment is the description given to subjects who have memory-related complaints without pathological results on neuropsychological tests. There is no consensus regarding this heterogeneous syndrome, but at least some of these patients may represent the earliest stage in AD. METHOD: We reviewed available literature in order to summarise current knowledge on subjective cognitive impairment. RESULTS: Although they may not present detectable signs of disease, SCI patients as a group score lower on neuropsychological tests than the general population does, and they also have a higher incidence of future cognitive decline. Depression and psychiatric co-morbidity play a role but cannot account for all cognitive complaints. Magnetic resonance imaging studies in these patients reveal a pattern of hippocampal atrophy similar to that of amnestic mild cognitive impairment and functional MRI shows increased activation during cognitive tasks which might indicate compensation for loss of function. Prevalence of an AD-like pattern of beta-amyloid (Aß42) and tau proteins in cerebrospinal fluid is higher in SCI patients than in the general population. CONCLUSIONS: Memory complaints are relevant symptoms and may predict AD. Interpatient variability and methodological differences between clinical studies make it difficult to assign a definition to this syndrome. In the future, having a standard definition and longitudinal studies with sufficient follow-up times and an emphasis on quantifiable variables may clarify aspects of early AD.

Heart failure and Alzheimer's disease.

It has recently been proposed that heart failure is a risk factor for Alzheimer's disease. Decreased cerebral blood flow and neurohormonal activation due to heart failure may contribute to the dysfunction of the neurovascular unit and cause an energy crisis in neurons. This leads to the impaired clearance of amyloid beta and hyperphosphorylation of tau protein, resulting in the formation of amyloid beta plaques and neurofibrillary tangles. In this article, we will summarize the current understanding of the relationship between heart failure and Alzheimer's disease based on epidemiological studies, brain imaging research, pathological findings and the use of animal models. The importance of atherosclerosis, myocardial infarction, atrial fibrillation, blood pressure and valve disease as well as the effect of relevant medications will be discussed.

Body mass index in dementia.

This review comprehensively examines the current knowledge on the relationship between body mass index (BMI) and dementia. The association between BMI and cognition is complex: in younger adults, higher BMIs are associated with impaired cognition. Overweight and obesity in middle age are linked to increased future dementia risk in old age. However, when examined in old age, higher BMIs are associated with better cognition and decreased mortality. Little is known about the optimal BMI for well-being and survival in populations already suffering from dementia. Lifetime trends in weight, rather than single measures, might predict prognosis better and help untangle these apparent contradictions. Thus, the need arises to properly monitor BMI trends in affected dementia patients. Registries can include BMI, improving the management of dementia patients throughout the whole course of the disease. The role of central obesity and systemic inflammation on brain pathology and cognitive decline are discussed in this review. Understanding the life-course changes in BMI and their influence on dementia risk, cognitive prognosis and mortality after diagnosis may provide new insights into the underlying pathophysiology of dementia and shape possible intervention and treatment strategies.

Transfer of omega-3 fatty acids across the blood-brain barrier after dietary supplementation with a docosahexaenoic acid-rich omega-3 fatty acid preparation in patients with Alzheimer's disease: the OmegAD study.

OBJECTIVE: Little is known about the transfer of essential fatty acids (FAs) across the human blood-brain barrier (BBB) in adulthood. In this study, we investigated whether oral supplementation with omega-3 (n-3) FAs would change the FA profile of the cerebrospinal fluid (CSF). METHODS: A total of 33 patients (18 receiving the n-3 FA supplement and 15 receiving placebo) were included in the study. These patients were participants in the double-blind, placebo-controlled randomized OmegAD study in which 204 patients with mild Alzheimer's disease (AD) received 2.3 g n-3 FA [high in docosahexaenoic acid (DHA)] or placebo daily for 6 months. CSF FA levels were related to changes in plasma FA and to CSF biomarkers of AD and inflammation. RESULTS: At 6 months, the n-3 FA supplement group displayed significant increases in CSF (and plasma) eicosapentaenoic acid (EPA), DHA and total n-3 FA levels (P < 0.01), whereas no changes were observed in the placebo group. Changes in CSF and plasma levels of EPA and n-3 docosapentaenoic acid were strongly correlated, in contrast to those of DHA. Changes in DHA levels in CSF were inversely correlated with CSF levels of total and phosphorylated tau, and directly correlated with soluble interleukin-1 receptor type II. Thus, the more DHA increased in CSF, the greater the change in CSF AD/inflammatory biomarkers. CONCLUSIONS: Oral supplementation with n-3 FAs conferred changes in the n-3 FA profile in CSF, suggesting transfer of these FAs across the BBB in adults.