2014 Alzheimer's disease facts and figures

Persisting gaps in dementia carer wellbeing and education: A qualitative exploration of dementia carer experiences

AIMS

To explore the emotional wellbeing of dementia carers in the lead up to and during transition of a person living with dementia to a residential aged care facility.

DESIGN

An interpretative qualitative study.

METHODS

Semi-structured interviews were conducted with informal carers of person living with dementia between February and June 2023. Data were analysed using an inductive thematic approach and resulted in three themes.

RESULTS

The majority of carers were adult children (n = 19) and six were wives. Carers lived across metropolitan (n = 20) and regional settings (n = 5) in the most populous state of Australia. Three themes were identified which were attributed to different aspects of the carer role: (1) Carer emotional journey as dementia progresses - impacted by knowledge and lack of support; (2) Questioning decision making-underpinned by knowledge and confidence; and (3) Challenges in re-establishing identity - impacted by ongoing concerns.

CONCLUSION

As dementia progresses carers of person living with dementia consistently reported gaps in knowledge including how to access support. Specifically, this study identified the need for more to be done to help carers to develop the skills needed for their role, including participation in care planning and identifying care preferences for the future. Nurses can play a key role in promoting referral to services that support carers. Findings offer practical solutions to ameliorate carer stress and promote shared decision making.

REPORTING METHOD

This research was guided by the Consolidated Criteria for Reporting Qualitative Research.

Pathways to Alzheimer's Disease: The Intersecting Roles of Clusterin and Apolipoprotein E in Amyloid-β Regulation and Neuronal Health

One of the hallmarks of Alzheimer's disease (AD) is the deposition of amyloid-β (Aβ) within the extracellular spaces of the brain as plaques and along the blood vessels in the brain, a condition also known as cerebral amyloid angiopathy (CAA). Clusterin (CLU), or apolipoprotein J (APOJ), is a multifunctional glycoprotein that has a role in many physiological and neurological conditions, including AD. The apolipoprotein E (APOE) is a significant genetic factor in AD, and while the primary physiological role of APOE in the brain and peripheral tissues is to regulate lipid transport, it also participates in various other biological processes, having three basic human forms: APOE2, APOE3, and APOE4. Notably, the APOE4 allele substantially increases the risk of developing late-onset AD. The main purpose of this review is to examine the roles of CLU and APOE in AD pathogenesis in order to acquire a better understanding of AD pathogenesis from which to develop targeted therapeutic approaches.

Integrated Physical-Mental Healthcare Services in Specialist Settings to Improve Outcomes for Older People Living With Mental Health Diagnoses: A Systematic Review

BACKGROUND

Many older people are now living with co-occurring physical and mental health disorders, but these often managed separately. The aim of this systematic review was to explore integrated physical-mental health care services available internationally for older people living with mental health diagnoses, and whether these result in improved health outcomes.

METHODS

Medline, Embase, CINAHL, PsycINFO and Scopus were searched with a predefined search strategy (PROSPERO: CRD42022383824), generating 6210 articles. Studies were included where an integrated physical-mental health care service model was utilised in a population of older people (aged >60 years) with a mental health diagnosis (including dementia or cognitive impairment) and at least one concomitant physical health condition requiring physical health care input. All studies were assessed for risk of bias (ROB 2.0, ROBINS-I) and results were synthesised narratively.

RESULTS

Nine studies were included across inpatient (n = 6, 1262 patients) and community (n = 3, 466 patients) settings. Studies were rated as low-moderate risk of bias. These covered joint physical-mental health wards, liaison services, embedded physicians in mental health wards, and joint multidisciplinary teams. Services with greater integration (e.g., joint wards) had more benefits for patients and carers. There were few benefits to traditional outcomes (e.g., hospital admissions, mortality), but greater care quality, carer satisfaction, and improved mood and engagement were demonstrated.

CONCLUSIONS

Multidisciplinary integrated care resulted in improvement of a range of health outcomes for older people with combined physical and mental health needs. Larger and more robust studies are needed to explore the development of these service models further, with cost-effectiveness analyses.

Amyloid-β neuropathology induces bone loss in male mice by suppressing bone formation and enhancing bone resorption

Alzheimer's disease (AD) and osteoporosis often coexist in the elderly. Although observational studies suggest an association between these two diseases, the pathophysiologic link between AD and skeletal health has been poorly defined. We examined the skeletal phenotype of 5xFAD mice, an AD model with accelerated neuron-specific amyloid-β accumulation causing full-blown AD phenotype by the age of 8 months. Micro-computed tomography indicated significantly lower trabecular and cortical bone parameters in 8-month-old male, but not female, 5xFAD mice than sex-matched wild-type littermates. Dynamic histomorphometry revealed reduced bone formation and increased bone resorption, and quantitative RT-PCR showed elevated skeletal RANKL gene expression in 5xFAD males. These mice also had diminished body fat percentage with unaltered lean mass, as determined by dual-energy X-ray absorptiometry (DXA), and elevated Ucp1 mRNA levels in brown adipose tissue, consistent with increased sympathetic tone, which may contribute to the osteopenia observed in 5xFAD males. Nevertheless, no significant changes could be detected between male 5xFAD and wild-type littermates regarding the serum and skeletal concentrations of norepinephrine. Thus, brain-specific amyloid-β pathology is associated with osteopenia and appears to affect both bone formation and bone resorption. Our findings shed new light on the pathophysiologic link between Alzheimer's disease and osteoporosis.

Novel gene signatures predicting and immune infiltration analysis in Parkinson's disease: based on combining random forest with artificial neural network

BACKGROUND

Parkinson's disease (PD) ranks as the second most prevalent neurodegenerative disorder globally, and its incidence is rapidly rising. The diagnosis of PD relies on clinical characteristics. Although current treatments aim to alleviate symptoms, they do not effectively halt the disease's progression. Early detection and intervention hold immense importance. This study aimed to establish a new PD diagnostic model.

METHODS

Data from a public database were adopted for the construction and validation of a PD diagnostic model with random forest and artificial neural network models. The CIBERSORT platform was applied for the evaluation of immune cell infiltration in PD. Quantitative real-time PCR was performed to verify the accuracy and reliability of the bioinformatics analysis results.

RESULTS

Leveraging existing gene expression data from the Gene Expression Omnibus (GEO) database, we sifted through differentially expressed genes (DEGs) in PD and identified 30 crucial genes through a random forest classifier. Furthermore, we successfully designed a novel PD diagnostic model using an artificial neural network and verified its diagnostic efficacy using publicly available datasets. Our research also suggests that mast cells may play a significant role in the onset and progression of PD.

CONCLUSION

This work developed a new PD diagnostic model with machine learning techniques and suggested the immune cells as a potential target for PD therapy.

Post-diagnostic support for persons with young-onset dementia - a retrospective analysis based on data from the Swedish dementia registry SveDem

BACKGROUND

Approximately 3.9 million persons worldwide have young-onset dementia. Symptoms related to young-onset dementia present distinct challenges related to finances, employment, and family. To provide tailored support, it is important to gain knowledge about the formal support available for persons with young-onset dementia. Therefore, this paper aims to describe formal support for persons with young-onset dementia in Sweden and the factors influencing this support.

METHODS

This retrospective study used data on persons under 65 years of age (n = 284) from The Swedish Registry for Cognitive/Dementia Disorders (SveDem) between 2021 and 2022. SveDem was established to monitor the quality of dementia care in Sweden. Characteristics of participants were obtained, including age, sex, dementia diagnosis, MMSE, medications, accommodation, and care setting. Descriptive statistics and logistic regression were used to test for associations between participant characteristics and post-diagnostic support.

RESULTS

Information and educational support were usually offered to the person with young-onset dementia (90.1%) and their family (78.9%). Approximately half of the sample were offered contact with a dementia nurse (49.3%), counsellor (51.4%), or needs assessor (47.9%). A minority (28.5%) were offered cognitive aids. Six regression models were conducted based on participant characteristics to predict the likelihood that persons were offered support. Support was not predicted by age, sex, children at home, accommodation, or medications. Lower MMSE scores (p < .05) and home help (p < .05) were significantly associated with offer of a needs assessor. Living together was a significant predictor (p < .01) for information and educational support offered to the family. Care setting significantly predicted (p < .01) an offer of information and educational support for the person and family members, as well as contact with a counsellor.

CONCLUSION

This study indicates potential formal support shortages for persons with young-onset dementia in some areas of dementia care. Despite equal support across most characteristics, disparities based on care setting highlight the importance of specialised dementia care. Pre-diagnostic support is minimal, indicating challenges for persons with young-onset dementia to access these services before diagnosis. While our study has identified areas in need of improvement, we recommend further research to understand the changing support needs of those with young-onset dementia.

Systematic evaluation and meta-analysis of the effects of major dietary patterns on cognitive function in healthy adults

PURPOSE

Evidence shows diet promotes brain health. Combining foods and nutrients may have beneficial synergistic effects, but the effects on cognitive function interventions are inconsistent. So, a meta-analysis of RCTs was conducted to examine the specific effects on cognitive function.

METHODS

We searched four databases from creation to April 2023. Eligible randomized controlled trials were identified. A random-effects meta-analysis was used to combine standardized mean differences (SMD) (95% confidence intervals [CI]), and homogeneity tests for a variance were calculated.

RESULTS

A total of 19 studies involving 12,119 participants were included in this systematic review. The dietary intervention group had a positive effect on overall cognitive functioning compared to the control group (SMD = 0.14, 95% CI [0.08, 0.20], P < 0.00001). The dietary intervention improved executive function, processing speed and language skills (SMD = -0.10, 95% CI [-0.17,-0.04], P = 0.002, I2 = 0%), (SMD = -0.16, 95% CI [-0.23,-0.09], P < 0.00001, I2 = 0%), (SMD = 0.10, 95% CI [0.01, 0.20], P = 0.03, I2 = 0%). The dietary intervention had no effect on delayed memory and spatial ability (SMD = 0.04, 95% CI [-0.02, 0.09], P = 0.20, I2 = 0%), (SMD = 0.08, 95% CI [-0.01, 0.16], P = 0.08, I2 = 0%).

CONCLUSION

The Mediterranean diet, a diet with restricted caloric intake, a diet incorporating aerobic exercise, a low-carbohydrate diet, and a healthy lifestyle diet (increased intake of fruits and vegetables, and weight and blood pressure management) appear to have positive effects on cognitively healthy adults, as reflected in their overall cognitive, processing speed, executive, and language functions.

PROSPERO REGISTRATION NUMBER

CRD42023414704.

Ablation of Mitochondrial RCC1-L Induces Nigral Dopaminergic Neurodegeneration and Parkinsonian-like Motor Symptoms

Mitochondrial dysfunction has been linked to both idiopathic and familial forms of Parkinson's disease (PD). We have previously identified RCC1-like (RCC1L) as a protein of the inner mitochondrial membrane important to mitochondrial fusion. Herein, to test whether deficits in RCC1L mitochondrial function might be involved in PD pathology, we have selectively ablated the Rcc1l gene in the dopaminergic (DA) neurons of mice. A PD-like phenotype resulted that includes progressive movement abnormalities, paralleled by progressive degeneration of the nigrostriatal tract. Experimental and control groups were examined at 2, 3-4, and 5-6 months of age. Animals were tested in the open field task to quantify anxiety, exploratory drive, locomotion, and immobility; and in the cylinder test to quantify rearing behavior. Beginning at 3-4 months, both female and male Rcc1l knockout mice show rigid muscles and resting tremor, kyphosis and a growth deficit compared with heterozygous or wild type littermate controls. Rcc1l knockout mice begin showing locomotor impairments at 3-4 months, which progress until 5-6 months of age, at which age the Rcc1l knockout mice die. The progressive motor impairments were associated with progressive and significantly reduced tyrosine hydroxylase immunoreactivity in the substantia nigra pars compacta (SNc), and dramatic loss of nigral DA projections in the striatum. Dystrophic spherical mitochondria are apparent in the soma of SNc neurons in Rcc1l knockout mice as early as 1.5-2.5 months of age and become progressively more pronounced until 5-6 months. Together, the results reveal the RCC1L protein to be essential to in vivo mitochondrial function in DA neurons. Further characterization of this mouse model will determine whether it represents a new model for in vivo study of PD, and the putative role of the human RCC1L gene as a risk factor that might increase PD occurrence and severity in humans.

A Relationship between the Structures and Neurotoxic Effects of Aβ Oligomers Stabilized by Different Metal Ions

Oligomeric assemblies of the amyloid β peptide (Aβ) have been investigated for over two decades as possible neurotoxic agents in Alzheimer's disease. However, due to their heterogeneous and transient nature, it is not yet fully established which of the structural features of these oligomers may generate cellular damage. Here, we study distinct oligomer species formed by Aβ40 (the 40-residue form of Aβ) in the presence of four different metal ions (Al3+, Cu2+, Fe2+, and Zn2+) and show that they differ in their structure and toxicity in human neuroblastoma cells. We then describe a correlation between the size of the oligomers and their neurotoxic activity, which provides a type of structure-toxicity relationship for these Aβ40 oligomer species. These results provide insight into the possible role of metal ions in Alzheimer's disease by the stabilization of Aβ oligomers.

Asian Cohort for Alzheimer's Disease (ACAD) pilot study on genetic and non-genetic risk factors for Alzheimer's disease among Asian Americans and Canadians

INTRODUCTION

Clinical research in Alzheimer's disease (AD) lacks cohort diversity despite being a global health crisis. The Asian Cohort for Alzheimer's Disease (ACAD) was formed to address underrepresentation of Asians in research, and limited understanding of how genetics and non-genetic/lifestyle factors impact this multi-ethnic population.

METHODS

The ACAD started fully recruiting in October 2021 with one central coordination site, eight recruitment sites, and two analysis sites. We developed a comprehensive study protocol for outreach and recruitment, an extensive data collection packet, and a centralized data management system, in English, Chinese, Korean, and Vietnamese.

RESULTS

ACAD has recruited 606 participants with an additional 900 expressing interest in enrollment since program inception.

DISCUSSION

ACAD's traction indicates the feasibility of recruiting Asians for clinical research to enhance understanding of AD risk factors. ACAD will recruit > 5000 participants to identify genetic and non-genetic/lifestyle AD risk factors, establish blood biomarker levels for AD diagnosis, and facilitate clinical trial readiness.

HIGHLIGHTS

The Asian Cohort for Alzheimer's Disease (ACAD) promotes awareness of under-investment in clinical research for Asians. We are recruiting Asian Americans and Canadians for novel insights into Alzheimer's disease. We describe culturally appropriate recruitment strategies and data collection protocol. ACAD addresses challenges of recruitment from heterogeneous Asian subcommunities. We aim to implement a successful recruitment program that enrolls across three Asian subcommunities.

A Cross-Sectional Study of Protein Changes Associated with Dementia in Non-Obese Weight Matched Women with and without Polycystic Ovary Syndrome

Dysregulated Alzheimer's disease (AD)-associated protein expression is reported in polycystic ovary syndrome (PCOS), paralleling the expression reported in type 2 diabetes (T2D). We hypothesized, however, that these proteins would not differ between women with non-obese and non-insulin resistant PCOS compared to matched control subjects. We measured plasma amyloid-related proteins levels (Amyloid-precursor protein (APP), alpha-synuclein (SNCA), amyloid P-component (APCS), Pappalysin (PAPPA), Microtubule-associated protein tau (MAPT), apolipoprotein E (apoE), apoE2, apoE3, apoE4, Serum amyloid A (SAA), Noggin (NOG) and apoA1) in weight and aged-matched non-obese PCOS (n = 24) and control (n = 24) women. Dementia-related proteins fibronectin (FN), FN1.3, FN1.4, Von Willebrand factor (VWF) and extracellular matrix protein 1 (ECM1) were also measured. Protein levels were determined by Slow Off-rate Modified Aptamer (SOMA)-scan plasma protein measurement. Only APCS differed between groups, being elevated in non-obese PCOS women (p = 0.03) relative to the non-obese control women. This differed markedly from the elevated APP, APCS, ApoE, FN, FN1.3, FN1.4 and VWF reported in obese women with PCOS. Non-obese, non-insulin resistant PCOS subjects have a lower AD-associated protein pattern risk profile versus obese insulin resistant PCOS women, and are not dissimilar to non-obese controls, indicating that lifestyle management to maintain optimal body weight could be beneficial to reduce the long-term AD-risk in women with PCOS.

Preliminary study on early diagnosis of Alzheimer's disease in APP/PS1 transgenic mice using multimodal magnetic resonance imaging

Alzheimer's disease (AD) has an insidious onset and lacks clear early diagnostic markers, and by the time overt dementia symptoms appear, the disease is already in the mid-to-late stages. The search for early diagnostic markers of AD may open a critical window for Alzheimer's treatment and facilitate early intervention to slow the progression of AD. In this study, we aimed to explore the imaging markers for early diagnosis of AD through the combined application of structural magnetic resonance imaging (sMRI), resting-state functional magnetic resonance imaging (rs-fMRI), and 1H-magnetic resonance spectroscopy (1H-MRS) multimodal magnetic resonance imaging (MRI) techniques at the animal experimental level, with the aim to provide a certain reference for early clinical diagnosis of AD. First, sMRI scans were performed on 4-month-old amyloid beta precursor protein/presenilin 1 (APP/PS1) transgenic AD model mice and wild type mice of the same litter using a 7.0 T animal MRI scanner to analyze the differential brain regions with structural changes in the gray matter of the brain by voxel-based morphometry (VBM). Next, rs-fMRI scans were performed to analyze the differential brain regions between groups for local spontaneous brain activity and functional connectivity (FC) between brain regions. Finally, 1H-MRS scans were performed to quantify and analyze intergroup differences in the relative concentrations of different metabolites within regions of interest (cortex and hippocampus). Compared with wild type mice, the volume of the left hippocampus, and right olfactory bulb of APP/PS1 transgenic AD model mice were reduced, the functional activity of the bilateral hippocampus, right piriform cortex and right caudate putamen was reduced, the functional network connectivity of the hippocampus was impaired, and the relative content of N-acetylaspartate (NAA)in the hippocampus was decreased. In addition, this study found that imaging changes in olfactory-related brain regions were closely associated with AD diagnosis, and these findings may provide some reference for the early diagnosis of AD.

A Cross-Sectional Study of Alzheimer-Related Proteins in Women with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine condition in women of reproductive age, and several risk factors found in PCOS are associated with an increased risk of Alzheimer's disease (AD). Proteins increased in AD have been reported to include fibronectin (FN) fragments 3 and 4 (FN1.3 and FN1.4, respectively) and ApoE. We hypothesized that Alzheimer-related proteins would be dysregulated in PCOS because of associated insulin resistance and obesity. In this comparative cross-sectional analysis, aptamer-based SomaScan proteomic analysis for the detection of plasma Alzheimer-related proteins was undertaken in a PCOS biobank of 143 women with PCOS and 97 control women. Amyloid precursor protein (APP) (p < 0.05) and amyloid P-component (APCS) (p < 0.001) were elevated in PCOS, while alpha-synuclein (SNCA) (p < 0.05) was reduced in PCOS. Associations with protective heat shock proteins (HSPs) showed that SNCA positively correlated with HSP90 (p < 0.0001) and HSP60 (p < 0.0001) in both the PCOS and control women. Correlations with markers of inflammation showed that APCS correlated with interleukin 6 (IL6) (p = 0.04), while Apolipoprotein (Apo) E3 correlated with TNF-alpha (p = 0.02). FN, FN1.3, FN1.4 and ApoE were all elevated significantly (p < 0.05). An AD-associated protein pattern with elevated FN, FN1.3, FN1.4 and ApoE was found in PCOS, in addition to elevated APP and reduced SNCA, which was the same as reported for type 2 diabetes (T2D) with, additionally, an elevation in APCS. With the AD biomarker pattern in PCOS being very similar to that in T2D, where there is an association between AD and T2D, this suggests that larger prospective cohort studies are needed in women with PCOS to determine if there is a causal association with AD.

Association of vitamin B2 intake with cognitive performance in older adults: a cross-sectional study

BACKGROUND

To scrutinize the relationship between vitamin B2 consumption and cognitive function based on the NHANES database.

METHODS

This cross-sectional study included eligible older adults from the NHANES 2011-2014. Vitamin B2 intake was determined from dietary interview data for two 24-h periods. Cognitive function was evaluated through the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), Animal Fluency Test (AFT), and Digit Symbol Substitution Test (DSST). The regression analyses were used to evaluate the association of vitamin B2 intake with cognitive performance. Stratified analyses based on gender, race, and body mass index (BMI) were conducted.

RESULTS

Higher vitamin B2 intake was correlated with higher scores on each test. As compared to the lowest quartile, the highest quartile of vitamin B2 intake was related to a 45.1-fold increase (P = 0.004) on the DSST test sores. Moreover, those who were males, non-Hispanic whites, or had a BMI of 18.5 to 30 kg/m2 had a stronger relationship between total vitamin B2 consumption and cognitive function.

CONCLUSION

It's possible that older persons who consume more vitamin B2 have enhanced performance in some areas of cognitive function. To determine the causal link between vitamin B2 consumption and cognitive performance, further long-term research is required.

Age at menopause is inversely related to the prevalence of common gynecologic cancers: a study based on NHANES

Background

The fluctuation or even loss of estrogen level caused by menopause in women, and most gynecological cancers often occur before and after menopause, so the age of menopause may be related to the occurrence of gynecological cancer.

Aim

To investigate whether the age at menopause is independently associated with the incidence of gynecological cancers and to analyze the possible influencing factors.

Methods

We selected the NHANES public database to conduct the study, and by excluding relevant influencing factors, we finally included 5706 NHANES participants who had full data on age at menopause and the occurrence of gynecologic cancers to analyze the relationship between the amount of age at menopause and gynecologic cancers based on univariate or multifactorial logistic regression analysis. Further, the relationship between age at menopause and the prevalence of different gynecologic cancers was investigated, and changes in the prevalence of different gynecologic cancers by age at menopause subgroups were observed. Finally, other relevant factors affecting the prevalence of gynecologic cancers were further investigated by subgroup analysis as well as subcluster analysis.

Results

Univariate logistic regression analysis between age at menopause and gynecologic tumor prevalence revealed a negative association between age at menopause and the prevalence of common gynecologic cancers ovarian and cervical cancer, and after adjusting for the effects of covariates, a higher risk of gynecologic tumors was found with statistically significant differences at earlier age at menopause. The regression results showed a negative association between age at menopause and gynecologic cancer prevalence in cervical and ovarian cancer patients (P<0.01,P<0.01). Cervical cancer (OR: 0.91, 95% CI: 0.87,0.94) and ovarian cancer (OR: 0.90, 95% CI: 0.86, 0.95) were more prevalent among those with younger age at menopause.

Conclusion

Age at menopause is negatively associated with the prevalence of cervical and ovarian cancers, and the earlier the age at menopause, the greater the risk of developing gynecological cancers.

A novel molecular class that recruits HDAC/MECP2 complexes to PU.1 motifs reduces neuroinflammation

Pervasive neuroinflammation occurs in many neurodegenerative diseases, including Alzheimer's disease (AD). SPI1/PU.1 is a transcription factor located at a genome-wide significant AD-risk locus and its reduced expression is associated with delayed onset of AD. We analyzed single-cell transcriptomic datasets from microglia of human AD patients and found an enrichment of PU.1-binding motifs in the differentially expressed genes. In hippocampal tissues from transgenic mice with neurodegeneration, we found vastly increased genomic PU.1 binding. We then screened for PU.1 inhibitors using a PU.1 reporter cell line and discovered A11, a molecule with anti-inflammatory efficacy and nanomolar potency. A11 regulated genes putatively by recruiting a repressive complex containing MECP2, HDAC1, SIN3A, and DNMT3A to PU.1 motifs, thus representing a novel mechanism and class of molecules. In mouse models of AD, A11 ameliorated neuroinflammation, loss of neuronal integrity, AD pathology, and improved cognitive performance. This study uncovers a novel class of anti-inflammatory molecules with therapeutic potential for neurodegenerative disorders.

Integrative Bayesian tensor regression for imaging genetics applications

Identifying biomarkers for Alzheimer's disease with a goal of early detection is a fundamental problem in clinical research. Both medical imaging and genetics have contributed informative biomarkers in literature. To further improve the performance, recently, there is an increasing interest in developing analytic approaches that combine data across modalities such as imaging and genetics. However, there are limited methods in literature that are able to systematically combine high-dimensional voxel-level imaging and genetic data for accurate prediction of clinical outcomes of interest. Existing prediction models that integrate imaging and genetic features often use region level imaging summaries, and they typically do not consider the spatial configurations of the voxels in the image or incorporate the dependence between genes that may compromise prediction ability. We propose a novel integrative Bayesian scalar-on-image regression model for predicting cognitive outcomes based on high-dimensional spatially distributed voxel-level imaging data, along with correlated transcriptomic features. We account for the spatial dependencies in the imaging voxels via a tensor approach that also enables massive dimension reduction to address the curse of dimensionality, and models the dependencies between the transcriptomic features via a Graph-Laplacian prior. We implement this approach via an efficient Markov chain Monte Carlo (MCMC) computation strategy. We apply the proposed method to the analysis of longitudinal ADNI data for predicting cognitive scores at different visits by integrating voxel-level cortical thickness measurements derived from T1w-MRI scans and transcriptomics data. We illustrate that the proposed imaging transcriptomics approach has significant improvements in prediction compared to prediction using a subset of features from only one modality (imaging or genetics), as well as when using imaging and transcriptomics features but ignoring the inherent dependencies between the features. Our analysis is one of the first to conclusively demonstrate the advantages of prediction based on combining voxel-level cortical thickness measurements along with transcriptomics features, while accounting for inherent structural information.

Electrochemical Immunosensors Developed for Amyloid-Beta and Tau Proteins, Leading Biomarkers of Alzheimer's Disease

Alzheimer's disease (AD) is the most common neurological disease and a serious cause of dementia, which constitutes a threat to human health. The clinical evidence has found that extracellular amyloid-beta peptides (Aβ), phosphorylated tau (p-tau), and intracellular tau proteins, which are derived from the amyloid precursor protein (APP), are the leading biomarkers for accurate and early diagnosis of AD due to their central role in disease pathology, their correlation with disease progression, their diagnostic value, and their implications for therapeutic interventions. Their detection and monitoring contribute significantly to understanding AD and advancing clinical care. Available diagnostic techniques, including magnetic resonance imaging (MRI) and positron emission tomography (PET), are mainly used to validate AD diagnosis. However, these methods are expensive, yield results that are difficult to interpret, and have common side effects such as headaches, nausea, and vomiting. Therefore, researchers have focused on developing cost-effective, portable, and point-of-care alternative diagnostic devices to detect specific biomarkers in cerebrospinal fluid (CSF) and other biofluids. In this review, we summarized the recent progress in developing electrochemical immunosensors for detecting AD biomarkers (Aβ and p-tau protein) and their subtypes (AβO, Aβ_(1-40), Aβ_(1-42), t-tau, cleaved-tau (c-tau), p-tau₁₈₁, p-tau₂₃₁, p-tau₃₈₁, and p-tau₄₄₁). We also evaluated the key characteristics and electrochemical performance of developed immunosensing platforms, including signal interfaces, nanomaterials or other signal amplifiers, biofunctionalization methods, and even primary electrochemical sensing performances (i.e., sensitivity, linear detection range, the limit of detection (LOD), and clinical application).

Mapping trends and hotspots of mitochondrial dysfunction in Alzheimer's disease from 2013 to 2022: a bibliometric analysis of global research

Objective

Alzheimer's disease (AD), a prevalent neurodegenerative affliction that predominantly affects the elderly population, imposes a substantial burden on not only patients but also their families and society at large. Mitochondrial dysfunction plays an important role in its pathogenesis. In this study, we conducted a bibliometric analysis of research on mitochondrial dysfunction and AD over the past 10 years, with the aim of summarizing current research hotspots and trends in this field.

Methods

On February 12, 2023, we searched for publications about mitochondrial dysfunction and AD in the Web of Science Core Collection database from 2013 to 2022. VOSview software, CiteSpace, SCImago, and RStudio were used to analyze and visualize countries, institutions, journals, keywords, and references.

Results

The number of publications on mitochondrial dysfunction and AD were on the rise until 2021 and decreased slightly in 2022. The United States ranks first in the number of publications, H-index, and intensity of international cooperation in this research. In terms of institutions, Texas Tech University in the United States has the most publications. The Journal of Alzheimer's Disease has the most publications in this field of research, while Oxidative Medicine and Cellular Longevity have the highest number of citations. Mitochondrial dysfunction is still an important direction of current research. Autophagy, mitochondrial autophagy, and neuroinflammation are new hotspots. The article from Lin MT is the most cited by analyzing references.

Conclusion

Research on mitochondrial dysfunction in AD is gaining significant momentum as it provides a crucial research avenue for the treatment of this debilitating condition. This study sheds light on the present research trajectory concerning the molecular mechanisms underlying mitochondrial dysfunction in AD.

Caffeine for Prevention of Alzheimer's Disease: Is the A2A Adenosine Receptor Its Target?

Alzheimer's disease (AD) is the most prevalent kind of dementia with roughly 135 million cases expected in the world by 2050. Unfortunately, current medications for the treatment of AD can only relieve symptoms but they do not act as disease-modifying agents that can stop the course of AD. Caffeine is one of the most widely used drugs in the world today, and a number of clinical studies suggest that drinking coffee may be good for health, especially in the fight against neurodegenerative conditions such as AD. Experimental works conducted "in vivo" and "in vitro" provide intriguing evidence that caffeine exerts its neuroprotective effects by antagonistically binding to A_2A receptors (A_2ARs), a subset of GPCRs that are triggered by the endogenous nucleoside adenosine. This review provides a summary of the scientific data supporting the critical role that A_2ARs play in memory loss and cognitive decline, as well as the evidence supporting the protective benefits against neurodegeneration that may be attained by caffeine's antagonistic action on these receptors. They are a novel and fascinating target for regulating and enhancing synaptic activity, achieving symptomatic and potentially disease-modifying effects, and protecting against neurodegeneration.

Age-based exclusion is common and multifactorial in spinal RCTs: a systematic review and quantitative analysis

Most diseases of the spine disproportionately impact older persons, with the modal (i.e., commonest) patient a female in their 8th decade of life. We examined the corpus of spinal RCTs to determine how many included "average" spine patients. We searched PubMed for randomized clinical trials published in the top 7 spine journals over a period of 5 years from 2016 to 2020 and extracted nominal upper age cut-offs and the distribution of ages actually recruited. We identified 186 trials of 26,238 patients. We found that only 4.8% of trials could be applied to an "average" 75-year-old patient. This age-based exclusion was not dependent on funding source. Age-based exclusion was exacerbated by explicit upper age cut-offs, however, the age-based exclusion went beyond explicit age cut-offs. Only few trials were applicable to older patients even amongst trials with no age cut-off specified. Age-based exclusion from clinical trials starts at late middle age. The mismatch between spinal patient's age seen in clinical practice and spinal patient's age in trials was so severe that over the 5 years (2016-2020) almost no RCT evidence was produced applicable to the "average" aged-patient across the body of literature available. In conclusion, age-based exclusion is ubiquitous, multifactorial, and happens on a supratrial level. Eliminating age-based exclusion involves more than an arbitrary lifting of explicitly stated upper age cut-offs. Instead, recommendations include increasing input from geriatricians and ethics committees, establishing updated or new models of cares, and creating new protocols to facilitate further research.

Unravelling the mechanotransduction pathways in Alzheimer's disease

Alzheimer's disease (AD) represents one of the most common and debilitating neurodegenerative disorders. By the end of 2040, AD patients might reach 11.2 million in the USA, around 70% higher than 2022, with severe consequences on the society. As now, we still need research to find effective methods to treat AD. Most studies focused on the tau and amyloid hypothesis, but many other factors are likely involved in the pathophysiology of AD. In this review, we summarize scientific evidence dealing with the mechanotransduction players in AD to highlight the most relevant mechano-responsive elements that play a role in AD pathophysiology. We focused on the AD-related role of extracellular matrix (ECM), nuclear lamina, nuclear transport and synaptic activity. The literature supports that ECM alteration causes the lamin A increment in the AD patients, leading to the formation of nuclear blebs and invaginations. Nuclear blebs have consequences on the nuclear pore complexes, impairing nucleo-cytoplasmic transport. This may result in tau hyperphosphorylation and its consequent self-aggregation in tangles, which impairs the neurotransmitters transport. It all exacerbates in synaptic transmission impairment, leading to the characteristic AD patient's memory loss. Here we related for the first time all the evidence associating the mechanotransduction pathway with neurons. In addition, we highlighted the entire pathway influencing neurodegenerative diseases, paving the way for new research perspectives in the context of AD and related pathologies.

Mortality of Alzheimer's Disease and Other Dementias in China: Past and Future Decades

Objectives: This study aimed to explore the distribution features and trends of dementia mortality in China from 2011 to 2020 and make a prediction for the next decade. Methods: Mortality-relevant data were gathered from the Chinese Center for Disease Control and Prevention's Disease Surveillance Points system. Joinpoint regression was applied to evaluate the trends. Results: Crude Mortality Rate (CMR) of AD and other dementias increased from 3.7 per 100,000 to 6.2 per 100,000 in 2011-2020, with an Average Annual Percent Change (AAPC) of 5.3% (95% CI 4.4%-6.3%). Age-Standardized Mortality Rate (ASMR) slightly decreased from 5.0 per 100,000 to 4.1 per 100,000 in 2011-2020, with AAPC of -0.4% (95% CI -2.5%-1.8%). CMR will increase to 9.66 per 100,000 while ASMR will decline to 3.42 per 100,000 in the following decade. Conclusion: The upward trend in CMR and downward trend in ASMR suggested the further development of population aging and dementia mortality in the past and future decades. In China, there were gender, urban-rural, regional and age differences.

Clinimetric properties of the diagnostic criteria for psychosomatic research among the elderly

INTRODUCTION

Among the elderly, the availability of tool assessing psychosomatic syndromes is limited. The present study aims at testing inter-rater reliability and concurrent validity of the semi-structured interview for the Diagnostic Criteria for Psychosomatic Research (DCPR-R-SSI) in the elderly of the general population.

METHOD

One hundred eight subjects were recruited. Participants received a clinical assessment which included the DCPR-R-SSI, the Illness Attitude Scale (IAS), the Geriatric Depression Scale (GDS), the Psychosocial Index (PSI), the Toronto Alexithymia Scale-20 (TAS-20). Analyses of inter-rater reliability of DCPR-R-SSI and concurrent validity between DCPR-R-SSI and self-administered questionnaires were conducted.

RESULTS

DCPR-R-SSI showed excellent inter-rater reliability with a percent of agreement of 90.7% (K Cohen: 0.856 [SE = 0.043], 95% CI: 0.77-0.94). DCPR-R demoralization showed fair concurrent validity with GDS; concurrent validity was also fair between DCPR-R Alexithymia and TAS-20, and between DCPR-R allostatic overload and PSI allostatic load, while the concurrent validity between DCPR-R Disease Phobia and IAS was moderate.

CONCLUSION

DCPR-R-SSI represents a reliable and valid tool to assess psychosomatic syndromes in the elderly. DCPR-R is in need of being implemented in the elderly clinical evaluation.

Ensemble Model for Diagnostic Classification of Alzheimer's Disease Based on Brain Anatomical Magnetic Resonance Imaging

Alzheimer's is one of the fast-growing diseases among people worldwide leading to brain atrophy. Neuroimaging reveals extensive information about the brain's anatomy and enables the identification of diagnostic features. Artificial intelligence (AI) in neuroimaging has the potential to significantly enhance the treatment process for Alzheimer's disease (AD). The objective of this study is two-fold: (1) to compare existing Machine Learning (ML) algorithms for the classification of AD. (2) To propose an effective ensemble-based model for the same and to perform its comparative analysis. In this study, data from the Alzheimer's Diseases Neuroimaging Initiative (ADNI), an online repository, is utilized for experimentation consisting of 2125 neuroimages of Alzheimer's disease (n = 975), mild cognitive impairment (n = 538) and cognitive normal (n = 612). For classification, the framework incorporates a Decision Tree (DT), Random Forest (RF), Naïve Bayes (NB), and K-Nearest Neighbor (K-NN) followed by some variations of Support Vector Machine (SVM), such as SVM (RBF kernel), SVM (Polynomial Kernel), and SVM (Sigmoid kernel), as well as Gradient Boost (GB), Extreme Gradient Boosting (XGB) and Multi-layer Perceptron Neural Network (MLP-NN). Afterwards, an Ensemble Based Generic Kernel is presented where Master-Slave architecture is combined to attain better performance. The proposed model is an ensemble of Extreme Gradient Boosting, Decision Tree and SVM_Polynomial kernel (XGB + DT + SVM). At last, the proposed method is evaluated using cross-validation using statistical techniques along with other ML models. The presented ensemble model (XGB + DT + SVM) outperformed existing state-of-the-art algorithms with an accuracy of 89.77%. The efficiency of all the models was optimized using Grid-based tuning, and the results obtained after such process showed significant improvement. XGB + DT + SVM with optimized parameters outperformed all other models with an efficiency of 95.75%. The implication of the proposed ensemble-based learning approach clearly shows the best results compared to other ML models. This experimental comparative analysis improved understanding of the above-defined methods and enhanced their scope and significance in the early detection of Alzheimer's disease.

Is vitamin D supplementation of potential benefit for community-living people with Alzheimer's disease?

BACKGROUND

Vitamin D is associated not only with effects on calcium and bone metabolisms but also with many chronic diseases. Low vitamin D levels in patients with Alzheimer's disease have been widely reported in the literature.

AIM

The purpose of this study was to critically review the potential benefit of vitamin D supplementation in individuals with Alzheimer's disease living in the community.

METHODS

A systematic literature search was conducted in PubMed, CINAHL, EMBASE and the Cochrane Library for papers published 2011-2018.

RESULTS

Seven papers were selected, consisting of one clinical trial, five cohort studies and one systematic review. Studies showed an association only between vitamin D deficiency and lower attention in older people. None of the reviewed studies provided evidence of a positive impact of vitamin D supplementation on cognitive function in older people with Alzheimer's disease.

CONCLUSION

There was no evidence that vitamin D supplementation has a direct benefit for Alzheimer's disease. The review synthesised the existing body of knowledge and concluded that optimum levels of vitamin D (neither too low nor too high) do appear to have positive effects on patient outcomes and quality of life. It is still unclear why vitamin D intake is inadequate as people age. Further research is needed to clarify vitamin-D-related aspects of Alzheimer's disease.

A Biopsychosocial Model of Mealtime Management in Persons with Dementia, an Asset-Based Approach to Patient-Centered Care

Considering the rapid increase in the population over the age of 65, there is increasing need to consider models of care for persons with dementia (PWD). One common deficit associated with dementia progression is difficulty with successful participation in mealtimes. Difficulty participating in mealtimes in PWD is not the result of one factor, but rather a confluence of biological, psychological, and social characteristics common in dementia. Factors leading to mealtime difficulties for PWD may include changes in cognitive status, altered sensorimotor functioning, and increased reliance on caregiver support. The complex nature of biological, psychological, and social factors leading to mealtime difficulty highlights the need for a pragmatic model that caregivers can utilize to successfully support PWD during mealtimes. Existing models of dementia and mealtime management were reviewed and collated to create a model of mealtime management that considers this complex interplay. The Biopsychosocial Model of Mealtime Management builds on past research around patient-centered care and introduces an asset-based approach to capitalize on a PWD's retained capabilities as opposed to compensating for disabilities associated with dementia. We hope this model will provide a framework for caregivers to understand what factors impact mealtime participation in PWD and provide appropriate means on intervention.

Novel molecular mechanisms in Alzheimer's disease: The potential role of DEK in disease pathogenesis

Alzheimer's disease and age-related dementias (AD/ADRD) are debilitating diseases that exact a significant physical, emotional, cognitive, and financial toll on the individual and their social network. While genetic risk factors for early-onset AD have been identified, the molecular and genetic drivers of late-onset AD, the most common subtype, remain a mystery. Current treatment options are limited for the 35 million people in the United States with AD/ADRD. Thus, it is critically important to identify novel molecular mechanisms of dementia-related pathology that may be targets for the development of new interventions. Here, we summarize the overarching concepts regarding AD/ADRD pathogenesis. Then, we highlight one potential molecular driver of AD/ADRD, the chromatin remodeling protein DEK. We discuss in vitro, in vivo, and ex vivo findings, from our group and others, that link DEK loss with the cellular, molecular, and behavioral signatures of AD/ADRD. These include associations between DEK loss and cellular and molecular hallmarks of AD/ADRD, including apoptosis, Tau expression, and Tau hyperphosphorylation. We also briefly discuss work that suggests sex-specific differences in the role of DEK in AD/ADRD pathogenesis. Finally, we discuss future directions for exploiting the DEK protein as a novel player and potential therapeutic target for the treatment of AD/ADRD.

Genetic architecture of RNA editing regulation in Alzheimer's disease across diverse ancestral populations

Most Alzheimer's disease (AD)-associated genetic variants do not change protein coding sequence and thus likely exert their effects through regulatory mechanisms. RNA editing, the post-transcriptional modification of RNA bases, is a regulatory feature that is altered in AD patients that differs across ancestral backgrounds. Editing QTLs (edQTLs) are DNA variants that influence the level of RNA editing at a specific site. To study the relationship of DNA variants genome-wide, and particularly in AD-associated loci, with RNA editing, we performed edQTL analyses in self-reported individuals of African American (AF) or White (EU) race with corresponding global genetic ancestry averaging 82.2% African ancestry (AF) and 96.8% European global ancestry (EU) in the two groups, respectively. We used whole-genome genotyping array and RNA sequencing data from peripheral blood of 216 AD cases and 212 age-matched, cognitively intact controls. We identified 2144 edQTLs in AF and 3579 in EU, of which 1236 were found in both groups. Among these, edQTLs in linkage disequilibrium (r2 > 0.5) with AD-associated genetic variants in the SORL1, SPI1 and HLA-DRB1 loci were associated with sites that were differentially edited between AD cases and controls. While there is some shared RNA editing regulatory architecture, most edQTLs had distinct effects on the rate of RNA editing in different ancestral populations suggesting a complex architecture of RNA editing regulation. Altered RNA editing may be one possible mechanism for the functional effect of AD-associated variants and may contribute to observed differences in the genetic etiology of AD between ancestries.

Glycation-induced age-related illnesses, antiglycation and drug delivery strategies

OBJECTIVES

Ageing is a major cause of multiple age-related diseases. Several mechanisms have been reported to contribute to these abnormalities including glycation, oxidative stress, the polyol pathway and osmotic stress. Glycation, unlike glycosylation, is an irregular biochemical reaction to the formation of active advanced glycation end-products (AGEs), which are considered to be one of the causes of these chronic diseases. This study provides a recent and comprehensive review on the possible causes, mechanisms, types, analytical techniques, diseases and treatments of the toxic glycation end products.

KEY FINDINGS

Several mechanisms have been found to play a role in generating hyperglycaemia-induced oxidative stress including an increase in the levels of reactive oxygen species (ROS), increase in the levels of AGEs, binding of AGEs and their receptors (RAGE) and the polyol pathway and thus have been investigated as promising novel targets.

SUMMARY

This review focuses on the key mechanisms attributed to cumulative increases of glycation and pathological RAGE expression as a significant cause of multiple age-related diseases, and reporting on different aspects of antiglycation therapy as a novel approach to managing/treating age-related diseases. Additionally, historical, current and possible future antiglycation approaches will be presented focussing on novel drug delivery methods.

Vitamin D supplementation worsens Alzheimer's progression: Animal model and human cohort studies

Vitamin D deficiency has been epidemiologically linked to Alzheimer's disease (AD) and other dementias, but no interventional studies have proved causality. Our previous work revealed that the genomic vitamin D receptor (VDR) is already converted into a non-genomic signaling pathway by forming a complex with p53 in the AD brain. Here, we extend our previous work to assess whether it is beneficial to supplement AD mice and humans with vitamin D. Intriguingly, we first observed that APP/PS1 mice fed a vitamin D-sufficient diet showed significantly lower levels of serum vitamin D, suggesting its deficiency may be a consequence not a cause of AD. Moreover, supplementation of vitamin D led to increased Aβ deposition and exacerbated AD. Mechanistically, vitamin D supplementation did not rescue the genomic VDR/RXR complex but instead enhanced the non-genomic VDR/p53 complex in AD brains. Consistently, our population-based longitudinal study also showed that dementia-free older adults (n = 14,648) taking vitamin D3 supplements for over 146 days/year were 1.8 times more likely to develop dementia than those not taking the supplements. Among those with pre-existing dementia (n = 980), those taking vitamin D3 supplements for over 146 days/year had 2.17 times the risk of mortality than those not taking the supplements. Collectively, these animal model and human cohort studies caution against prolonged use of vitamin D by AD patients.

The Emerging Applications of Nanotechnology in Neuroimaging: A Comprehensive Review

Neuroimaging modalities such as computer tomography and magnetic resonance imaging have greatly improved in their ability to achieve higher spatial resolution of neurovascular and soft tissue neuroanatomy, allowing for increased accuracy in the diagnosis of neurological conditions. However, the use of conventional contrast agents that have short tissue retention time and associated renal toxicities, or expensive radioisotope tracers that are not widely available, continue to limit the sensitivity of these imaging modalities. Nanoparticles can potentially address these shortcomings by enhancing tissue retention and improving signal intensity in the brain and neural axis. In this review, we discuss the use of different types of nanotechnology to improve the detection, diagnosis, and treatment of a wide range of neurological diseases.

Spotlight on Age: An Overlooked Construct in Medical Sociology

Medical sociology gives limited attention to age-a surprising observation given the aging of the population and the fact that age is among the strongest determinants of health. We examine this issue through an analysis of articles published in Journal of Health and Social Behavior (JHSB) and Sociology of Health & Illness (SHI) between 2000 and 2019. One in 10 articles focused on age or aging, with attention increasing over the period. However, the journals differed. More JHSB than SHI articles addressed it, but fewer focused on the latest life stages when frailty often appears. We discuss three dimensions of age that would enrich medical sociology: as a dimension of inequality akin to race and gender with similar health effects, as an institution interacting with the medical one, and as an identity-again, akin to race and gender-through which people process their experiences in ways that affect health.

Gender/Sex Differences in the Association of Mild Behavioral Impairment with Cognitive Aging

BACKGROUND

While the gender/sex differences in neuropsychiatric symptoms in dementia population are well described, gender/sex differences in mild behavioral impairment (MBI) in dementia-free populations and the relationship to cognitive performance and to subsequent cognitive decline have not been studied.

OBJECTIVE

We aimed to explore gender/sex differences in the association of MBI with the level of cognitive performance and its rate of decline in a dementia-free cohort.

METHODS

We studied 8,181 older adults enrolled in the online PROTECT UK Study. MBI was assessed using the MBI Checklist and cognition was measured by digit span, paired associate learning, spatial working memory, and verbal reasoning. Statistical analysis was conducted using linear regression models and linear mixed-effects models.

RESULTS

Out of 8,181 individuals (median age 63 years, 73% females), 11% of females and 14% of males had MBI syndrome. Females exhibited less often symptoms of decreased motivation (45% versus 36% in males), impulse dyscontrol (40% versus 44% in males; p = 0.001) and social inappropriateness (12% versus 15% ; p <  0.001), while they showed more often symptoms of emotional dysregulation (45% versus 36% ; p <  0.001). The associations of MBI domains with some measures of cognitive performance and decline were stronger in males than females, with the exception of the association of emotional dysregulation with the rate of cognitive decline in verbal reasoning, which was present exclusively in females.

CONCLUSION

MBI may influence cognition to a greater extent in males than in females. We propose that predictors and biomarkers of dementia should consider gender/sex as an effect modifier.

Explicit and implicit timing in older adults: Dissociable associations with age and cognitive decline

This study aimed to test two common explanations for the general finding of age-related changes in the performance of timing tasks within the millisecond-to-second range intervals. The first explanation is that older adults have a real difficulty in temporal processing as compared to younger adults. The second explanation is that older adults perform poorly on timing tasks because of their reduced cognitive control functions. These explanations have been mostly contrasted in explicit timing tasks that overtly require participants to process interval durations. Fewer studies have instead focused on implicit timing tasks, where no explicit instructions to process time are provided. Moreover, the investigation of both explicit and implicit timing in older adults has been restricted so far to healthy older participants. Here, a large sample (N = 85) comprising not only healthy but also pathological older adults completed explicit (time bisection) and implicit (foreperiod) timing tasks within a single session. Participants’ age and cognitive decline, measured with the Mini-Mental State Examination (MMSE), were used as continuous variables to explain performance on explicit and implicit timing tasks. Results for the explicit timing task showed a flatter psychometric curve with increasing age or decreasing MMSE scores, pointing to a deficit at the level of cognitive control functions rather than of temporal processing. By contrast, for the implicit timing task, a decrease in the MMSE scores was associated with a reduced foreperiod effect, an index of implicit time processing. Overall, these findings extend previous studies on explicit and implicit timing in healthy aged samples by dissociating between age and cognitive decline (in the normal-to-pathological continuum) in older adults.

The Distribution of Glucosinolates in Different Phenotypes of Lepidium peruvianum and Their Role as Acetyl- and Butyrylcholinesterase Inhibitors-In Silico and In Vitro Studies

The aim of the study was to present the fingerprint of different Lepidium peruvianum tuber extracts showing glucosinolates-containing substances possibly playing an important role in preventinting dementia and other memory disorders. Different phenotypes of Lepidium peruvianum (Brassicaceae) tubers were analysed for their glucosinolate profile using a liquid chromatograph coupled with mass spectrometer (HPLC-ESI-QTOF-MS/MS platform). Qualitative analysis in 50% ethanolic extracts confirmed the presence of ten compounds: aliphatic, indolyl, and aromatic glucosinolates, with glucotropaeolin being the leading one, detected at levels between 0–1.57% depending on phenotype, size, processing, and collection site. The PCA analysis showed important variations in glucosinolate content between the samples and different ratios of the detected compounds. Applied in vitro activity tests confirmed inhibitory properties of extracts and single glucosinolates against acetylcholinesterase (AChE) (15.3–28.9% for the extracts and 55.95–57.60% for individual compounds) and butyrylcholinesterase (BuChE) (71.3–77.2% for the extracts and 36.2–39.9% for individual compounds). The molecular basis for the activity of glucosinolates was explained through molecular docking studies showing that the tested metabolites interacted with tryptophan and histidine residues of the enzymes, most likely blocking their active catalytic side. Based on the obtained results and described mechanism of action, it could be concluded that glucosinolates exhibit inhibitory properties against two cholinesterases present in the synaptic cleft, which indicates that selected phenotypes of L. peruvianum tubers cultivated under well-defined environmental and ecological conditions may present a valuable plant material to be considered for the development of therapeutic products with memory-stimulating properties.

Exploring the Motivations for Completing Advance Care Directives: A Qualitative Study of Majority/Minority Israeli People Without Dementia

Background

Completing advance directives has been declared an essential instrument for preserving and respecting the autonomy and preferences for end-of-life care of people living with dementia. However, research deciphering the reasoning behind the decision to complete or not advance directives in the case of dementia remains limited, especially among people pertaining to different majority/minority groups.

Objectives

To explore the motivations of people without dementia in Israel to complete or not to complete advance directives and to compare these motivations among the majority veteran Jewish group, the minority Jewish Former Soviet Union immigrant group, and the minority Arab group.

Methods

This qualitative study used purposive sampling and focus groups with discussions elicited by a vignette. A total of 42 Israeli people without dementia participated in 6 focus groups: two with veteran Jews (n = 14), two with Jewish immigrants from the Former Soviet Union (n = 14), and two with Arabs (n = 14). The analysis followed recommended steps for thematic content analysis.

Results

Four overarching themes were identified: (1) the meaning of dementia-related advance directives, (2) motivations for willingness to complete advance directives, (3) motivations for not being willing to complete advance directives, and (4) ethical dilemmas. Some of the themes were common to all groups, while others were informed by the groups' unique characteristics. Participants displayed a lack of knowledge and misunderstanding about advance directives, and central concepts such as autonomy and competence. Furthermore, stigmatic images of dementia and of the person with the diagnosis were associated to participants' motivations to complete advance directives.

Conclusions

There is need to expand comparative research among culturally and socially similar and dissimilar groups within a country as well as between countries in order to better guide public health efforts to increase the rates of advance directives completion. Special attention should be paid to decreasing stigmatic beliefs and understanding unique cultural values and motivations.

Neuropathologic Correlates of Human Cortical Proteins in Alzheimer Disease and Related Dementias

BACKGROUND AND OBJECTIVES

Alzheimer dementia is a complex clinical syndrome that can be defined broadly as an amnestic multidomain dementia. We previously reported human cortical proteins that are implicated in Alzheimer dementia. To understand the pathologic correlates of these proteins for underlying disease mechanisms, we investigated cortical protein associations with common age-related neuropathologies.

METHODS

Participants were community-dwelling older adults from 2 cohort studies of aging and dementia. All underwent detailed annual clinical evaluations, and brain autopsies were performed after death. We use Alzheimer disease (AD) to refer to pathologically defined disease and Alzheimer dementia to refer to the clinical syndrome. Indices for AD, cortical Lewy bodies, limbic predominant age-related TAR DNA binding protein 43 encephalopathy neuropathologic changes (LATE-NC), hippocampal sclerosis, macroscopic infarcts, microinfarcts, cerebral amyloid angiopathy, atherosclerosis, and arteriolosclerosis were quantified during uniform structured neuropathologic evaluations. High-throughput protein abundances from frozen dorsolateral prefrontal cortex were quantified with mass spectrometry-based tandem mass tag proteomics analysis. Eleven human cortical proteins implicated in Alzheimer dementia, including angiotensin-converting enzyme, calcium-regulated heat-stable protein 1 (CHSP1), procathepsin H (CATH), double C2-like domain-containing protein α, islet cell autoantigen 1-like protein, serine β-lactamase-like protein LACTB, mitochondrial, pleckstrin homology domain-containing family A member 1, replication termination factor 2, sorting nexin-32, syntaxin-4, and syntaxin-6 (STX6), were previously identified with an integrative approach. Logistic regression analysis examined the association of protein expression with each of the neuropathologic indices.

RESULTS

A total of 391 older adults were included. We did not observe associations of these protein targets with pathologic diagnosis of AD. In contrast, multiple proteins were associated with non-AD neurodegenerative and cerebrovascular conditions. In particular, higher CHSP1 expression was associated with cortical Lewy bodies and macroscopic infarcts, and higher CATH expression was associated with LATE-NC and arteriolosclerosis. Furthermore, while higher STX6 expression increased the risk of Alzheimer dementia, the protein was not associated with any of the neuropathologic indices investigated.

DISCUSSION

Cortical proteins implicated in Alzheimer dementia do not necessarily work through AD pathogenesis; rather, non-AD neurodegenerative and vascular diseases and other pathways are at play. Furthermore, some proteins are pleiotrophic and associated with both neurodegenerative and cerebrovascular pathologies.

Factors associated with the perception of services by dementia informal caregivers in Greece: the role of familism

AIM

To investigate perceptions of informal caregivers of community-dwelling persons with dementia (PwD) regarding health and social care services and their correlates using the Behavioral Model of Healthcare Utilization as the theoretical framework.

METHODS

This was a cross-sectional study using a purposive sampling technique to identify, through community-based health and social care services, caregivers of PwD. Face-to-face interviews were conducted with 118 informal caregivers (78.8% female, mean age = 58.9 years) via a structured questionnaire.

RESULTS

Three 'Perceptions of Services' subscales were identified: 'Availability and Adequacy of Services' (AAS), 'Physicians' Competence' (COMP), and 'Professionals' Behavior' (PB). Predisposing factors (gender, employment, familism) and enabling/impeding factors (caregiving impedes work, quality of life aspects - environment and social relationships, information about dementia) were significant correlates of the AAS and COMP subscales. Familism was negatively associated with the AAS subscale. PwD's perceived declined physical and behavioral functioning was related to worse perceptions regarding professionals' behavior (PB) toward the PwD.

CONCLUSION

Understanding the factors associated with caregivers' perceptions of health and social care community services may guide the development of interventions that facilitate the appropriate use of those services, provide increased support to PwD and their caregivers, and delay potential institutionalization.

Development and psychometric evaluation of the Dementia Public Stigma Scale

OBJECTIVES

Dementia is a stigmatised condition and dementia-related stigma is associated with low self-esteem, poor psychological wellbeing, social isolation and poor quality of life in people living with dementia and their families. There is, however, a lack of valid measures that accurately quantify dementia-related stigma in the general public. This study reports the initial psychometric evaluation of a new tool designed to measure dementia-related public stigma amongst community dwelling adults.

METHODS

A sample of 3250 individuals aged 18 and over completed an online survey on their beliefs and feelings regarding dementia and people living with dementia, and their behavioural intentions towards people living with dementia. Exploratory factor analysis (EFA) using Maximum Likelihood with oblique rotation was performed to extract factors. Confirmatory factor analysis (CFA) was used to confirm the factor structure using goodness-of-fit index (GFI), the comparative fit index (CFI), and the root mean square error of approximation (RMSEA) to evaluate the model fit. Internal consistency was measured for the final scale version.

RESULTS

EFA resulted in a 16-item, 5-factor model (Fear and discomfort, Negative perceptions, Positive perceptions, Burden, and Exclusion) that explained 50.43% of the total variance. The CFA-estimated model demonstrated a good fit; all fit indices were larger than 0.95 (GFI = 0.967, CFI = 0.959) and smaller than 0.05 (RMSEA = 0.048). The final scale showed moderate to high reliability scores ranging from α = 0.738 to 0.805.

CONCLUSIONS

The Dementia Public Stigma Scale is a tool with reliability, and some demonstrated validity. This scale can be used to measure the public stigma of dementia amongst adults and may be used in the development and evaluation of interventions aimed at dementia-related stigma reduction.

Characteristics of Cortical Atrophy and White Matter Lesions Between Dementia With Lewy Bodies and Alzheimer's Disease: A Case-Control Study

Introduction: Currently, there is still clinical overlap between dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) patients, which may affect the accuracy of the early diagnosis of DLB. For better diagnosis and prognosis, further exploration of local cortical atrophy patterns and white matter lesions is needed.

Methods: We reviewed the outpatient medical records of 97 DLB patients and 173 AD patients from January 2018 to September 2020 along with 30 matched outpatient clinic normal elderly people. MRI visual rating scales, including medial temporal lobe atrophy (MTA), global cortical atrophy-frontal subscale (GCA-F), posterior atrophy (PA), Fazekas scale, Evans Index and cerebral microbleeds were evaluated and analyzed in DLB and AD patients with different severities and normal controls.

Results: Overall, patients with DLB had higher scores on all visual rating scales than the normal controls. Meanwhile, compared with AD, DLB had lower MTA scores in the mild to moderate groups (both p ≤ 0.001), but the GCA-F and PA scores were similar (all p > 0.05). The Fazekas scores in the moderate to severe DLB group were lower than those in the AD group (p = 0.024 and p = 0.027, respectively). In addition, the diagnostic performance and sensitivity of multiple imaging indicators for DLB were better than that of MTA alone (the combination of MTA, GCA-F, PA, Fazekas visual rating scales, AUC = 0.756, 95%CI: 0.700–0.813, sensitivity = 0.647, specificity = 0.804 and MTA visual rating scale, AUC = 0.726, 95%CI: 0.667–0.785, sensitivity = 0.497, specificity = 0.876, respectively).

Conclusion: The medial temporal lobe of DLB patients was relatively preserved, the frontal and parietal lobes were similarly atrophied to AD patients, and the white matter hyperintensity was lighter than that in AD patients. Combined multiple visual rating scales may provide a novel idea for the diagnosis of early DLB.

Analysis of plasma proteins using 2D gels and novel fluorescent probes: in search of blood based biomarkers for Alzheimer's disease

BACKGROUND

The Australian Imaging and Biomarker Lifestyle (AIBL) study of aging is designed to aid the discovery of biomarkers. The current study aimed to discover differentially expressed plasma proteins that could yield a blood-based screening tool for Alzheimer's disease.

METHODS

The concentration of proteins in plasma covers a vast range of 12 orders of magnitude. Therefore, to search for medium to low abundant biomarkers and elucidate mechanisms of AD, we immuno-depleted the most abundant plasma proteins and pre-fractionated the remaining proteins by HPLC, prior to two-dimensional gel electrophoresis. The relative levels of approximately 3400 protein species resolved on the 2D gels were compared using in-gel differential analysis with spectrally resolved fluorescent protein detection dyes (Zdyes™). Here we report on analysis of pooled plasma samples from an initial screen of a sex-matched cohort of 72 probable AD patients and 72 healthy controls from the baseline time point of AIBL.

RESULTS

We report significant changes in variants of apolipoprotein E, haptoglobin, α1 anti-trypsin, inter-α trypsin inhibitor, histidine-rich glycoprotein, and a protein of unknown identity. α1 anti-trypsin and α1 anti-chymotrypsin demonstrated plasma concentrations that were dependent on APOE ε4 allele dose. Our analysis also identified an association with the level of Vitamin D binding protein fragments and complement factor I with sex. We then conducted a preliminary validation study, on unique individual samples compared to the discovery cohort, using a targeted LC-MS/MS assay on a subset of discovered biomarkers. We found that targets that displayed a high degree of isoform specific changes in the 2D gels were not changed in the targeted MS assay which reports on the total level of the biomarker.

CONCLUSIONS

This demonstrates that further development of mass spectrometry assays is needed to capture the isoform complexity that exists in theses biological samples. However, this study indicates that a peripheral protein signature has potential to aid in the characterization of AD.

Mechanistic Insights of Chelator Complexes with Essential Transition Metals: Antioxidant/Pro-Oxidant Activity and Applications in Medicine

The antioxidant/pro-oxidant activity of drugs and dietary molecules and their role in the maintenance of redox homeostasis, as well as the implications in health and different diseases, have not yet been fully evaluated. In particular, the redox activity and other interactions of drugs with essential redox metal ions, such as iron and copper, need further investigation. These metal ions are ubiquitous in human nutrition but also widely found in dietary supplements and appear to exert major effects on redox homeostasis in health, but also on many diseases of free radical pathology. In this context, the redox mechanistic insights of mainly three prototype groups of drugs, namely alpha-ketohydroxypyridines (alpha-hydroxypyridones), e.g., deferiprone, anthraquinones, e.g., doxorubicin and thiosemicarbazones, e.g., triapine and their metal complexes were examined; details of the mechanisms of their redox activity were reviewed, with emphasis on the biological implications and potential clinical applications, including anticancer activity. Furthermore, the redox properties of these three classes of chelators were compared to those of the iron chelating drugs and also to vitamin C, with an emphasis on their potential clinical interactions and future clinical application prospects in cancer, neurodegenerative and other diseases.

Subjective cognitive decline symptoms and its association with socio-demographic characteristics and common chronic diseases in the southern Chinese older adults

Background

Subjective cognitive decline (SCD) may be the first symptomatic manifestation of Alzheimer’s disease, but information on its health correlates is still sparse in Chinese older adults. This study aimed to estimate SCD symptoms and its association with socio-demographic characteristics, common chronic diseases among southern Chinese older adults.

Methods

Participants aged 60 years and older from 7 communities and 2 nursing homes in Guangzhou were recruited and interviewed with standardized assessment tools. Pittsburgh Sleep Quality Index (PSQI), Patient Health Questionnaire–9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) were used to measure poor sleep quality, depression symptoms and anxiety symptoms. The SCD symptoms were measured by SCD questionnaire 9 (SCD-Q9) which ranged from 0 to 9 points, with a higher score indicating increased severity of the SCD. Participants were divided into low score group (SCD-Q9 score ≤ 3) and higher score group (SCD-Q9 score > 3). Chi-square tests and multivariate logistic regression analysis were used for exploring the influences of different characteristics of socio-demographic and lifestyle factors on SCD symptoms. Univariate and multivariate logistic regression analysis were applied to explore the association between SCD symptoms with common chronic diseases.

Results

A total of 688 participants were included in our analysis with a mean age of 73.79 (SD = 8.28, range: 60–101), while 62.4% of the participants were females. The mean score of the SCD-Q9 was 3.81 ± 2.42 in the whole sample. A total of 286 participants (41.6%) were defined as the low score group (≤3 points), while 402 participants (58.4%) were the high score group (> 3 points). Multivariate logistic regression analysis revealed that female (OR = 1.99, 95%CI: 1.35–2.93), primary or lower education level (OR = 2.58, 95%CI: 1.38–4.83), nursing home (OR = 1.90, 95%CI: 1.18–3.05), napping habits (OR = 1.59, 95%CI: 1.06–2.40), urolithiasis (OR = 2.72, 95%CI: 1.15–6.40), gout (OR = 2.12, 95%CI: 1.14–3.93), poor sleep quality (OR = 1.93, 95%CI: 1.38–2.71), depression symptoms (OR = 3.01, 95%CI: 1.70–5.34) and anxiety symptoms (OR = 3.11, 95%CI: 1.29–7.46) were independent positive related to high SCD-Q9 score. On the other hand, tea-drinking habits (OR = 0.64, 95%CI: 0.45–0.92), current smoking (OR = 0.46, 95%CI: 0.24–0.90) were independent negative related to high SCD-Q9 score.

Conclusions

Worse SCD symptoms were closely related to common chronic diseases and socio-demographic characteristics. Disease managers should pay more attention to those factors to early intervention and management for SCD symptoms among southern Chinese older adults.

Zuoguiwan Ameliorates Cognitive Deficits and Neuro-Inflammation in Streptozotocin-Induced Alzheimer's Disease Rats

INTRODUCTION

Alzheimer's disease is the most popular neurodegenerative disorder with no effective drugs to stop the progression. Zuoguiwan (ZGW), a traditional Chinese herbal medicine, has been applied in many diseases. Our study aimed to detect the function and mechanisms of ZGW in Alzheimer's disease (AD).

METHODS

The rat models of AD were established by streptozotocin (STZ), and the function of ZGW on cognitive dysfunction was measured with the Morris water maze test. The concentration of pro-inflammatory mediators was accessed by enzyme-linked immunosorbent assay. The relative mRNA expression of ERβ was detected by real-time quantitative PCR.

RESULTS

The treatment with ZGW could suppress the cognitive impairment by the findings of escape latency and time spent in the target quadrant and the increased concentration of IL-1β, IL-6, and TNF-α induced by STZ. STZ might repress the mRNA levels of ERβ, and ZGW management weakened the declined mRNA expression of ERβ. ZGW might play a protective role in AD rats against the injury of STZ on cognition and neuro-inflammation by improving the mRNA expression of ERβ.

CONCLUSION

The results indicated that ZGW might be a novel therapeutic strategy to slow the process of AD by modulating ERβ.

Non-genomic rewiring of vitamin D receptor to p53 as a key to Alzheimer's disease

Observational epidemiological studies have associated vitamin D deficiency with Alzheimer's disease (AD). However, whether vitamin D deficiency would result in some impacts on the vitamin D binding receptor (VDR) remains to be characterized in AD. Vitamin D helps maintain adult brain health genomically through binding with and activating a VDR/retinoid X receptor (RXR) transcriptional complex. Thus, we investigated the role of VDR in AD using postmortem human brains, APP/PS1 mice, and cell cultures. Intriguingly, although vitamin D was decreased in AD patients and mice, hippocampal VDR levels were inversely increased. The abnormally increased levels of VDR were found to be colocalized with Aβ plaques, gliosis and autophagosomes, implicating a non-genomic activation of VDR in AD pathogenesis. Mechanistic investigation revealed that Aβ upregulated VDR without its canonical ligand vitamin D and switched its heterodimer binding-partner from RXR to p53. The VDR/p53 complex localized mostly in the cytosol, increased neuronal autophagy and apoptosis. Chemically inhibiting p53 switched VDR back to RXR, reversing amyloidosis and cognitive impairment in AD mice. These results suggest a non-genomic rewiring of VDR to p53 is key for the progression of AD, and thus VDR/p53 pathway might be targeted to treat people with AD.

Family-Centered Primary Care for Older Adults with Cognitive Impairment

Cognitive impairment (e.g. dementia) presents challenges for individuals, their families, and healthcare professionals alike. The primary care setting presents a unique opportunity to care for older adults living with cognitive impairment, who present with complex care needs that may benefit from a family-centered approach. This indepth systematic review was completed to address three aims: (a) identify the ways in which families of older-adult patients with cognitive impairment are engaged in primary care settings, (b) examine the outcomes of family engagement practices, and (c) organize and discuss the findings using CJ Peek's Three World View. Researchers searched PubMed, Embase, and PsycINFO databases through July 2019. The results included 22 articles out of 6743 identified in the initial search. Researchers provided a description of the emerging themes for each of the three aims. It revealed that family-centered care and family engagement yields promising results including improved health outcomes, quality care, patient experience, and caregiver satisfaction. Furthermore, it promotes and advances the core values of medical family therapy: agency and communion. This review also exposed the inconsistent application of family-centered practices and the need for improved interprofessional education of primary care providers to prepare multidisciplinary teams to deliver family-centered care. Utilizing the vision of Patient- and Family-Centered Care and the lens of the Three World View, this systematic review provides Medical Family Therapists, healthcare administrators, policy makers, educators, and clinicians with information related to family engagement and how it can be implemented and enhanced in the care of patients with cognitive impairment.

Comparative Value of Cholinesterase Inhibitors and Memantine in Persons with Moderate-to-Severe Alzheimer's Disease in the United States: A Cost-Effectiveness Analysis

Background:

Pharmacological treatment of Alzheimer’s disease (AD) involves symptomatic improvement of cognition using cholinesterase inhibitors (ChEIs) and memantine. The cost-effectiveness of these medications will guide decision-makers in making judicious use of scarce healthcare resources, particularly during the advanced disease stages.

Objective:

To evaluate the cost-effectiveness of ChEIs, memantine, and ChEI-memantine combinations in persons with moderate-to-severe AD from the US healthcare perspective.

Methods:

This pharmacoeconomic evaluation study used a state-transition Markov cohort model to simulate the costs and effectiveness of ChEI-memantine combinations compared with monotherapies of ChEI (donepezil, galantamine and rivastigmine) and memantine in persons with moderate-to-severe AD over a lifetime horizon with a 1-year cycle length. We estimated expected quality-adjusted life-years (QALYs), costs (in 2020 $US), net monetary benefits, and incremental cost-effectiveness ratios (ICERs). We discounted future costs and QALYs at the rate of 3%.

Results:

In this study, donepezil monotherapy, galantamine-memantine combination, and rivastigmine transdermal patch formed the cost-effectiveness frontier. Findings suggests that rivastigmine transdermal patch is the optimal treatment strategy at a willingness-to-pay (WTP) threshold of $150,000/QALY (ICER = $93,307/QALY [versus donepezil monotherapy]). Results across subgroups by age and sex also suggest that the rivastigmine transdermal patch is the optimal treatment strategy with the highest net benefit.

Conclusion:

From the US healthcare perspective, we found that, for persons with moderate-to-severe AD at a WTP threshold of $150,000/QALY, the rivastigmine transdermal patch is the most cost-effective pharmacological treatment option. Given that the transdermal patch is a preferred route of administration for persons with AD and their caregivers due to its convenience, our findings provide additional incentives for its use.

The Effect of Type-2 Diabetes on Cognitive Status and the Role of Anti-diabetes Medications

Type-2 diabetes mellitus prevalence is constantly increasing; this is explained by the increase of its risk factors and the amelioration of its management. Therefore, people are living longer with diabetes mellitus, which, in turn, has revealed new complications of the disease. Dementia is represented mainly by Alzheimer's disease and is an interesting topic of study. Accordingly, statistics have shown that dementia incidence is doubled in diabetic patients. The establishment of a relation between type-2 diabetes mellitus was studied on several levels in both humans and animal subjects. First, insulin receptors were found in the brain, especially the hippocampus, and insulin transport to the brain is mainly accomplished through the blood-brain barrier. Secondly, several studies showed that insulin affects multiple neurotransmitters in favor of promoting memory and cognition status. Thirdly, multiple pathological studies showed that insulin and Alzheimer's disease share many common lesions in the brain, such as beta-amyloid plaques, amylin-Aβ plaques, hyper-phosphorylated tau protein, and brain atrophy, especially in the hippocampus. After recognizing the positive effect of insulin on cognitive status, and the harmful effect of insulin resistance on cognitive status, multiple studies were focused on the role of anti-diabetes medications in fighting dementia. Consequently, these studies showed a positive impact of oral anti-diabetes medication, as well as insulin in limiting the progression of dementia and promoting cognitive status. Moreover, their effects were also noticed on limiting the pathological lesions of Alzheimer's disease. Accordingly, we can consider type-2 diabetes mellitus as a risk factor for dementia and Alzheimer's disease. Therefore, this can be used on the pharmaceutical level by the promising implication of antidiabetics as a treatment of dementia and Alzheimer's disease or at least to limit its progression. However, multiple clinical studies should be dedicated to proving the true benefits of anti-diabetes medications in treating dementia before they can be used in reality.

Palliative care interventions in advanced dementia

BACKGROUND

Dementia is a chronic, progressive and ultimately fatal neurodegenerative disease. Advanced dementia is characterised by profound cognitive impairment, inability to communicate verbally and complete functional dependence. Usual care of people with advanced dementia is not underpinned universally by a palliative approach. Palliative care has focused traditionally on care of people with cancer, but for more than a decade, there have been calls worldwide to extend palliative care services to include all people with life-limiting illnesses in need of specialist care, including people with dementia. This review is an updated version of a review first published in 2016.

OBJECTIVES

To assess the effect of palliative care interventions in advanced dementia.

SEARCH METHODS

We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group's Specialised Register on 7 October 2020. ALOIS contains records of clinical trials identified from monthly searches of several major healthcare databases, trial registries and grey literature sources. We ran additional searches across MEDLINE (OvidSP), Embase (OvidSP), four other databases and two trial registries on 7 October 2020 to ensure that the searches were as comprehensive and as up-to-date as possible.

SELECTION CRITERIA

We searched for randomised (RCTs) and non-randomised controlled trials (nRCTs), controlled before-and-after studies and interrupted time series studies evaluating the impact of palliative care interventions for adults with advanced dementia of any type. Participants could be people with advanced dementia, their family members, clinicians or paid care staff. We included clinical interventions and non-clinical interventions. Comparators were usual care or another palliative care intervention. We did not exclude studies based on outcomes measured.

DATA COLLECTION AND ANALYSIS

At least two review authors (SW, EM, PC) independently assessed all potential studies identified in the search against the review inclusion criteria. Two authors independently extracted data from eligible studies. Where appropriate, we estimated pooled treatment effects in a fixed-effect meta-analysis. We assessed the risk of bias of included studies using the Cochrane Risk of Bias tool and the overall certainty of the evidence for each outcome using GRADE.

MAIN RESULTS

Nine studies (2122 participants) met the review inclusion criteria. Two studies were individually-randomised RCTs, six were cluster-randomised RCTs and one was a controlled before-and-after study. We conducted two separate comparisons: organisation and delivery of care interventions versus usual care (six studies, 1162 participants) and advance care planning interventions versus usual care (three studies, 960 participants). Two studies were carried out in acute hospitals and seven in nursing homes or long-term care facilities. For both comparisons, we found the included studies to be sufficiently similar to conduct meta-analyses. Changes to the organisation and delivery of care for people with advanced dementia may increase comfort in dying (MD 1.49, 95% CI 0.34 to 2.64; 5 studies, 335 participants; very low certainty evidence). However, the evidence is very uncertain and unlikely to be clinically significant. These changes may also increase the likelihood of having a palliative care plan in place (RR 5.84, 95% CI 1.37 to 25.02; 1 study, 99 participants; I² = 0%; very low certainty evidence), but again the evidence is very uncertain. Such interventions probably have little effect on the use of non-palliative interventions (RR 1.11, 95% CI 0.71 to 1.72; 2 studies, 292 participants; I² = 0%; moderate certainty evidence). They may also have little or no effect on documentation of advance directives (RR 1.46, 95% CI 0.50 to 4.25; 2 studies, 112 participants; I² = 52%; very low certainty evidence), or whether discussions take place about advance care planning (RR 1.08, 95% CI 1.00 to 1.18; 1 study, 193 participants; I² = 0%; very low certainty evidence) and goals of care (RR 2.36, 95% CI 1.00 to 5.54; 1 study, 13 participants; I² = 0%; low certainty evidence). No included studies assessed adverse effects. Advance care planning interventions for people with advanced dementia probably increase the documentation of advance directives (RR 1.23, 95% CI 1.07 to 1.41; 2 studies, 384; moderate certainty evidence) and the number of discussions about goals of care (RR 1.33, 95% CI 1.11 to 1.59; 2 studies, 384 participants; moderate certainty evidence). They may also slightly increase concordance with goals of care (RR 1.39, 95% CI 1.08 to 1.79; 1 study, 63 participants; low certainty evidence). On the other hand, they may have little or no effect on perceived symptom management (MD -1.80, 95% CI -6.49 to 2.89; 1 study, 67 participants; very low certainty evidence) or whether advance care planning discussions occur (RR 1.04, 95% CI 0.87 to 1.24; 1 study, 67 participants; low certainty evidence).

AUTHORS' CONCLUSIONS

The evidence on palliative care interventions in advanced dementia is limited in quantity and certainty. When compared to usual care, changes to the organisation and delivery of care for people with advanced dementia may lead to improvements in comfort in dying, but the evidence for this was of very low certainty. Advance care planning interventions, compared to usual care, probably increase the documentation of advance directives and the occurrence of discussions about goals of care, and may also increase concordance with goals of care. We did not detect other effects. The uncertainty in the evidence across all outcomes in both comparisons is mainly driven by imprecision of effect estimates and risk of bias in the included studies.