Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission

Biomarkers of aging: from molecules and surrogates to physiology and function

Many countries face an unprecedented challenge in aging demographics. This has led to an exponential growth in research on aging, which, coupled to a massive financial influx of funding in the private and public sectors, has resulted in seminal insights into the underpinnings of this biological process. However, critical validation in humans has been hampered by the limited translatability of results obtained in model organisms, additionally confined by the need for extremely time-consuming clinical studies in the ostensible absence of robust biomarkers that would allow monitoring in shorter time frames. In the future, molecular parameters might hold great promise in this regard. In contrast, biomarkers centered on function, resilience, and frailty are available at the present time, with proven predictive value for morbidity and mortality. In this review, the current knowledge of molecular and physiological aspects of human aging, potential antiaging strategies, and the basis, evidence, and potential application of physiological biomarkers in human aging are discussed.

Patterns of Factors in the National Institute on Aging Health Disparities Research Framework Domains and Mild Cognitive Impairment Risk

Introduction

Alzheimer's disease and related dementias are public health and social care challenges. This study used the National Institute on Aging Health Disparities Research Framework to organize potential cognitive impairment risk factors. It aimed to examine patterns of environmental, sociocultural, behavioral, and biological factors and identify key components that predict mild cognitive impairment risk.

Methods

This study comprised 2,812 participants from the Mayo Clinic Study of Aging who were cognitively unimpaired at baseline (aged ≥50 years, mean age [SD]=68.9 [9.7] years, 50.4% female). Analyses utilized a 2-stage approach using factor and principal component analyses to group factors from multiple National Institute on Aging Health Disparities Research Framework domains and identify components that predict cognitive impairment risk. Using a cohort study design, the resulting composite scores were considered as covariates for incident mild cognitive impairment analysis using Cox proportional hazards models.

Results

Three principal components explained 40.30% of the variance and were differentially associated with mild cognitive impairment risk. One component (Principal Component 2), which included factors from all 4 domains of the National Institute on Aging Health Disparities Research Framework (including social, group, and playing game activities [sociocultural domain]; exercise and physical activity [behavioral domain]; education/occupation [environmental domain]; and absence of cardiometabolic risk factors/health self-rating [biological domain]), was associated with lower mild cognitive impairment risk (hazard ratio=0.80, 95% CI=0.73, 0.89). The other 2 principal components, also including factors from multiple framework domains, were associated with increased mild cognitive impairment risk.

Conclusions

Derived principal components included factors from multiple framework domains, supporting the multietiology pathways leading to cognitive impairment. These principal components were differentially associated with mild cognitive impairment risk. Identifying key factors from multiple National Institute on Aging Health Disparities Research Framework domains associated with cognitive impairment risk has implications for effectively targeting interventions at multiple levels (e.g., medical, societal, policy) to avert or delay cognitive impairment risk.

Exploring the connection between dementia and cardiovascular risk with a focus on ADAM10

Alzheimer's disease (AD) represents a leading cause of dementia, characterized by progressive cognitive and functional decline. Although extensive research has unraveled critical aspects of AD pathology, its etiology remains incompletely understood, urging further exploration into potential risk factors. Growing evidence underscores a significant link between cardiovascular disease (CVD) risk factors and AD, with modifiable lifestyle elements - such as physical inactivity, high low-density lipoprotein (LDL) levels, obesity, hypertension, atherosclerosis, and diabetes - emerging as contributors to cerebrovascular damage and neurodegeneration. ADAM10, a disintegrin and metalloproteinase involved in the non-amyloidogenic processing of amyloid precursor protein (APP), has garnered interest for its dual role in cardiovascular and neurodegenerative processes. ADAM10's regulation of neuroinflammation, endothelial function, and proteolytic cleavage of APP potentially moderates amyloid-β (Aβ) peptide formation, thus influencing both cardiovascular and brain health. Given these interconnected roles, this narrative review investigates whether ADAM10-driven vascular dysfunction accelerates neurodegeneration, how lipid metabolism influences ADAM10 activity in CVD and AD, and whether targeting ADAM10 could offer a dual-benefit therapeutic strategy to mitigate disease burden. By exploring epidemiological data, clinical studies, and molecular pathways, we aim to clarify ADAM10's bridging function between AD and cardiovascular risk, offering a new perspective into therapeutic opportunities to alleviate the dual burden of these interrelated conditions.

Exploring the nexus: Sleep disorders, circadian dysregulation, and Alzheimer's disease

We reviewed the connections among Alzheimer's disease (AD), sleep deprivation, and circadian rhythm disorders. Evidence is mounting that disrupted sleep and abnormal circadian rhythms are not merely symptoms of AD, but are also involved in accelerating the disease. Amyloid-beta (Aβ) accumulates, a feature of AD, and worsens with sleep deprivation because glymphatic withdrawal is required to clear toxic proteins from the brain. In addition, disturbances in circadian rhythm can contribute to the induction of neuroinflammation and oxidative stress, thereby accelerating neurodegenerative processes. While these interactions are bidirectional, Alzheimer's pathology further disrupts sleep and circadian function in a vicious cycle that worsens cognitive decline, which is emphasized in the review. The evidence that targeting sleep and circadian mechanisms may serve as therapeutic strategies for AD was strengthened by this study through the analysis of the molecular and physiological pathways. Further work on this nexus could help unravel the neurobiological mechanisms common to the onset of Alzheimer's and disrupted sleep and circadian regulation, which could result in earlier intervention to slow or prevent the onset of the disease.

Association of Early- to Midlife Weight Trajectories With Mid- to Late-Life Cognitive Decline in the ELSA-Brasil Study

BACKGROUND AND OBJECTIVES

While midlife obesity is consistently associated with cognitive decline in later life, there is limited understanding of how weight variations from early life to midlife affect cognitive decline. We investigated the association between early- to midlife weight trajectories and mid- to late-life cognitive decline.

METHODS

This is a longitudinal cohort study that used data from 3 waves (2008-2019) of the Brazilian Longitudinal Study of Adult Health, a multicenter cohort study that enrolled active and retired public servants aged 35+ years from public universities in Brazil. Participants with a history of stroke, missing cognitive data at baseline, and with incomplete body shape data were excluded from the analyses. Self-reported body shapes from ages 5 to 40 using the Stunkard Figure Rating Scale were categorized as underweight, normal, overweight, and obese. Sequence analysis and hierarchical clustering identified weight trajectories. Global cognition Z-scores were derived from memory (immediate recall, delayed recall, and recognition of a word list), phonemic and semantic verbal fluency, and Trail Making Test part B (TMT-B). Linear mixed models adjusted for sociodemographic, clinical, and lifestyle covariates investigated associations between clusters of weight trajectories and global cognition Z-scores. Inverse probability of attrition weighting was used to account for attrition bias.

RESULTS

Among 11,361 participants (mean age: 51.5 ± 8.6, 55% women, 42.4% Black/mixed race), "normal to overweight," "underweight to normal," and "stable overweight" trajectories exhibited faster global cognitive decline than "stable normal" trajectory (β = -0.024; 95% CI -0.043 to -0.005; p = 0.015; β = -0.026; 95% CI -0.040 to -0.012; p < 0.001; β = -0.034; 95% CI -0.066 to -0.001; p = 0.043, respectively), representing 4.6-6.5 excess years of cognitive aging over a median follow-up of 8 years. Cognitive decline associated with weight trajectories was driven mainly by declines in memory and TMT-B performance. Associations were observed only in Black/mixed races and women when stratified.

DISCUSSION

Weight gain and stable overweight trajectories from early life to midlife were associated with faster cognitive decline than stable normal weight trajectories. Weight management during early life may mitigate cognitive decline. Study limitations include reliance on self-reported body shape data, potential recall bias, and residual confounding from unmeasured early-life factors.

Electroacupuncture ameliorates cognitive impairment and white matter injury in vascular dementia rats via activating HIF-1α/VEGF/VEGFR2 pathway

Vascular dementia (VaD) significantly impairs patients' quality of life and imposes a major social and economic burden. Electroacupuncture (EA), a contemporary modification of traditional acupuncture, has demonstrated potential in improving cognitive function in VaD, particularly when applied at the Shenting and Baihui. However, the underlying mechanisms remain inadequately understood. Elucidating how EA ameliorates cognitive deficits is critical for validating its clinical application and advancing non-pharmacological interventions for neurodegenerative disorders. This study aimed to investigate the neuroprotective mechanisms of electroacupuncture at these acupoints on cognitive function in VaD rats. VaD was induced in male Sprague-Dawley rats through bilateral common carotid artery occlusion (BCAO), with sham rats serving as controls. Rats were subsequently divided into three groups: BCAO, BCAO + EA and BCAO + EA + YC-1 (a HIF-1α inhibitor). Electroacupuncture was applied to the Shenting and Baihui. Cerebral blood flow (CBF) was measured using dynamic susceptibility contrast functional MRI, and cognitive recovery was evaluated through the Morris water maze. Immunohistochemical analysis quantified myelin repair and angiogenesis, while expression of HIF-1α, VEGF and VEGFR2 in white matter was quantified using PCR and Western blot. The results indicated that electroacupuncture improved learning and memory, increased CBF, enhanced myelin recovery and promoted angiogenesis in VaD rats. The expression of HIF-1α, VEGF and VEGFR2 in the white matter was significantly elevated in VaD rats. Electroacupuncture at Shenting and Baihui activates the HIF-1α/VEGF/VEGFR2 pathway, enhances angiogenesis, white matter perfusion and myelin repair, thereby restoring cognitive function in VaD rats.

Integrating neural substrates, diabetes self-management, and behavior change for tailored lifestyle interventions in type-2 diabetes: A neurobehavioral perspective

Understanding the neural mechanisms that underlie behavior change is critical for improving lifestyle management in type 2 diabetes. Individuals with type 2 diabetes face unique challenges in adopting and maintaining healthy behaviors, which can be influenced by alterations in brain function and plasticity, potentially leading to cognitive impairment. Diabetes self-management education and support (DSMES) programs aim to enhance lifestyle changes and promote better health outcomes while reducing cognitive decline. However, complex neural disruptions in critical regions for cognitive processes like the prefrontal cortex and parietal lobe present significant challenges. Given the likely role of neural mechanisms in behavioral choices, understanding how type 2 diabetes affects these neural substrates is crucial for developing effective interventions. Despite considerable research efforts aimed at testing lifestyle interventions, a critical gap remains in understanding the cognitive and behavioral components of successful diabetes self-management, the neural substrates of those components, and the impact of diabetes on those neural substrates. Bridging this gap necessitates a comprehensive examination integrating neural processes, DSMES strategies, and behavior change models. Thus, this perspective review highlights the urgent need to address the knowledge gaps surrounding the neural correlates of diabetes self-management and the integration of behavioral models into intervention frameworks. We propose a hypothesis-generating question and present preliminary findings comparing neural plasticity, executive functions, and lifestyle behavior among individuals with type 2 diabetes, pre-diabetes, and healthy controls. By elucidating the neural substrates underpinning diabetes and exploring their implications for DSMES and readiness to change, we can pave the way for more effective, personalized approaches to diabetes care.

Use of sodium-glucose cotransporter-2 inhibitors and risk of dementia: A population-based cohort study

BACKGROUND AND AIMS

The effects of sodium-glucose co-transporter 2 inhibitors (SGLT-2i) on dementia risk have not been assessed in the Chinese population. We aimed to assess the association between the use of SGLT-2i and dementia incidence in a mainland Chinese population.

MATERIALS AND METHODS

A target trial of SGLT-2i vs. dipeptidyl peptidase 4 inhibitors (DPP-4i) was emulated, with cohorts of type 2 diabetes mellitus patients who were new users of SGLT-2i or DPP-4i being assembled using the Yinzhou Regional Health Care Database. Inverse probability of treatment weighting (IPTW) was applied to control potential confounding, and a Cox model was used to estimate the hazard ratio (HR) of the association between the use of SGLT-2i and incident dementia.

RESULTS

The final cohort included 47 335 new users of DPP-4i or SGLT-2i. In the primary analysis, the incidence of dementia was 500.2 and 347.5 per 100 000 person-years in users of DPP-4i and SGLT-2i, respectively. SGLT-2i use was associated with a reduced risk of incident dementia after adjusting for potential confounding using IPTW, with an HR of 0.74 (95% CI, 0.60-0.93). The results were generally consistent in various subgroup analyses and sensitivity analyses.

CONCLUSIONS

The use of SGLT-2i is associated with a decreased risk of dementia incidence in the study population in mainland China.

Predicting Progression to Dementia Using Auditory Verbal Learning Test in Community-Dwelling Older Adults Based On Machine Learning

BACKGROUND

Primary healthcare institutions find identifying individuals with dementia particularly challenging. This study aimed to develop machine learning models for identifying predictive features of older adults with normal cognition to develop dementia.

METHODS

We developed four machine learning models: logistic regression, decision tree, random forest, and gradient-boosted trees, predicting dementia of 1,162 older adults with normal cognition at baseline from the Hubei Memory and Aging Cohort Study. All relevant variables collected were included in the models. The Shanghai Aging Study was selected as a replication cohort (n = 1,370) to validate the performance of models including the key features after a wrapper feature selection technique. Both cohorts adopted comparable diagnostic criteria for dementia to most previous cohort studies.

RESULTS

The random forest model exhibited slightly better predictive power using a series of auditory verbal learning test, education, and follow-up time, as measured by overall accuracy (93%) and an area under the curve (AUC) (mean [standard error]: 088 [0.07]). When assessed in the external validation cohort, its performance was deemed acceptable with an AUC of 0.81 (0.15). Conversely, the logistic regression model showed better results in the external validation set, attaining an AUC of 0.88 (0.20).

CONCLUSION

Our machine learning framework offers a viable strategy for predicting dementia using only memory tests in primary healthcare settings. This model can track cognitive changes and provide valuable insights for early intervention.

Initiation of Hearing Aids Use and Incident Dementia Among Mid-to-late Life Adults: The Health and Retirement Study 2010-2018

Background and ObjectivesHearing aids may reduce the risk of dementia among individuals with hearing loss. However, no evidence is available from randomized controlled trials (RCTs) on the effectiveness of hearing aids use in reducing incident dementia. Using target trial emulation, we leveraged an existing longitudinal cohort study to estimate the association between hearing aids initiation and risk of dementia.Research Design and MethodsThe Health and Retirement Study was used to emulate target trials among non-institutionalized participants aged ≥50 years with self-reported hearing loss, without dementia at baseline, and without use of hearing aids in the previous 2 years. Intention-to-treat analysis was conducted to estimate the risk of dementia associated with hearing aids initiation vs controls who did not initiate hearing aids. Pooled logistic regression models with inverse-probability of treatment and censoring weights were applied to estimate risk ratios, and 95% confidence intervals were calculated using 1000 sets of bootstrapping.ResultsAmong 2314 participants (328 in the intervention group and 1986 in the control group; average age: 72.3 ± 9.7 years, 49% women, and 81% White), after 8 years of follow-up, risk of dementia was significantly lower among individuals who initiated hearing aids (risk difference (RD): -0.05, 95% confidence interval (CI): -0.08, -0.01). A lower risk was observed particularly among adults aged 50-74 years, men, and individuals with cardiovascular disease.Discussion and ImplicationsHearing aids use was associated with a significant reduction of incident dementia. Future interventional studies are needed to further assess the effectiveness of hearing aids in preventing dementia.

C-reactive protein-mediated dementia

Loss of memory is the main feature of dementia, accompanied by personality changes. Alzheimer's disease (AD) is the most prevalent type of dementia globally and a major contributor to disability and mortality in older individuals. Most notably, the neurological damage caused by AD is irreversible, but the current market still lacks effective medications for the treatment of dementia. Numerous research studies have indicated that the inflammatory response is significantly involved in the development of cognitive impairment, and elevated C-reactive protein (CRP) levels in healthy people increases the likelihood of future AD. CRP is a nonspecific indicator of inflammation. In clinical practice, CRP has long been proven to be one of the risk factors and powerful predictors of neurodegenerative diseases. Given the accessibility and cost-effectiveness of CRP testing, it is reasonable to anticipate its utilisation for early screening and monitoring the progression of AD in the future. This review therefore focuses on the specific relationship between CRP and various types of dementia and explores how CRP contributes to cognitive impairment.

Cardiovascular health and its association with dementia, Parkinson's Disease, and mortality among UK older adults

Background

Previous research has primarily examined individual factors of cardiovascular health (CVH) and disease in PD and dementia, but no study has examined CVH measures with PD, dementia, and mortality simultaneously while accounting for potentially confounding factors.

Objectives

To examine the relationship between CVH, all-cause dementia, Parkinson's disease (PD), and mortality, focusing on associations and health transitions from a large population-based study.

Methods

We investigated these relationships using Cox Proportional Hazards and multistate parametric models with Weibull regression from the UK Biobank data (n = 269,816, Age = 50 + y individuals, ≤15y follow-up, 2006-2021).

Results

Full Cox models found poor CVH (measured with standardized reverse-coded Life's Essential 8 total score, LE8zrev), to be associated with increased risks for all-cause dementia (Hazard Ratio (HR) = 1.14, 95 % CI: 1.11-1.18, P < 0.001) and all-cause mortality (HR = 1.31, 95 % CI: 1.29-1.33, P < 0.001). Unlike "Healthy to PD" and "Dementia→Death" transitions, PD→Death (Weibull full model: HR = 1.18, 95 % CI: 1.06-1.31, P = 0.002), Healthy→dementia (HR = 1.15, 95 % CI: 1.12-1.19, P < 0.001), and Healthy→Death (HR = 1.33, 95 % CI: 1.32-1.35, P < 0.001) exhibited a positive relationship with poor CVH.

Conclusions

Poor CVH is directly associated with an increased risk of mortality from PD, transition into Dementia, and all-cause mortality without dementia or PD occurrence. Clinicians should aggressively screen for and manage CVH risk measures to reduce the risk of poor cognitive health outcomes.

Enhanced social interaction protects cognition by preserving synapse numbers

BACKGROUND

According to the NIA-AA guidelines, pathological diagnosis as Intermedia (I) or High (H) via ABC scores qualifies as pathological Alzheimer's disease (AD). Multiple studies indicated that some individuals, while pathologically diagnosed with AD, maintain normal cognitive function during their lifetime, here defined as resilient AD (rAD). In contrast to typical AD (tAD), characterized by both pathological AD diagnosis and dementia, rAD brains exhibited no significant differences in AD pathology but showed increased synapse numbers. To date, there is limited systematic reporting on the epidemiology and protective factors for rAD.

METHODS

This study surveyed reports from multiple global centers to estimate the prevalence of rAD within the pathological AD population. Based on the PUMC Human Brain Bank, I analyzed risk factors and gene mutations associated with dementia severity in pathological AD. Additionally, mouse models were employed to explore the protective effects of enhanced social interaction on cognitive function in pathological AD.

RESULTS

Analysis of multiple global cohorts revealed that rAD accounted for 25-36 % of pathological AD cases. Analysis of the PUMC Human Brain Bank indicated that the severity of dementia in pathological AD was not associated with age or gender. However, the tAD group showed a significantly higher prevalence of social isolation. Genetic analysis suggested that TREM2 rs2234255 GG > CC and APP rs281865161 TC > GG may be risk variants for cognitive impairment in pathological AD, while CLU rs9331896 CC > TT may serve as a protective variant for cognitive resilience. In 5 × FAD mice, increased social interaction did not significantly alter Aβ pathology progression but reduced synaptic loss, thereby improving cognitive function.

CONCLUSION

These findings suggested that promoting emotional care and social interaction for the elderly may help slow cognitive decline in AD patients.

An overview of World Health Organization guidance aiming to increase global access to critical hearing aid services

OBJECTIVE

Equitable access to hearing aids and related services remains a global health challenge, particularly in resource-limited settings. A major barrier to access is the lack of diagnostic and rehabilitative services, which is substantially attributable to the persistent shortage of ear and hearing care specialists. This discussion article provides an overview of limitations in the ear and hearing care workforce, the relevance of task sharing to ear and hearing care, and a new, evidence-based World Health Organization (WHO) technical resource aimed at improving access to hearing aids worldwide.

DESIGN AND STUDY SAMPLE

A synthesis of current research and expert opinion.

RESULTS

First, this article describes the global shortage of qualified ear and hearing care specialists. Next, it describes how community-based care, supported by task sharing among trained non-specialist providers and qualified ear and hearing care providers, could overcome these workforce limitations, and describes the critical role of qualified ear and hearing care providers in task sharing. Finally, this article provides an overview of a WHO resource which provides practical information for hearing aid service provision in resource-limited settings.

CONCLUSION

Innovative strategies to expand the ear and hearing care workforce are essential to advance efforts towards equitable access to hearing aids and related services.

Housing damage and forgetfulness following the 2024 Noto Peninsula earthquake, Japan

On January 1, 2024, a major earthquake struck Japan's Noto Peninsula. From 2021 to 2023, we conducted a baseline survey. Four months after the disaster, we conducted a follow-up survey to investigate the relationship between house damage and forgetfulness in older adults without dementia. A total of 923 individuals were included. Among the respondents, 32.2% and 33.8% reported as suffered major house damages and increased forgetfulness, respectively. Multivariate analysis revealed major house damage was significantly associated with self-reported forgetfulness, which are partly mediated through sleep disturbance and sedentary behavior in the cognitively unimpaired and mild cognitive impairment groups, respectively.

Harmonized prevalence estimates of dementia in Europe vary strongly with childhood education

Up-to-date, strictly cross-nationally comparable and nationally representative data on cognitive health are essential for our understanding of the dementia-related challenges in healthcare, to detect shortcomings in healthcare systems and to design effective prevention strategies. Such data have been missing in Europe. We use the most recent 2022 wave of the strictly harmonized Survey of Health, Ageing and Retirement in Europe (SHARE, 47,773 individuals age 65 and older) to obtain prevalence estimates of mild cognitive impairment and dementia for 27 European countries and Israel in 2022. The novelty of the paper is to validate these estimates using the Harmonized Cognitive Assessment Protocol (HCAP) as a validation tool. These new data exhibit much higher prevalence rates of dementia in the Mediterranean and Southeastern European countries and a much larger variation of cognitive impairment across Europe and Israel than previously known. Dementia prevalence ranges from 4.5% in Switzerland to 22.7% in Spain, MCI prevalence from 17.2% in Sweden to 31.1% in Portugal. Most of this variation can be explained by differences in education when respondents were young. Prevalence rates vary plausibly with other risk factors such as age and comorbidities associated with dementia.

Sex differences in body mass index and waist circumference trajectories and dementia risk: the HUNT4 70+ study

We examined associations between body mass index (BMI), waist circumference (WC), and dementia risk, and differences in BMI and WC trajectories before dementia diagnosis. We included 9,739 participants (54% women) aged 70+ from the Trøndelag Health Study (HUNT4 70+). BMI was measured four times (1984-2019) and WC three times (1995-2019). Dementia diagnoses were clinically assessed at HUNT4 70+ . Women and men with dementia had higher midlife BMI and WC than those without dementia. These differences diminished closer to diagnosis, especially in women. Midlife obesity in both sexes and midlife overweight, high WC, and overweight/obesity with high WC in men were linked to higher dementia risk. Lower dementia risk was observed with late-life overweight for both sexes, late-life high WC in women, late-life overweight/obesity with normal WC in men or high WC in women. Adiposity measures and their changes influence dementia risk differently in women and men.

What Information do Systemic Pathological Changes Bring to the Diagnosis and Treatment of Alzheimer's Disease?

Alzheimer's disease (AD) is regarded as a neurodegenerative disease, and it has been proposed that AD may be a systemic disease. Studies have reported associations between non-neurological diseases and AD. The correlations between AD pathology and systemic (non-neurological) pathological changes are intricate, and the mechanisms underlying these correlations and their causality are unclear. In this article, we review the association between AD and disorders of other systems. In addition, we summarize the possible mechanisms associated with AD and disorders of other systems, mainly from the perspective of AD pathology. Regarding the relationship between AD and systemic pathological changes, we aim to provide a new outlook on the early warning signs and treatment of AD, such as establishing a diagnostic and screening system based on more accessible peripheral samples.

Hydrate to keep the amyloid away

Despite older adults being more susceptible to dehydration, the relation between hydration and Alzheimer's disease and related dementias (ADRD) remains largely unexplored. A recent study by Jee Wook Kim and colleagues examined the association between daily fluid intake and ADRD neuroimaging biomarkers in 287 cognitively normal older adults. They found that lower daily fluid intake was associated with greater brain Aβ deposition and cerebrovascular injury. Here, we discuss the strengths and limitations of this study. We further highlight the potential for reverse causality and how hydration may play a role in the clinic and future ADRD research studies.

Telomere Length and Cognitive Function Among Middle-Aged and Older Participants From Communities Underrepresented in Aging Research: A Preliminary Study

ObjectiveAccelerated biological aging is a plausible and modifiable determinant of dementia burden facing minoritized communities but is not well-studied in these historically underrepresented populations. Our objective was to preliminarily characterize relationships between telomere length and cognitive health among American Indian/Alaska Native (AI/AN) and Black/African American (B/AA) middle-aged and older adults.MethodsThis study included data on telomere length and neuropsychological test performance from 187 participants, enrolled in one of two community-based cognitive aging cohorts and who identified their primary race as AI/AN or B/AA.ResultsNested multivariable regression models revealed preliminary evidence for associations between telomere length and cognitive performance, and these associations were partially independent of chronological age.DiscussionSmall sample size limited estimate precision; however, findings suggest future work on telomere length and cognitive health in underrepresented populations at high risk for dementia is feasible and valuable as a foundation for social and behavioral intervention research.

Association between social networking and dementia: A systematic review of observational studies

Poor social networking (SN) is associated with the development of cognitive impairment and dementia. Our objective was to perform a systematic review of the evidence on the associations between SN and the incidence of dementia, disease pathology, level of cognition, and brain structure. Bibliographic databases (PubMed, Embase, Cochrane Library, CINAHL) and additional sources (Open Gray, Google Scholar, manual searches) were screened through November 30, 2024. Observational studies assessing the SN-dementia link were selected, with data extraction and bias evaluation performed independently by two authors via the PRISMA checklist and Newcastle-Ottawa Scale. We included 17 observational studies (355 initially screened), involving 20,678 participants aged 40-90 years, published between 2000 and 2024. Studies have utilized various SN assessment tools and cognitive measures, including the MMSE and MoCA. Poor SN was consistently associated with increased risks of dementia, cognitive decline, and severe disease pathology, particularly Alzheimer's disease (AD). Larger and more integrated SNs were linked to better cognitive resilience and lower conversion rates from mild cognitive impairment (MCI) to dementia. One study on frontotemporal dementia (FTD) indicated that the SN might mitigate cortical atrophy. SN size and density are also correlated with favorable structural brain changes, such as greater gray matter volume. This review highlights SN as a modifiable factor in dementia risk. However, its role in non-AD dementia, particularly FTD, requires further investigation. Future research should include more culturally diverse and methodologically robust studies. Randomized controlled trials will be important to determine whether intervention to expand social networks decreases incidence of progression of dementia.

Incident Hearing Loss and Subsequent Risk of Dementia: The Health and Retirement Study 2010-2018

Background and ObjectivesWhile hearing loss is a known risk factor for dementia, the impact of incident hearing loss on subsequent dementia risk remains underexplored. This study examined the association between newly reported hearing loss and dementia risk in U.S. adults, focusing on critical intervention periods for dementia prevention.Research Design and MethodsParticipants from the Health and Retirement Study who reported no hearing loss or hearing aid use in 2010 or 2012 were included. Incident hearing loss and dementia were assessed via self-report and proxy report. Pooled logistic regression models with inverse probability weighting estimated the cumulative incidence of dementia at 2, 4, 6, and 8 years after baseline. Risk ratios (RR) with 95% confidence intervals were calculated from 200 bootstrap samples. Subgroup analyses were conducted by age, sex, and cardiovascular disease (CVD) status.ResultsAmong 13,599 participants, 1125 (8.3%) reported incident hearing loss. Dementia incidence was higher among those with hearing loss (6.6%) compared to those without (4.9%). Starting at 4 years, incident hearing loss was associated with a higher dementia risk, persisting at 8 years (RR = 1.34; 95% CI: 1.05, 1.59). This association was significant among individuals aged 50-64 years and those with CVD.Discussion and ImplicationsIncident hearing loss is associated with a heightened dementia risk, particularly in midlife and among individuals with CVD. Future research should investigate the effectiveness of timely interventions aimed at preventing dementia in individuals with hearing loss.

Global trends in prevalence, disability adjusted life years, and risk factors for early onset dementia from 1990 to 2021

This study aims to analyze temporal trends in the prevalence and disability-adjusted life year (DALY) burden of early-onset dementia (EOD) globally from 1990 to 2021 and assess the attributable burdens of modifiable risk factors. Data from the Global Burden of Disease Study (GBD) 2021 were used. EOD was defined as dementia in individuals aged 40-64. The analysis included case numbers, age-standardized prevalence rates (ASPRs), and DALY rates (ASDRs) with 95% confidence intervals (CIs), stratified by global, regional, and national levels, sociodemographic index (SDI), and sex. Joinpoint regression analysis evaluated the average annual percent change (AAPC). Population attributable fractions (PAFs) estimated the proportion of DALYs attributable to risk factors. The global number of EOD cases and DALYs nearly doubled from 1990 to 2021, reaching 7.758 million cases (95% CI 5.827-10.081) and 3.774 million DALYs (95% CI 1.696-8.881) in 2021. ASPR and ASDR increased slightly to 355.9 (95% CI 267.2-462.8) and 173.3 (95% CI 77.9-407.7) per 100,000 in 2021. In 2021, the highest ASPR was in high-middle SDI countries at 387.6 per 100,000 (95% CI 291.1-506.8), while the highest ASDR was in middle SDI at 182.9 per 100,000 (95% CI 82.2-431). The fastest ASDR increase was in low and low-middle SDI countries from 2010 to 2021, with AAPCs of 0.42% (95% CI 0.34-0.50) and 0.36% (95% CI 0.33-0.39), respectively. A significant negative correlation was found between SDI and ASDR. During the COVID-19 pandemic (2019-2021), ASPR and ASDR in high-SDI countries declined, while other SDI regions saw an accelerated increase. In 2021, high fasting plasma glucose (FPG) was the most significant attributable risk factor for EOD-related DALYs globally, with PAFs for high body mass index and high FPG increasing in nearly all regions since 1990, while the PAF for smoking decreased. In 2021, EOD burden was highest in high-middle and middle SDI countries, particularly rising during the COVID-19 pandemic. The growing influence of metabolic risk factors underscores the need for targeted public health policies and resource allocation to mitigate the EOD burden.

Multimorbidity and risk of dementia: A systematic review and meta-analysis of longitudinal cohort studies

BACKGROUND

Chronic diseases (e.g., hypertension, diabetes, and heart diseases) have been proposed as marked predictors of incident dementia. However, synthesised evidence on the effect of multimorbidity on dementia is still lacking. We aim to summarise the association between multimorbidity and risk of dementia in longitudinal cohorts.

METHODS

In this systematic review and meta-analysis, we conducted a systematic search in PubMed, Web of Science and Embase from inception to Dec 14, 2024, to identify longitudinal cohort studies reporting the association between multimorbidity or multimorbidity patterns and risk of dementia. Information of included studies were extracted by three reviewers (YaZ, YY and YuZ), and the quality assessment was conducted using the Newcastle-Ottawa Scale. The inverse-variance weighted random effects meta-analysis was performed to obtain the pooled hazard ratios (HRs) and 95 % confidence intervals (CIs) for dementia associated with multimorbidity and cardiometabolic multimorbidity (CMM). Cochran's Q test and the I2 statistic were used to indicate heterogeneity among the studies. Meta-regression analysis, subgroup analysis and sensitivity analysis were conducted to determine any valid sources of heterogeneity. This study was registered with PROSPERO (CRD42023403684).

RESULTS

We included 17 longitudinal cohort studies (2262,885 middle-aged and older participants) in the systematic review, of which seven were included in meta-analysis. All studies presented moderate to high methodological quality. Meta-analysis showed a positive association between multimorbidity and incident dementia (HR=1.53, 95 % CI=1.12 to 2.09), with substantial heterogeneity (I2=95.2 %). Studies using health records to measure dementia tend to find a stronger positive relationship between multimorbidity and risk of dementia than those using self-report (HRhealth records=1.94, 95 % CI=1.35 to 2.78, I2=94 %; HRself-report=1.17, 95 % CI=1.07 to 1.28, I2=0 %). The impacts of CMM were also observed, and the HRs for dementia ranged from 2.49 (combination of heart diseases and stroke: 95 % CI=1.64 to 3.78) to 3.77 (combination of diabetes, heart diseases and stroke: 95 % CI=2.02 to 7.02). The heterogeneity was moderate, with I2 ranging from 46.9 % (p for heterogeneity=0.152) to 84.1 % (p for heterogeneity=0.002). The impacts of number of diseases, multimorbidity clusters, and multimorbidity trajectory on risk of dementia were narratively summarised due to lacking comparable studies. Limited evidence (only one study) precluded quantitative synthesis for the association of physical and psychological multimorbidity with dementia.

CONCLUSION

Multimorbidity and CMM pattern were significantly associated with risk of dementia, while the effect of physical and psychological multimorbidity remain inconclusive. Individuals affected by multimorbidity should be prioritised in risk factor modification and dementia prevention. Preventing the development of multimorbidity is also crucial-particularly those who already have one chronic disease-in order to maintain cognitive health.

Human skeletal muscle mitochondrial pathways are impacted by a neuropathologic diagnosis of Alzheimer's disease

Alzheimer's disease (AD) is associated with reduced lean mass and impaired skeletal muscle mitochondrial and motor function. Although primary mitochondrial defects in AD may underlie these findings, molecular alterations in AD have not been thoroughly examined in human skeletal muscle. Here, we used two human skeletal muscle types, quadriceps (n = 81) and temporalis (n = 66), to compare the proteome of individuals with a neuropathologic AD diagnosis based on AD Neuropathologic Change (ADNPC+: n = 54 temporalis, 44 quadriceps) to controls (ADNPC-: n = 27 temporalis, 22 quadriceps). We determined the effects of ADNPC status within each muscle and within apolipoprotein E4 (APOE4) carriers and APOE4 non-carriers. Pathways that support mitochondrial metabolism, including oxidative phosphorylation, were downregulated in skeletal muscle of ADNPC+ versus ADNPC- individuals. Similar mitochondrial effects were observed across muscle types and APOE4 carrier groups, but nearly four times as many proteins were altered in temporalis versus quadriceps tissue and mitochondrial effects were most pronounced in APOE4 carriers compared to APOE4 non-carriers. Of all detected oxidative phosphorylation proteins, the expression of ∼29-61 % (dependent on muscle/APOE4 carrier group) significantly correlated with AD progression, ranked by Clinical Dementia Rating and ADNPC scores. Of these, 23 proteins decreased in expression with greater AD progression in all skeletal muscle type and APOE4 carrier groups. This is the first study to assess differences in the human skeletal muscle proteome in the context of AD. Our work shows that systemic mitochondrial alterations in AD extend to skeletal muscle and these effects are amplified by APOE4 and correlate with AD progression.

Association between trajectories of life-course group sports participation and dementia: A 3-year longitudinal study

OBJECTIVES

The evidence for a causal effect of physical activity (PA) on dementia risk remains inconclusive. Group sports participation may impact dementia risk differently compared to PA. This study aimed to examine the association between long-term group sports participation trajectories across the life course and dementia onset among older Japanese adults.

STUDY DESIGN

Cohort study.

METHODS

This cohort study included 8277 adults aged ≥65 years from the Japan Gerontological Evaluation Study. Life-course group sports participation was assessed through self-reported questionnaires, and Group-Based Trajectory Modelling (GBTM) was used to identify participation trajectories. Dementia onset was determined using public long-term care insurance-system registries, and Cox proportional hazards models were employed to assess associations between trajectory groups and dementia onset.

RESULTS

GBTM identified four trajectories: persistently low (n = 5164, 62.4 %), dropout after high school (n = 2150, 26.0 %), dropout after young adulthood (n = 446, 5.4 %), and increase in midlife (n = 517, 6.2 %). During a mean follow-up of 3.2 years, 311 participants developed dementia. After adjusting for confounders, the dropout after young adulthood group had a significantly higher dementia risk than did the persistently low group (hazard ratio, 95 % confidence interval, 1.85, 1.09-3.16). No significant differences were observed between the dropout after high school (1.13, 0.84-1.52) and the increase in midlife (1.36, 0.78-2.39) groups compared to the persistently low group.

CONCLUSIONS

The risk of dementia may vary depending on life-course group sports participation patterns. Further studies are needed to establish these findings, including examining specific types of sports and individual PA levels.

Risk of Dementia in Individuals With Emergency Department Visits or Hospitalizations Due to Cannabis

Importance

Cannabis use is associated with short-term memory impairment and long-term changes in brain structure; however, little is known about whether disordered cannabis use is associated with an increased risk of a dementia diagnosis.

Objective

To investigate the association between emergency department visits or hospitalizations (acute care encounters) due to cannabis and future dementia diagnosis.

Design, Setting, and Participants

Population-based, retrospective, matched cohort study using health administrative data from Ontario, Canada, between 2008 and 2021 (with follow-up until 2022) including all individuals aged 45 to 105 years living in Ontario who were eligible and did not have a diagnosis of dementia at cohort entry (2 620 083 individuals excluded).

Exposure

Individuals with incident acute care due to cannabis use, defined using International Classification of Diseases and Related Health Problems, Tenth Revision coding.

Main Outcomes and Measures

We used cause-specific adjusted hazard models to compare new diagnoses of dementia (from a validated algorithm) between individuals with acute care due to cannabis use with (1) individuals with all-cause acute care (excluding cannabis), (2) the general population, and (3) individuals with acute care due to alcohol use.

Results

The study included 6 086 794 individuals, of whom 16 275 (0.3%) had incident acute care due to cannabis use (mean age, 55.2 [SD, 8.3] years; 60.3% male). Annual rates of incident acute care due to cannabis use increased 5.0-fold in individuals aged 45 to 64 years (from 10.16 to 50.65 per 100 000) and 26.7-fold in individuals aged 65 years or older (from 0.65 to 16.99 per 100 000) between 2008 and 2021. Individuals with incident acute care due to cannabis use were at a 1.5-fold and 3.9-fold increased risk of dementia diagnosis within 5 years relative to individuals with all-cause acute care and the general population of the same age and sex, respectively (absolute rates of dementia diagnosis: 5.0% for cannabis-related acute care, 3.6% for all-cause acute care, and 1.3% in the general population). After adjustment for sociodemographics and chronic health conditions, individuals with acute care due to cannabis use remained at elevated risk relative to those with all-cause acute care (adjusted hazard ratio [aHR], 1.23; 95% CI, 1.09-1.39) and the general population (aHR, 1.72; 95% CI, 1.38-2.15). Individuals with acute care due to cannabis use were at lower risk than those with acute care due to alcohol use (aHR, 0.69; 95% CI, 0.62-0.76).

Conclusions and Relevance

Individuals with cannabis use severe enough to require hospital-based care were at increased risk of a new dementia diagnosis compared with those with all-cause hospital-based care or the general population. These findings have important implications considering increasing cannabis use among older adults.

Alzheimer disease seen through the lens of sex and gender

Alzheimer disease (AD) is a life-limiting neurodegenerative disorder that disproportionately affects women. Indeed, sex and gender are emerging as crucial modifiers of diagnostic and therapeutic pathways in AD. This Review provides an overview of the interactions of sex and gender with important developments in AD and offers insights into priorities for future research to facilitate the development and implementation of personalized approaches in the shifting paradigm of AD care. In particular, this Review focuses on the influence of sex and gender on important advances in the treatment and diagnosis of AD, including disease-modifying therapies, fluid-based biomarkers, cognitive assessment tools and multidomain lifestyle interventional studies.

A meta-analysis of technology use and cognitive aging

The first generation who engaged with digital technologies has reached the age where risks of dementia emerge. Has technological exposure helped or harmed cognition in digital pioneers? The digital dementia hypothesis predicts that a lifetime of technology exposure worsens cognitive abilities. An alternative hypothesis is that such exposures lead to technological reserve, wherein digital technologies promote behaviours that preserve cognition. We tested these hypotheses in a meta-analysis and systematic review of studies published in Medline, PsycInfo, CINAHL, Science Direct, Scopus, Cochrane Library, ProQuest and Web of Science. Studies were included if they were observational or cohort studies focused on general digital technology use in older adults (over age 50) and included either a cognitive or dementia diagnosis outcome. We identified 136 papers that met inclusion criteria, of which 57 were compatible with odds ratio or hazard ratio meta-analysis. These studies included 411,430 adults (baseline age M = 68.7 years; 53.5% female) from cross-sectional and longitudinal observational studies (range: 1-18 years, M = 6.2 years). Use of digital technologies was associated with reduced risk of cognitive impairment (OR = 0.42, 95% CI 0.35-0.52) and reduced time-dependent rates of cognitive decline (HR = 0.74, 95% CI 0.66-0.84). Effects remained significant when accounting for demographic, socioeconomic, health and cognitive reserve proxies. All studies were evaluated for quality on the basis of a standardized checklist; the primary outcomes replicated when limiting analyses to the highest-quality studies. Additional work is needed to test bidirectional causal interpretations, understand mechanisms that underpin technological reserve, and identify how types and timings of technology exposures influence cognitive health.

Culturally Tailored Community Brain Health Education for Chinese Americans Aged 50 or Above: A Mixed-Methods Open Pilot Study

Background: Chinese Americans, the largest Asian American subgroup in the U.S., face linguistic, cultural, and socio-economic barriers to dementia prevention. To promote brain health in this population, a culturally tailored community approach is essential. This study evaluates a culturally tailored community brain health education program to enhance brain health knowledge and motivate lifestyle changes to prevent the risk of dementia among Chinese Americans aged 50 or older. Methods: The program was developed and evaluated in four phases. First, we assessed participants' interests in brain health topics, availability, and preferred delivery modes. Next, experts on the identified topics developed educational content and outcome assessments. The third phase focused on implementing a six-session program covering general knowledge about Alzheimer's disease and related dementias, diet, sleep, physical exercise, health checks, and mindfulness. Finally, we evaluated the program's feasibility and effectiveness using pre-post surveys, feedback questionnaires, and focus groups. Results: Seventy-seven participants registered for the program, and sixty-nine (90%) attended at least four sessions. The quantitative results, based on paired t-tests, showed significant increases in brain health knowledge, sleep quality, and behavioral motivation for lifestyle changes, and a decrease in depressive symptoms, with two-tailed p-values lower than 0.05. The qualitative results further revealed promising feasibility and acceptability, as well as the perceived benefits of the program. Conclusions: The findings highlight the feasibility, acceptability, and potential effectiveness of a culturally tailored community education approach for promoting brain health and lifestyle changes. Sustained community outreach and education efforts among Chinese Americans are needed.

"We have a behaviour support plan, let's have a mental health support plan": Perspectives of staff, residents and family carers on understanding, responding to and promoting the mental health of residents within long-term care

Up to two thirds of people living in long-term care homes experience mental health conditions such as anxiety and depression. In addition, over half of residents have cognitive impairment or dementia. However, the quality of mental health care provided in residential care homes is often poor, and the use of mental health quality indictors is lacking. As the first step in a larger project to develop mental health quality indicators for long-term care (MHICare project), this study aimed to explore factors considered important for understanding and responding to mental health conditions and promoting mental well-being of residents. Individual interviews and small group discussions were conducted with twelve residents (both with and without dementia), eight family carers of residents with dementia, and six care home staff members, from across Australia. Qualitative data were analysed using an inductive thematic analysis approach to generate themes and a deductive approach to generate factors and map these to a Balanced Score Card quality indicator framework. Four main factors with several inter-related themes were identified: (1) Resident-related (Transitional impacts, Social connections and active engagement, and Pre-existing and co-morbid conditions); (2) Care and Communication Practices (Assessment and care strategies, Person-centred mental health care, Cultural and generational communication differences, and Staff handover and knowledge sharing); (3) Staff-related (Staff mental health awareness, Staff knowledge, practical skills and training needs, and Staff values and attitudes); and (4) Organisational (Internal staffing levels, Access to external mental health professionals, and Provision of volunteer programs). Findings will inform the key areas and initial content for mental health indicators for use in residential care homes. Once developed, these have the potential to highlight both strengths and gaps in current mental health care practices, and drive quality improvement initiatives.

Physical activity in Alzheimer's disease prevention: Sex differences and the roles of BDNF and irisin

Alzheimer's disease (AD) disproportionately affects women, with postmenopausal hormonal changes contributing to elevated risk. Physical exercise is a promising, non-pharmacological strategy to mitigate cognitive decline and AD progression. Brain-derived neurotrophic factor (BDNF) and irisin are key molecular mediators of exercise-induced brain health and protection against AD pathology by promoting synaptic plasticity, neurogenesis, and reducing amyloidosis, tau pathology, and neuroinflammation in sex-specific mechanisms. This review explores sex and gender influences on exercise outcomes and their interaction with FNDC5/irisin and BDNF signaling pathways in the context of AD prevention. We highlight emerging evidence on the interplay between exercise, sex, and neuroprotective pathways, emphasizing the need for sex-sensitive research designs to advance precision approaches for AD prevention.

Herpes zoster as risk factor for dementia: a matched cohort study over 20 years in a 10-million population in Italy

BACKGROUND

Herpes Zoster is caused by the reactivation of the Varicella-Zoster Virus. Zoster may influence the occurrence of dementia, but contradictory results about this association emerged from recent studies. These findings did not consider the severity of Zoster and observed individuals for limited follow-up time. Our study used a region-wide Italian registry to investigate the association between severe Zoster infection and dementia occurrence over a 23-year period.

METHODS

We included people aged ≥ 50 and hospitalised with Zoster, and two comparison cohorts from both the general population and the hospitalised population without Zoster. By random sampling, the matching 1:5 was based on sex, birth year, and entry date in the cohort. Dementia and Zoster were identified through validated algorithms. A Fine-Gray sub-distribution hazard model was used, accounting for competing risk of death.

RESULTS

We identified 132,968 individuals, of whom 12,088 with severe Zoster, 60,440 matched controls among the general population, and 60,440 matched controls among the hospitalised population. In severe cases of Herpes Zoster, the overall adjusted sub-distributed hazard ratio of dementia was 1.13 (95 % CI 1.07-1.19) compared to the general population, and 1.08 (95 % CI 1.03-1.14) compared to hospitalised population. Hazard ratios were still significant in different strata group, including by sex, age group (including in 50-65 younger adults) and at different follow-up period.

CONCLUSIONS

Our population-based study found an increased risk of developing dementia among severe Zoster cases. Those results support the importance of improving Zoster prevention and extending the vaccination recommendations to younger age groups.

Associations between the EAT-Lancet planetary health diet and incident dementia

BACKGROUND

The impact of the environmentally sustainable EAT-Lancet diet on dementia risk remains poorly understood. The aim was to investigate associations between the EAT-Lancet diet and incident dementia.

METHODS

Associations of the EAT-Lancet diet with all-cause dementia, Alzheimer's disease (AD), and vascular dementia (VaD) were investigated among 25,898 participants from the Malmö Diet and Cancer study, Sweden. Participants aged 45-73 years were recruited for the baseline examination between 1991 and 1996, and the mean follow-up time was 18 years. To assess robustness of estimations, we used seven previously constructed EAT-Lancet diet scores. Multi-adjusted Cox proportional hazard analyses were performed, with results presented per 10 % in increment scores. Additionally, we explored the potentially modifying effect of APOE ε4 status in this context.

RESULTS

With one of the scores, higher adherence to the EAT-Lancet diet was associated with a reduced risk of AD and all-cause dementia. Moreover, the results suggest an interplay between the EAT-Lancet diet and APOE ε4 status. A risk-reducing effect was observed among APOE ε4 non-carriers with three of the scores in relation to AD, and with five of the scores in relation to all-cause dementia. No associations were observed among APOE ε4 carriers, or in relation to VaD.

CONCLUSION

The results indicate a risk reducing effect of adhering to the EAT-Lancet diet among APOE ε4 non-carriers, and no negative effects on dementia risk were detected. Future studies should consider the potentially modifying effect of APOE ε4 status, and the implications of methodological differences in measuring adherence to the EAT-Lancet diet.

Visual impairment, age-related eye disease, and sleep dysfunction in older adults

BACKGROUND/OBJECTIVES

The visual system affects circadian rhythms, and both visual and sleep difficulties are common in older adults. This study examines the association between visual impairment, age-related eye disease, and sleep disturbances among older adults in the United States.

SUBJECTS/METHODS

This cross-sectional study used Round 11 of the National Health and Aging Trends Study (NHATS). Vision was assessed using self-report and objective assessments (distance and near acuity, contrast sensitivity). Medicare claims data were used to identify diagnoses of age-related macular degeneration, glaucoma, diabetic retinopathy, and cataract. Primary outcomes included self-reported sleep disturbances, defined by difficulties in sleep initiation, maintenance, and medication use. Logistic regression models were adjusted for demographic and clinical variables.

RESULTS

Among 3817 participants (56% female), difficulty with sleep initiation, maintenance, and medication use were reported by 41.7%, 44.2%, and 26.5% of the cohort, respectively. In unadjusted models, self-reported visual difficulty was associated with sleep initiation (OR 1.80, 95% CI: 1.43-2.29) and maintenance difficulties (OR 1.53, 95% CI: 1.16-2.02) and sleep medication use (OR 1.68, 95% CI: 1.27-2.24). After adjusting for covariates, self-reported visual difficulty remained significantly associated with sleep medication use (OR 1.40, 95% CI: 1.00-1.95). Near acuity and contrast sensitivity were associated with sleep initiation difficulties but did not remain significant after adjustment. No associations were found between ophthalmic diagnoses and outcomes.

CONCLUSION

Self-reported visual difficulty is associated with increased sleep medication use in older adults. Because visual impairment and sleep medications are associated with falls and cognitive decline, future studies should consider these comorbidity patterns.

Association of psychological stress and subjective cognitive decline

Psychological stress is associated with several long-term consequences, including cognitive decline. Our study examined the relationship between psychological stress levels and subjective cognitive decline (SCD) using cross-sectional data from CDC's Behavioral Risk Factor Surveillance System (BRFSS 2020-2022) for participants aged 45 years and older. Among 881,479 participants, 7.5 % were African American, and 10.7 % reported high psychological stress, with 29 % experiencing SCD. High psychological stress had a 3-fold risk of SCD compared to low psychological stress (OR: 3.3; 95 % CI: 2.8, 4.0). A significant interaction between psychological stress and BMI was found in their association with SCD (p = 0.013). Individuals with high psychological stress and a BMI ≥ 25 had 4.3 times higher SCD risk (OR: 4.3; 95 % CI: 3.9, 4.7) compared to those with low psychological stress and a BMI < 25 (OR: 0.23, 95 % CI: 0.2, 0.3). These results highlight the importance of addressing stress to prevent cognitive decline.

Towards an adult hearing screening procedure

OBJECTIVE

The first aim was to develop a simple, yet effective adult hearing screening protocol, based on the existing World Health Organization recommendations. Secondary aim was to gain insight in the possibilities and potential obstacles for implementation of national adult hearing screening programs across the globe.

METHODS

An expert working group was formed with 14 experts from six countries. Based on their recommendations a HEARRING screening protocol was devised and shared with all HEARRING group members. A survey was sent out to 62 clinicians from 22 countries to hear their considerations and the potential challenges they expect for the introduction of national adult hearing screening programs.

RESULTS

The proposed adult hearing screening protocol is made as simple and least time consuming as possible. The tablet-based screening tool consists of two red flag questions, followed by the Hearing Handicap Inventory for the Elderly Screening (HHIE-S) questionnaire and the Digits-in-Noise test, and is developed to be implemented in the primary care setting. The results of our survey indicate that most participants deem a national adult hearing screening to be cost-effective, but the major concerns regarding costs and funding, and infrastructure have to be discussed.

CONCLUSION

The HEARRING screening protocol is developed to assist clinicians and policy makers in their efforts to initiate effective local and national adult hearing screening programs.

Determinants influencing the implementation of community health management for cognitive impairment: a qualitative study

BACKGROUND

Cognitive impairment constitutes a significant global public health challenge, particularly for countries or regions experiencing the largest increases in aging populations. Most countries have reached a consensus that cognitive impairment screening, care, and intervention should be conducted within community settings.

OBJECTIVE

To identify multilevel barriers and facilitators for community health management for cognitive impairment, this study utilized the Consolidated Framework for Implementation Research (CFIR) to systematically evaluate the implementation of strategies for managing cognitive impairment in Shanghai, China.

METHODS

A semi-structured interview guide was developed based on the CFIR. Purposeful sampling was used to select 14 stakeholders from diverse sectors, including public health authorities, community health service centers, and experts in health management related to cognitive impairment, for semi-structured interviews. CFIR served as the coding framework for inductive analysis to identify and clarify the facilitators and barriers to cognitive impairment health management within the existing policy environment.

RESULTS

Qualitative interviews with stakeholders in community-based cognitive impairment health management revealed eight facilitators and ten barriers. The facilitators included enhanced social engagement for older adults, efficient digital tools, a supportive policy environment, adequate funding, integration into basic public health services, sufficient community human resources, supportive internal and external teams, and health education. Collectively, these factors fostered a conducive environment for effective cognitive impairment health management. In contrast, the identified barriers comprised a lack of validation for smart tools, absence of collaborative mechanisms, insufficient incentives for primary care physicians (PCPs), a lack of long-term mechanisms, inadequate professional expertise, low energy levels, limited training channels, insufficient disease awareness among older adults, absence of standardized implementation plans, and superficial work practices. These barriers hindered the effective execution of community-based cognitive impairment health management strategies.

CONCLUSION

This study identified the primary facilitators and barriers to community-based cognitive impairment management within the context of current policies. To enhance the effectiveness of interventions, policymakers, health departments, and community organizations should actively address the identified barriers and leverage the facilitators. Additionally, the findings provide valuable insights for other countries facing similar challenges in cognitive impairment management. Future research should focus on integrating these factors into practical applications and evaluating the effectiveness of such interventions.

CLINICAL TRIAL NUMBER

Not applicable.

Knowledge, attitude, and practice related to dementia and cognitive impairment among medical specialists with expertise unrelated to dementia

To explore the knowledge, attitude, and practice (KAP) on dementia and cognitive impairment among medical specialists with expertise unrelated to dementia. This study enrolled medical specialists with expertise unrelated to dementia from 318 medical institutions in China, between March and April 2023. A self-designed questionnaire was used for data collection and KAP assessment. A total of 1288 valid questionnaires were collected, 62.58% from female participants. The KAP scores were 11.02 ± 2.11 (range: 0-13), 22.16 ± 3.40 (range: 0-24), and 29.48 ± 6.92 (range: 0-32), respectively. The structural equation model showed that knowledge was positively associated with attitude (path coefficient = 0.503, P < 0.001), while both knowledge (path coefficient = 0.713, P < 0.001) and attitude (path coefficient = 0.797, P < 0.001) were positively associated with practice. Type of institution (path coefficient = 0.184, P = 0.035) and professional title (path coefficient = 0.133, P = 0.026) were positively associated with knowledge score. The mediation analysis revealed the significant total effects for professional title on knowledge, knowledge and professional title on attitude, and knowledge, attitude, and education on practice. Medical specialists in China with expertise unrelated to dementia might have good knowledge, a positive attitude, and proactive practice toward dementia and cognitive impairment. Tailored educational interventions should be specifically designed for individuals with lower professional titles and those working outside public tertiary hospitals.

Higher soluble ADAM10 plasma levels are associated with decreased cognitive performance in older adults carrying APOEε4

The APOE gene, particularly its ε4 allele, is a significant genetic risk factor for Alzheimer's disease (AD) and influences amyloid-β (Aβ) pathology and cognitive decline. This study explores the relationship between APOEε4 genotype, plasma levels of soluble ADAM10 (sADAM10), and cognitive performance in cognitively unimpaired (CU) older adults and those with AD dementia. It is a cross-sectional analysis that included 85 participants assessed for cognitive function, APOE genotype, and plasma sADAM10 levels. ADAM10, a key enzyme in the non-amyloidogenic pathway of Aβ precursor protein (APP) processing, has emerged as a promising biomarker due to its altered levels in AD patients. Our findings revealed significantly higher plasma sADAM10 levels in AD participants compared to CU individuals, with APOEε4 carriers exhibiting a nearly twofold increase in sADAM10 levels. A negative correlation was observed between plasma sADAM10 concentrations and cognitive performance, independent of APOEε4 status. Notably, the study highlights the potential of sADAM10 as a blood-based biomarker, emphasizing its relevance in APOEε4-mediated AD pathology. Importantly, most studies exploring ADAM10 and APOE interactions have been conducted in high-income countries, limiting the generalizability of their findings to diverse populations. This study is the first to be conducted in a Global South country, offering critical insights into underrepresented populations and underscoring the need for more inclusive research in AD. Future research should include larger cohorts and longitudinal designs to validate these findings and explore targeted interventions leveraging sADAM10 activity in the context of APOEε4-associated AD progression.

Chronotype as a potential risk factor for cognitive decline: The mediating role of sleep quality and health behaviours in a 10-year follow-up study

BACKGROUND

- With rising life expectancies and ageing populations worldwide, preserving cognitive health is an urgent global priority. Chronotype could be a potential risk factor for cognitive decline, potentially through mediators sleep quality, alcohol intake, physical activity, and smoking.

METHODS

- This study used data from participants aged 40 years and older from the Lifelines cohort study (n = 23,798). Chronotype, assessed with the Munich ChronoType Questionnaire, was included as a continuous score of mid-point sleep corrected for sleep debt on workdays. Multiple linear regression examined the association between chronotype and cognitive decline, including moderation by age, educational attainment, and sex. The KHB-method was applied to test mediation by sleep quality, alcohol intake, physical activity, and smoking.

OUTCOMES

- Cognition was assessed with the Ruff Figural Fluency Test (RFFT), measuring non-verbal fluency and executive functioning. Cognitive decline was calculated by subtracting the RFFT sum score at baseline from the 10-year follow-up score.

RESULTS

- Chronotype was associated with cognitive decline. Educational attainment, but not age or sex, moderated the relationship. No significant associations were observed in the low- (0.07, 95 % CI: -0.44, 0.57) or middle- (-0.41, 95 % CI: -0.88, 0.06) educational groups. In the high-educational group each one-hour increase in chronotype corresponded to a 0.80-point decline in cognition per decade (95 % CI: -1.34, -0.26). In this group, sleep quality and current smoking mediated 13.52 % and 18.64 % of the association, respectively.

INTERPRETATION

- Chronotype was associated with greater decline in non-verbal fluency and executive functioning among higher educated participants, highlighting the importance of targeted prevention strategies.

FUNDING

- This work is part of the BIRD-NL consortium funded by the Dutch Medical Research Council, ZonMw (Dementia research program) project number:10,510,032,120,005.

Baseline habitual dietary nitrate intake and Alzheimer's Disease related neuroimaging biomarkers in the Australian Imaging, Biomarkers and Lifestyle study of ageing

BACKGROUND

Dietary nitrate, as a nitric oxide (NO) precursor, may support brain health and protect against dementia.

OBJECTIVE

Our primary aim was to investigate whether dietary nitrate is associated with neuroimaging markers of brain health linked with Alzheimer's disease (AD).

PARTICIPANTS

Study participants were cognitively unimpaired individuals from the Australian Imaging, Biomarkers and Lifestyle Study of Ageing (AIBL) who had β-amyloid positron emission tomography (PET) scans (n = 554) and magnetic resonance imaging (MRI) scans (n = 335) and had completed a Food Frequency Questionnaire at baseline.

METHODS

Source-specific nitrate intakes were estimated using comprehensive nitrate food composition databases. Rates of cerebral β-amyloid (Aβ) deposition, measured using PET, and rates of brain atrophy, measured using MRI, were assessed between baseline and 126-months follow-up, at intervals of 18 months. Multivariable-adjusted linear mixed effect models were used to examine associations between baseline source-specific nitrate intake and rates of (i) cerebral Aβ deposition and (ii) brain atrophy, over the 126 months of follow-up. Analyses were carried out following stratification of the sample by established dementia Alzheimer's disease (AD) risk factors including sex and presence or absence of the apolipoprotein E (APOE) ε4 allele.

RESULTS

In women carriers of the APOE ε4 allele, higher plant sourced nitrate intake (median intake 121 mg/day), was associated with a slower rate of cerebral Aβ deposition [β: 4.47 versus 8.99 Centiloid (CL) /18 months, p < 0.05] and right hippocampal atrophy [-0.01 versus -0.03 mm3 /18 months, p < 0.01], after multivariable adjustments. Moderate intake showed protective associations in men carriers and in both men and women non-carriers of APOE ε4.

CONCLUSIONS

Associations were observed between plant-derived nitrate intake and cerebral Aβ deposition, particularly in high-risk populations (women and APOE ε4 carriers). Associations were also observed for brain volume atrophy, however these exhibited subgroup variability without clear patterns relative to sex and APOE ε4 allele carriage. These findings suggest a potential link between plant-sourced nitrate and AD related neuroimaging markers of brain health improved brain health, but further validation in larger studies is required.

Glucagon-like peptide-1 receptor agonists for major neurocognitive disorders

Disease-modifying treatments for major neurocognitive disorders, including Alzheimer's disease, Parkinson's disease and other cognitive deficits, are among the main unmet needs in modern medicine. Glucagon-like peptide-1 receptor agonists (GLP-1RAs), currently licensed for the treatment of type 2 diabetes mellitus and obesity, offer a novel, multilayered mechanism for intervention in neurodegeneration through intermediate, aetiology-agnostic pathways, likely involving metabolic, inflammatory and several other relevant neurobiological processes. In vitro and animal studies have revealed promising signals of neuroprotection, with preliminary supportive evidence emerging from recent pharmacoepidemiological investigations and clinical trials. In this article, we comprehensively review studies that investigate the impact of GLP-1RAs on the various aetiologies of cognitive impairment and dementia syndromes. Focusing on evidence from human studies, we highlight how brain energy homeostasis, neurogenesis, synaptic functioning, neuroinflammation and other cellular stress responses, pathological protein aggregates, proteostasis, cerebrovascular system and blood-brain barrier dynamics may underlie GLP-1RA putative neuroprotective effects. We then report and appraise evidence from clinical studies, including observational investigations, clinical trials and pooled analyses. Finally, we discuss current challenges and perspectives ahead for research and clinical implementation of GLP-1RAs for the care of people with major neurocognitive disorders, including their individual brain penetrance potential, the need for response biomarkers and disease stage-based indications, their possible non-specific effects on brain health, their profile in terms of adverse events and other unwanted effects, the lack of long-term data for efficacy and safety, and issues surrounding cost and availability of treatment.

Dementia-related adverse events associated with direct oral anticoagulants use: a real-world, pharmacovigilance study based on the FAERS database

BACKGROUND

Direct oral anticoagulants (DOACs) are commonly used to prevent and treat thromboembolic diseases. This study aimed to assess and compare dementia related adverse events (AEs) associated with DOACs.

RESEARCH DESIGN AND METHODS

AEs related to DOACs from January 2014 to June 2023 were extracted from the FDA Adverse Event Reporting System (FAERS) database. Disproportionality analysis methods, including reporting odds ratio (ROR), proportional reporting ratio, Bayesian Confidence Propagation Neural Network, and Multi-Item Gamma Poisson Shrinker, were used to evaluate the association between DOACs and dementia-related AEs.

RESULTS

There were 12,692,968 AEs reported in FAERS after deduplication. Among these, 165, 206, 1574, and 12 dementia-related AEs that were attributed to dabigatran, rivaroxaban, apixaban, and edoxaban, respectively. Apixaban showed the strongest association with dementia-related AEs (ROR 7.66, 95% confidence interval (CI) 7.27-8.06), while rivaroxaban had the lowest ROR (0.95, 95%CI 0.83-1.09). Women exhibited higher RORs for all DOACs, with apixaban showing the most significant correlation. Subgroup analysis indicated a significant link between apixaban and dementia, dementia Alzheimer's type and senile dementia.

CONCLUSIONS

Apixaban appears most associated with dementia-related AEs among DOACs, whereas rivaroxaban poses a lower risk. Further research is needed to validate these findings through large-scale prospective studies.

Mediators of educational differences in dementia risk later in life: evidence from the HUNT study

Despite a well-known inverse association between education and dementia risk, the mediating mechanisms are not well understood. We explored how lifestyle and health risk factors across the life-course mediate the relationship between education and dementia among adults aged 70 + years. We included 7,655 participants with dementia diagnoses and education information, using a historical cohort design linking prospective exposure data across the life course from the HUNT4 70 + Study with registry data from Statistics Norway and earlier HUNT surveys. We conducted causal mediation analysis to assess the mediating roles of occupational characteristics, lifestyle factors (smoking, physical inactivity), and health risk factors (obesity, hypertension, diabetes, hearing impairment, cardiovascular diseases, LDL cholesterol, depression, anxiety) assessed during early, middle, and late adulthood in the relationship between education and dementia in later life. Participants with lower education were more likely to have dementia with odds ratios of 1.99, 1.88, 1.83 for the model's accounting exposure to mediators during early, middle, and late adulthood, respectively. These associations were partially mediated by the joint effect of health and lifestyle risk factors from early through late adulthood (mediated 11.55-19.50%). Health risk factors from early to late adulthood jointly mediated 6.85-13.06% of the effect of low education on dementia risk later in life. Additionally, lifestyle factors during middle and late adulthood jointly mediated 4.11-4.96% of the total effect of low education on dementia risk later in life. Educational differences in dementia risk can partly mediated by lifestyle and health factors across the life course. These findings suggest potential targets to address varying dementia risks linked to education levels.

Role of saturated fatty acid metabolism in posttranslational modifications of the Tau protein

The relationship between metabolic alterations induced by the consumption of a high-fat diet (HFD) and the risk of developing neurodegenerative diseases such as Alzheimer's disease (AD) has been extensively studied. In particular, the induction of neuronal insulin resistance, endoplasmic reticulum stress, and the production of reactive oxygen species by chronic exposure to high concentrations of saturated fatty acids (sFAs), such as palmitic acid (PA), have been proposed as the cellular and molecular mechanisms underlying cognitive decline. Lipid metabolism affects many processes critical for cellular homeostasis. However, questions remain as to whether neuronal exposure to high sFA levels contributes to the onset and progression of AD features, and how their metabolism plays a role in this process. Therefore, the aim of this work is to review the accumulated evidence for the potential mechanisms by which the neuronal metabolism of sFAs affects signaling pathways that may induce biochemical changes in the AD hallmark protein Tau, ultimately promoting its aggregation and the subsequent generation of neurofibrillary tangles. In particular, the data presented here provide evidence that PA-dependent metabolic stress results in an imbalance in the activities of protein kinases and deacetylases that potentially contribute to the post-translational modifications (PTMs) of Tau.