How can dementia and disability be prevented in older adults: where are we today and where are we going?

Joint daily functional trajectory and risk of new-onset Alzheimer's disease and related dementias in older adults with normal and abnormal weight

BACKGROUND

Associations between daily functional trajectories and new-onset all-cause dementia and Alzheimer's disease (AD) and the role of body weight are underexplored.

METHODS

Data were from the Health and Retirement Study (HRS) 1994-2020. Daily function was assessed using (instrumental) activities of daily living ([I]ADLs). All-cause dementia and AD were defined by self- or proxy-reported physician diagnoses. Body weight was assessed using body mass index (BMI) and categorized as normal (18.5 kg/m2 ≤ BMI < 30 kg/m2) and abnormal (BMI < 18.5 kg/m2 or ≥30 kg/m2). The group-based trajectory modeling and Cox proportional hazards regression were utilized.

RESULTS

Of 18,763 adults included, 1236 developed new-onset dementia during a 10-year follow-up. The associations of ADL and IADL limitations at baseline with all-cause dementia and AD were much more pronounced in those with abnormal weight (P for interaction < 0.005). Five joint trajectories of ADL and IADL limitations were identified: No (72.7 %), Recovery (4.0 %), Recent emerging (16.4 %), Early emerging (4.8 %), and Severe (2.1 %). Furthermore, the 'Severe' joint trajectory (vs. 'No') was associated with 3.57- and 3.59-times higher risks of new-onset all-cause dementia and AD in participants with abnormal weight (P for interaction = 0.002 and 0.005). Notably, the Recovery joint trajectory (vs. No) was not associated with increased risks of all-cause dementia or AD.

LIMITATIONS

Self-/proxy-reported all-cause dementia and AD may introduce misclassification bias. Lifestyle factors were not quantified. BMI at baseline, but not its trajectory, was utilized. Potential reverse causation deserved attention.

CONCLUSIONS

Body weight control can help reduce the risk of progression from functional limitations to all-cause dementia and AD.

Development and Validation of a Predictive Model for Early Identification of Cognitive Impairment Risk in Community-Based Hypertensive Patients

Objective: To investigate the risk factors for the development of mild cognitive dysfunction in hypertensive patients in the community and to develop a risk prediction model. Method: The data used in this study were obtained from two sources: the China Health and Retirement Longitudinal Study (CHARLS) and the Chinese Longitudinal Healthy Longevity Survey (CLHLS). A total of 1121 participants from CHARLS were randomly allocated into a training set and a validation set, following a 70:30 ratio. Meanwhile, an additional 4016 participants from CLHLS were employed for external validation of the model. The patients in this study were divided into two groups: those with mild cognitive impairment and those without. General information, employment status, pension, health insurance, and presence of depressive symptoms were compared between the two groups. LASSO regression analysis was employed to identify the most predictive variables for the model, utilizing 14-fold cross-validation. The risk prediction model for cognitive impairment in hypertensive populations was developed using generalized linear models. The model's discriminatory power was evaluated through the area under the receiver operating characteristic (ROC) curve and calibration curves. Results: In the modeling group, eight variables such as gender, age, residence, education, alcohol use, depression, employment status, and health insurance were ultimately selected from an initial pool of 21 potential predictors to construct the risk prediction model. The area under the curve (AUC) values for the training, internal, and external validation sets were 0.777, 0.785, and 0.782, respectively. All exceeded the threshold of 0.7, suggesting that the model effectively predicts the incidence of mild cognitive dysfunction in community-based hypertensive patients. A risk prediction model was developed using a generalized linear model in conjunction with Lasso regression. The model's performance was evaluated using the area under the receiver operating characteristic (ROC) curve. Hosmer-Lemeshow test values yielded p = .346 and p = .626, both of which exceeded the 0.05 threshold. Calibration curves demonstrated a significant agreement between the nomogram model and observed outcomes, serving as an effective tool for evaluating the model's predictive performance. Discussion: The predictive model developed in this study serves as a promising and efficient tool for evaluating cognitive impairment in hypertensive patients, aiding community healthcare workers in identifying at-risk populations.

Prediction Model for Cognitive Impairment among Disabled Older Adults: A Development and Validation Study

Disabled older adults exhibited a higher risk for cognitive impairment. Early identification is crucial in alleviating the disease burden. This study aims to develop and validate a prediction model for identifying cognitive impairment among disabled older adults. A total of 2138, 501, and 746 participants were included in the development set and two external validation sets. Logistic regression, support vector machine, random forest, and XGBoost were introduced to develop the prediction model. A nomogram was further established to demonstrate the prediction model directly and vividly. Logistic regression exhibited better predictive performance on the test set with an area under the curve of 0.875. It maintained a high level of precision (0.808), specification (0.788), sensitivity (0.770), and F1-score (0.788) compared with the machine learning models. We further simplified and established a nomogram based on the logistic regression, comprising five variables: age, daily living activities, instrumental activity of daily living, hearing impairment, and visual impairment. The areas under the curve of the nomogram were 0.871, 0.825, and 0.863 in the internal and two external validation sets, respectively. This nomogram effectively identifies the risk of cognitive impairment in disabled older adults.

Peripheral GFAP and NfL as early biomarkers for dementia: longitudinal insights from the UK Biobank

BACKGROUND

Peripheral glial fibrillary acidic protein (GFAP) and neurofilament light chain (NfL) are sensitive markers of neuroinflammation and neuronal damage. Previous studies with highly selected participants have shown that peripheral GFAP and NfL levels are elevated in the pre-clinical phase of Alzheimer's disease (AD) and dementia. However, the predictive value of GFAP and NfL for dementia requires more evidence from population-based cohorts.

METHODS

This was a prospective cohort study to evaluate UK Biobank participants enrolled from 2006 to 2010 using plasma GFAP and NfL measurements measured by Olink Target Platform and prospectively followed up for dementia diagnosis. Primary outcome was the risk of clinical diagnosed dementia. Secondary outcomes were cognition. Linear regression was used to assess the associations between peripheral GFAP and NfL with cognition. Cox proportional hazard models with cross-validations were used to estimate associations between elevated GFAP and NfL with risk of dementia. All models were adjusted for covariates.

RESULTS

A subsample of 48,542 participants in the UK Biobank with peripheral GFAP and NfL measurements were evaluated. With an average follow-up of 13.18 ± 2.42 years, 1312 new all-cause dementia cases were identified. Peripheral GFAP and NfL increased up to 15 years before dementia diagnosis was made. After strictly adjusting for confounders, increment in NfL was found to be associated with decreased numeric memory and prolonged reaction time. A greater annualized rate of change in GFAP was significantly associated with faster global cognitive decline. Elevation of GFAP (hazard ratio (HR) ranges from 2.25 to 3.15) and NfL (HR ranges from 1.98 to 4.23) increased the risk for several types of dementia. GFAP and NfL significantly improved the predictive values for dementia using previous models (area under the curve (AUC) ranges from 0.80 to 0.89, C-index ranges from 0.86 to 0.91). The AD genetic risk score and number of APOE*E4 alleles strongly correlated with GFAP and NfL levels.

CONCLUSIONS

These results suggest that peripheral GFAP and NfL are potential biomarkers for the early diagnosis of dementia. In addition, anti-inflammatory therapies in the initial stages of dementia may have potential benefits.

Coping target checklist for home-based older adults living with disabilities and their spousal caregivers

BACKGROUND

The substantial rise in the population of older adults living with disabilities is a prominent concern, presenting a profound challenge for healthcare and social welfare systems. Community-based home care is seen as an effective approach to meet the care needs of older adults living with disabilities.

OBJECTIVE

To construct a coping target checklist for home-based older adults living with disabilities and their spousal caregivers.

METHODS

The initial draft was developed based on a comprehensive literature review, followed by two rounds of Delphi correspondence final version.

RESULTS

A comprehensive literature review resulted in the development of 7 modules, 20 topics. After round 1, 3 items were removed, 3 sections, 1 topic and 1 objective were new additions, 16 items were modified, split or combined. Four sections, 3 sections (Individual coping target for spousal caregivers, Individual coping target for older adults living with disabilities, and Shared coping target), 7 modules, 18 topics and 49 objectives were finally identified in round 2. The content of the list tool is derived from three perspectives: self-management strategies for older adults living with disabilities, caregiving strategies for spousal caregivers, and combined.

CONCLUSIONS

The coping target checklist was intended to be evidence-based and reflective of a practical direction for home-based older adults living with disabilities and their spousal caregivers living at home.

Factors associated with the intrinsic capacity in older adults: A scoping review

INTRODUCTION

In 2015, the term 'intrinsic capacity' (IC) was proposed by the World Health Organisation to promote healthy aging. However, the factors associated with IC are still discrepant and uncertain.

AIM

We aim to synthesise the factors connected with IC.

METHODS

This scoping review followed the five-stage framework of Arksey and O'Malley and was reported using PRISMA-ScR guidelines.

RESULTS

In all, 29 articles were included. IC of older adults is associated with demographic characteristics, socioeconomic factors, disease conditions, behavioural factors, and biomarkers. Age, sex, marital status, occupation status, education, income/wealth, chronic diseases, hypertension, diabetes, disability, smoking status, alcohol consumption, and physical activity were emerged as important factors related to the IC of older adults.

CONCLUSIONS

This review shows that IC is related to multiple factors. Understanding these factors can provide the healthcare personnel with the theoretical basis for intervening and managing IC in older adults.

RELEVANCE TO CLINICAL PRACTICE

The influencing factors identified in the review help to guide older adults to maintain their own intrinsic capacity, thereby promoting their health and well-being. The modifiable factors also provide evidence for healthcare personnel to develop targeted intervention strategies to delay IC decline.

NO PATIENT OR PUBLIC CONTRIBUTION

As this is a scoping review, no patient or public contributions are required.

Exploring the occurrence and the risk factors of the desire for hastened death and depression in people with early-stage dementia in Greece

OBJECTIVES

To assess the factors associated with desire for hastened death and depression in early-stage dementia as well as the association between them. Also, to explore the mediator and moderator role of age in the relationship between depression and desire for hasten death.

METHODS

A prospective cross-sectional study including 100 patients diagnosed with early-stage dementia from a rehabilitation center between December 2018 and July 2019. Measurement tools used were the Mini-Mental State Examination, the Greek Montreal Cognitive Assessment, the Greek Schedule of Attitudes toward Hastened Death, and the Geriatric Depression Scale-15 item. Patients diagnosed with dementia as a result of Stroke history were excluded.

RESULTS

Factors of multifactorial analysis significantly associated with desire for hastened death were as follows: age (p = 0.009), marital status (p = 0.001), and depression (p < 0.001). The factor significantly associated with depression was age (p = 0.001). Also, a mediation/moderation analysis has shown that depression and age are significant predictors of desire for hasten death.

SIGNIFICANCE OF RESULTS

The desire for hastened death and depression in people diagnosed with early-stage dementia includes many components. Younger patients, men, higher educated patients, single, childless, and those with higher depression scores had higher desire for hastened death, while men and older patients had higher scores of desire for depression. Our study provides important information about the desire for hastened death and depression in early-stage dementia, their risk factors, and their association.

GOIZ ZAINDU study: a FINGER-like multidomain lifestyle intervention feasibility randomized trial to prevent dementia in Southern Europe

BACKGROUND

GOIZ ZAINDU ("caring early" in Basque) is a pilot study to adapt the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) methodology to the Basque population and evaluate the feasibility and adherence to a FINGER-like multidomain intervention program. Additional aims included the assessment of efficacy on cognition and data collection to design a large efficacy trial.

METHOD

GOIZ ZAINDU is a 1-year, randomized, controlled trial of a multidomain intervention in persons aged 60+ years, with Cardiovascular Risk Factors, Aging and Dementia (CAIDE) risk score ≥ 6, no diagnosis of dementia, and below-than-expected performance in at least one of three cognitive screening tests. Randomization to a multidomain intervention (MD-Int) or regular health advice (RHA) was stratified by sex, age (>/≤ 75), and cognitive status (mild cognitive impairment (MCI)/normal cognition). MD-Int included cardiovascular risk factor control, nutritional counseling, physical activity, and cognitive training. The primary outcomes were retention rate and adherence to the intervention program. Exploratory cognitive outcomes included changes in the Neuropsychological Test Battery z-scores. Analyses were performed according to the intention to treat.

RESULTS

One hundred twenty-five participants were recruited (mean age: 75.64 (± 6.46); 58% women). The MD-Int (n = 61) and RHA (n = 64) groups were balanced in terms of their demographics and cognition. Fifty-two (85%) participants from the RHA group and 56 (88%) from the MD-Int group completed the study. More than 70% of the participants had high overall adherence to the intervention activities. The risk of cognitive decline was higher in the RHA group than in the MD-Int group in terms of executive function (p =.019) and processing speed scores (p =.026).

CONCLUSIONS

The GOIZ-ZAINDU study proved that the FINGER methodology is adaptable and feasible in a different socio-cultural environment. The exploratory efficacy results showed a lower risk of decline in executive function and processing speed in the intervention group. These results support the design of a large-scale efficacy trial.

TRIAL REGISTRATION

GOIZ ZAINDU feasibility trial was approved and registered by the Euskadi Drug Research Ethics Committee (ID: PI2017134) on 23 January 2018. Retrospectively registered in ClinicalTrials.gov (NCT06163716) on 8 December 2023.

The Association between Acupuncture Therapy and the Risk of Disability Development in Dementia Patients: A Nationwide Cohort Study

Purpose

Disability is the comorbidity of dementia for which there is no available preventive measure. The aim of this study was to investigate the association between acupuncture treatment and the risk of disability development in dementia patients.

Patients and Methods

A cohort study was performed using a nationwide health database in Taiwan. The included dementia patients were divided into acupuncture and non-acupuncture cohorts based on whether they received acupuncture treatment during the follow-up period. The variables in the two cohorts were controlled by 1:1 propensity-score matching. The difference in disability development in dementia patients between the acupuncture and non-acupuncture cohorts was also analyzed. Subgroup analyses were performed using socioeconomic variables, comorbidities and anti-dementia agents (donepezil, rivastigmine, galantamine and memantine) used for dementia treatment.

Results

A total of 9,760 dementia patients met our inclusion criteria, and patients were divided into an equal number (n=2,422) of acupuncture and non-acupuncture groups, respectively, after 1:1 propensity-score matching. The dementia patients had a lower risk of disability development after acupuncture treatment than those who did not receive acupuncture treatment (adjusted hazard ratio 0.65, 95% confidence interval 0.60-0.70, p < 0.001). The results were independent of basic variables or comorbidities in the two cohorts. Patients who did not use anti-dementia agents had a lower risk of developing disability after receiving acupuncture intervention than those who used anti-dementia agents.

Conclusion

Our results revealed the relationship between acupuncture intervention and decreased risk of developing disability in dementia patients. The results are useful for dementia treatment, trial design and further planning of care programs.

A Longitudinal Study on Cognitive Training for Cognitively Preserved Adults in Liguria, Italy

In this study, we examined the effects of memory training on cognitive function and depressive symptoms in a cohort of 794 healthy adults aged 50 years or older. Participants were divided into an active intervention group and a passive intervention group, with various cognitive measures assessed over a one-year period. Univariate analysis revealed that the active intervention group consistently outperformed the passive group in measures of memory self-perception (Memory Complaint Questionnaire-MACQ), depressive symptoms (Geriatric Depression Scale-GDS-4), verbal memory and recall ability (A3LP), and verbal fluency (VF). Significant differences in MACQ scores were observed between the two groups at all time points, indicating enhanced memory self-perception in the active group. GDS-4 scores consistently favored the active group, suggesting a reduction in depressive symptoms. A3LP scores demonstrated that the active group had better verbal memory and recall abilities. VF scores consistently favored the active group, indicating superior language skills and cognitive flexibility. Linear regression model and mixed linear regression model reinforced these findings, with highly significant interaction effects observed between the active/passive group, gender, age, education, and time. These effects were particularly pronounced for MACQ and A3LP scores, indicating the combined impact of these factors on memory self-perception and verbal memory. This study highlights the positive impact of memory training intervention on cognitive function and depressive symptoms in older adults and underscores the importance of considering gender, age, and education in cognitive interventions. Notably, these benefits persist for up to six months from the end of the program. The results provide valuable insights into cognitive changes in aging populations and suggest that tailored memory training programs can yield significant improvements.

Using magnetic resonance imaging to measure head muscles: An innovative method to opportunistically determine muscle mass and detect sarcopenia

BACKGROUND

Sarcopenia is associated with multiple adverse outcomes. Traditional methods to determine low muscle mass for the diagnosis of sarcopenia are mainly based on dual-energy X-ray absorptiometry (DXA), whole-body magnetic resonance imaging (MRI) and bioelectrical impedance analysis. These tests are not always available and are rather time consuming and expensive. However, many brain and head diseases require a head MRI. In this study, we aim to provide a more accessible way to detect sarcopenia by comparing the traditional method of DXA lean mass estimation versus the tongue and masseter muscle mass assessed in a standard brain MRI.

METHODS

The H70 study is a longitudinal study of older people living in Gothenburg, Sweden. In this cross-sectional analysis, from 1203 participants aged 70 years at baseline, we included 495 with clinical data and MRI images available. We used the appendicular lean soft tissue index (ALSTI) in DXA images as our reference measure of lean mass. Images from the masseter and tongue were analysed and segmented using 3D Slicer. For the statistical analysis, the Spearman correlation coefficient was used, and concordance was estimated with the Kappa coefficient.

RESULTS

The final sample consisted of 495 participants, of which 52.3% were females. We found a significant correlation coefficient between both tongue (0.26) and masseter (0.33) with ALSTI (P < 0.001). The sarcopenia prevalence confirmed using the alternative muscle measure in MRI was calculated using the ALSTI (tongue = 2.0%, masseter = 2.2%, ALSTI = 2.4%). Concordance between sarcopenia with masseter and tongue versus sarcopenia with ALSTI as reference has a Kappa of 0.989 (P < 0.001) for masseter and a Kappa of 1 for the tongue muscle (P < 0.001). Comorbidities evaluated with the Cumulative Illness Rating Scale were significantly associated with all the muscle measurements: ALSTI (odds ratio [OR] 1.16, 95% confidence interval [CI] 1.07-1.26, P < 0.001), masseter (OR 1.16, 95% CI 1.07-1.26, P < 0.001) and tongue (OR 1.13, 95% CI 1.04-1.22, P = 0.002); the higher the comorbidities, the higher the probability of having abnormal muscle mass.

CONCLUSIONS

ALSTI was significantly correlated with tongue and masseter muscle mass. When performing the sarcopenia diagnostic algorithm, the prevalence of sarcopenia calculated with head muscles did not differ from sarcopenia calculated using DXA, and almost all participants were correctly classified using both methods.

Prevalence of functional dependence and chronic diseases in the community-dwelling Brazilian older adults: an analysis by dependence severity and multimorbidity pattern

BACKGROUND

Despite the advancements in knowledge about health care for older adults, essential gaps persist regarding the effects of chronic diseases as epidemiological markers of the state of functional dependence. This study aimed to identify the prevalence of moderate and severe functional dependence in Brazilian older adults and its association with chronic diseases and verify the multimorbidity patterns by dependence status.

METHODS

This cross-sectional analytical study used data from 11,177 community-dwelling Brazilian older adults from the 2013 National Health Survey conducted in Brazil. The dependent variables were moderate and severe functional dependence in basic activities of daily living (BADLs) and instrumental ADLs (IADLs). The independent variables were defined based on the questions applied to measure each morbidity in a self-reported manner and asked, "Has a doctor ever diagnosed you as having (each disease)? Multimorbidity was simultaneously considered present for older adults with ≥ 2 chronic morbidities. The association between functional dependence on BADLs and IADLs separately by severity and the independent variables was verified from crude and adjusted estimates of the point prevalence ratios and their 95% confidence intervals using the regression model Poisson with robust variance. To group diseases into patterns, exploratory factor analysis was used.

RESULTS

The prevalences of moderate and severe BADL dependence were 10.2% (95% CI, 9.6-10.7) and 4.8% (95% CI, 4.4-5.2), respectively. Moderate and severe IADL dependence prevalences were 13.8% (95% CI, 13.1-14.4) and 15.6% (95% CI, 14.9%-16.2), respectively. When changing the condition from moderate to severe dependence in BADLs, in the presence of other mental illnesses and stroke, the probability of dependence increased more than four times in the case of other mental illnesses and more than five times for stroke. There was a linear trend for dependence severity, both moderate and severe, whereas, for severe dependence on IADLs, this same factor maintained a linear trend toward an increase in probability as the number of diseases simultaneously increased.

CONCLUSIONS

Chronic diseases are associated with functional dependence, with greater emphasis on mental illnesses and stroke in severe disability, considering their acute adverse effects.

Disability transitions in Dutch community-dwelling older people aged 75 years or older

BACKGROUND

Recent world population predictions show that the world population aged >=65 years will increase from 10% in 2022 to 16% in 2050. Population aging is accompanied by an increase in people with disability. It is important to pay special attention to people with disability, as these people are at high risk of adverse outcomes. Our study aimed to investigate the transitions of disability among Dutch community-dwelling older people aged 75 years or older, using a follow-up of nine years. We used socio-demographic factors gender, age, marital status, education, and income, but also lifestyle, diseases, and life events to predict the disability transitions over time.

METHODS

We used a sample of 484 people that was randomly drawn from the municipality of Roosendaal (the Netherlands), a municipality with 78,000 inhabitants. A subset of people who completed part A of the Tilburg Frailty Indicator (TFI) at baseline and the Groningen Activity Restriction Scale (GARS) questionnaires was used with a nine-year follow-up. Paired Wilcoxon tests were used to compare the consecutive measurements. Socio-demographic factors gender, age, marital status, education, and income, but also lifestyle, diseases, and life events were included to predict the disability transitions over time. For the univariable and multivariable analysis of the measurements over time with the predictor variables, we used generalized estimation equations (GEE). A p-value <0.05 was considered significant. R version 3.4.4 was used for all analyses.

RESULTS

Of the participants, 65% were younger than 80 years, 50% were married or cohabiting, 87% reported a healthy lifestyle, and 63% had no diseases or chronic disorders. Each year, more participants changed from status not disabled to disabled than vice versa. The GEE analyses showed that lifestyle ('not healthy') and diseases or chronic disorders ('two or more') were significant in the multivariable analysis for the disability score and only diseases or chronic disorders ('two or more') was significant in the multivariable analysis for the dichotomous disability score.

CONCLUSIONS

The transition of the disability score is strongly influenced by lifestyle and diseases or disorders. This applies to a lesser extent to the dichotomous disability score. There, only diseases or disorders are an important predictor. For health care professionals our study provides starting points for interventions focused on the prevention of worsening disability and for community-dwelling older people >= 75, the most important recommendation is: live healthy!

Do physical fitness and cognitive function mediate the relationship between basic activities of daily living and quality of life in older adults with dementia?

PURPOSE

Independence in activities of daily living (ADLs) is associated with quality of life (QoL) in individuals with dementia. However, the contribution of physical and cognitive functions to this relationship needs further examination. This study aims to examine the mediating effect of physical fitness and cognitive function in the relationship between independence in basic ADLs and QoL among older adults with dementia.

METHODS

This cross-sectional study included 107 older adults with dementia (74.8% women; age 78.21 ± 7.70 years). Independence in basic ADL and QoL were evaluated using the Barthel Index (BI) and QoL- Alzheimer's Disease Scale, respectively. The Alzheimer's Disease Assessment Scale-Cognitive Subscale and the Mini-Mental State Examination were applied to assess cognitive function. Physical fitness was evaluated using the 30-s chair stand, 2-min step and the Timed-Up and Go tests. A structural equation modelling (SEM) with bootstrapping estimation was conducted to determine the relationship between all variables.

RESULTS

Independence in basic ADL positively affected QoL and this association was mediated by physical fitness (β = 0.242, p = 0.011). No statistically significant results were observed when testing cognitive function as a mediator between BI and QoL (β = 0.009, p = 0.345).

CONCLUSIONS

Physical fitness (i.e., lower body strength, aerobic capacity, and mobility) plays a role in the relationship between basic ADL independence and QoL of older adults with dementia, reinforcing the need to improve and monitor these parameters throughout the disease progression. Future longitudinal studies should explore the temporal relationship between physical and cognitive function and its contribution to basic ADL independence and QoL.

Assessing Gait & Balance in Adults with Mild Balance Impairment: G&B App Reliability and Validity

Smartphone applications (apps) that utilize embedded inertial sensors have the potential to provide valid and reliable estimations of different balance and gait parameters in older adults with mild balance impairment. This study aimed to assess the reliability, validity, and sensitivity of the Gait&Balance smartphone application (G&B App) for measuring gait and balance in a sample of middle- to older-aged adults with mild balance impairment in Pakistan. Community-dwelling adults over 50 years of age (N = 83, 50 female, range 50-75 years) with a Berg Balance Scale (BBS) score between 46/56 and 54/56 were included in the study. Data collection involved securing a smartphone to the participant's lumbosacral spine. Participants performed six standardized balance tasks, including four quiet stance tasks and two gait tasks (walking looking straight ahead and walking with head turns). The G&B App collected accelerometry data during these tasks, and the tasks were repeated twice to assess test-retest reliability. The tasks in quiet stance were also recorded with a force plate, a gold-standard technology for measuring postural sway. Additionally, participants completed three clinical measures, the BBS, the Functional Reach Test (FRT), and the Timed Up and Go Test (TUG). Test-retest reliability within the same session was determined using intraclass correlation coefficients (ICCs) and the standard error of measurement (SEM). Validity was evaluated by correlating the G&B App outcomes against both the force plate data and the clinical measures using Pearson's product-moment correlation coefficients. To assess the G&B App's sensitivity to differences in balance across tasks and repetitions, one-way repeated measures analyses of variance (ANOVAs) were conducted. During quiet stance, the app demonstrated moderate reliability for steadiness on firm (ICC = 0.72) and compliant surfaces (ICC = 0.75) with eyes closed. For gait tasks, the G&B App indicated moderate to excellent reliability when walking looking straight ahead for gait symmetry (ICC = 0.65), walking speed (ICC = 0.93), step length (ICC = 0.94), and step time (ICC = 0.84). The TUG correlated with app measures under both gait conditions for walking speed (r -0.70 and 0.67), step length (r -0.56 and -0.58), and step time (r 0.58 and 0.50). The BBS correlated with app measures of walking speed under both gait conditions (r 0.55 and 0.51) and step length when walking with head turns (r = 0.53). Force plate measures of total distance wandered showed adequate to excellent correlations with G&B App measures of steadiness. Notably, G&B App measures of walking speed, gait symmetry, step length, and step time, were sensitive to detecting differences in performance between standard walking and the more difficult task of walking with head turns. This study demonstrates the G&B App's potential as a reliable and valid tool for assessing some gait and balance parameters in middle-to-older age adults, with promise for application in low-income countries like Pakistan. The app's accessibility and accuracy could enhance healthcare services and support preventive measures related to fall risk.

Impact of type, intensity, frequency, duration and volume of physical activity on dementia and mild cognitive impairment in older adults: protocol for a systematic review and meta-analysis

INTRODUCTION

Worldwide, the prevalence of degenerative diseases such as dementia and mild cognitive impairment (MCI) is increasing with population ageing and increasing life expectancy. Both conditions share modifiable risk factors. Physical inactivity is one of these modifiable risk factors, and research points to the protective effect of physical activity on the incidence of dementia and MCI. However, this association tends to change according to type, intensity, frequency, duration and volume of physical activity. Furthermore, it remains unclear which of these characteristics offers the greatest protective effect. Therefore, this study aims to evaluate the impacts of different types, intensities, frequencies, duration and volume of physical activity on dementia and cognitive decline in older adults.

METHODS AND ANALYSIS

The search will be carried out from October 2023, using the following databases: PubMed, Embase, Scopus, CINAHL and Web of Science. Cohort studies with a follow-up time of 1 year or longer that have investigated the incidence of dementia and/or MCI in older adults exposed to physical activity will be included. There will be no limitations on the date of publication of the studies. Studies published in English, Spanish or Portuguese will be analysed. Two researchers will independently screen the articles and extract the data. Any discrepancies will be resolved by a third reviewer. Association measures will be quantified, including OR, HR, relative risk and incidence ratio, with a 95% CI. If the data allow, a meta-analysis will be performed. To assess the methodological quality of the selected studies, the Grading of Recommendations, Assessment, Development and Evaluations instrument, and the Downs and Black instrument to assess the risk of bias, will be used.

ETHICS AND DISSEMINATION

Ethical approval is not required. The results will be submitted for publication in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42023400411.

Protective effects of dog ownership against the onset of disabling dementia in older community-dwelling Japanese: A longitudinal study

This prospective study examined the associations of dog/cat ownership with incident disabling dementia using propensity score matching based on the physical, social, and psychological characteristics of dog and cat owners. We also examined associations of the interaction between dog/cat ownership and exercise habit and social isolation with dementia. Overall, 11,194 older adults selected using stratified and random sampling strategies in 2016 were analyzed. Dog/cat ownership was defined as "current" or "past and never". Disabling dementia was defined according to physicians' rating in the long-term care insurance system in Japan during the approximately 4-year follow-up period. Statistical analysis was weighted by the inverse of the propensity score in the generalized estimating equation after adjusting for follow-up period. Current dog owners (8.6 %) had an odds ratio (OR) of 0.60 (95 %CI: 0.37-0.977) of having disabling dementia compared to past and never owners. For cat ownership, the corresponding OR was 0.98 (95 %CI: 0.62-1.55). Current dog owners with a regular exercise habit had an OR of 0.37 (0.20-0.68) compared to past and never dog owners with no exercise habit. Further, current dog owners with no social isolation had an OR of 0.41 (0.23-0.73) compared to past and never dog owners with social isolation. Dog ownership had a suppressive effect on incident disabling dementia after adjusting for background factors over a 4-year follow-up period. Specifically, dog owners with an exercise habit and no social isolation had a significantly lower risk of disabling dementia.

Risk factors of cognitive impairment: Impact of decline in oral function

Cognitive impairment and subsequent dementia are the major causes of disability and need for nursing care among older people in worldwide. The purpose is to review well-known risk factors for cognitive impairment and dementia, focusing on the relationship between decline in oral function and current prevention strategies. Various non-modifiable and modifiable risk factors are related to cognitive impairment. Effects of oral function to cognitive impairment is not yet well recognized in the medical community, although masticatory function, occlusal force, and number of teeth have been reported to be related to cognitive function. Furthermore, occlusal force rather than number of teeth was significantly related to the early stages of cognitive impairment, and that a decline in occlusal force seemed to lead to cognitive impairment directly and indirectly through dietary intake. This relationship was significant only for occlusal force, which may be associated with the early stages of cognitive decline. Nutritional change caused by reduced masticatory function is suggested as a possible explanation. Therefore, rehabilitation or maintenance of oral function should be sought to prevent cognitive impairment.

Artificial intelligence for dementia prevention

INTRODUCTION

A wide range of modifiable risk factors for dementia have been identified. Considerable debate remains about these risk factors, possible interactions between them or with genetic risk, and causality, and how they can help in clinical trial recruitment and drug development. Artificial intelligence (AI) and machine learning (ML) may refine understanding.

METHODS

ML approaches are being developed in dementia prevention. We discuss exemplar uses and evaluate the current applications and limitations in the dementia prevention field.

RESULTS

Risk-profiling tools may help identify high-risk populations for clinical trials; however, their performance needs improvement. New risk-profiling and trial-recruitment tools underpinned by ML models may be effective in reducing costs and improving future trials. ML can inform drug-repurposing efforts and prioritization of disease-modifying therapeutics.

DISCUSSION

ML is not yet widely used but has considerable potential to enhance precision in dementia prevention.

HIGHLIGHTS

Artificial intelligence (AI) is not widely used in the dementia prevention field. Risk-profiling tools are not used in clinical practice. Causal insights are needed to understand risk factors over the lifespan. AI will help personalize risk-management tools for dementia prevention. AI could target specific patient groups that will benefit most for clinical trials.

Association between napping and cognitive impairment: A systematic review and meta-analysis

STUDY OBJECTIVES

Increasing evidence suggests that napping is associated with cognitive impairment and dementia, but the conclusions are inconsistent. Moreover, the extent of the risk is uncertain. We therefore conducted a systematic review and meta-analysis to quantify the connection between napping and cognitive impairment.

METHODS

We performed a systematic search of PubMed, EMBASE, Web of Science, and Cochrane Library for studies that were published up to June 2023, and assessed associations between napping and cognitive impairment. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated as the effect sizes for all studies. Heterogeneity and potential publication biases were assessed.

RESULTS

A total of 4535 papers were retrieved, with 20 reports assessing the relationships between napping and cognitive impairment. Pooled analysis indicated that napping was associated with dementia (OR = 1.14; 95% CI: 1.07-1.21). Importantly, we found that those napping longer than 30, 45, and 60 min/day were 35%, 41%, and 40%, respectively, more likely to have an increased risk of cognitive impairment (30 min: OR = 1.35; 95% CI: 1.24-1.48; 45 min: OR = 1.41; 95% CI: 1.27-1.58; 60 min: OR = 1.40; 95% CI: 1.26-1.56). North America and Europe showed that associations existed between napping and cognitive impairment (North America: OR = 1.15; 95% CI: 1.04-1.27; Europe: OR = 1.13; 95% CI: 1.08-1.18).

CONCLUSIONS

This meta-analysis indicated associations between long napping durations and cognitive impairment or dementia, suggesting that longer napping might be a potential risk factor of adverse cognitive outcomes.

The neurocognitive disorder cohort RIFADE: Aims, methods, first results showing cognitive improvement in a subgroup

BACKGROUND

The NCD cohort study RIFADE (RIsk FActors of DEmentia) investigates the interaction of risk factors and neurocognitive disorders (NCDs) due to Alzheimer's disease (NCD-AD) and NCD of vascular type (NCD-vascular). Retrospective recruitment referred to a period from 2007 to 2018 in a single centre. In addition to the baseline visit, follow-up visits took place at 3, 6, 12 months followed by yearly visits. Visit times varied in part depending on adherence. The study also comprises an EEG bank and a bank with cerebral MRI (c-MRI).

METHODS

Inclusion criteria were broad in order to cover a wide range of patterns of NCD. At baseline, patients underwent a large panel of assessments, e.g. including clinical history, diagnostic evaluation for NCD according to DSM-IV and NINDS AIREN criteria, a cognitive test battery including the DemTect, the clock drawing test and the Instrumental-Activities-of-Daily-Living-scale of Lawton and Brodie, EEG and c-MRI. At each follow-up visit, cognitive tests were repeated, in most cases also EEGs and in some cases c-MRIs. Numerous risk factors (RF) including vascular RF, atrial fibrillation, heart failure, sleep apnoea and lifestyle factors such as sedentary lifestyle, low cognitive style and smoking were evaluated for presence and for correction status at each visit, and modulation of uncorrected RF was initiated.

RESULTS

Overall, 126 subjects with a clinical diagnosis of NCD were included (52% female, mean age 71 ± 10.6 years (range 35e86)), number of follow-up visits per subject 2.9 ± 2.4, observation time per subject 3.4 ± 2.8 years). Of these, 55/28/17% presented with the clinical stages subjective cognitive decline (SCD)/mild cognitive impairment (MCI)/dementia (major NCD). Clinical diagnoses, retrospectively re-evaluated according to DSM-5, were 5/21/68/6% Alzheimer´s disease (NCD-AD)/vascular NCD (NCD-vascular) / mixed NCD (NCD-AD + NCD-vascular)/unspecified NCD. First longitudinal results revealed a mean DemTect score at baseline 12.6 ± 4.2 vs last visit 12.0 ± 4.8 (p = 0.08) and a clock drawing test score at baseline 1.9 ± 1.3 vs last visit 2.3 ± 1.5 (p < 0.0001). Of all subjects with MCI or major NCD (n = 57), 19 improved in the clinical stage from baseline to last visit (33.3%). Sixteen subjects progressed from SCD or MCI (n = 104) to major NCD (15.4%).

CONCLUSION

The German NCD cohort RIFADE comprises patients with all clinical stages of NCD. A considerable subgroup improved in clinical stage. Further analysis is needed to answer the question of whether modulation of multiple risk factors provides a favourable effect on cognitive outcome in NCD.

The association between Gabapentin or Pregabalin use and the risk of dementia: an analysis of the National Health Insurance Research Database in Taiwan

Objective: Previous studies have shown that gabapentin or pregabalin use is associated with cognitive decline. Herein, we aimed to evaluate the association between gabapentin or pregabalin use and the risk of dementia. Methods: In this retrospective, population-based matched cohort study, all research data were collected from the 2005 Longitudinal Health Insurance Database, which contains data of 2 million people randomly selected from the National Health Insurance Research Database of Taiwan in 2005. The study extracted data from 1 January 2000, to 31 December 2017. Adult patients taking gabapentin or pregabalin were included in the exposure group, and patients not using gabapentin or pregabalin matched to exposure subjects in a 1:5 ratio by propensity scores composed of age, sex and index date were included in the non-exposure group. Results: A total of 206,802 patients were enrolled in the study. Of them, 34,467 gabapentin- or pregabalin-exposure and 172,335 non-exposure patients were used for analysis. The mean follow-up day (±standard deviation) after the index date was 1724.76 (±1282.32) and 1881.45 (±1303.69) in the exposure and non-exposure groups, respectively; the incidence rates of dementia were 980.60 and 605.48 per 100,000 person-years, respectively. The multivariate-adjusted hazard ratio of risk of dementia for gabapentin or pregabalin exposure versus the matched non-exposed group was 1.45 (95% confidence interval [CI], 1.36-1.55). The risk of dementia increased with higher cumulative defined daily doses during the follow-up period. Moreover, the stratification analysis revealed that the risk of dementia associated with gabapentin or pregabalin exposure was significant in all age subgroups; however, it was higher in younger patients (age <50) than in the older patients (hazard ratio, 3.16; 95% CI, 2.23-4.47). Conclusion: Patients treated with gabapentin or pregabalin had an increased risk of dementia. Therefore, these drugs should be used with caution, particularly in susceptible individuals.

Tooth-Cutting-Induced Maxillary Malocclusion Exacerbates Cognitive Deficit in a Mouse Model of Vascular Dementia

Treatments to restore the balance of the temporomandibular joint (TMJ) are performed in the field of complementary and alternative medicine; however, evidence supporting this approach remains weak. Therefore, this study attempted to establish such evidence. Bilateral common carotid artery stenosis (BCAS) operation, which is commonly used for the establishment of a mouse model of vascular dementia, was performed, followed by tooth cutting (TEX) for maxillary malocclusion to promote the imbalance of the TMJ. Behavioural changes, changes in nerve cells and changes in gene expression were assessed in these mice. The TEX-induced imbalance of the TMJ caused a more severe cognitive deficit in mice with BCAS, as indicated by behavioural changes in the Y-maze test and novel object recognition test. Moreover, inflammatory responses were induced via astrocyte activation in the hippocampal region of the brain, and the proteins involved in inflammatory responses were found to be involved in these changes. These results indirectly show that therapies that restore the balance of the TMJ can be effectively used for the management of cognitive-deficit-related brain diseases associated with inflammation.

Dementia-related disability in the population aged 90 years and over: differences over time and the role of comorbidity in the vitality 90 + study

BACKGROUND

The burden of dementia, multimorbidity, and disability is high in the oldest old. However, the contribution of dementia and comorbidities to functional ability in this age group remains unclear. We examined the combined effects of dementia and comorbidities on ADL and mobility disability and differences between dementia-related disability between 2001, 2010, and 2018.

METHODS

Our data came from three repeated cross-sectional surveys in the population aged 90 + in the Finnish Vitality 90 + Study. The associations of dementia with disability and the combined effects of dementia and comorbidity on disability adjusted for age, gender, occupational class, number of chronic conditions, and study year were determined by generalized estimating equations. An interaction term was calculated to assess differences in the effects of dementia on disability over time.

RESULTS

In people with dementia, the odds of ADL disability were almost five-fold compared to people with three other diseases but no dementia. Among those with dementia, comorbidities did not increase ADL disability but did increase mobility disability. Differences in disability between people with and without dementia were greater in 2010 and 2018 than in 2001.

CONCLUSION

We found a widening gap in disability between people with and without dementia over time as functional ability improved mainly in people without dementia. Dementia was the main driver of disability and among those with dementia, comorbidities were associated with mobility disability but not with ADL disability. These results imply the need for strategies to maintain functioning and for clinical updates, rehabilitative services, care planning, and capacity building among care providers.

Association between hearing loss and trauma based on population data of Korea

BACKGROUND

Although several studies have been conducted to assess the association between hearing loss (HL) and trauma, no studies have analyzed trauma comprehensively based on population-based data.

OBJECTIVES

To investigate the association between HL and trauma in daily life using National Health Insurance Service National Sample Cohort data of Korea.

MATERIALS AND METHODS

People who were registered with severe or mild hearing disability by the Korean government from 2002 to 2015, were included in this study. Trauma was defined as an outpatient visit or admission under diagnostic codes associated with trauma. The risk for trauma was analyzed using multiple logistic regression model.

RESULTS

There were 5,114 subjects in the mild hearing disability group and 1,452 in the severe hearing disability group. The risk for trauma was significantly higher in the mild and severe hearing disability groups than in the control group. The risk was higher in the mild hearing disability group than in the severe hearing disability group.

CONCLUSIONS AND SIGNIFICANCE

Individuals with hearing disability are at a higher risk for trauma based on population-based data in Korea, which indicates that HL increases the risk for trauma.

Atrial fibrillation as a contributor to the mortality in patients with dementia: A nationwide cohort study

Background

Knowledge of the risk of death in patients with dementia is essential for planning preventive strategies. This study aimed to evaluate the effect of atrial fibrillation (AF) on death risks and other factors associated with death in patients with dementia and AF.

Methods

We conducted a nationwide cohort study using Taiwan's National Health Insurance Research Database. We identified subjects with dementia diagnosed for the first time and AF diagnosed concomitantly between 2013 and 2014. Subjects under the age of 18 years were excluded. Age, sex, and CHA2DS2-VASc scores were 1: 4 matched for AF patients (N = 1,679) and non-AF controls (N = 6,176) using the propensity score technique. The conditional Cox regression model and competing risk analysis were applied. The risk of mortality was tracked till 2019.

Results

AF history was associated with higher risks of all-cause death (hazard ratio [HR]: 1.208; 95% confidence interval [CI]: 1.142–1.277) and cardiovascular death (subdistribution HR: 1.210; 95% CI: 1.077–1.359) in dementia patients than patients without a diagnosis of AF. For patients with both dementia and AF, they had a higher risk of death due to higher age, diabetes mellitus, congestive heart failure, chronic kidney disease, and prior stroke. Anti-arrhythmic drugs and novel oral anticoagulants significantly reduced the risk of death in patients with AF and dementia.

Conclusion

This study found that AF is a risk factor for mortality in patients with dementia and explored several risk factors for AF-related mortality. This study highlights the importance of controlling AF especially in patients with dementia.

Senior Health Clinic for 75-year-old home-dwelling Finns - study design, clinic protocol and non-response analysis

BACKGROUND

In the Finnish policy on older people preventive activities, which maintain functional capacity and independent living, are emphasized. The Turku Senior Health Clinic, aimed at maintaining independent coping of all home-dwelling 75-year-old citizens in the city of Turku, was founded in the beginning of 2020. The aim of this paper is to describe design and protocol of the Turku Senior Health Clinic Study (TSHeC) and provide results of the non-response analysis.

METHODS

The non-response analysis used data from 1296 participants (71% of those eligible) and 164 non-participants of the study. Sociodemographic, health status, psychosocial and physical functional ability indicators were included in the analysis. Participants and non-participants were also compared in respect to their neighborhood socioeconomic disadvantage. Differences between participants and non-participants were tested using the Chi squared or Fisher´s exact test for categorical variables and t-test for continuous variable.

RESULTS

The proportions of women (43% vs. 61%) and of those with only satisfying, poor or very poor self-rated financial status (38% vs. 49%) were significantly lower in non-participants than in participants. Comparison of the non-participants and participants in respect to their neighborhood socioeconomic disadvantage showed no differences. The prevalence of hypertension (66% vs. 54%), chronic lung disease (20% vs. 11%), and kidney failure (6% vs. 3%) were higher among non-participants compared to participants. Feelings of loneliness were less frequent among non-participants (14%) compared to participants (32%). The proportions of those using assistive mobility devices (18% vs. 8%) as well as those having previous falls (12% vs. 5%) were higher in non-participants than in participants.

CONCLUSIONS

The participation rate of TSHeC was high. No neighborhood differences in participation were found. Health status and physical functioning of non-participants seemed to be slightly worse than those of the participants, and more women than men participated. These differences may weaken the generalizability of the findings of the study. The differences have to be taken into account when recommendation for the content and implementation of preventive nurse-managed health clinic in primary health care in Finland is going to be given.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05634239; registration date; 1st of December 2022. Retrospectively registered.

The role of nutrition and the Mediterranean diet on the trajectories of cognitive decline

The worldwide burden of dementia is immense, and set to increase to unprecedented levels in the coming decades, due to population aging. In the absence of disease-modifying treatment, there is therefore a strong rationale to support the assumption that acting on modifiable risk factors, especially in midlife, is a good strategy for reducing the burden of dementia. Among these risk factors, nutrition is key, as it is fundamental to healthy aging, and has interrelated benefits on a number of organ systems, metabolic processes and health states that can all contribute to modifying the risk of dementia. In this paper, we review the methodological challenges of comparing studies of dietary interventions. We then discuss the effect of genetics and the environment on brain health, and review in particular the literature data on the effect of nutrition on cognition. We summarize the body of data reporting the largely beneficial effects of the Mediterranean diet on brain health, and the possible mechanisms that mediate these effects. Finally, we discuss future perspectives for further research in the field, notably the "gut-brain axis", thought to be a key mediator of the effect of nutrition on brain health.

A Decision-Aware Ambient Assisted Living System with IoT Embedded Device for In-Home Monitoring of Older Adults

Older adults' independent life is compromised due to various problems, such as memory impairments and decision-making difficulties. This work initially proposes an integrated conceptual model for assisted living systems capable of providing helping means for older adults with mild memory impairments and their caregivers. The proposed model has four main components: (1) an indoor location and heading measurement unit in the local fog layer, (2) an augmented reality (AR) application to make interactions with the user, (3) an IoT-based fuzzy decision-making system to handle the direct and environmental interactions with the user, and (4) a user interface for caregivers to monitor the situation in real time and send reminders once required. Then, a preliminary proof-of-concept implementation is performed to evaluate the suggested mode's feasibility. Functional experiments are carried out based on various factual scenarios, which validate the effectiveness of the proposed approach. The accuracy and response time of the proposed proof-of-concept system are further examined. The results suggest that implementing such a system is feasible and has the potential to promote assisted living. The suggested system has the potential to promote scalable and customizable assisted living systems to reduce the challenges of independent living for older adults.

Beneficial and Impeding Factors for the Implementation of Health-Promoting Lifestyle Interventions-A Gender-Specific Focus Group Study

(1) Background: The prevalence of dementia increases and so does the number of interventions that address modifiable risk factors for dementia. Recent evidence suggests that there are gender differences in the prevalence of those lifestyle factors as well as in the effectiveness of interventions. This study aims to identify differences in factors that benefit or hinder the effectiveness of interventions since a target group's perspective gets more relevant. (2) Methods: Two focus groups, a female (n = 11) and a male (n = 8) group, were interviewed, audio recorded and transcribed. Qualitative analyses were performed and main- and subcategories were identified. (3) Results: Main differences were observed including aspects of lifestyle changes (e.g., respective diet and importance of an active lifestyle) and gender-typical behavior and perception by relevant healthcare actors. (4) Conclusions: Identified differences might help to address and raise the efficiency of lifestyle interventions. Further, the importance of social aspects and retirement as an auspicious moment to start interventions were identified as relevant by study participants.

27-hydroxycholesterol promotes oligodendrocyte maturation: Implications for hypercholesterolemia-associated brain white matter changes

Oxidized cholesterol metabolite 27-hydroxycholesterol (27-OH) is a potential link between hypercholesterolemia and neurodegenerative diseases since unlike peripheral cholesterol, 27-OH is transported across the blood-brain barrier. However, the effects of high 27-OH levels on oligodendrocyte function remain unexplored. We hypothesize that during hypercholesterolemia 27-OH may impact oligodendrocytes and myelin and thus contribute to the disconnection of neural networks in neurodegenerative diseases. To test this idea, we first investigated the effects of 27-OH in cultured oligodendrocytes and found that it induces cell death of immature O4⁺ /GalC⁺ oligodendrocytes along with stimulating differentiation of PDGFR⁺ oligodendrocyte progenitors (OPCs). Next, transgenic mice with increased systemic 27-OH levels (Cyp27Tg) underwent behavioral testing and their brains were immunohistochemically stained and lysed for immunoblotting. Chronic exposure to 27-OH in mice resulted in increased myelin basic protein (MBP) but not 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase) or myelin oligodendrocyte glycoprotein (MOG) levels in the corpus callosum and cerebral cortex. Intriguingly, we also found impairment of spatial learning suggesting that subtle changes in myelinated axons of vulnerable areas like the hippocampus caused by 27-OH may contribute to impaired cognition. Finally, we found that 27-OH levels in cerebrospinal fluid from memory clinic patients were associated with levels of the myelination regulating CNPase, independently of Alzheimer's disease markers. Thus, 27-OH promotes OPC differentiation and is toxic to immature oligodendrocytes as well as it subtly alters myelin by targeting oligodendroglia. Taken together, these data indicate that hypercholesterolemia-derived higher 27-OH levels change the oligodendrocytic capacity for appropriate myelin remodeling which is a crucial factor in neurodegeneration and aging.

Association between Ambient Illumination and Cognitive Impairment: A Population-Based Study of Older

It is well-established that light therapy can alleviate cognitive impairment, and ambient illumination (AI) can quantify the amount of exposure to light. However, the relationship between AI and cognitive impairment has been largely understudied. Objectives. We aimed to examine the cross-sectional associations between AI and impaired cognition using data from the National Health and Nutrition Examination Survey (NHANES) (2011-2013) database. Methods. The correlation between AI and cognitive impairment was analyzed using multivariate logistic regression models. Nonlinear correlations were explored using curve fitting. Results. Multivariate logistic regression yielded an OR of 0.872 (95% CI 0.699, 1.088) for the association between AI and cognitive impairment after adjusting for covariates. Smooth curve fitting showed that the correlation was nonlinear, with an inflection point at 1.22. Conclusions. These results suggested that the level of AI may be linked to cognitive impairment. We found a nonlinear relationship of AI with cognitive impairment.

Quantitative EEG for early differential diagnosis of dementia with Lewy bodies

Introduction

Differentiating between the two most common forms of dementia, Alzheimer's dementia and dementia with Lewy bodies (DLB) remains difficult and requires the use of invasive, expensive, and resource-intensive techniques. We aimed to investigate the sensitivity and specificity of electroencephalography quantified using the statistical pattern recognition method (qEEG-SPR) for identifying dementia and DLB.

Methods

Thirty-two outpatients and 16 controls underwent clinical assessment (by two blinded neurologists), EEG recording, and a 6-month follow-up clinical assessment. EEG data were processed using a qEEG-SPR protocol to derive a Dementia Index (positive or negative) and DLB index (positive or negative) for each participant which was compared against the diagnosis given at clinical assessment. Confusion matrices were used to calculate sensitivity, specificity, and predictive values for identifying dementia and DLB specifically.

Results

Clinical assessment identified 30 cases of dementia, 2 of which were diagnosed clinically with possible DLB, 14 with probable DLB and DLB was excluded in 14 patients. qEEG-SPR confirmed the dementia diagnosis in 26 out of the 32 patients and led to 6.3% of false positives (FP) and 9.4% of false negatives (FN). qEEG-SPR was used to provide a DLB diagnosis among patients who received a positive or inconclusive result of Dementia index and led to 13.6% of FP and 13.6% of FN. Confusion matrices indicated a sensitivity of 80%, a specificity of 89%, a positive predictive value of 92%, a negative predictive value of 72%, and an accuracy of 83% to diagnose dementia. The DLB index showed a sensitivity of 60%, a specificity of 90%, a positive predictive value of 75%, a negative predictive value of 81%, and an accuracy of 75%. Neuropsychological scores did not differ significantly between DLB and non- DLB patients. Head trauma or story of stroke were identified as possible causes of FP results for DLB diagnosis.

Conclusion

qEEG-SPR is a sensitive and specific tool for diagnosing dementia and differentiating DLB from other forms of dementia in the initial state. This non-invasive, low-cost, and environmentally friendly method is a promising diagnostic tool for dementia diagnosis which could be implemented in local care settings.

Is Carer Management Style Associated with Longitudinal Functional Decline in Dementia?

BACKGROUND

Various intrinsic (related to dementia) and extrinsic (not related to dementia) factors have been suggested to contribute separately to disability in people living with dementia (PLwD).

OBJECTIVE

To investigate if the combination of specific intrinsic and extrinsic factors at baseline is associated with longitudinal declines in activities of daily living (ADL) performance of PLwD at 12-month follow-up.

METHODS

141 community-dwelling PLwD-carer dyads were assessed on their global cognition (ACE-III), apathy (CBI-R), carer management styles (DMSS), medical comorbidities (CCI), and ADL performance (DAD) at baseline, and for a subset of participants (n = 53), at 12-month follow-up. Multiple linear regression models were run to assess: 1) the relationships between PLwD's DAD scores and the remaining variables at baseline and 2) whether these variables' scores at baseline were associated with longitudinal change in the PLwD's DAD scores.

RESULTS

At baseline, having lower ACE-III (β= 0.354, p < 0.001), higher CBI-R (β= -0.284, p < 0.001), higher DMSS criticism (β= -0.367, p = 0.013), lower DMSS encouragement (β= 0.370, p = 0.014), and higher CCI scores (β= -2.475, p = 0.023) were significantly associated with having lower DAD scores. The PLwD's DAD scores significantly declined from baseline to follow-up (p < 0.001, d = 1.15), however this decline was not associated with the baseline scores of any of the independent variables. Instead, it was associated with declines in the PLwD's ACE-III scores from baseline to follow-up (β= 1.021, p = 0.001).

CONCLUSIONS

In our limited sample, cognitive changes seem to be the main factor underlying longitudinal decline in ADL performance for PLwD. Carer management styles appear associated with current ADL performance but not with longitudinal ADL decline.

Best Medicine for Dementia: The Life-Long Defense of the Brain

This review deals with an unwelcome reality about several forms of dementia, including Alzheimer's disease- that these dementias are caused, in part or whole, by the aging of the vasculature. Since the vasculature ages in us all, dementia is our fate, sealed by the realit!ies of the circulation; it is not a disease with a cure pending. Empirically, cognitive impairment before our 7th decade is uncommon and considered early, while a diagnosis in our 11th decade is late but common in that cohort (>40%). Projections from earlier ages suggest that the prevalence of dementia in people surviving into their 12th decade exceeds 80%. We address the question why so few of many interventions known to delay dementia are recognized as therapy; and we try to resolve this few-and-many paradox, identifying opportunities for better treatment, especially pre-diagnosis. The idea of dementia as a fate is resisted, we argue, because it negates the hope of a cure. But the price of that hope is lost opportunity. An approach more in line with the evidence, and more likely to limit suffering, is to understand the damage that accumulates with age in the cerebral vasculature and therefore in the brain, and which eventually gives rise to cognitive symptoms in late life, too often leading to dementia. We argue that hope should be redirected to delaying that damage and with it the onset of cognitive loss; and, for each individual, it should be redirected to a life-long defense of their brain.

Recognition of social health: A conceptual framework in the context of dementia research

Objective

The recognition of dementia as a multifactorial disorder encourages the exploration of new pathways to understand its origins. Social health might play a role in cognitive decline and dementia, but conceptual clarity is lacking and this hinders investigation of associations and mechanisms. The objective is to develop a conceptual framework for social health to advance conceptual clarity in future studies.

Process

We use the following steps: underpinning for concept advancement, concept advancement by the development of a conceptual model, and exploration of its potential feasibility. An iterative consensus-based process was used within the international multidisciplinary SHARED project.

Conceptual framework

Underpinning of the concept drew from a synthesis of theoretical, conceptual and epidemiological work, and resulted in a definition of social health as wellbeing that relies on capacities both of the individual and the social environment. Consequently, domains in the conceptual framework are on both the individual (e.g., social participation) and the social environmental levels (e.g., social network). We hypothesize that social health acts as a driver for use of cognitive reserve which can then slow cognitive impairment or maintain cognitive functioning. The feasibility of the conceptual framework is demonstrated in its practical use in identifying and structuring of social health markers within the SHARED project.

Discussion

The conceptual framework provides guidance for future research and facilitates identification of modifiable risk and protective factors, which may in turn shape new avenues for preventive interventions. We highlight the paradigm of social health in dementia as a priority for dementia research.

Psychological resilience, activities of daily living, and cognitive functioning among older male Tekun adults in rural long-term care facilities in China

Most of the rural long-term care (LTC) facilities in China are ill-equipped to manage the physical and psychological needs of older residents with dementia. These facilities mostly consist of older male Tekun (socially and economically vulnerable) adults. Preventing or delaying the onset of dementia is especially crucial for these older Tekun adults. A sample of 711 older male Tekun adults from rural LTC facilities in the Anhui province of China was used to investigate the association between psychological resilience and cognitive functioning, and to examine the moderating effect of activities of daily living (ADLs) on that association. Linear and quantile regression found that resilience was positively associated with cognitive functioning for the total sample, with a greater effect among those with a lower level of cognitive functioning. The benefit of resilience on cognitive functioning was observed only in participants with disability in ADLs. Our findings present evidence in support of interventions to foster psychological resilience and potentially improve cognitive functioning among vulnerable older adults. Resilience-promoting intervention is a strength-based approach that aligns with social work values and can be used in practice. The implications for social work practice were discussed.

Multi-task longitudinal forecasting with missing values on Alzheimer's disease

BACKGROUND AND OBJECTIVE

Machine learning techniques typically used in dementia assessment are not able to learn multiple tasks jointly and deal with time-dependent heterogeneous data containing missing values. In this paper, we reformulate SSHIBA, a recently introduced Bayesian multi-view latent variable model, for jointly learning diagnosis, ventricle volume, and ADAS score in dementia on longitudinal data with missing values.

METHODS

We propose a novel Bayesian Variational inference framework capable of simultaneously imputing missing values and combining information from several views. This way, we can combine different data views from different time-points in a common latent space and learn the relationships between each time-point, using the semi-supervised formulation to fully exploit the temporal structure of the data and handle missing values. In turn, the model can combine all the available information to simultaneously model and predict multiple output variables.

RESULTS

We applied the proposed model to jointly predict diagnosis, ventricle volume, and ADAS score in dementia. The comparison of imputation strategies demonstrated the superior performance of the semi-supervised formulation of the model, improving the best baseline methods. Moreover, the performance in simultaneous prediction of diagnosis, ventricle volume, and ADAS score led to an improved prediction performance over the best baseline method.

CONCLUSIONS

The results demonstrate that the proposed SSHIBA framework can learn an excellent imputation of the missing values and outperforming the baselines while simultaneously predicting three different tasks.

Mediating role of homebound status between depressive symptoms and cognitive impairment among community-dwelling older adults in the USA: a cross-sectional analysis of a cohort study

OBJECTIVE

Depressive symptoms are known modifiable factors of cognitive impairment in older adults. However, the pathway through which depressive symptoms lead to cognitive impairment is not well understood. This study aimed to investigate whether homebound status (defined as usually unable to leave home unassisted) mediates the association between depressive symptoms and cognitive impairment in community-dwelling older adults in the USA.

DESIGN

A secondary analysis of cross-sectional data.

SETTINGS

Communities in the USA.

PARTICIPANTS

Community-dwelling older adults (N=7537) from the 2011 National Health and Aging Trends Study, a nationally representative survey of Medicare Beneficiaries in the USA.

MAIN OUTCOME MEASURES

Participants' cognitive impairment status was classified using a composite measure. Depressive symptoms were assessed using Patient Health Questionnaire-2. Homebound status was determined by the frequency, difficulty and needing help in getting outdoors. We used logistic regression and the Paramed command in STATA to analyse whether homebound mediated the association between depressive symptoms and cognitive impairment.

RESULTS

Participants were on average, 77.7 years old, female (58.3%) and non-Hispanic white (68.1%). About 26% of the participants were classified as having cognitive impairment, 16% reported depressive symptoms and 25% were homebound. Depressive symptoms (adjusted OR, 1.60; 95% CI 1.36 to 1.89) and homebound status (adjusted OR, 1.58; 95% CI 1.34 to 1.86) were independently associated with cognitive impairment. Homebound significantly mediated 12.5% of the total effect between depressive symptoms and cognitive impairment, with significant indirect effect (OR, 1.07; 95% CI 1.04 to 1.10), direct effect (OR, 1.61; 95% CI 1.36 to 1.91) and total effect (OR, 1.72; 95% CI 1.46 to 2.03).

CONCLUSIONS

This study supports a mediating role of homebound status in the relationship between depressive symptoms and cognitive impairment. Interventions to promote outdoor mobility should be studied for their ability to delay cognitive impairment for older adults with depressive symptoms.

Preclinical Alzheimer's dementia: a useful concept or another dead end?

The term, preclinical dementia, was introduced in 2011 when new guidelines for the diagnosis of Alzheimer's dementia (AD) were published. In the intervening 11 years, many studies have appeared in the literature focusing on this early stage. A search conducted in English on Google Scholar on 06.23.2022 using the term "preclinical (Alzheimer's) dementia" produced 121, 000 results. However, the label is arguably more relevant for research purposes, and it is possible that the knowledge gained may lead to a cure for AD. The term has not been widely adopted by clinical practitioners. Furthermore, it is still not possible to predict who, after a diagnosis of preclinical dementia, will go on to develop AD, and if so, what the risk factors (modifiable and non-modifiable) might be. This Review/Theoretical article will focus on preclinical Alzheimer's dementia (hereafter called preclinical AD). We outline how preclinical AD is currently defined, explain how it is diagnosed and explore why this is problematic at a number of different levels. We also ask the question: Is the concept 'preclinical AD' useful in clinical practice or is it just another dead end in the Holy Grail to find a treatment for AD? Specific recommendations for research and clinical practice are provided.

Reading activities compensate for low education-related cognitive deficits

BACKGROUND

The incidence of cognitive impairment is increasing with an aging population. Developing effective strategies is essential to prevent dementia. Higher education level is associated with better baseline cognitive performance, and reading activities can slow down cognitive decline. However, it is unclear whether education and reading activities are synergistic or independent contributors to cognitive performance.

METHODS

This was a sub-study of an ongoing prospective community cohort of China National Clinical Research Center Alzheimer's Disease and Neurodegenerative Disorder Research (CANDOR). Demographic and clinical information, educational levels, and reading activities were collected. All participants finished neuropsychological testing batteries and brain MRIs. We analyzed cognitive performance and brain structures with education and reading activities.

RESULTS

Four hundred fifty-nine subjectively cognitively normal participants were enrolled in the study. One hundred sixty-nine (36.82%) of them had regular reading activities. Participants in the reading group had better performance in all cognitive tests compared with those in the non-reading group, but no difference in brain MRI variables. Participants with higher education levels (more than 13 years) had better cognitive performance and higher hippocampal volumes. In low education groups (less than 12 years), more reading activities were associated with better cognitive test scores.

CONCLUSIONS

Both education and reading activities are important and synergistic for baseline cognitive function. Higher education level is associated with larger hippocampal volumes. Education may stimulate the growth and development of the hippocampus. Reading activities help to maintain and improve cognitive function in people with low levels of education.

TRIAL REGISTRATION

NCT04320368.

Propolis induces cardiac metabolism changes in 6-hydroxydopamine animal model: A dietary intervention as a potential cardioprotective approach in Parkinson’s disease

While there is sustained growth of the older population worldwide, ageing is a consistent risk factor for neurodegenerative diseases, such as Parkinson’s-disease (PD). Considered an emblematic movement disorder, PD comprises a miscellany of non-motor symptoms, for which effective management remains an unfulfilled need in clinical practice. Highlighted are the cardiovascular abnormalities, that cause significant burden in PD patients. Evidence suggests that key biological processes underlying PD pathophysiology can be modulated by diet-derived bioactive compounds, such as green propolis, a natural functional food with biological and pharmacological properties. The effects of propolis on cardiac affection associated to PD have received little coverage. In this study, a metabolomics approach and Positron Emission Tomography (PET) imaging were used to assess the metabolic response to diet supplementation with green propolis on heart outcomes of rats with Parkinsonism induced by 6-hydroxydopamine (6-OHDA rats). Untargeted metabolomics approach revealed four cardiac metabolites (2-hydroxybutyric acid, 3-hydroxybutyric acid, monoacylglycerol and alanine) that were significantly modified between animal groups (6-OHDA, 6-OHDA + Propolis and sham). Propolis-induced changes in the level of these cardiac metabolites suggest beneficial effects of diet intervention. From the metabolites affected, functional analysis identified changes in propanoate metabolism (a key carbohydrate metabolism related metabolic pathway), glucose-alanine cycle, protein and fatty acid biosynthesis, energy metabolism, glutathione metabolism and urea cycle. PET imaging detected higher glucose metabolism in the 17 areas of the left ventricle of all rats treated with propolis, substantially contrasting from those rats that did not consume propolis. Our results bring new insights into cardiac metabolic substrates and pathways involved in the mechanisms of the effects of propolis in experimental PD and provide potential novel targets for research in the quest for future therapeutic strategies.

EFFECT OF AIR ENDURANCE TRAINING ON ATHLETE’S LOWER LIMB EXPLOSIVE STRENGTH

ABSTRACT Introduction: The explosion force is the neuromuscular system's capacity to overcome resistance with the highest possible contraction speed. It is the result of a kinetic combination between power and speed. The effect of outdoor resistance training is used in several athletics areas to improve the explosive power of the lower limbs. However, there are still few studies focused on basketball athletes. Objective: Verify the effect of outdoor resistance training on the explosive power of the lower limbs of basketball players. Methods: The article uses mathematical statistics and randomized controlled trials by analytical comparison to explore the influence of compound training methods on basketball players’ lower explosive limb power. Results: There was no performance gain in the control group at 30 days. Was an improved ability in the experimental group jumping after high-intensity composite training. Conclusion: Compound training plays a crucial role in improving lower limb explosive power in college basketball players. Evidence Level II; Therapeutic Studies - Investigating the result.

Association between osteoarthritis and urinary tract infection in older adults: A nationwide population-based cohort study

Osteoarthritis (OA) may increase urinary tract infection (UTI) in older adults. However, this issue remains unclear. We identified 8599 older patients (≥65 years) with OA, and an equal number of older patients without OA, matched by age, sex, and index date from the Taiwan National Health Insurance Research Database between 2001 and 2005. Past histories, including UTI and underlying comorbidities, were included in the analyses. Comparisons for any UTI, ≥1 hospitalization for UTI, and ≥3 hospitalizations for UTI between the 2 cohorts by following up until 2015 were performed. In both cohorts, the percentages of age subgroups were 65-74 years (65.7%), 75-84 years (30.1%), and ≥85 years (4.2%). The male sex was 42.4%. Patients with OA had an increased risk of any UTI compared with those without OA after adjusting for all past histories (adjusted hazard ratio [AHR]: 1.72; 95% confidence interval [CI]: 1.64-1.80). Compared with patients without OA, patients with OA also had an increased risk of ≥1 hospitalization for UTI and ≥3 hospitalizations for UTI (AHR: 1.13; 95% CI: 1.06-1.19 and AHR: 1.25; 95% CI: 1.13-1.38, respectively). In addition to OA, age 75-84 years, female sex, history of UTI, benign prostatic hyperplasia, indwelling urinary catheter, cerebrovascular disease, dementia, and urolithiasis were independent predictors for any UTI. This study showed that OA was associated with UTI in older adults. We suggest appropriately managing OA and controlling underlying comorbidities to prevent subsequent UTI.

The effect of risk factors on cognition in adult cochlear implant candidates with severe to profound hearing loss

Hearing loss has been identified as a major modifiable risk factors for dementia. Adult candidates for cochlear implantation (CI) represent a population at risk of hearing loss-associated cognitive decline. This study investigated the effect of demographics, habits, and medical and psychological risk factors on cognition within such a cohort. Data from 34 consecutive adults with post-lingual deafness scheduled for CI were analyzed. Pure tone audiometry (PTA4) and Speech Discrimination Score (SDS) were recorded. The Repeatable Battery for Assessment of Neuropsychological Status for Hearing impaired individuals (RBANS-H) was used to measure cognition. Demographics (sex, age, years of education), habits (smoking, alcohol intake, physical inactivity), and medical factors (hypertension, diabetes, traumatic brain injury) were evaluated. Depression was measured using the Hospital Anxiety and Depression Scale (HADS), and social inhibition with the Type D questionnaire (DS14). All participants (mean age 62 ± 15 years) suffered from severe to profound hearing loss (PTA4:129 ± 60 dB; SDS:14 ± 24%). The mean RBANS-H total score was 83 ± 16. Participants reported a mean of years of formal education of 12 ± 5 years. The prevalence of habits and medical risk factors was: physical inactivity (29%), body mass index >30 (28%), traumatic brain injury (25%), hypertension (24%), heavy alcohol consumption (13%), smoking (13%), and diabetes (0%). Regarding psychological factors, the mean scores of social inhibition and depression were 10 ± 6 and 6 ± 5, respectively. The number of years of education was significantly correlated with the RBANS-H total score (p < 0.001), and with the domains “Immediate memory” (p = 0.003), “Visuospatial/constructional” (p < 0.001), and “Attention” (p < 0.001). The mean RBANS-H total score in participants who had university studies or higher level (12/34) was 97 ± 9, with the remaining participants reporting a mean score of 75 ± 15. Men performed better in the “Visuospatial/constructional” (p = 0.008). Physical inactivity was associated with lower scores in the “Delayed memory” (p = 0.031); hypertension correlated with lower RBANS-H total scores (p = 0.025) and “Attention” (p = 0.006). Depression and social inhibition were negatively correlated with RBANS-H total score and with the “Immediate memory,” “Visuospatial/constructional,” and “Attention” (all p < 0.05). In adults with late-onset deafness scheduled to CI, educational level has a significant effect. Additionally, sex, physical inactivity, hypertension, and psychological traits of social inhibition and depression may also influence cognitive status. Long-term studies with more participants would enable us better understand the effects different risk factors on cognitive status.

Management of Type 2 Diabetes Mellitus in Elderly Patients with Frailty and/or Sarcopenia

The life expectancy of the population is increasing worldwide due to improvements in the prevention, diagnosis, and treatment of diseases. This favors a higher prevalence of type 2 diabetes mellitus (T2DM) in the elderly. Sarcopenia and frailty are also frequently present in aging. These three entities share common mechanisms such as insulin resistance, chronic inflammation, and mitochondrial dysfunction. The coexistence of these situations worsens the prognosis of elderly patients. In this paper, we review the main measures for the prevention and management of sarcopenia and/or frailty in elderly patients with T2DM.

How does the onset of physical disability or dementia in older adults affect economic wellbeing and co-payments for health care? the impact of gender

BACKGROUND

Existing studies have illustrated how the onset of physical disability or dementia negatively impacts economic wellbeing and increases out of pocket costs. However, little is known about this relationship in older individuals. Consequently, this study aimed to identify how the onset of physical disability or dementia in older adults affects economic wellbeing and out of pocket costs, and to explore the impact of gender in the context of Australia.

METHODS

The data was collected from a large, randomized clinical study, ASPirin in Reducing Events in the Elderly (ASPREE). Two generalized linear models (with and without interaction effects) of total out of pocket costs for those who did and did not develop physical disability or dementia were generated, with adjustment for sociodemographic characteristics at baseline.

RESULTS

We included 8,568 older Australian individuals with a mean age of 74.8 years and 53.2% being females. After adjustment for the baseline sociodemographic characteristics, the onset of physical disability did statistically significantly raise out of pocket costs (cost ratio = 1.25) and costs among females were 13.1% higher than males.

CONCLUSIONS

This study highlights that classifying different types of health conditions to identify the drivers of out of pocket costs and to explore the gender differences in a long-term follow-up is of importance to examine the financial impact on the older population. These negative financial impacts and gender disparities of physical disability and dementia must be considered by policymakers.

Association of Long-term Exposure to Ambient Air Pollution With Cognitive Decline and Alzheimer's Disease-Related Amyloidosis

BACKGROUND

Air pollution induces neurotoxic reactions and may exert adverse effects on cognitive health. We aimed to investigate whether air pollutants accelerate cognitive decline and affect neurobiological signatures of Alzheimer's disease (AD).

METHODS

We used a population-based cohort from the Chinese Longitudinal Healthy Longevity Survey with 31,573 participants and a 10-year follow-up (5878 cognitively unimpaired individuals in Chinese Longitudinal Healthy Longevity Survey followed for 5.95 ± 2.87 years), and biomarker-based data from the Chinese Alzheimer's Biomarker and Lifestyle study including 1131 participants who underwent cerebrospinal fluid measurements of AD-related amyloid-β (Aβ) and tau proteins. Cognitive impairment was determined by education-corrected performance on the China-Modified Mini-Mental State Examination. Annual exposures to fine particulate matter (PM_2.5), ground-level ozone (O₃), and nitrogen dioxide (NO₂) were estimated at areas of residence. Exposures were aggregated as 2-year averages preceding enrollments using Cox proportional hazards or linear models.

RESULTS

Long-term exposure to PM_2.5 (per 20 μg/m³) increased the risk of cognitive impairment (hazard ratio, 1.100; 95% CI: 1.026-1.180), and similar associations were observed from separate cross-sectional analyses. Exposures to O₃ and NO₂ yielded elevated risk but with nonsignificant estimates. Individuals exposed to high PM_2.5 manifested increased amyloid burdens as reflected by cerebrospinal fluid-AD biomarkers. Moreover, PM_2.5 exposure-associated decline in global cognition was partly explained by amyloid pathology as measured by cerebrospinal fluid-Aβ₄₂/Aβ₄₀, P-tau/Aβ₄₂, and T-tau/Aβ₄₂, with mediation proportions ranging from 16.95% to 21.64%.

CONCLUSIONS

Long-term exposure to PM_2.5 contributed to the development of cognitive decline, which may be partly explained by brain amyloid accumulation indicative of increased AD risk.