The Journal of Prevention of Alzheimer's Disease最新文献

Background

Little is known about the impact of short, low-intensity multidomain dementia risk reduction interventions in older adults.

Objectives

To examine the effectiveness and feasibility of a low-intensity multidomain lifestyle intervention on dementia risk and dementia literacy in Australian older adults.

Design

Single-group pre-post design.

Setting

Community-dwelling.

Participants

A total of 853 older Australians (Mean age=73.3 years, SD=6.1) recruited from the community.

Intervention

A 3-month dementia risk reduction program, BRAIN BOOTCAMP, including education, personalised risk information, physical cues for healthier choices and goal setting and planning to target four modifiable risk factors of diet, exercise, cognitive activity and social interaction in older adults.

Measurements

The ‘LIfestyle for BRAin health’ (LIBRA) index was used to assess participants’ modifiable dementia risk based on 12 factors, with higher scores indicating greater risk. Dementia literacy was measured using a modified questionnaire derived from Dutch and British surveys, encompassing knowledge, risk reduction, and awareness aspects. Paired t-tests were used to compare dementia risk scores and dementia literacy before and after the program. Multivariate regressions were performed to identify sociodemographic and psychological factors associated with change in the LIBRA index.

Results

Program attrition was high (58.3%). Participants who completed the program had decreased dementia risk scores (Cohen’s d=0.59, p<0.001), increased dementia literacy and awareness (Cohen’s d=0.64, p<0.001) and increased motivation to change lifestyle behaviors (Cohen’s d=0.25–0.52, p<0.016). Participants with higher motivational beliefs had greater dementia risk reduction.

Conclusions

Improving older adults’ motivation and knowledge may help modify lifestyle behaviors to reduce dementia risk. However, program attrition remains a challenge, suggesting the need for strategies to enhance participant engagement and retention in such interventions.

Background

The preceding evidence indicates a close correlation between imbalances in the gut microbiome and Alzheimer’s disease (AD), yet the direct causal relationship remains unclear. Our objective is to investigate this potential causal connection.

Methods

We obtained summary results from two significant genome-wide association studies (GWAS) on gut microbiota (the MibioGen consortium and the Dutch Microbiome Project), along with one GWAS summary result for AD. Using a two-sample Mendelian randomization (TSMR) analysis, we examined the potential causal effects of gut microbiota on AD.

Results

Our TSMR analysis revealed that 16 gut bacterial taxa were linked to a reduced risk of AD. These included phylum Tenericutes, classes Bacilli and Clostridia along with its order Clostridiales, family Bacteroidaceae, genus Bacteroides, and species Bifidobacterium bifidum (OR: 0.867∼0.971, P ≤ 0.045). Conversely, the presence of 12 taxa correlated with an increased risk of AD. These comprised class Actinobacteria and its family Coriobacteriaceae, as well as class Betaproteobacteria, its order Burkholderiales, and its family Sutterellaceae (OR: 1.042∼1.140, P ≤ 0.035).

Conclusion

Our research uncovered evidence suggesting certain gut bacterial species might play a causal role in AD risk, providing a fresh angle for AD treatment strategies.

Recent positive results of three phase III anti-amyloid monoclonal antibody trials are transforming the landscape of disease-modifying therapeutics for Alzheimer’s disease, following several decades of failures. Indeed, all three trials have met their primary endpoints. However, the absolute size of the benefit measured in these trials has generated a debate on whether the change scores observed on clinical outcome assessments represent a clinically meaningful benefit to patients. An evidence-based conclusion is urgently required to inform decision-making related to the approval, reimbursement, and ultimately, the management of emerging therapies in clinical practice. The EU-US CTAD Task Force met in Boston to address this important question. The current state-of-the-art knowledge for interpreting clinical meaningfulness of AD clinical trial results, including the point of view of patients and study partners on what is clinically meaningful, was discussed and is summarized here. A combination of methodologies to address the challenges emerged. There remain gaps in the understanding of clinical meaningfulness that only long-term longitudinal studies will be able to address.

Background

Alzheimer’s disease (AD), the main type of dementia, involves in complex pathophysiological processes, including abnormal lysosomes function. Cathepsins are the predominant proteases responsible for the degradation of diverse substrates in the endo-lysosomal system. However, there was still a lack of systematic study on the causal association between cathepsins and AD.

Methods

This study utilized Mendelian randomization (MR) to investigate the association between blood cathepsins and the risk of AD, as well as the level of amyloid-β (Aβ) and p-Tau in cerebrospinal fluid. Furthermore, an independent dataset was employed to corroborate the above result. Importantly, this study incorporated the Alzheimer’s disease Immunization and Microbiota Initiative study Cohort to further validate the alteration of blood cathepsins expression level and examine its correlation with cognitive level and plasma AD-related pathological markers.

Results

Using MR method, we observed that high level of cathepsin L (CTSL) was associated with a lower risk of AD in both training and validation data. In observational cohort, we found there was decreased blood CTSL expression level in Aβ+ cognitive impaired (CI) group, compared with Aβ− cognitive unimpaired (CU) group. Correlation analysis revealed that blood CTSL expression level was negatively correlated with Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) score, plasma Aβ42 and Aβ42/40 level in Aβ+ CI group. Mediation analysis showed that plasma Aβ42/40 level was the key mediator in the association between blood CTSL and MMSE score in Aβ+ CI participants.

Conclusion

This study revealed that blood CTSL was an important factor affecting the risk of AD, and it affected the cognitive level of AD patients through plasma Aβ42/40 level.

Background

It has been suggested that up to 40% of dementia cases worldwide are associated with modifiable risk factors; however, these estimates are not known in Canada. Furthermore, sleep disturbances, an emerging factor, has not been incorporated into the life-course model of dementia prevention.

Objective

To estimate the population impact of 12 modifiable risk factors in Canadian adults including sleep disturbances, by sex and age groups, and to compare with other countries.

Design

Cross-sectional analysis of Canadian Longitudinal Study on Aging baseline data.

Setting

Community.

Participants

30,097 adults aged 45 years and older.

Measuremments

Prevalence and Population Attributable

Fractions (PAFs) associated with less education, hearing loss, traumatic brain injury, hypertension, excessive alcohol, obesity, smoking, depression, social isolation, physical inactivity, diabetes, and sleep disturbances

Results

The risk factors with the largest PAF were later life physical inactivity (10.2%; 95% CI, 6.8% to 13%), midlife hearing loss (6.5%; 3.7% to 9.3%), midlife obesity (6.4%; 4.1% to 7.7%), and midlife hypertension (6.2%; 2.7% to 9.3%). The PAF of later life sleep disturbances was 3.0% (95% CI, 1.8% to 3.8%). The 12 risk factors accounted for 51.9% (32.2% to 68.0%) of dementia among men and 52.4% (32.5% to 68.7%) among women. Overall, the combined PAF of all risk factors was 49.2% (31.1% to 64.9%), and it increased with age.

Conclusion

Nearly up to 50% of dementia cases in Canada are attributable to 12 modifiable risk factors across the lifespan. Canadian risk reduction strategies should prioritize targeting physical inactivity, hearing loss, obesity, and hypertension.

Playing mahjong is a popular intellectual and social leisure activity in Asian countries. It is culturally believed that this activity is beneficial to cognitive and psychological functioning in older adults. However, empirical evidence of the benefits of playing mahjong is scant and scattered across the Western and Asian literature. This scoping review comprehensively examined previous studies of the relationships between playing mahjong and cognitive, psychological, and functional abilities in older adults, highlighted gaps in the literature, and identified directions for future research. A systematic search of the literature was conducted across thirteen Western and Asian databases. Fifty-three studies, including forty-seven observational and six intervention studies, were identified. Overall, the results of the observational studies suggested that more mahjong-playing experience was associated with better cognitive, psychological, and functional abilities. As an intervention, playing mahjong was found to enhance general cognitive abilities and short-term memory and relieve depressive symptoms. However, because most of the reviewed studies adopted a correlational methodology, the neural mechanism underlying the benefits of playing mahjong awaits further elucidation. The findings of this review suggest that more randomized controlled trials should be conducted to explore the effects of playing mahjong on higher-level cognitive functioning in older populations.

Digital health technologies offer valuable advantages to dementia researchers and clinicians as screening tools, diagnostic aids, and monitoring instruments. To support the use and advancement of these resources, a comprehensive overview of the current technological landscape is essential. A multi-stakeholder working group, convened by the Digital Medicine Society (DiMe), conducted a landscape review to identify digital health technologies for Alzheimer’s disease and related dementia populations. We searched studies indexed in PubMed, Embase, and APA PsycInfo to identify manuscripts published between May 2003 to May 2023 reporting analytical validation, clinical validation, or usability/feasibility results for relevant digital health technologies. Additional technologies were identified through community outreach. We collated peer-reviewed manuscripts, poster presentations, or regulatory documents for 106 different technologies for Alzheimer’s disease and related dementia assessment covering diverse populations such as Lewy Body, vascular dementias, frontotemporal dementias, and all severities of Alzheimer’s disease. Wearable sensors represent 32% of included technologies, non-wearables 61%, and technologies with components of both account for the remaining 7%. Neurocognition is the most prevalent concept of interest, followed by physical activity and sleep. Clinical validation is reported in 69% of evidence, analytical validation in 34%, and usability/feasibility in 20% (not mutually exclusive). These findings provide clinicians and researchers a landscape overview describing the range of technologies for assessing Alzheimer’s disease and related dementias. A living library of technologies is presented for the clinical and research communities which will keep findings up-to-date as the field develops.