Dementia in China: epidemiology, clinical management, and research advances

Associations between resting heart rate and cognitive decline in Chinese oldest old individuals: a longitudinal cohort study

BACKGROUND

The trajectories of cognitive function in the oldest old individuals is unclear, and the relationship between resting heart rate (RHR) and cognitive decline is controversial.

METHODS

3300 participants who had cognitive function repeatedly measured 4 ~ 8 times were included, and latent class growth mixed models were used to identified the cognitive function trajectories. Cognitive decline was defined by the trajectory shapes, considering level and slope. After excluding individuals with sinus rhythm abnormal, 3109 subjects were remained and were divided into five groups by their RHR. Logistic regression models were used to estimate the relationship between RHR and cognitive decline.

RESULTS

Three distinct cognitive function trajectory groups were identified: high-stable (n = 1226), medium-decreasing (n = 1526), and rapid-decreasing (n = 357). Individuals of medium/rapid-decreasing group were defined as cognitive decline. Adjusting for covariates, the odds ratios (95% confidence intervals) of RHR sub-groups were 1.19 (0.69, 2.05), 1.27 (1.03, 1.56), 1.30 (1.01, 1.67) and 1.62 (1.07, 2.47) for those RHR < 60 bpm, 70 ~ 79 bpm, 80 ~ 89 bpm and > 90 bpm respectively, compared with those RHR 60 ~ 69 bpm. The interaction effect between RHR and physical activity (PA) on cognitive decline was found, and stratification analysis was presented that higher RHR would only show risk effects on cognitive decline in those with physical inactivity (P < 0.05 for all).

CONCLUSIONS

Our study demonstrates RHR more than 70 bpm present significant risk effect on cognitive decline, and this relationship is modified by PA. Elder population with physical inactivity and higher RHR should be paid more attention to prevent cognitive decline.

Vascular Risk Factors and Brain Health in Aging: Insights from a Community-Based Cohort Study

Background

The aging population and high rates of Alzheimer's disease (AD) create significant medical burdens, prompting a need for early prevention. Targeting modifiable risk factors like vascular risk factors (VRFs), closely linked to AD, may provide a promising strategy for intervention.

Objective

This study investigates how VRFs influence cognitive performance and brain structures in a community-based cohort.

Methods

In this cross-sectional study, 4,667 participants over 50 years old, drawn from the Beijing Ageing Brain Rejuvenation Initiative project, were meticulously examined. Cognitive function and VRFs (diabetes mellitus, hypertension, hyperlipidemia, obesity, and smoking), were comprehensively assessed through one-to-one interviews. Additionally, a subset of participants (n = 719) underwent MRI, encompassing T1-weighted and diffusion-weighted scans, to elucidate gray matter volume and white matter structural network organization.

Results

The findings unveil diabetes as a potent detriment to memory, manifesting in atrophy within the right supramarginal gyrus and diminished nodal efficiency and degree centrality in the right inferior parietal lobe. Hypertension solely impaired memory without significant structural changes. Intriguingly, individuals with comorbid diabetes and hypertension exhibited the most pronounced deficits in both brain structure and cognitive performance. Remarkably, hyperlipidemia emerged as a factor associated with enhanced cognition, and preservation of brain structure.

Conclusions

This study illuminates the intricate associations between VRFs and the varied patterns of cognitive and brain structural damage. Notably, the synergistic effect of diabetes and hypertension emerges as particularly deleterious. These findings underscore the imperative to tailor interventions for patients with distinct VRF comorbidities, especially when addressing cognitive decline and structural brain changes.

Insights on the Correlation between Mitochondrial Dysfunction and the Progression of Parkinson's Disease

The aetiology of a progressive neuronal Parkinson's disease has been discussed in several studies. However, due to the multiple risk factors involved in its development, such as environmental toxicity, parental inheritance, misfolding of protein, ageing, generation of reactive oxygen species, degradation of dopaminergic neurons, formation of neurotoxins, mitochondria dysfunction, and genetic mutations, its mechanism of involvement is still discernible. Therefore, this study aimed to review the processes or systems that are crucially implicated in the conversion of MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) into its lethal form, which directly blockades the performance of mitochondria, leading to the formation of oxidative stress in the dopaminergic neurons of substantia nigra pars compacta (SNpc) and resulting in the progression of an incurable Parkinson's disease. This review also comprises an overview of the mutated genes that are frequently associated with mitochondrial dysfunction and the progression of Parkinson's disease. Altogether, this review would help future researchers to develop an efficient therapeutic approach for the management of Parkinson's disease via identifying potent prognostic and diagnostic biomarkers.

An Alzheimer's Disease classification network based on MRI utilizing diffusion maps for multi-scale feature fusion in graph convolution

Graph convolutional networks (GCN) have been widely utilized in Alzheimer's disease (AD) classification research due to its ability to automatically learn robust and powerful feature representations. Inter-patient relationships are effectively captured by constructing patients magnetic resonance imaging (MRI) data as graph data, where nodes represent individuals and edges denote the relationships between them. However, the performance of GCNs might be constrained by the construction of the graph adjacency matrix, thereby leading to learned features potentially overlooking intrinsic correlations among patients, which ultimately causes inaccurate disease classifications. To address this issue, we propose an Alzheimer's disease Classification network based on MRI utilizing diffusion maps for multi-scale feature fusion in graph convolution. This method aims to tackle the problem of features neglecting intrinsic relationships among patients while integrating features from diffusion mapping with different neighbor counts to better represent patients and achieve an accurate AD classification. Initially, the diffusion maps method conducts diffusion information in the feature space, thus breaking free from the constraints of diffusion based on the adjacency matrix. Subsequently, the diffusion features with different neighbor counts are merged, and a self-attention mechanism is employed to adaptively adjust the weights of diffusion features at different scales, thereby comprehensively and accurately capturing patient characteristics. Finally, metric learning techniques enhance the similarity of node features within the same category in the graph structure and bring node features of different categories more distant from each other. This study aims to enhance the classification accuracy of AD, by providing an effective tool for early diagnosis and intervention. It offers valuable information for clinical decisions and personalized treatment. Experimentation on the publicly accessible Alzheimer's disease neuroimaging initiative (ADNI) dataset validated our method's competitive performance across various AD-related classification tasks. Compared to existing methodologies, our approach captures patient characteristics more effectively and demonstrates superior generalization capabilities.

Machine learning in Alzheimer's disease drug discovery and target identification

Alzheimer's disease (AD) stands as a formidable neurodegenerative ailment that poses a substantial threat to the elderly population, with no known curative or disease-slowing drugs in existence. Among the vital and time-consuming stages in the drug discovery process, disease modeling and target identification hold particular significance. Disease modeling allows for a deeper comprehension of disease progression mechanisms and potential therapeutic avenues. On the other hand, target identification serves as the foundational step in drug development, exerting a profound influence on all subsequent phases and ultimately determining the success rate of drug development endeavors. Machine learning (ML) techniques have ushered in transformative breakthroughs in the realm of target discovery. Leveraging the strengths of large dataset analysis, multifaceted data processing, and the exploration of intricate biological mechanisms, ML has become instrumental in the quest for effective AD treatments. In this comprehensive review, we offer an account of how ML methodologies are being deployed in the pursuit of drug discovery for AD. Furthermore, we provide an overview of the utilization of ML in uncovering potential intervention strategies and prospective therapeutic targets for AD. Finally, we discuss the principal challenges and limitations currently faced by these approaches. We also explore the avenues for future research that hold promise in addressing these challenges.

Bridging integrator 1 fragment accelerates tau aggregation and propagation by enhancing clathrin-mediated endocytosis in mice

The bridging integrator 1 (BIN1) gene is an important risk locus for late-onset Alzheimer's disease (AD). BIN1 protein has been reported to mediate tau pathology, but the underlying molecular mechanisms remain elusive. Here, we show that neuronal BIN1 is cleaved by the cysteine protease legumain at residues N277 and N288. The legumain-generated BIN1 (1-277) fragment is detected in brain tissues from AD patients and tau P301S transgenic mice. This fragment interacts with tau and accelerates its aggregation. Furthermore, the BIN1 (1-277) fragment promotes the propagation of tau aggregates by enhancing clathrin-mediated endocytosis (CME). Overexpression of the BIN1 (1-277) fragment in tau P301S mice facilitates the propagation of tau pathology, inducing cognitive deficits, while overexpression of mutant BIN1 that blocks its cleavage by legumain halts tau propagation. Furthermore, blocking the cleavage of endogenous BIN1 using the CRISPR/Cas9 gene-editing tool ameliorates tau pathology and behavioral deficits. Our results demonstrate that the legumain-mediated cleavage of BIN1 plays a key role in the progression of tau pathology. Inhibition of legumain-mediated BIN1 cleavage may be a promising therapeutic strategy for treating AD.

Prediction of survival of persons with advanced dementia using the advanced dementia prognostic tool: A 2-year prospective study

BACKGROUND

In this prospective study, we evaluated the usefulness of the advanced dementia prognostic tool (ADEPT) for estimating the 2-year survival of persons with advanced dementia (AD) in China.

METHODS

The study predicted the 2-year mortality of 115 persons with AD using the ADEPT score.

RESULTS

In total, 115 persons with AD were included in the study. Of these persons, 48 died. The mean ADEPT score was 13.0. The AUROC for the prediction of the 2-year mortality rate using the ADEPT score was 0.62. The optimal threshold of the ADEPT score was 11.2, which had an AUROC of 0.63, specificity of 41.8, and sensitivity of 83.3.

CONCLUSIONS

The ADEPT score based on a threshold of 11.2 may serve as a prognostic tool to determine the 2-year survival rate of persons with AD in Chongqing, China. However, further studies are needed to explore the nature of this relationship.

Comorbidity of Dementia: A Cross-Sectional Study of PUMCH Dementia Cohort

BACKGROUND

Comorbidities reduce quality of life for people with dementia and caregivers. Some comorbidities share a genetic basis with dementia.

OBJECTIVE

The objective of this study is to assess comorbidity in patients with different dementia subtypes in order to better understand the pathogenesis of dementias.

METHODS

A total of 298 patients with dementia were included. We collected some common comorbidities. We analyzed the differences in comorbidities among patients with dementia according to clinical diagnosis, age of onset (early-onset: < 65 and late-onset: ≥65 years old) and apolipoprotein (APOE) genotypes by using the univariate and multivariate approaches.

RESULTS

Among 298 participants, there were 183 Alzheimer's disease (AD), 40 vascular dementia (VaD), 37 frontotemporal dementia (FTLD), 20 Lewy body dementia (LBD), and 18 other types of dementia. Based on age of onset, 156 cases had early-onset dementia and 142 cases had late-onset dementia. The most common comorbidities observed in all dementia patients were hyperlipidemia (68.1%), hypertension (39.9%), insomnia (21.1%), diabetes mellitus (19.5%), and hearing impairment (18.1%). The prevalence of hypertension and cerebrovascular disease was found to be higher in patients with VaD compared to those with AD (p = 0.002, p < 0.001, respectively) and FTLD (p = 0.028, p = 0.004, respectively). Additionally, patients with late-onset dementia had a higher burden of comorbidities compared to those with early-onset dementia. It was observed that APOE ɛ4/ɛ4 carriers were less likely to have insomnia (p = 0.031).

CONCLUSIONS

Comorbidities are prevalent in patients with dementia, with hyperlipidemia, hypertension, insomnia, diabetes, and hearing impairment being the most commonly observed. Comorbidity differences existed among different dementia subtypes.

Alpha 2-Macroglobulin Polymorphisms and Susceptibility to Alzheimer's Disease: A Comprehensive Meta-Analysis Based on 62 Studies

Background

The relationship between alpha 2-macroglobulin (A2M) gene and Alzheimer's disease (AD) has been widely studied across populations; however, the results are inconsistent.

Objective

This study aimed to evaluate the association of A2M gene with AD by the application of meta-analysis.

Methods

Relevant studies were identified by comprehensive searches. The quality of each study was assessed using the Newcastle-Ottawa Scale. Allele and genotype frequencies were extracted from each of the included studies. Odds ratio (OR) with corresponding 95% confidence intervals (CI) was calculated using a random-effects or fixed-effects model. The Cochran Q statistic and I2 metric was used to evaluate heterogeneity, and Egger's test and Funnel plot were used to assess publication bias.

Results

A total of 62 studies were identified and included in the current meta-analysis. The G allele of rs226380 reduced AD risk (OR: 0.64, 95% CI: 0.47-0.87, pFDR = 0.012), but carrier with the TT genotype was more likely to develop AD in Asian populations (OR: 1.56, 95% CI: 1.12-2.19, pFDR = 0.0135). The V allele of the A2M-I/V (rs669) increased susceptibility to AD in female population (OR, 95% CI: 2.15, 1.38-3.35, pFDR = 0.0024); however, the II genotype could be a protective factor in these populations (OR, 95% CI: 0.43, 0.26-0.73, pFDR = 0.003). Sensitivity analyses confirmed the reliability of the original results.

Conclusions

Existing evidence indicate that A2M single nucleotide polymorphisms (SNPs) may be associated with AD risk in sub-populations. Future studies with larger sample sizes will be necessary to confirm the results.

The effects of heatwave on cognitive impairment among older adults: Exploring the combined effects of air pollution and green space

The association between heatwaves and cognitive impairment in older adults, especially the joint effect of air pollution and green space on this association, remains unknown. The present cohort study used data from waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) from 2008 to 2018. Heatwaves were defined as having daily maximum temperature ≥ 92.5th, 95th and 97.5th percentile that continued at least two, three and four days, measured as the one-year heatwave days prior to the participants' incident cognitive impairment. Data on the annual average air pollutant concentrations of fine particulate matter (PM2.5) and ozone (O3) as well as green space exposure (according to the Normalized Difference Vegetation Index (NDVI)) were collected. Time-varying Cox proportional hazards models were constructed to examine the independent effect of heatwaves on cognitive impairment and the combined effect of heatwaves, air pollution, and green space on cognitive impairment. Potential multiplicative interactions were examined by adding a product term of air pollutants and NDVI with heatwaves in the models. The relative excess risk due to interaction (RERI) was calculated to reflect additive interactions. We found that heatwave exposure was associated with higher risks of cognitive impairment, with hazard ratios (HRs) and 95 % confidence intervals (CIs) ranging from 1.035 (95 % CI: 1.016-1.055) to 1.058 (95 % CI: 1.040-1.075). We observed a positive interaction of PM2.5 concentrations, O3 concentrations, lack of green space, and heatwave exposure on a multiplicative scale (HRs for product terms >1). Furthermore, we found a synergistic interaction of PM2.5 concentrations, O3, lack of green space, and heatwave exposure on an additive scale, with RERIs >0. These results suggest that extreme heat exposure may be a potential risk factor for cognitive impairment in older adults. Additionally, coexposure to air pollution and lack of green space exacerbated the adverse effects of heatwaves on cognitive function.

SNAP25 is a potential target for early stage Alzheimer's disease and Parkinson's disease

BACKGROUND

Alzheimer's disease (AD) and Parkinson's disease (PD), two common irreversible neurodegenerative diseases, share similar early stage syndromes, such as olfaction dysfunction. Yet, the potential comorbidity mechanism of AD and PD was not fully elucidated.

METHODS

The gene expression profiles of GSE5281 and GSE8397 were downloaded from the Gene Expression Omnibus (GEO) database. We utilized a series of bioinformatics analyses to screen the overlapped differentially expressed genes (DEGs). The hub genes were further identified by the plugin CytoHubba of Cytoscape and validated in the hippocampus (HIP) samples of APP/PS-1 transgenic mice and the substantial nigra (SN) samples of A53T transgenic mice by real-time quantitative polymerase chain reaction (RT-qPCR). Meanwhile, the expression of the target genes in the olfactory epithelium/bulb was detected by RT-qPCR. Finally, molecular docking was used to screen potential compounds for the target gene.

RESULTS

One hundred seventy-four overlapped DEGs were identified in AD and PD. Five of the top ten enrichment pathways mainly focused on the synapse. Five hub genes were identified and further validated. As a common factor in AD and PD, the changes of synaptosomal-associated protein 25 (SNAP25) mRNA in olfactory epithelium/bulb were significantly decreased and had a strong association with those in the HIP and SN samples. Pazopanib was the optimal compound targeting SNAP25, with a binding energy of - 9.2 kcal/mol.

CONCLUSIONS

Our results provided a theoretical basis for understanding the comorbidity mechanism of AD and PD and highlighted that SNAP25 in the olfactory epithelium may serve as a potential target for early detection and intervention in both AD and PD.

Speed of aging of populations by socioeconomics subgroups in China: A cross-sectional study of cognitive performance

Objectives

Although there is an association between socioeconomic factors and cognition, there are shortcomings in terms of examining the age of onset of decline between people with varying social backgrounds. This study aims to present the disparities in cognitive performance among older adults by simultaneously integrating health status, social characteristics, and age into an understandable metric.

Study design

This study is cross-sectional.

Methods

A sample of 3422 adults aged at least 60 was utilised from the 2015 wave of the China Health and Nutrition Survey to analyse the trajectories of cognitive ageing through the Characteristics approach. This approach generates an age-differential schedule whereby, as a hypothetical example, the cognition level Z of an individual aged 60 who has not completed schooling is demonstrated at age 66 by someone who has completed secondary schooling.

Results

There was an increasing advantage with cognitive performance as the level of education completed increased; men aged 61.9 with a primary level of schooling and those aged 67.8 with postsecondary qualifications exhibit the same cognition performance as those aged 60 with no completed schooling. The observation also suggested that cognition advantages diminish through age. In terms of income, the age-differential schedule follows a similar pattern. albeit lower outcomes, to that of education differentials.

Conclusion

When comparing education and income levels and their respective impacts on cognitive functioning, the former has been noted to have a larger effect. Education's effect has continuity in that it can influence opportunities until later ages.

Critical thinking of Alzheimer's transgenic mouse model: current research and future perspective

Transgenic models are useful tools for studying the pathogenesis of and drug development for Alzheimer's Disease (AD). AD models are constructed usually using overexpression or knock-in of multiple pathogenic gene mutations from familial AD. Each transgenic model has its unique behavioral and pathological features. This review summarizes the research progress of transgenic mouse models, and their progress in the unique mechanism of amyloid-β oligomers, including the first transgenic mouse model built in China based on a single gene mutation (PSEN1 V97L) found in Chinese familial AD. We further summarized the preclinical findings of drugs using the models, and their future application in exploring the upstream mechanisms and multitarget drug development in AD.

Neuroprotective evaluation of diospyrin against drug-induced Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease linked to memory impairment. A current investigation was performed to assess the neuroprotective effect of Diospyrin, a novel therapeutic agent, for the curing of Alzheimer's disease. For this purpose, in-vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory assays and antioxidant studies were conducted, whereas in-vivo studies involved different behavioral animal models tests such as elevated plus maze (EPM), morris water maze (MWM) and paddling Y-maze test. Results of the in-vitro analysis showed IC50 values of 95 μg/mL for AChE and 110 μg/mL for BChE as compared to the standard drug donepezil (IC50: 95 & 85 μg/mL, respectively). DPPH antioxidant assay showed a maximum of 72.85% inhibition (IC50: 139.74 μg/mL) of DPPH-free radicals at the highest concentration of 1000 μg/mL as compared to the ascorbic acid (IC50: 13.72 μg/mL). Moreover, the in-vivo analysis revealed that diospyrin treatment demonstrated gradual betterment in memory and enhanced motor functionality. On the other hand, the computational analysis also showed that the diospyrin had exceptional binding affinities for both AChE and BChE enzymes. In the net shell, it may be deduced that our compound diospyrin could be a valuable drug candidate in managing neurodegenerative disorders like AD.

Influence of Gender on Tau Precipitation in Alzheimer's Disease According to ATN Research Framework

Tau proteins accumulation and their spreading pattern were affected by gender in cognitive impairment patients, especially in the progression of Alzheimer's disease (AD). However, it was unclear whether the gender effects for tau deposition influenced by amyloid deposition. The aim of this study was to investigate gender differences for tau depositions in Aβ positive (A+) subjects. In this study, tau and amyloid positron emission tomography images, structural magnetic resonance imaging images, and demographic information were collected from 179 subjects in Alzheimer's Disease Neuroimaging Initiative (ADNI) database and 63 subjects from Huashan Hospital. Subjects were classified as T+ or T- according to the presence or absence of tau (T) biomarkers. We used two-sample t test and one-way analysis of variance test to analyze the effect of gender with adjusting for age, years of education, and Minimum Mental State Examination. In the ADNI cohort, we found differences in Tau deposition in fusiform gyrus, inferior temporal gyrus, middle temporal gyrus and parahippocampal gyrus between the female T+ (FT+) and male T+ (MT+) groups (p < 0.05). Tau deposition did not differ significantly between female T- (FT-) and male T- (MT-) subjects (p > 0.05). In the Huashan Hospital cohort, there was no difference in Tau deposition between FT+ and MT+ (p > 0.05). The results show that tau depositions significantly increased in females in above brain regions. Our findings suggest that tau deposition is influenced by gender in the A+ subjects. This result has important clinical implications for the development of gender-guided early interventions for patients with both Tau and Amyloid depositions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43657-022-00076-9.

High prevalence of subjective cognitive decline in older Chinese adults: a systematic review and meta-analysis

Background

Subjective cognitive decline (SCD) is considered a preclinical stage of Alzheimer's disease. However, reliable prevalence estimates of SCD in the Chinese population are lacking, underscoring the importance of such metrics for policymakers to formulate appropriate healthcare strategies.

Objective

To systematically evaluate SCD prevalence among older Chinese adults.

Methods

PubMed, Web of Science, The Cochrane Library, Embase, CNKI, Wanfang, VIP, CBM, and Airiti Library databases were searched for studies on SCD in older Chinese individuals published before May 2023. Two investigators independently screened the literature, extracted the information, and assessed the bias risk of the included studies. A meta-analysis was then conducted using Stata 16.0 software via a random-effects model to analyze SCD prevalence in older Chinese adults.

Results

A total of 17 studies were included (n = 31,782). The SCD prevalence in older Chinese adults was 46.4% (95% CI, 40.6-52.2%). Further, subgroup analyzes indicated that SCD prevalence was 50.8% in men and 58.9% among women. Additionally, SCD prevalence in individuals aged 60-69, 70-79, and ≥ 80 years was 38.0, 45.2, and 60.3%, respectively. Furthermore, SCD prevalence in older adults with BMI <18.5, 18.5-24.0, and > 24.0 was 59.3, 54.0, and 52.9%, respectively. Geographically, SCD prevalence among older Chinese individuals was 41.3% in North China and 50.0% in South China. In terms of residence, SCD prevalence was 47.1% in urban residents and 50.0% among rural residents. As for retired individuals, SCD prevalence was 44.2% in non-manual workers and 49.2% among manual workers. In the case of education, individuals with an education level of "elementary school and below" had an SCD prevalence rate of 62.8%; "middle school, "52.4%; "high school, "55.0%; and "college and above, "51.3%. Finally, SCD prevalence was lower among married individuals with surviving spouses than in single adults who were divorced, widowed, or unmarried.

Conclusion

Our systematic review and meta-analysis identified significant and widespread SCD prevalence in the older population in China. Therefore, our review findings highlight the urgent requirement for medical institutions and policymakers across all levels to prioritize and rapidly develop and implement comprehensive preventive and therapeutic strategies for SCD.Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023406950, identifier: CRD42023406950.

A metabolism-functional connectome sparse coupling method to reveal imaging markers for Alzheimer's disease based on simultaneous PET/MRI scans

Abnormal glucose metabolism and hemodynamic changes in the brain are closely related to cognitive function, providing complementary information from distinct biochemical and physiological processes. However, it remains unclear how to effectively integrate these two modalities across distinct brain regions. In this study, we developed a connectome-based sparse coupling method for hybrid PET/MRI imaging, which could effectively extract imaging markers of Alzheimer's disease (AD) in the early stage. The FDG-PET and resting-state fMRI data of 56 healthy controls (HC), 54 subjective cognitive decline (SCD), and 27 cognitive impairment (CI) participants due to AD were obtained from SILCODE project (NCT03370744). For each participant, the metabolic connectome (MC) was constructed by Kullback-Leibler divergence similarity estimation, and the functional connectome (FC) was constructed by Pearson correlation. Subsequently, we measured the coupling strength between MC and FC at various sparse levels, assessed its stability, and explored the abnormal coupling strength along the AD continuum. Results showed that the sparse MC-FC coupling index was stable in each brain network and consistent across subjects. It was more normally distributed than other traditional indexes and captured more SCD-related brain areas, especially in the limbic and default mode networks. Compared to other traditional indices, this index demonstrated best classification performance. The AUC values reached 0.748 (SCD/HC) and 0.992 (CI/HC). Notably, we found a significant correlation between abnormal coupling strength and neuropsychological scales (p < .05). This study provides a clinically relevant tool for hybrid PET/MRI imaging, allowing for exploring imaging markers in early stage of AD and better understanding the pathophysiology along the AD continuum.

Analysis of Effect of Intensity of Aerobic Exercise on Cognitive and Motor Functions and Neurotrophic Factor Expression Patterns in an Alzheimer's Disease Rat Model

The effect of aerobic exercise at different intensities on Alzheimer's disease (AD) still remains unclear. We investigated the effect of aerobic exercise at different intensities on cognitive and motor functions and neurotrophic factor expression. Thirty-two AD-induced rats were randomly assigned to control (CG), low-intensity (Group I), medium-intensity (Group II), and high-intensity (Group III) exercise groups. Each group, except for the CG, performed aerobic exercise for 20 min a day five times a week. After performing aerobic exercise for 4 weeks, their cognitive and motor functions and neurotrophic factor expression patterns were analyzed and compared between the groups. All variables of cognitive and motor functions and neurotrophic factor expression were significantly improved in Groups I, II, and III compared to those in the CG (p < 0.05). Among the neurotrophic factors, brain-derived neurotrophic factor (BDNF) expression was significantly improved in Group III compared to that in Groups I and II (p < 0.05). In the intra-group comparison of cognitive and motor functions, no significant difference was observed in CG, but the aerobic exercise groups showed improvements. Only Group III showed a significant improvement in the time it took to find eight food items accurately (p < 0.05). Aerobic exercise improved the cognitive and motor functions and neurotrophic factor expression patterns in the AD-induced rat model, with high-intensity aerobic exercise having greater effects on cognitive function and BDNF expression.

Effectiveness of the Stress Process Model-Based Program in Dementia Caregiving (DeCare-SPM) for Family Caregivers: A Study Protocol for a Randomized Controlled Trial

This paper aims to describe a randomized controlled trial protocol evaluating the effectiveness, cost, and process of a stress process model-based program in dementia caregiving (DeCare-SPM) for family caregivers. Family caregivers of individuals with dementia will be recruited from memory clinics and community settings and randomly assigned to either DeCare-SPM or usual care. DeCare-SPM comprises three face-to-face sessions (ie, problem-based coping, emotion-based coping, meaning-based coping), and a fourth session (ie, social support) including weekly telephone-based consultation for four weeks and then monthly face-to-face boosters. Outcomes will be measured at baseline (T0), and at one (T1), three (T2), and six months (T3). The primary outcome is positive aspects of caregiving and secondary outcomes are caregiving (ie, sense of competence, caregiver burden, social support, anxiety, depression, and quality of life), dementia-related (ie, care dependency, neuropsychiatric symptoms, and quality of life), and stress-related biomarkers of blood and saliva. In addition, process and economic evaluations will be performed. Mixed-effects models will be used to assess intervention effects. Content analysis will be performed on the qualitative data. This paper described the protocol for comprehensive evaluation of the effectiveness, cost, and process of the theory-driven DeCare-SPM to inform how and why interventions work. It highlights the need to reduce challenges and enhance the positive aspects of dementia care. The DeCare-SPM will provide evidence-based insights into how to support and empower family caregivers in their important roles, thereby, leading to improved dementia care.

Threats to personhood from within the family? A study of family caregivers of people with dementia in the Chinese context

BACKGROUND AND OBJECTIVES

Dementia care creates ethical and legal dilemmas due to the struggle to balance the quality of care and personhood. Disagreement and conflict in caregiving relationships are common. However, limited attention has been given to particular stressful circumstances, such as care practice and decision disagreements. Moreover, the cultural context of personhood has been overlooked. This study drew on Hong Kong family caregivers' reports of their cargiving practice and disagreements with care recipients about care-related decisions and their implications for personhood to identify person-centered family care support needs.

RESEARCH DESIGN AND METHODS

We conducted 18 semi-structured interviews with family caregivers of people with dementia in Hong Kong, China. Participants were asked to share their family dementia caregiving experience and practice, specifically regarding decisions and practices that elicited disagreement. We used thematic analysis to analyze data generated from interviews.

RESULTS

Six caregiver practices were identified: exchange for mutual agreement, a foot-in-the-door approach, acceptance of requests/behaviors contrary to the caregivers' views, infantilization, treachery, and exclusion and imposition.

DISCUSSION AND IMPLICATIONS

These findings highlight the importance of providing support and guidelines for person-centered care to promote personhood in the family caregiving context in dementia care.

Dementia increases the risk of death in stroke patients: A retrospective cohort-based risk score model study

BACKGROUND

The relationship between dementia and the mortality of stroke is a significant concern for patients and careers. However, there are few research about it in China and a lack of reliable data on the risk of dementia. We aim to analyze and compare the risk of death in stroke patients with and without dementia. Further investigation into the predictive value of dementia for stroke death.

METHODS

All patients with stroke who were identified among residents of Ningxia, between January 1, 2014 to December 31, 2021, set death or May 22, 2022 as the observation endpoint. All patients were screened by 1:4 propensity score matching (PSM). The association between dementia and all-cause mortality was evaluated using Cox regression with survival time. Evaluation of the predictive value of dementia using decision curve analysis (DCA) and clinical impact curve (CIC) curves.

RESULT

Mortality of stroke with dementia is 45.4% and without dementia is 13.8%, further calculated one-year mortality is higher in the patients with dementia than without dementia (17.3%vs. 5.4%, p < 0.001). Stroke patients with dementia had a 3.74 times higher risk of death (95% CI = 3.29,4.26) and had a shorter survival time than those without dementia. Dementia was an independent predictor of death in all models (hazard ratio [HR]=3.77,95%CI: 3.31-4.30, p < 0.001). DCA and CIC curves indicated that dementia has a high value in predicting the risk of death in stroke patients.

CONCLUSION

Dementia is an independent risk factor for death and reduces survival time in stroke patients.

Prevalence and risk factors for subjective cognitive decline and the correlation with objective cognition among community-dwelling older adults in China: Results from the Hubei memory and aging cohort study

INTRODUCTION

The prevalence and risk factors for subjective cognitive decline (SCD) and its correlation with objective cognition decline (OCD) among community-dwelling older adults is inconsistent.

METHODS

Older adults underwent neuropsychological and clinical evaluations to reach a consensus on diagnoses.

RESULTS

This study included 7486 adults without mild cognitive impairment and dementia (mean age: 71.35 years [standard deviation = 5.40]). The sex-, age-, and residence-adjusted SCD prevalence was 58.33% overall (95% confidence interval: 58.29% to 58.37%), with higher rates of 61.25% and 59.87% in rural and female subgroups, respectively. SCD global and OCD language, SCD memory and OCD global, SCD and OCD memory, and SCD and OCD language were negatively correlated in fully adjusted models. Seven health and lifestyle factors were associated with an increased risk for SCD.

DISCUSSION

SCD affected 58.33% of older adults and may indicate concurrent OCD, which should prompt the initiation of preventative intervention for dementia.

HIGHLIGHTS

SCD affects 58.33% of older adults in China. SCD may indicate concurrent objective cognitive decline. Difficulty finding words and memory impairments may indicate a risk for AD. The presence of SCD may prompt preventative treatment initiation of MCI or dementia. Social network factors may be initial targets for the early prevention of SCD.

Association between self-perception of aging and cognitive function in Chinese older adults: The mediation effect of health behaviors

OBJECTIVE

To investigate the association between self-perception of aging (SPA) and cognitive function in Chinese older adults, and to explore the mediating role of health behaviors.

METHODS

This study included 5,445 Chinese older adults from the 2018 wave of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Correlation, linear regression and mediation effect analysis were employed to evaluate the association.

RESULTS

SPA is significantly related to the health behaviors (r = 0.160, P < 0.01) and cognition (r = 0.086, P < 0.01), and health behaviors exhibited a positive correlation with cognition (r = 0.179, P < 0.01). SPA and health behaviors significantly impacted cognition (β = 0.032, P = 010; β = 0.103, P < 0.001). Health behaviors partially mediated the effect of SPA on cognitive function, accounting for 27.12 % of the total effect.

CONCLUSION

Health behaviors mediate the association between SPA and cognitive function. Healthcare providers should prioritize addressing SPA of older adults and encourage them to engage in health behaviors for cognitive health.

Rutaecarpine Mitigates Cognitive Impairment by Balancing Mitochondrial Function Through Activation of the AMPK/PGC1α Pathway

Mitochondrial dysfunction plays a fundamental role in the pathogenesis of cognitive deficit. Rutaecarpine (Rut) is a natural alkaloid with anti-inflammatory and antioxidant properties. This study explored whether Rut treatment could enhance cognitive function by improving mitochondrial function and examined the potential mechanisms underlying this ameliorative effect. We used the Morris water maze and Y-maze tests to evaluate the behavioral effects of Rut in a mouse model of cognitive impairment induced by subcutaneous injection of D-galactose (D-gal). Furthermore, we assessed the effects of Rut on mitochondrial function using cell viability assays, flow cytometry, western blotting, biochemical analysis, and immunochemical techniques in vivo and in vitro. The results indicated Rut treatment attenuated cognitive deficits and mitochondrial dysfunction in the mouse model. Similarly, it maintained the balance of mitochondrial dynamics in neurocytes and reduced oxidative stress and mitochondrial apoptosis in the HT22 cell model. Moreover, we found that these protective effects were dependent on the activation of the AMP-activated protein kinase/proliferator-activated receptor gamma coactivator 1-alpha (AMPK/PGC1α) signaling pathway. Our data indicate that Rut treatment are sensitive to reversal cognitive deficits and mitochondrial dysfunction induced by D-gal; this suggests that Rut is a promising mitochondria-targeted therapeutic agent for treating cognitive impairment.

The application of saccades to assess cognitive impairment among older adults: a systematic review and meta-analysis

BACKGROUND

Saccade is a novel and feasible method for cognition assessment and has potential to screen older people with cognitive impairment.

OBJECTIVES

To systematically summarize the evidence and determine whether different saccade parameters can effectively identify patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD).

METHODS

English and Chinese databases were searched until 19 April 2022. Studies analyzing saccade parameters in older adults with normal cognition, MCI, or AD were included. Two researchers independently performed the screening, data extraction, and quality appraisal. Meta-analyses were conducted and standard mean differences and 95% confidence intervals were estimated with a random effects model.

RESULTS

Thirty-five studies were included, and 26 studies were pooled for the meta-analysis. The results demonstrated that patients with cognitive impairment exhibited longer latency and lower accuracy rates in the prosaccade and antisaccade tasks, along with lower corrected error rates in the antisaccade tasks. However, the pooled results for antisaccades were more stable, providing the ability to distinguish patients with cognitive impairment among older adults. The results of the subgroup analyses revealed that only the accuracy rates of the antisaccades differed significantly between people with MCI and AD. Regarding the differences between older adults with normal cognition and those with MCI, the effect sizes of latency and the accuracy rates of saccades as well as the corrected error rates of antisaccades were significant.

CONCLUSIONS

Saccades, especially antisaccades, are a potential screening and assessment tool for distinguishing older adults with MCI or AD from those with normal cognition.

Effects of dance therapy on cognitive and mental health in adults aged 55 years and older with mild cognitive impairment: a systematic review and meta-analysis

BACKGROUND

Individuals with mild cognitive impairment are at high risk of developing dementia. Dance therapy has promising applications in delaying cognitive decline. However, the effectiveness of dance therapy for older adults with mild cognitive impairment is unclear. The objective of this review was to evaluate the effectiveness of dance therapy on global cognitive function, specific cognitive subdomains, quality of life, and mental health in older adults with mild cognitive impairment to enrich health management strategies for dementia.

METHODS

Electronic databases and grey literature were searched from inception up to September 23, 2023. The language was limited to English and Chinese. Relevant studies were screened and assessed for risk of bias. A meta-analysis and subgroup analyses stratified by measurement instrument, dance type, intervention duration, and frequency were conducted using the STATA 16.0 software. This review was conducted in accordance with the PRISMA guidelines.

RESULTS

Ten studies involving 984 participants aged 55 years and over who met the eligibility criteria were included. Dance therapy significantly improved global cognitive function, memory, executive function, attention, language, and mental health (i.e., depression and neuropsychiatric symptoms). However, the effects of dance therapy on processing speed, visuospatial ability, and quality of life in older adults with mild cognitive impairment remain inconclusive. Moreover, dance interventions of longer duration (> 3 months) improved global cognition more than shorter interventions.

CONCLUSION

This review reported that dance therapy was effective in improving global cognitive function, memory, executive function, attention, language, and mental health (i.e., depression and neuropsychiatric symptoms). Hence, it may be an effective non-pharmacological complementary treatment for older adults with mild cognitive impairment.

Predicting mild cognitive impairment among Chinese older adults: a longitudinal study based on long short-term memory networks and machine learning

Background

Mild cognitive impairment (MCI) is a transitory yet reversible stage of dementia. Systematic, scientific and population-wide early screening system for MCI is lacking. This study aimed to construct prediction models using longitudinal data to identify potential MCI patients and explore its critical features among Chinese older adults.

Methods

A total of 2,128 participants were selected from wave 5-8 of Chinese Longitudinal Healthy Longevity Study. Cognitive function was measured using the Chinese version of Mini-Mental State Examination. Long- short-term memory (LSTM) and three machine learning techniques, including 8 sociodemographic features and 12 health behavior and health status features, were used to predict individual risk of MCI in the next year. Performances of prediction models were evaluated through receiver operating curve and decision curve analysis. The importance of predictors in prediction models were explored using Shapley Additive explanation (SHAP) model.

Results

The area under the curve values of three models were around 0.90 and decision curve analysis indicated that the net benefit of XGboost and Random Forest were approximate when threshold is lower than 0.8. SHAP models showed that age, education, respiratory disease, gastrointestinal ulcer and self-rated health are the five most important predictors of MCI.

Conclusion

This screening method of MCI, combining LSTM and machine learning, successfully predicted the risk of MCI using longitudinal datasets, and enables health care providers to implement early intervention to delay the process from MCI to dementia, reducing the incidence and treatment cost of dementia ultimately.

Association between body mass index and cognitive impairment in Chinese older adults

Background

The association between body mass index (BMI) and the risk of cognitive impairment remains uncertain. Relatively few studies have analyzed the dose-response relationship between BMI and cognitive impairment. This article utilized nationally representative longitudinal data to assess the association between BMI and cognitive impairment in Chinese older adults.

Objective

The present study aimed to analyze the association between BMI and cognitive impairment in Chinese older people, including an investigation of gender differences and the dose-response relationship.

Methods

Data were obtained from the China Health and Retirement Longitudinal Study database in 2015 and 2018. The present study used logistic regression to analyze the relationship between baseline BMI and cognitive impairment, and adopted a restricted cubic spline model to plot dose-response curves for baseline BMI and prevalence of risk of cognitive impairment.

Results

The mean BMI of the survey population was 23.48 ± 3.66 kg/m2, and the detection rate of cognitive impairment was 34.2%. Compared to the normal weight group (18.5 ≤ BMI < 23.9 kg/m2), the odds ratio (OR) for cognitive impairment was 1.473 (95% CI: 1.189-1.823) in the underweight group (BMI < 18.5 kg/m2), whereas the corresponding OR was 0.874 (95% CI: 0.776-0.985) for the overweight or obese group (BMI ≥ 24.0 kg/m2) after adjusting for confounders. Gender subgroup analysis showed that overweight or obese older women were less likely to develop cognitive impairment (OR = 0.843; 95% CI: 0.720-0.987). The results of the restricted cubic spline analysis revealed a curvilinear L-shaped relationship between BMI and the risk of cognitive impairment (P non-linearity <0.05). In particular, the risk of cognitive impairment was higher at a lower baseline BMI. In contrast, BMI in the range of 23.2-27.8 kg/m2 was associated with a decreased risk of cognitive impairment.

Conclusion

BMI is a dose-dependent related factor for cognitive impairment in Chinese older adults. Being underweight is a risk factor for the development of cognitive impairment, while being overweight or obese is less likely to have cognitive impairment, particularly in female older people. Keeping BMI ranging from 23.2-27.8 kg/m2 in older adults can help maintain cognitive function.

IL-33/ST2 Axis: A Potential Therapeutic Target in Neurodegenerative Diseases

Interleukin 33 (IL-33) belongs to the IL-1 family and is localized in the nucleus. IL-33 is primarily composed of three distinct domains, namely the N-terminal domain responsible for nuclear localization, the intermediate sense protease domain, and the C-terminal cytokine domain. Its specific receptor is the suppression of tumorigenicity 2 (ST2), which is detected in serum-stimulated fibroblasts and oncogenes. While most other cytokines are actively produced in cells, IL-33 is passively produced in response to tissue damage or cell necrosis, thereby suggesting its role as an alarm following cell infection, stress, or trauma. IL-33 plays a crucial role in congenital and acquired immunity, which assists in the response to environmental stress and maintains tissue homeostasis. IL-33/ST2 interaction further produces many pro-inflammatory cytokines. Moreover, IL-33 is crucial for central nervous system (CNS) homeostasis and the pathogenic mechanisms underlying CNS degenerative disorders. The present work summarizes the structure of IL-33, its fundamental activities, and its role in immunoregulation and neurodegenerative diseases. Therefore, this work proposes that IL-33 may play a role in the pathogenic mechanism of diseases and can be used in the development of treatment strategies.

An integrated neuroimaging-omics approach for the gut-brain communication pathways in Alzheimer's disease

A key role of the gut microbiota in the pathogenesis of neurodegenerative diseases, such as Alzheimer's disease (AD), has been identified over the past decades. Increasing clinical and preclinical evidence implicates that there is bidirectional communication between the gut microbiota and the central nervous system (CNS), which is also known as the microbiota-gut-brain axis. Nevertheless, current knowledge on the interplay between gut microbiota and the brain remains largely unclear. One of the primary mediating factors by which the gut microbiota interacts with the host is peripheral metabolites, including blood or gut-derived metabolites. However, mechanistic knowledge about the effect of the microbiome and metabolome signaling on the brain is limited. Neuroimaging techniques, such as multi-modal magnetic resonance imaging (MRI), and fluorodeoxyglucose-positron emission tomography (FDG-PET), have the potential to directly elucidate brain structural and functional changes corresponding with alterations of the gut microbiota and peripheral metabolites in vivo. Employing a combination of gut microbiota, metabolome, and advanced neuroimaging techniques provides a future perspective in illustrating the microbiota-gut-brain pathway and further unveiling potential therapeutic targets for AD treatments.

The Expectations and Acceptability of a Smart Nursing Home Model Among Chinese Older Adults and Family Members: A Qualitative Study

PURPOSE

This study aims to explore the expectations and acceptability of a smart nursing home model among Chinese older adults and their family members based on a scoping review that defines the concept of smart nursing homes.

METHODS

A qualitative case study was employed for this research. Semi-structured, in-depth interviews and focus group discussions were conducted on WeChat. Participants were purposively sampled through snowball sampling in Hainan and Dalian, China. A total of 28 older adults aged 60-75 and six adult children were interviewed until data saturation was achieved, followed by a thematic analysis.

RESULTS

The expectations of smart nursing homes include: 1) quality of care supported by governments and societies; 2) smart technology applications; 3) the presence of a skilled healthcare professional team; 4) access to and scope of basic medical services; and 5) integration of medical services. The acceptability of smart nursing homes included factors such as stakeholders' perceived efficaciousness, usability, and collateral damages of using smart technologies, and the coping process of adoption was influenced by factors such as age, economic status, health status, education, and openness to smart technologies among older adults.

CONCLUSIONS

Chinese older adults and their family members have a positive perception of the smart nursing home model. The qualitative evidence regarding their expectations and acceptability of smart nursing homes contributes valuable insights for a wide range of stakeholders involved in the planning and implementation of smart nursing homes.

Exploring the mechanism of metformin action in Alzheimer's disease and type 2 diabetes based on network pharmacology, molecular docking, and molecular dynamic simulation

Background

Metformin, which has been shown to be highly effective in treating type 2 diabetes (T2D), is also believed to be valuable for Alzheimer's disease (AD). Computer simulation techniques have emerged as an innovative approach to explore mechanisms.

Objective

To study the potential mechanism of metformin action in AD and T2D.

Methods

The chemical structure of metformin was obtained from PubChem. The targets of metformin were obtained from PubChem, Pharm Mapper, Batman, SwissTargetPrediction, DrugBank, and PubMed. The pathogenic genes of AD and T2D were retrieved from the GeneCards, OMIM, TTD, Drugbank, PharmGKB, and DisGeNET. The intersection of metformin with the targets of AD and T2D is represented by a Venn diagram. The protein-protein interaction (PPI) and core targets networks of intersected targets were constructed by Cytoscape 3.7.1. The enrichment information of GO and Kyoto Encyclopedia of Gene and Genomics (KEGG) pathways obtained by the Metascape was made into a bar chart and a bubble diagram. AutoDockTools, Pymol, and Chem3D were used for the molecular docking. Gromacs software was used to perform molecular dynamics (MD) simulation of the best binding target protein.

Results

A total of 115 key targets of metformin for AD and T2D were obtained. GO analysis showed that biological process mainly involved response to hormones and the regulation of ion transport. Cellular component was enriched in the cell body and axon. Molecular function mainly involved kinase binding and signal receptor regulator activity. The KEGG pathway was mainly enriched in pathways of cancer, neurodegeneration, and endocrine resistance. Core targets mainly included TP53, TNF, VEGFA, HIF1A, IL1B, IGF1, ESR1, SIRT1, CAT, and CXCL8. The molecular docking results showed best binding of metformin to CAT. MD simulation further indicated that the CAT-metformin complex could bind well and converge relatively stable at 30 ns.

Conclusion

Metformin exerts its effects on regulating oxidative stress, gluconeogenesis and inflammation, which may be the mechanism of action of metformin to improve the common pathological features of T2D and AD.

Association between oral health and cognitive function among Chinese older adults: the Taizhou imaging study

BACKGROUND

We aimed to investigate the association between oral health and cognitive function in a sample of older adults from a Chinese rural community.

METHODS

The cross-sectional cognitive function of 677 individuals were assessed by Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). A comprehensive profile of the oral health status was evaluated by questionnaire and clinical examination.

RESULTS

Multiple covariates-adjusted regression models demonstrated decayed teeth (DT) and decayed/missing/filled teeth (DMFT) were negatively associated with MoCA score (all p < 0.05). Calculus index (CI) and clinical attachment loss (CAL) were significantly associated with the lower MoCA, short-term memory and executive function score, respectively (all p < 0.05). Additionally, participants with missing teeth unrestored tend to get lower MMSE and MoCA scores (p < 0.05). The results also showed that increased DT and CI were modestly associated with higher odds of cognitive impairment (p < 0.05).

CONCLUSIONS

There is an association between oral health and global cognition. Poor periodontal status was strongly associated with worse global cognition performance, especially in the short-term memory and executive domain for the aging population.

Longitudinal associations between social relationships and cognitive function among Chinese older adults: The mediating role of healthy lifestyles

BACKGROUND

We aimed to explore whether social relationships and cognitive function were reciprocally related and whether healthy lifestyles mediate their association.

METHODS

This study included 3372 Chinese adults from the years 2014-2018 wave of the Chinese Longitudinal Healthy Longevity Survey.

RESULTS

Baseline social relationships were negatively associated with a change in cognitive function (β = -0.030, p = 0.043). Participants with a 1 standard deviation (SD) increase in social relationships had an approximately 6% reduced risk of developing cognitive impairment. However, baseline cognitive function did not independently predict social relationships. The association between △social relationships and △cognitive function was partially mediated by △a healthy lifestyle (B = 0.025, 95% CI = 0.013-0.041).

CONCLUSIONS

The association between social relationships and cognitive function may be unidirectional. Policies that promote cognitive function based on social relationships would benefit by taking into account lifestyle factors.

Plasma long non-coding RNAs ASMTL-AS1, AP001363.1, AC005730.3 and AL133415.1 as a potential biomarker for Alzheimer's disease

BACKGROUND

Long non-coding RNAs (lncRNAs) play critical role in the pathogenesis of neurodegenerative diseases. Human plasma contains lncRNAs that are present in the blood, and their disease-specific profile has been considered a potential biomarker in some diseases.

METHODS

This study reports screening of the plasma levels of lncRNAs between Alzheimer disease(AD) (n = 45) and matched healthy controls (n = 45). The plasma samples of 5 AD patients and 5 matched healthy controls were randomly selected for expression levels of lncRNAs using the TruSeq RNA Sample Prep Kit (Illumina). The receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to study the potential of lncRNAs as biomarkers.

RESULTS

The differential expression profiles of plasma showed that 514 lncRNAs were upregulated, whereas 499 lncRNAs were downregulated.We found that the lncRNAs AL133415.1, AC020916.1, ENST00000654948, ASMTL-AS, AC005730.3, and AP001363.1 levels in the plasma of the AD patients were significantly lower compared to the control group (p1 = 0.0006, p2 < 0.001, p3 < 0.001, p4 = 0.039, p5 = 0.006, p6 < 0.001, respectively). ROC curve analysis revealed that the AUC of AL133415.1 was 0.635 (95% CI]: 0.507-0.763, p = 0.036), the AUC of ASMTL-AS1 was 0.658 (95% CI: 0.513-0.785, p = 0.015), the AUC of AC005730.3 was 0.627 (95%CI: 0.498-0.756, p = 0.049), and the AUC of AP001363.1 was 0.708 (95%CI: 0.595-0.822, p = 0.001).

CONCLUSION

This study indicated that the plasma levels of the lncRNAs ASMTL-AS1, AP001363.1, AC005730.3, and AL133415.1 might be considered potential biomarkers for AD in the Chinese Population.

Constituent isoflavones of Puerariae radix as a potential neuroprotector in cognitive impairment: Evidence from preclinical studies

With the increasing aging population worldwide, the incidence of senile cognitive impairment (CI) is increasing, posing a serious threat to the health of elderly persons. Despite developing new drugs aimed at improving CI, progress in this regard has been insufficient. Natural preparations derived from plants have become an unparalleled resource for developing new drugs. Puerariae radix (PR) has a long history as Chinese herbal medicine. PR is rich in various chemical components such as isoflavones, triterpenes, and saponins. The isoflavones (puerarin, daidzein, formononetin, and genistein) exhibit potential therapeutic effects on CI through multiple mechanisms. Relevant literature was organized from major scientific databases such as PubMed, Elsevier, SpringerLink, ScienceDirect, and Web of Science. Using "Puerariae radix," "Pueraria lobata," "isoflavones," "puerarin," "antioxidant," "daidzein," "formononetin," "genistein," "Alzheimer"s disease," and "vascular cognitive impairment" as keywords, the relevant literature was extracted from the databases mentioned above. We found that isoflavones from PR have neuroprotective effects on multiple models of CI via multiple targets and mechanisms. These isoflavones prevent Aβ aggregation, inhibit tau hyperphosphorylation, increase cholinergic neurotransmitter levels, reduce neuroinflammation and oxidative stress, improve synaptic plasticity, promote nerve regeneration, and prevent apoptosis. PR has been used as traditional Chinese herbal medicine for a long time, and its constituent isoflavones exert significant therapeutic effects on CI through various neuroprotective mechanisms. This review will contribute to the future development of isoflavones present in PR as novel drug candidates for the clinical treatment of CI.

Post-COVID cognitive dysfunction: current status and research recommendations for high risk population

Post-COVID cognitive dysfunction (PCCD) is a condition in which patients with a history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, usually three months from the onset, exhibit subsequent cognitive impairment in various cognitive domains, and cannot be explained by an alternative diagnosis. While our knowledge of the risk factors and management strategy of PCCD is still incomplete, it is necessary to integrate current epidemiology, diagnosis and treatment evidence, and form consensus criteria to better understand this disease to improve disease management. Identifying the risk factors and vulnerable population of PCCD and providing reliable strategies for effective prevention and management is urgently needed. In this paper, we reviewed epidemiology, diagnostic markers, risk factors and available treatments on the disease, formed research recommendation framework for vulnerable population, under the background of post-COVID period.

Vitamin B12 supplementation improves cognitive function in middle aged and elderly patients with cognitive impairment

Introduction

Objectives: to determine the effects of vitamin B12 supplementation on neuropsychological function and disease progression in middle aged and elderly patients with cognitive impairment. Methods: this was a prospective case-control study. From May 2020 to May 2021, 307 participants clinically diagnosed with cognitive impairment in the Department of Neurology of the First Affiliated Hospital of Chongqing Medical University were enrolled. A total of 115 patients were included in this study. Meanwhile, 115 participants with cognitive impairment were randomly assigned in equal proportions to two groups: vitamin B12 treatment group (n = 58, vitamin B12 500 mg/d intramuscularly for seven days, followed by cobamamide 0.25 mg/d and methylcobalamin 0.50 mg/d) and the control group (n = 57). Demographic characteristics and blood biochemical variables were obtained from all participants. Cognitive performance was measured using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Cognitive performance was measured at baseline and after six months. Results: the vitamin B12 supplementation treatment patients who presented with cognitive impairment showed significant improvement, especially in attention, calculation (p < 0.01) and visual-constructional ability (p < 0.05), in their neuropsychological function compared to their matched group. Conclusion: vitamin B12 supplementation may improve frontal function in patients with cognitive decline. Vitamin B12 levels should be investigated in all patients with cognitive impairment.

Age and sex differences in the association between APOE genotype and Alzheimer's disease in a Taiwan Chinese population

Introduction

The Apolipoprotein E (APOE) epsilon (ε) 4 allele is a well-established risk factor for late-onset Alzheimer's disease (AD). Reports on white ancestry populations have showed that age, sex, and ethnicity have different effects on the association between APOE genotype and AD. However, studies on Asian populations such as Taiwan Chinese populations are limited. This study aimed to evaluate the association between APOE genotype and AD in a Taiwan Chinese population, and to explore if the association varies by age and sex.

Methods

We conducted a case-control study in 725 patients with AD and 1,067 age- and sex- matched controls without dementia from a Taiwan Chinese population. Logistic regression models were used to test the association between AD and APOE genotypes. Secondary analyses considered age (<75 or ≥75 years old), and sex stratified models.

Results

The risk of AD was significantly increased for people with at least one copy of APOE ε4 (OR = 2.52, 95% CI = 2.01-3.17, p < 0.001) and in a dose-dependent manner. Our results did not show an statistically significance different in AD risk when women and men carrying APOEε4 were compared. Despite not reaching statistical significance, the risk of APOE ε4 for AD was higher among younger participants (OR = 3.21, 95% CI = 2.26-4.56, p < 0.001) compared to older ones (OR = 2.13, 95% CI = 1.53-2.97, p < 0.001). When considering both sex and age, the risk of AD was higher among older men carrying APOE ε4 (OR = 2.64, 95% CI = 1.51-4.60 in men; OR = 1.90, 95% CI = 1.26-2.86 in women), while women carrying APOE ε4 appeared to have an increased risk at a younger age (OR = 3.29, 95% CI = 2.20-4.93 in women; OR = 2.91, 95% CI = 1.40-6.05 in men).

Discussion

The APOE ε4 allele represents a major risk factor for AD in the Taiwanese population. The effect of APOE ε4 allele on AD risk appeared to be stronger among men aged 75 years or more and among younger women.

Unraveling the link: exploring the causal relationship between diabetes, multiple sclerosis, migraine, and Alzheimer's disease through Mendelian randomization

Introduction

Observational studies suggested that diabetes mellitus [type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM)], multiple sclerosis (MS), and migraine are associated with Alzheimer's disease (AD). However, the causal link has not been fully elucidated. Thus, we aim to assess the causal link between T1DM, T2DM, MS, and migraine with the risk of AD using a two-sample Mendelian randomization (MR) study.

Methods

Genetic instruments were identified for AD, T1DM, T2DM, MS, and migraine respectively from genome-wide association study. MR analysis was conducted mainly using the inverse-variance weighted (IVW) method.

Results

The result of IVW method demonstrated that T2DM is causally associated with risk of AD (OR: 1.237, 95% CI: 1.099-1.391, P: 0.0003). According to the IVW method, there is no causal association between TIDM, MS, migraine, and the risk of AD (all p value > 0.05). Here we show, there is a causal link between T2DM and the risk of AD.

Conclusion

These findings highlight the significance of active monitoring and prevention of AD in T2DM patients. Further studies are required to actively search for the risk factors of T2DM combined with AD, explore the markers that can predict T2DM combined with AD, and intervene and treat early.

Using gamma-band transcranial alternating current stimulation (tACS) to improve sleep quality and cognition in patients with mild neurocognitive disorders due to Alzheimer's disease: A study protocol for a randomized controlled trial

BACKGROUND

Sleep disturbances are highly prevalent in patients with age-related neurodegenerative diseases, which severely affect cognition and even lead to accumulated β-amyloid. Encouraging results from recent studies on transcranial direct current stimulation (tDCS) showed moderate positive effects on sleep quality in preclinical Alzheimer's disease (AD). Compared to tDCS, transcranial alternating current stimulation (tACS) enables the entrainment of neuronal activity with optimized focality through injecting electric current with a specific frequency and has significant enhancement effects on slow wave activities.

METHODS AND DESIGN

This is a randomized, double-blind, sham-controlled clinical trial comparing 40 Hz tACS with tDCS in mild neurocognitive disorders due to AD with sleep disturbances. Magnetic resonance imaging (MRI) data is used to construct personalized realistic head model. Treatment outcomes, including sleep quality, cognitive performance and saliva Aβ levels will be conducted at baseline, 4th week, 8th week, 12th week and 24th week.

CONCLUSIONS

It is expected that the repeated gamma-band tACS will show significant improvements in sleep quality and cognitive functions compared to tDCS and sham tDCS. The findings will provide high-level evidence and guide further advanced studies in the field of neurodegenerative diseases and sleep medicine.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05544201.

Associations Between Dysphagia and Adverse Health Outcomes in Older Adults with Dementia in Intensive Care Units: A Retrospective Cohort Study

BACKGROUND

Dysphagia is common in elderly patients with dementia and is one of the common clinical geriatric syndromes. It imposes a heavy burden on patients and their caregivers and is becoming an important public health problem. This study examined the association between dysphagia in older dementia patients in the ICU and the subsequent adverse health outcomes they experience.

PATIENTS AND METHODS

A retrospective analysis of adults (≥65 years) with dementia in ICUs of a Boston tertiary academic medical center was conducted. Using the International Classification of Diseases' Ninth and Tenth Revisions, dementia patients were identified. The study cohort comprised 1009 patients, median age 84.82 years, 56.6% female, predominantly White (72.9%). Patients were grouped based on swallowing function: dysphagia (n=282) and no-dysphagia (n=727). Dysphagia was identified via positive bedside swallowing screening. Primary outcomes were 90- and 180-day mortality, secondary outcomes included aspiration pneumonia, pressure injury, and delirium. Cohort characteristics were compared using the Wilcoxon rank-sum and chi-square tests. Dysphagia and outcomes correlations were examined via Kaplan-Meier survival analysis, Cox proportional-hazards regression models, logistic regression models, and subgroup analysis.

RESULTS

After adjusting for covariates, the results from multivariate Cox proportional-hazards regression indicated that dysphagia was significantly associated with increased 90-day (HR=1.36, 95% CI=1.07-1.73, E-value=1.78) and 180-day (HR=1.47, 95% CI=1.18-1.82, E-value=1.94) mortality; the multifactorial logistic regression results indicated that dysphagia was associated with significant increases in pressure injury (OR=1.58, 95% CI=1.11-2.23, E-value=1.83) and aspiration pneumonia occurrence (OR=4.04, 95% CI=2.72-6.01, E-value=7.54), but was not significantly associated with delirium prevalence (OR=1.27, 95% CI=0.93-1.74).

CONCLUSION

Dysphagia is likely to increase the risk of adverse health outcomes in older adults with dementia in ICU, and these adverse outcomes mostly include 90- and 180-day mortality, aspiration pneumonia, and pressure injury.

Contribution of Alzheimer's disease pathology to biological and clinical progression: A longitudinal study across two cohorts

INTRODUCTION

Amyloid beta (Aβ) deposition, tau accumulation, and brain atrophy occurr in sequence, but the contribution of Alzheimer's disease (AD) pathology to biological and clinical progression remains unclear.

METHODS

We included 290 and 70 participants with longitudinal assessment on Aβ-positron emission tomography (PET), tau-PET, magnetic resonance imaging, and cognitive function from the Harvard Aging Brain Study (HABS) and Alzheimer's Disease Neuroimaging Initiative (ADNI) datasets, respectively. Partial least squares structural equation modeling (PLS-SEM) was used to determine the contribution of AD pathology to the biological and clinical longitudinal changes.

RESULTS

Imaging biomarkers and cognitive function were significantly associated in cross-sectional and longitudinal analyses. At the final time point, the percentage of variance explained by PLS-SEM was 27% for Aβ, 30% for tau (Aβ accounted for 61%), 29% for brain atrophy (tau accounted for 37%), and 37% for cognitive decline (brain atrophy accounted for 35%).

DISCUSSION

This study highlights distinctive contributing proportions of AD pathology to biological and clinical progression. Treatments targeting Aβ and tau may partially block AD progression.

The impact of sensory impairments and eye diseases on cognitive function in elderly Chinese: The mediating effects of social participation

Background

Sensory impairments and eye diseases increase the risk of cognitive decline, but little is known regarding their influence on cognitive function in elderly Chinese and the underlying mechanisms. We aimed to explore these influence mechanism from the social participation perspective.

Methods

We selected 2876 respondents aged ≥60 from the China Health and Retirement Longitudinal Study (CHARLS) conducted in 2013, 2015, and 2018. We assessed sensory impairments and eye diseases based on self-reported responses, and evaluated its relation to social participation and cognitive function by fixed-effects regression and mediation effect analysis over a five-year period.

Results

Respondents with visual impairment and cataracts had poor memory and mental status. Compared with near visual impairment, distance visual impairment was associated with a 1.7 times higher likelihood of cognitive decline (correlation coefficient (β) = -0.051; 95% confidence interval (CI) = -0.065, -0.036)). Respondents with hearing impairment had bad memory (β = -0.046; 95% CI = -0.065, -0.036), but not mental status. Social participation partially mediated the relationships of sensory impairments and cataracts with cognitive function in elderly Chinese. Individuals with sensory impairments affected by limited social participation reported a faster cognitive decline compared to those with eye disease.

Conclusions

We found that sensory impairments and eye diseases were negatively associated with cognitive function. Furthermore, sensory impairments and cataracts influence cognitive function partly via social participation. Our results have important theoretical and practical implications and suggests that early interventions for sensory impairments and eye diseases may improve the cognitive function of elderly people.

Association between housework and the risk of dementia among older Chinese adults: a prospective cohort study

OBJECTIVES

Physical activity (PA) is known to improve physical functioning and mental health and to reduce the incidence of dementia. However, studies of the effects of non-recreational PA on the incidence of dementia, especially in East Asian populations, remain limited. In this study, we evaluate the association of doing housework with the risk of dementia among participants in the Chinese Longitudinal Healthy Longevity Survey (CLHLS).

METHODS

The analysis was conducted with data from 7,237 CLHLS participants age over 65 obtained in 2008/2009, 2011/2012, 2014, and 2018. The frequency of housework performance was classified into four groups. A Cox proportional-hazards model was used to examine the association of the baseline housework frequency with the incidence of dementia, with adjustment for demographic and socioeconomic characteristics and lifestyle and health conditions.

RESULTS

The adjusted multivariate model showed that the incidence of dementia was lower among participants who did housework almost every day than among those who rarely or never did housework (hazard ratio = 0.49; 95% confidence interval, 0.39-0.61). The subgroup and sensitivity analyses yielded similar results.

CONCLUSION

A high frequency of housework performance was associated with a reduced incidence of dementia among older Chinese adults, especially those who did not exercise regularly. The encouragement of engagement in housework would be a cost-effective measure promoting healthy aging in the Chinese population.

Study on the mechanism of Coptis chinensis Franch. And its main active components in treating Alzheimer's disease based on SCFAs using Orbitrap Fusion Lumos Tribrid MS

ETHNOPHARMACOLOGICAL RELEVANCE

Coptis chinensis Franch. (CCF), as an extensively used traditional Chinese medicine, has therapeutic effects on Alzheimer's disease (AD), but its mechanism of action has not yet been elucidated.

AIM OF THE STUDY

This study aims to reveal the mechanism of action of CCF via the gut-brain axis, and provide a new strategy for the clinical treatment of AD.

MATERIALS AND METHODS

APPswe/PS1ΔE9 mice were used as AD models, and were given CCF extract by intragastric administration. Barnes maze was used to test the therapeutic effect of CCF on the treatment of AD. To reveal the mechanism of action of CCF in the treatment of AD, Vanquish Flex UHPLC-orbitrap fusion lumos mass was chosen to detect endogenous differential metabolite; MetaboAnalyst 5.0 was applied to derive relevant metabolic pathways; similarly, to explore the effects of CCF on the gut-brain axis, Vanquish Flex UPLC-Orbitrap fusion lumos mass was utilized to detect the changes in the content of SCFAs in AD mice after CCF administration; the prototype components and metabolites in CCF were identified by UPLC/ESI/qTOF-MS, then their effects on Bifidobacterium breve were explored.

RESULTS

CCF shortened the latency time of AD mice, improved the target quadrant ratio of AD mice, and made the maze roadmap simpler of AD mice; CCF regulated fifteen potential metabolites of AD mice, interestingly, ILA (indole-3-lactic acid) in SCFAs (short-chain fatty acids) was also included; CCF acted on histidine and phenylalanine metabolic pathways of AD mice; CCF increased the contents of acetic acid and ILA in AD mice; magnoflorine, jatrorrhizine, coptisine, groenlandicine, thalifendine, palmatine, berberine, epiberberine, hydroxylated jatrorrhizine, and 3-methoxydemethyleneberberine in CCF were detected in fecal samples of AD mice; magnoflorine, palmatrubine, 13-methylberberine, berberine, coptisine, and palmatine promoted the growth of Bifidobacterium breve.

CONCLUSIONS

we have demonstrated that CCF acts on the gut-brain axis by regulating SCFAs to treat AD.

Smartphone-based versus traditional face-to-face collaborative care for community-dwelling older adults living with dementia in China: protocol for an implementation science-based sequential multiple assignment randomised trial

INTRODUCTION

The high costs of institutional care and the burdensome demands of home care are challenging for families of adults with dementia. The collaborative care model (CCM) provides a potential solution to these challenges. Leveraging advancements in mobile technologies, smartphone-based management could offer a feasible means of providing collaborative care in a community setting. Therefore, this study aims to establish a CCM for home-cared older adults with dementia to determine the best strategy to deliver collaborative care, including both the channel and frequency of delivery.

METHODS AND ANALYSIS

This study will be conducted in the communities of Chengdu city, Sichuan province, China. It is designed under the framework of implementation science. In the first stage, intervention strategies for community-dwelling older adults with dementia and their caregivers will be developed using Delphi methods and focus group interviews. The second stage will involve designing a sequential multiple assignment randomised trial to compare the effectiveness of face-to-face intervention versus a WeChat mini program-based intervention. This comparison will involve 358 pairs of older adults with dementia and their caregivers, with the frequency of intervention also assessed. Follow-up evaluations will be implemented at the 6th, 12th and 18th months post-intervention initiation. Primary outcomes encompass the proportion of patients demonstrating an improvement in quality of life and the proportion of caregivers exhibiting a reduction in caregiver burden. Analysis will be based on the intention-to-treat principle, and the generalised estimating equation approach will be used. Incremental cost-effectiveness ratios will be used to evaluate the cost-effectiveness of different delivery methods and frequencies.

ETHICS AND DISSEMINATION

This study has received approval from the Ethics Committee of West China Fourth Hospital/School of Public Health, Sichuan University (Gwll2022004). Informed consent will be obtained for all participants. The findings of the study will be disseminated through peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

ChiCTR2200057945.

Effects of adverse childhood health experiences on cognitive function in Chinese middle-aged and older adults: mediating role of depression

BACKGROUND

Adverse childhood experiences are critical factors in depression and cognitive decrease, but the effect of adverse childhood health experiences (ACHEs) on cognitive function and the role of depression have not been fully studied.

METHODS

Data were taken from the China Health and Retirement Longitudinal Study (CHARLS) of 2014 and 2018. This study used indicators of situational memory ability and mental status to measure cognitive capacity. Besides analyzing the different types of ACHEs, scores for ACHEs were calculated to represent the severity of ACHEs. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to assess depression. The analysis of this study employed two different analytical strategies in order to examine the mediated effects of depression. We used Sobel's test and Baron and Kenny's causal step approach, which utilized a generalized least squares regression model. Furthermore, a logistic regression model was used to evaluate the robustness of the Karlson-Holm-Breen (KHB) approach.

RESULTS

In this study, 6301 individuals who met the requirements of the study were included. We found that being confined to bed (ACHE3) (β=-0.3846, p = 0.022) in childhood had a negative impact on cognitive function. Similarly, ACHEs had a negative effect on cognitive function (β=-0.0819, p = 0.090). And after the depression had been introduced into the model, the regression coefficient of ACHEs on cognitive function was no longer significant (β=-0.0170, p = 0.727). The Sobel test showed that for ACHE3, the mediated proportion of the total effect of depression was 36.92%. While for ACHEs, the proportion of the mediated effect of depression was 70.11%. Finally, a robustness test of the mediating effect using the KHB method revealed that the mediating effect still existed. Further, based on different gender, age, and educational levels, the heterogeneity test indicated that the relationship between ACHEs and cognitive function and mediating effects of the depression were different as well as passing the robustness test of the interaction.

CONCLUSION

The decline in cognition had been shown to be correlated with ACHEs and depression mediated this relationship. Positive interventions might help to improve cognitive performance in individuals suffering from ACHEs and depression.

Relationship between digital exclusion and cognitive impairment in Chinese adults

Objective

We aimed to evaluate the relationship between digital exclusion, such as neither mobile payments nor WeChat use, and cognitive impairment in Chinese individuals aged 45 and older.

Methods

A population-based cross-sectional study utilizing data from the fourth national survey of the China Health and Retirement Longitudinal Study (CHARLS). In the fourth wave of CHARLS, 10,325 participants aged 45 and older with complete information were included in this analysis. Self-reported mobile payments and WeChat usage constituted our exposure. Cognitive impairment was the primary outcome. Univariate and multivariate logistic regression were used to assess the relationships between cognitive impairment risk and digital exclusion.

Results

Data were analyzed from 10,325 participants [mean (SD) age, 60.3 (9.1) years; 44.8% women], including 1,232 individuals with cognitive impairment and 9,093 cognitively normal individuals. The overall proportion of users who did not use either mobile payment or WeChat and those who only used WeChat were 81.3 and 6.7%, for cognitively impaired individuals 95.0 and 3.1%, and for cognitively normal individuals 79.5 and 7.2% [neither WeChat nor mobile payments vs. control unadjusted odds ratio (OR), 8.16; P < 0.001; only WeChat use vs. control unadjusted OR, 2.91; P < 0.001]. Participants who did not use either WeChat or mobile payments had an elevated risk for cognitive impairment after adjusting for a number of covariates (neither WeChat nor mobile payments vs. control adjusted OR, 3.48; P < 0.001; only WeChat use vs. control adjusted OR, 1.86; P = 0.021).

Conclusion

Our study reveals a positive correlation between digital exclusion and cognitive impairment in Chinese adults, providing insights for promoting active digital integration among older adults. Further longitudinal research is needed to further validate this hypothesis.

Current Diagnostic Pathways for Alzheimer's Disease: A Cross-Sectional Real-World Study Across Six Countries

Background

Diagnostic pathways for patients presenting with cognitive complaints may vary across geographies.

Objective

To describe diagnostic pathways of patients presenting with cognitive complaints across 6 countries.

Methods

This real-world, cross-sectional study analyzed chart-extracted data from healthcare providers (HCPs) for 6,744 patients across China, France, Germany, Spain, UK, and the US.

Results

Most common symptoms at presentation were cognitive (memory/amnestic; 89.86%), followed by physical/behavioral (87.13%). Clinical/cognitive tests were used in > 95%, with Mini-Mental State Examination being the most common cognitive test (79.0%). Blood tests for APOE ɛ4/other mutations, or to rule out treatable causes, were used in half of the patients. Clinical and cognitive tests were used at higher frequency at earlier visits, and amyloid PET/CSF biomarker testing at higher frequency at later visits. The latter were ordered at low rates even by specialists (across countries, 5.7% to 28.7% for amyloid PET and 5.0% to 27.3% for CSF testing). Approximately half the patients received a diagnosis (52.1% of which were Alzheimer's disease [AD]). Factors that influenced risk of not receiving a diagnosis were HCP type (higher for primary care physicians versus specialists) and region (highest in China and Germany).

Conclusion

These data highlight variability in AD diagnostic pathways across countries and provider types. About 45% of patients are referred/told to 'watch and wait'. Improvements can be made in the use of amyloid PET and CSF testing. Efforts should focus on further defining biomarkers for those at risk for AD, and on dismantling barriers such low testing capacity and reimbursement challenges.