The prevalence of dementia and Alzheimer's disease in Shanghai, China: impact of age, gender, and education

Relationship between different physical activity parameters and cognitive impairment in middle-aged and older adults: insights from a 4-year longitudinal study

BACKGROUND

Physical activity (PA) is crucial for the prevention and management of chronic diseases and may be associated with cognitive impairment. This study investigated the longitudinal relationship between PA from different parameters (e.g., frequency, duration, intensity, and volume) and the incidence of cognitive impairment in middle-aged and older adults.

METHODS

Data were derived from the China Health and Retirement Longitudinal Study (2011-2015). A total of 891 adults aged 45 and older were included in this study. Cognitive function was assessed using the Telephone Interview for Cognitive Status criteria, focused on episodic memory and executive function. We categorized participants into normal cognition and cognitive impairment groups. Self-reported PA information including frequency, duration, intensity, and volume was collected through a representative survey. Poisson regression analysis was employed to explore the relationship between PA parameters and the incidence of cognitive impairment over four years.

RESULTS

Engaging in moderate or light PA (MPA or LPA) at least three days per week, and vigorous PA (VPA) one to two days per week, was associated with a reduced incidence of cognitive impairment. Additionally, spending 30-119 min per day or 150 min per week or more on any PA intensity was linked to lower cognitive impairment prevalence. Sensitivity analysis, excluding individuals with neurological, mental, or memory impairments, confirmed these findings.

CONCLUSIONS

The findings highlight that the frequency, duration, and volume of VPA, MPA, or LPA are linked to the incidence of cognitive impairment. Regular PA may reduce the risk of cognitive impairment in middle-aged and older adults.

Relationship between development trajectories of leisure activity and sleep time on incident cognitive impairment: A study based on the Chinese Longitudinal Healthy Longevity Survey (CLHLS)

BackgroundLeisure activity and sleep time are key factors in cognitive impairment, but the impact of their long-term trajectories on incident cognitive impairment remains unclear.ObjectiveTo examine the association of leisure activity trajectories, sleep time trajectories and their combined effects with incident cognitive impairment in older adults.MethodsData from the Chinese Longitudinal Healthy Longevity Survey (2008-2018) were analyzed, including adults aged ≥65 who participated in at least three surveys. Group-based trajectory modeling explored leisure activity and sleep time patterns. Cox proportional-hazards regression model assessed the association of leisure activity trajectories and sleep time trajectories and their combined effects with incident cognitive impairment.ResultsWe included 3094 participants with a median follow-up of 6.07 years. The optimal trajectory groups for leisure activity and sleep time were four and three, respectively. The low-level leisure activity group were associated with an increased risk of cognitive impairment (HR, 95%CI: 2.07, 1.37-3.13), whereas the high-level leisure activity group were associated with a reduced risk of cognitive impairment (HR, 95%CI: 0.60, 0.36-0.99). Short sleep time group was associated with a reduced risk of cognitive impairment (HR, 95%CI: 0.62, 0.41-0.92). In the combined effect, leisure activity belonging to the low-level group and sleep time belonging to the moderate sleep time group or the long sleep time group were associated with an increased risk of cognitive impairment.ConclusionsLong-term high-level leisure activity and short sleep time are associated with a reduced risk of cognitive impairment in older adults.

The impact of cognitive reserve relative to risk of Alzheimer's disease and rate of progression: an up-to-date review of the literature

INTRODUCTION

Cognitive reserve (CR) is a crucial factor in explaining individual differences in the risk of Alzheimer's disease (AD) and cognitive decline. CR refers to the brain's ability to cope with pathology through compensatory mechanisms. This review examines the various methods used to measure, predict, and influence CR.

AREAS COVERED

Based on a search of PubMed, PubMed Central, EMBASE, Scopus, and the Cochrane Library (up to 1 June 2024), this review addresses key CR proxies, highlighting their strengths and limitations. The review also explores established and emerging interventions. We critically evaluate the statistical methods used to measure CR and assess its practical application.

EXPERT OPINION

CR plays a crucial role in delaying the onset and progression of AD. Lifestyle choices and experiences build CR and impact cognitive aging. However, practical challenges remain in applying CR in clinical settings, particularly in individuals with advanced cognitive decline. Education, while commonly used as a proxy for CR, may not fully capture its complexity. Alternatives like occupational complexity could offer more practical measures, but their application is still evolving. Addressing these limitations is key to advancing dementia prevention strategies.

Closing the gap in dementia research by community-based cohort studies in the Chinese population

China accounts for 1/5 of the global population and China faces a particularly heavy dementia burden due to its rapidly ageing population. Unique historical events, genetic background, sociocultural factors, lifestyle, and the COVID-19 pandemic further influence cognitive outcomes in the Chinese population. We searched PubMed, Web of Science, and Embase for community-based cohort studies related to dementia in the Chinese population, and summarized the characteristics, methodologies, and major findings published over the last 25 years from 39 cohorts. We identified critical research gaps and propose future directions, including enhancing sample representativeness, investigating China-specific risk factors, expanding exposure measurements to the whole life-span, collecting objective data, conducting administer-friendly domain-specific cognitive assessments, adopting pathological diagnostic criteria, standardizing biobank construction, verifying multi-modal biomarkers, examining social and genetic-environmental aspects, and monitoring post-COVID cognitive health, to approach high quality of dementia studies that can provide solid evidence to policy making and promote global brain health research.

Multi-metal mixture exposure and cognitive function in urban older adults: The mediation effects of thyroid hormones

The existing studies on the association between multi-metal mixture exposure and cognitive function in the older adults are limited and controversial, with no studies considering the mediating effect of thyroid hormones on the connection between them. This study of 441 urban older adults assessed 21 urinary metal levels and cognitive function using the Mini-Mental State Examination (MMSE). Urinary metal levels were measured via inductively coupled plasma mass spectrometry (ICP-MS), and thyroid hormones levels were obtained from medical records. Mediation analysis evaluated the role of thyroid hormones in the link between metals exposure and cognitive function. The General Linear Model (GLM) showed negative correlations between MMSE scores and titanium (Ti), copper (Cu), rubidium (Rb), and molybdenum (Mo), and positive correlations with selenium (Se) and barium (Ba). Nonlinear inverse U-shaped associations between Mo, Rb, and MMSE scores were identified using Restricted Cubic Splines (RCS) and Bayesian Kernel Machine Regression (BKMR). Mediation analysis revealed that Free Thyroxine (FT4) mediated the relationship between Rb and MMSE scores by 29.10 % and between Zinc (Zn) and language performance by 35.00 %. Total thyroxine (TT4) mediated the link between Cu and orientation score by 24.69 %, and Thyroid Stimulating Hormone (TSH) mediated the association between Cu and attention score by 38.96 %. Ti, Se, Rb, Mo, Ba and Cu were significantly associated with cognitive impairment risk. Mixed exposure to Mo and Rb was linked to an increased risk of cognitive impairment. Additionally, levels of TSH, FT4 and TT4 were associated with cognitive function, mediating the effects of Rb, Zn and Cu on cognitive function.

Altered interactions between attentional networks in older adults with mild cognitive impairment

Previous research using the Attention Network Test (ANT) paradigm has indicated that older adults with mild cognitive impairment (MCI) experience declines in attentional performance across the three core networks: alerting, orienting, and executive control, primarily focusing on main effects. The present study sought to expand these findings by exploring whether interactions between these networks are also affected in the presence of MCI. To achieve this, we used the Revised Attention Network Test (ANT-R) to examine both the individual attentional networks and their interactions in 21 older adults with MCI and 27 healthy controls (HCs) matched on demographic variables. Results indicated that the MCI group exhibited lower accuracy than the HC group in both executive control and orienting functions. In addition, the MCI group demonstrated a weakened interaction between the orienting and executive control networks, suggesting that valid cues are less effective in facilitating conflict resolution for individuals with MCI compared to HCs. No significant group differences were observed for the interaction between the executive control and alerting networks, or between the flanker conflict effect and the location conflict effect within the executive control network. This study extends previous findings by identifying changes related to MCI in the interaction between the orienting and executive control networks, highlighting the challenges individuals with MCI face in utilizing spatial cues during attentional processing.

Clinical characteristics and biomarker profile in early- and late-onset Alzheimer's disease: the Shanghai Memory Study

Early-onset Alzheimer's disease constitutes ∼5-10% of Alzheimer's disease. Its clinical characteristics and biomarker profiles are not well documented. To compare the characteristics covering clinical, neuropsychological and biomarker profiles between patients with early- and late-onset Alzheimer's disease, we enrolled 203 patients (late-onset Alzheimer's disease = 99; early-onset Alzheimer's disease = 104) from a Chinese hospital-based cohort, the Shanghai Memory Study. A full panel of plasma biomarkers under the amyloid/tau/neurodegeneration framework including plasma amyloid beta 40, amyloid beta 42, total-tau, neurofilament light chain and phosphorylated tau 181 were assayed using ultra-sensitive Simoa technology. Seventy-five patients underwent an amyloid molecular positron emission tomography scan whereas 43 received comprehensive amyloid, Tau deposition and hypometabolism analysis. Clinical features, plasma and imaging biomarkers were compared cross-sectionally. Compared to those with late-onset Alzheimer's disease, patients with early-onset Alzheimer's disease presented more severe impairment in language function, lower frequency of APOE ɛ4 and lower levels of plasma neurofilament light chain (all P < 0.05). The plasma phosphorylated tau 181 concentration and phosphorylated tau 181/amyloid beta 42 ratios were higher in early-onset Alzheimer's disease than in late-onset Alzheimer's disease (all P < 0.05). More severe Tau deposition as indicated by 18F-florzolotau binding in the precuneus, posterior cingulate cortex and angular gyrus was observed in the early-onset Alzheimer's disease group. Plasma phosphorylated tau 181 was associated with earlier age at onset and domain-specific cognitive impairment, especially in patients with early-onset Alzheimer's disease. We concluded that patients with early-onset Alzheimer's disease differed from late-onset Alzheimer's disease in cognitive performance and biomarker profile. A higher burden of pathological tau was observed in early-onset Alzheimer's disease and was associated with earlier age at onset and more profound cognitive impairment.

Effects of Protein Intake on Cognitive Function in Chinese Older Adults: A 10-Year Follow-Up Study

BACKGROUND

As the global population ages, there is an increasing prevalence of mild cognitive impairment and dementia. Protecting and preserving cognitive function in older adults has become a critical public health concern.

METHODS

This study utilized data from four phases of the Chinese Longitudinal Healthy Longevity Survey conducted from 2008 to 2018, encompassing a total of 2454 participants. Latent growth curve modeling was employed to analyze the trajectory and role of protein intake frequency and cognitive function.

RESULTS

The frequency of protein intake among older adults tends to rise, with individuals exhibiting higher initial levels experiencing smaller subsequent increases. Conversely, cognitive function generally declines, with those starting at higher levels experiencing more pronounced decreases. Notably, the initial frequency of protein intake is positively correlated with the initial level of cognitive function (β = 0.227, 95% CI: 0.156 to 0.299, p < 0.001), but does not significantly influence the rate of change in cognitive function (β = -0.030, 95% CI: -0.068 to 0.009, p = 0.128). The rate of change in protein intake frequency is positively associated with the rate of change in cognitive function (β = 0.152, 95% CI: 0.023 to 0.280, p = 0.020).

CONCLUSIONS

The alterations in protein intake frequency are linked to alterations in cognitive function among older adults. Maintaining a stable high frequency of protein intake or increasing the frequency of protein intake may contribute to stabilizing cognitive function as well as reducing the risk of cognitive impairment and dementia in older adults.

Proteomic Insight Into Alzheimer's Disease Pathogenesis Pathways

Alzheimer's disease (AD) is a leading cause of dementia, but the pathogenesis mechanism is still elusive. Advances in proteomics have uncovered key molecular mechanisms underlying AD, revealing a complex network of dysregulated pathways, including amyloid metabolism, tau pathology, apolipoprotein E (APOE), protein degradation, neuroinflammation, RNA splicing, metabolic dysregulation, and cognitive resilience. This review examines recent proteomic findings from AD brain tissues and biological fluids, highlighting potential biomarkers and therapeutic targets. By examining the proteomic landscape of them, we aim to deepen our understanding of the disease and support developing precision medicine strategies for more effective interventions.

Unstable functional brain states and reduced cerebro-cerebellar modularity in elderly individuals with subjective cognitive decline

The preclinical stage of Alzheimer's Disease (AD) holds great potential for intervention, therefore, it is crucial to elucidate the neural mechanisms underlying the progression of subjective cognitive decline (SCD). Previous studies have predominantly focused on the neural changes in the cerebrum associated with SCD, but have relatively neglected the cerebellum, and its functional relationship with the cerebrum. In the current study, we employed dynamic functional connectivity and large-scale brain network approaches to investigate the pathological characteristics of dynamic brain states and cerebro-cerebellar collaboration between SCD (n = 32) and the healthy elderly (n = 29) using resting-state fMRI. Two-way repeated measures ANOVA and permutation t-tests revealed significant group differences, with individuals with SCD exhibiting shorter state duration and more frequent transitions between states compared to the healthy elderly individuals. Additionally, individuals with SCD showed lower levels of intracerebellar functional connectivity, but higher levels of cerebellar-cerebral functional integration. Furthermore, the hub nodes of the functional networks in SCD shifted between the cerebellum and cerebrum across different brain states. These findings indicate that SCD exhibits greater state instability but may compensate for the negative effects of early disease by integrating cerebellar and cerebral networks, thereby maintaining cognitive performance. This study enhances our theoretical understanding of cerebellar-cerebral relationship changes in the early stages of AD and provides evidence for early interventions targeting the cerebellum.

Prevalence of cognitive impairment and its related factors among Chinese older adults: an analysis based on the 2018 CHARLS data

Background

Cognitive impairment is a major public health concern in aging societies. This study aimed to investigate the prevalence of cognitive impairment and its associated factors among Chinese adults aged 60 years and older using data from the 2018 China Health and Retirement Longitudinal Study (CHARLS).

Methods

Utilizing data from the 2018 wave of CHARLS, we assessed participants' cognitive status using the Mini-Mental State Examination (MMSE), and the influencing factors related to cognitive impairment were analyzed by using the chi-square test and multifactor logistic regression. The prevalence of cognitive impairment was stratified by gender, education level, residence, marital status, daytime napping, and nighttime sleep duration, and the trend of cognitive impairment prevalence with age was observed.

Results

9,804 participants were finally included in the study and the overall prevalence of cognitive impairment was 44.04% (95%CI, 43.02-45.06%). The prevalence was significantly higher in females (50.8%) than males (37.1%), and increased with age, from 41.5% in those aged 60-64 years to 57.7% in those aged ≥75 years. Lower educational level, rural residence, and being divorced/ widowed/unmarried were associated with a higher prevalence of cognitive impairment (all p < 0.001). Multifactor logistic regression indicated that older age (OR = 1.51, 95%CI, 1.33-1.73 for ≥75 vs. 60-64 years), female gender (OR = 1.54, 95%CI, 1.35-1.77), higher education (OR = 0.46, 95%CI, 0.42-0.51 for primary school and below vs. illiteracy), rural areas (OR = 2.35, 95%CI, 2.07-2.65 for village vs. the center of city/town), divorced/ widowed/unmarried status (OR = 1.40, 95%CI, 1.25-1.57) and participation in physical activity (OR = 0.80, 95%CI, 0.73-0.87) were significantly associated with cognitive impairment.

Conclusion

Cognitive impairment is highly prevalent among older adults in China with substantial demographic disparities. Targeted interventions and public health strategies are needed to promote cognitive health in this rapidly aging population.

The comparative analysis between sporadic and genetic Creutzfeldt-Jakob disease in China

OBJECTIVES

Creutzfeldt-Jakob disease (CJD) is a transmissible neurodegenerative disorder with a fatal outcome. The present study investigated the difference on demographic, clinical and laboratory data between the patients with sporadic CJD (sCJD) and genetic CJD (gCJD).

METHODS

Thirty-eight patients with CJD were enrolled in this study, including 28 patients with sCJD and 10 patients with gCJD. All patients were administered cognitive tests, brain magnetic resonance imaging (MRI), electroencephalogram (EEG), cerebrospinal fluid (CSF) 14-3-3 protein.

RESULTS

The patients with sCJD had similar onset age, mean death and survival time to the patients with gCJD. There were slightly more males in the patients with sCJD than in the patients with gCJD (p = 0.095). The percentages of onset symptoms were similar between sCJD and gCJD groups. Patients with sCJD had more parkinsonism than patients with gCJD on neurological examinations (p = 0.037). The patients with gCJD also had slightly more disinhibitation than the patients with sCJD (p = 0.090). There were similar abnormalities percentages on MRI, EEG, and CSF 14-3-3 protein. The gCJD patients had more widespread cortex abnormalities involving the frontal, temporal, parietal and occipital lobe, compared with the sCJD patients (p = 0.012).

CONCLUSION

The patients with sCJD had similar epidemiological and clinical characteristics to the patients with gCJD, except more parkinsonism signs and less widespread cortex abnormalities on MRI.

Association of plasma homocysteine with cognitive impairment in patients with Parkinson's disease

Background

Elevated plasma homocysteine (Hcy) has been reported as a risk factor for cognitive impairment in the general population. However, there are conflicting results regarding the relationship between Hcy and cognitive impairment across various cognitive domains in Parkinson's disease (PD).

Objective

This study aims to explore the association between plasma Hcy levels, cognitive impairment, and dysfunction in various cognitive domains among PD patients with and without mild cognitive impairment (MCI).

Methods

A total of 101 PD patients underwent plasma Hcy measurement, comprising 50 PD-MCI patients and 51 patients with normal cognition (PD-NC). A battery of neuropsychological tests was administered to assess different cognitive domains. Adjusted generalized linear models were used to assess the correlations between Hcy levels and cognitive functions.

Results

As anticipated, PD-MCI patients demonstrated a significant decline in cognitive function across all five cognitive domains (memory, executive function, attention/working memory, language, and visuospatial function). Elevated plasma Hcy levels (≥ 10 μmol/L) were associated with a higher odds of PD-MCI, even within the normal range of Hcy levels (< 15 μmol/L). After adjusting for confounding factors, a negative correlation was observed between plasma Hcy levels and the performance on specific cognitive tests evaluating executive functions in PD, such as the Stroop Color-Word Test-C (β = -1.123, 95% CI = -1.845 ∼-0.401, p = 0.0023).

Conclusion

This study underscores a significant link between plasma Hcy levels and PD-MCI, particularly concerning executive dysfunction, even within the normal range of Hcy levels (< 15 μmol/L).

The updated prevalence and risk factors of dementia in old adults in China: A cross-sectional study

BACKGROUND

The continuously increasing aging population and life expectancy have led to an inconsistent and underestimated dementia prevalence in China. An updated epidemiologic study is urgently needed.

OBJECTIVE

To update the prevalence rate and risk factors of dementia in China.

METHODS

For this national cross-sectional study, 20,438 participants aged ≥65 from 28 communities and 56 villages from 14 centers were recruited using a multistage cluster sampling design between May 2019 and December 2019. Participants were assessed with a series of clinical and neuropsychological measurements. The prevalence rates of dementia, Alzheimer's disease (AD), and vascular dementia (VaD), as well as the risk factors, were calculated using multivariate-adjusted models.

RESULTS

The crude prevalence rates were 9.1% (95% CI, 8.7%-9.5%) for dementia, 6.0% (95% CI, 5.7%-6.3%) for AD, 1.4% (95% CI, 1.2%-1.5%) for VaD, and 1.8% (95% CI, 1.6%-2.0%) for other dementias in a population aged ≥65 years. The overall sex- and age-standardized prevalence was 8.8%. Apart from VaD, the prevalence rates of dementia and AD were higher in females than males (10.3% versus 7.7%, respectively). Moreover, the prevalence rates of dementia and AD increased significantly with age. Being unmarried and having fewer social activities increased the risks of dementia and main subtypes. Risk factors were not exactly the same for participants with AD and VaD.

CONCLUSIONS

The prevalence of dementia is increased and almost comparable with that of developed countries for individuals aged ≥65 years. These findings may serve as new evidence for government interventions in aging.

Behavioral change in fruit and vegetable consumption and associated cognitive impairment among Chinese older adults

BACKGROUND

Previous research has examined how fruit and vegetable consumption may affect cognitive impairment among older adults. However, knowledge regarding the behavioral change in fruit and vegetable consumption remains limited in the Chinese older adult population. This research aimed to fill the literature gap.

METHODS

We used data from five waves of the Chinese Longitudinal Healthy Longevity Study (2005-2018, observations = 18,856 from 11,388 participants) and selected older adult participants (65 years old or above). A behavioral change was defined as a consumption change in the study sample. Cognitive impairment was measured based on the mini-mental state examination. We used the Cox multi-state model as the major statistical analysis.

RESULTS

Chinese older adults who transitioned from non-daily to daily consumption of vegetables had lower odds of reporting cognitive impairment deteriorating from normal cognitive function to severe, compared with those who did not change their consumption behavior (HR [hazard ratio] = 0.88, 95% CI 0.80, 0.97; p < 0.05). All transitions in fruit consumption were negatively associated with cognitive changes from normal cognitive function to mild-moderate cognitive impairment. In our additional stratified analysis examining rural-urban disparity, we observed similar significant findings among rural older adults (Vegetable consumption change: HR = 0.83, 95% CI 0.75, 0.93; p < 0.01) but not urban older adults.

CONCLUSION

Behavioral change in consumption of vegetables may affect Chinese older adults' cognitive health. Future interventions should focus on the critical role of behavioral change in vegetable consumption in reducing older adults' cognitive impairment. However, the contradictory findings of fruit consumption warrant further investigation to draw a conclusive claim regarding its benefits for cognitive health.

Neuroglia in cognitive reserve

The concept of cognitive reserve was born to account for the disjunction between the objective extent of brain damage in pathology and its clinical and intellectual outcome. The cognitive reserve comprises structural (brain reserve) and functional (brain maintenance, resilience, compensation) aspects of the nervous tissue reflecting exposome-driven life-long plasticity, which defines the ability of the brain to withstand aging and pathology. The mechanistic background of this concept was primarily focused on adaptive changes in neurones and neuronal networks. We present arguments favoring the more inclusive view, positing that neuroglia are fundamental for defining the cognitive reserve through homeostatic, neuroprotective, and neurodegenerative mechanisms. Neuroglia are critical for the life-long shaping of synaptically connected neuronal circuits as well as the brain connectome thus defining cognitive reserve. Neuroglial homeostatic and protective physiological responses define brain maintenance and resilience, while neuroglia regenerative capabilities are critical for brain compensation in pathology. Targeting neuroglia may represent an untrodden path for prolonging cognitive longevity.

Effect of a Group-Based Personal Assistive RObot (PARO) Robot Intervention on Cognitive Function, Autonomic Nervous System Function, and Mental Well-being in Older Adults with Mild Dementia: A Randomized Controlled Trial

OBJECTIVES

Personal Assistive RObot (PARO) interventions have been used to treat agitation and mood symptoms of dementia effectively. However, the effects of a PARO intervention on physiological and cognitive function are unclear. To examine the effects of a group-based PARO intervention for older adults with mild dementia.

DESIGN

Using a group-based PARO intervention randomized controlled trial with 2-arm parallel groups.

SETTING AND PARTICIPANTS

Older adults with mild dementia aged 65 years or older from 4 dementia day care centers were recruited.

METHODS

Physiological parameters were assessed using the finger tapping test (FTT) and heart rate variability (HRV). The Mini-Mental State Examination (MMSE), Geriatric Depression Scale-Short Form (GDS-SF), University of California Los Angeles loneliness scale-version 3 (UCLA-3), and Warwick-Edinburgh Mental Well-being Scale (WEMWBS) were assessed before the intervention, end of the intervention, and 1-month after the intervention.

RESULTS

Using a repeated-measures generalized linear model, significant time × group interactions were found in the MMSE [F(2, 115) = 19.54, P < .001], FTT [F(2, 115) = 4.87, P = .01], HRV high-frequency [F(2, 115) = 3.57, P = .03], and high-frequency/low-frequency ratio [F(2, 115) = 0.96, P = .01], UCLA-3 [F(2, 115) = 54.7, P < .001], GDS-SF [F(2, 115) = 3.36, P = .04], and WEMWBS [F(2, 115) = 5.93, P < .001]. Furthermore, psychological parameters improved significantly and continuously even 1 month after the PARO intervention was finished. Physiological parameters significantly improved at week 6, but the effects had diminished by week 10.

CONCLUSIONS AND IMPLICATIONS

A PARO intervention may effectively improve the physiological and psychological responses of people with mild dementia.

Neurotransmitter Metabolism in Arsenic Exposure-Induced Cognitive Impairment: Emerging Insights and Predictive Implications

Scholars have long been interested in the association between arsenic (As) exposure and neurological disorders; however, existing systematic epidemiological investigations are insufficient and lack the inclusion of diagnostic or predictive biological markers. This study sought to evaluate the association between As exposure and cognitive impairment and identify potential biomarkers by developing predictive models. Here, we found that logarithm (Ln)-transformed urinary As concentrations were negatively linearly related to the mini-mental state examination (MMSE) score exposure-response curves. Subsequently, we identified a unique plasma neurometabolite profile in subjects exposed to As compared with the reference group. Further analyses showed that tryptophan, tyrosine, dopamine, epinephrine, and homovanillic acid were all significantly associated with both urinary As concentrations and MMSE scores. Notably, the association between As exposure and MMSE scores was partly mediated by tryptophan, tyrosine, dopamine, and epinephrine. Importantly, an unprecedented prediction model utilizing neurotransmitters was established to assess the risk of cognitive impairment due to As exposure. A 91.1% consistency rate was found between the predicted and the actual probabilities. Additionally, machine learning models also produced highly accurate predictions. Overall, this study revealed a dose-dependent cognitive decline in As-exposed adults accompanied by a disturbance in the signature of neurotransmitter metabolites, offering new predictive insights.

Longitudinal association between depressive symptoms and cognitive function: the neurological mechanism of psychological and physical disturbances on memory

BACKGROUND

The neural correlates underlying late-life depressive symptoms and cognitive deterioration are largely unclear, and little is known about the role of chronic physical conditions in such association. This research explores both concurrent and longitudinal associations between late-life depressive symptoms and cognitive functions, with examining the neural substrate and chronic vascular diseases (CVDs) in these associations.

METHODS

A total of 4109 participants (mean age = 65.4, 63.0% females) were evaluated for cognitive functions through various neuropsychological assessments. Depressive symptoms were assessed by the Geriatric Depression Scale and CVDs were self-reported. T1-weighted magnetic resonance imaging (MRI), diffusion tensor imaging, and functional MRI (fMRI) data were acquired in a subsample (n = 791).

RESULTS

Cognitively, higher depressive symptoms were correlated with poor performance across all cognitive domains, with the strongest association with episodic memory (r = ‒0.138, p < 0.001). Regarding brain structure, depressive symptoms were negatively correlated with thalamic volume and white matter integrity. Further, white matter integrity was found to mediate the longitudinal association between depressive symptoms and episodic memory (indirect effect = -0.017, 95% CI -0.045 to -0.002) and this mediation was only significant for those with severe CVDs (β = -0.177, p = 0.008).

CONCLUSIONS

This study is one of the first to provide neural evidence elucidating the longitudinal associations between late-life depressive symptoms and cognitive dysfunction. Additionally, the severity of CVDs strengthened these associations, which enlightens the potential of managing CVDs as an intervention target for preventing depressive symptoms-related cognitive decline.

Empty nest but better off? Association between empty nest status and cognitive function among older adults with chronic diseases in rural China

BACKGROUND

The increasing prevalence of cognitive impairment poses substantial risks to older adults, particularly those with chronic diseases. While existing studies have examined the connection between the empty nest phenomenon and cognitive function, few have attempted to consider endogeneity issues within this relationship, with limited attention given to older adults with chronic diseases. This study investigates the impact of empty nest status on cognitive function among rural Chinese older adults with chronic diseases and explores the possible mechanisms underlying this effect.

METHODS

A cross-sectional study involved 365 older adults aged 60 or above with chronic diseases in rural areas of Shaanxi province, northwest China. Cognitive function was measured using the Mini-Mental State Examination. Multiple regression models and the instrumental variable (IV) method were employed to examine the association between empty nest and cognitive function.

RESULTS

Among the 365 older adults aged 60 or above with chronic diseases, 43% experienced cognitive impairment. Results from both multiple regression and IV analyses consistently demonstrate a significant association between empty nest status and higher cognitive function scores (β = 1.757, p = 0.007; β = 3.682, p = 0.034, respectively). Mechanism analysis further supports that the positive association may arise from empty nesters receiving more social support from children and friends, and perceiving loneliness experiences as inadequate. Heterogeneity analysis reveals that the association between empty nest status and cognitive function is more pronounced among male adults with chronic diseases.

CONCLUSIONS

This study challenges the notion that empty nest status is a risk factor for cognitive decline in older adults with chronic diseases in rural China. The positive impact is attributed to the robust social relationships of empty nesters, encompassing sustained support from their social network, and the absence of an increase in loneliness. Therefore, future interventions aimed at improving cognitive function in older adults may benefit from promoting the development of social relationships.

The Impact of Engagement with the PARO Therapeutic Robot on the Psychological Benefits of Older Adults with Dementia

OBJECTIVES

This study aimed to examine the effect of 8-weeks of a 60-minute PARO intervention to reduce depressive symptoms and loneliness in older adults with dementia and investigated changes in their emotional or behavioral expressions and level of engagement with the PARO robot.

METHODS

This was a quasi-experimental study with a repeated measures design. The outcome measures were evaluated at four time-points: before the intervention, week 4, immediately after the intervention, and one month after the PARO intervention.

RESULTS

Fifty-two participants were recruited. The age of the participants ranged from 65 to 96 years, with a mean age of 81.81 years (SD = 8.54) in the PARO group and 79.08 years (SD = 7.71) in the control group. Using a mixed between-within subjects' analysis of variance, the results showed that there were significant interaction effects between the groups and time-periods for depression (p < .000), loneliness (p < .000), and engagement (p < .000).

CONCLUSIONS

The PARO intervention alleviated depression and loneliness for older adults. Furthermore, the process of engagement with PARO may play an important role in the PARO effects.

CLINICAL IMPLICATIONS

A tailored PARO intervention of at least 4 weeks could engender positive psychological benefits for older adults.

Atrophy in the supramarginal gyrus associated with impaired cognitive inhibition in grieving Chinese Shidu parents

Background: The loss of an only child, known as Shidu in China, is a profoundly distressing experience, often leading to Prolonged Grief Disorder (PGD). Despite its impact, the structural brain alterations associated with PGD, potentially influencing cognitive impairments in Shidu parents, remain understudied.Objective: This study aims to identify brain structural abnormalities related to prolonged grief and their relation with cognitive inhibition in Shidu parents.Methods: The study included 40 Shidu parents and 42 non-bereaved participants. Prolonged grief was evaluated using the Prolonged Grief Questionnaire (PG-13). We employed voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) to assess brain structural alterations and their correlation with cognitive inhibition, as measured by Stroop interference scores.Results: Findings suggest that greater prolonged grief intensity correlates with reduced grey matter volume in the right amygdala and the left supramarginal gyrus (SMG). Additionally, enhanced amygdala-to-whole-brain structural connectivity showed a marginal association with prolonged grief, particularly with emotional-related symptoms. Furthermore, a decrease in SMG volume was found to mediate the relation between prolonged grief and Stroop Time Inference (TI) score, indicating an indirect effect of prolonged grief on cognitive inhibition.Conclusions: The study provides insight into the neural correlates of prolonged grief in Shidu parents, highlighting the SMG's role in cognitive inhibition. These findings emphasise the need for comprehensive grief interventions to address the complex cognitive and emotional challenges faced by this unique bereaved population.

Association of education attainment, smoking status, and alcohol use disorder with dementia risk in older adults: a longitudinal observational study

BACKGROUND

Previous research on the risk of dementia associated with education attainment, smoking status, and alcohol use disorder (AUD) has yielded inconsistent results, indicating potential heterogeneous treatment effects (HTEs) of these factors on dementia risk. Thus, this study aimed to identify the important variables that may contribute to HTEs of these factors in older adults.

METHODS

Using 2005-2021 data from the National Alzheimer's Coordinating Center (NACC), we included older adults (≥ 65 years) with normal cognition at the first visit. The exposure of interest included college education or above, current smoking, and AUD and the outcome was all-cause dementia. We applied doubly robust learning to estimate risk differences (RD) and 95% confidence intervals (CI) between exposed and unexposed groups in the overall cohort and subgroups identified through a decision tree model.

RESULTS

Of 10,062 participants included, 929 developed all-cause dementia over a median 4.4-year follow-up. College education or above was associated with a lower risk of all-cause dementia in the overall population (RD, -1.5%; 95%CI, -2.8 to -0.3), especially among the subpopulations without hypertension, regardless of the APOE4 status. Current smoking was not related to increased dementia risk overall (2.8%; -1.5 to 7.2) but was significantly associated with increased dementia risk among men with (21.1%, 3.1 to 39.1) and without (8.4%, 0.9 to 15.8) cerebrovascular disease. AUD was not related to increased dementia risk overall (2.0%; -7.7 to 11.7) but was significantly associated with increased dementia risk among men with neuropsychiatric disorders (31.5%; 7.4 to 55.7).

CONCLUSIONS

Our studies identified important factors contributing to HTEs of education, smoking, and AUD on risk of all-cause dementia, suggesting an individualized approach is needed to address dementia disparities.

Association between blood pressure and dementia in older adults: a cross-sectional study from China

Background and aims

The association between blood pressure (BP) and dementia in older adults remains unclear, prompting this study to investigate the relationship between various BP indicators and dementia in this population.

Methods

A cross-sectional survey was conducted in 2019, including 3,599 participants aged 65 years or older. The basic demographic characteristics of participants were collected. BP measurements and neuropsychological assessments were performed. From the systolic BP (SBP) and diastolic BP (DBP) values, mean arterial pressure (MAP), pulse pressure (PP) and blood pressure index (BPI) were calculated. Generalized additive models and logistic regression models were used to analyze the association between BP indicators and dementia.

Results

Generalized additive models identified a U-shaped relationship between DBP and dementia, which was more significant in males and people 70 years of age and older. The optimal DBP associated with the lowest dementia risk was 85 mmHg. Logistic regression models revealed that compared to the DBP subgroup (80-89 mmHg), participants in the DBP < 80 mmHg subgroup and the DBP ≥100 mmHg subgroup had OR for dementia of 1.611 (95% CI: 1. 252-2.073, P < 0.001) and 1.423 (95% CI: 0.999-2.028, p = 0.050), respectively. A significant association was observed between BPI and dementia (OR:1.746 95% CI: 1.142-2.668, p = 0.010).

Conclusion

In older adults, we found a U-shaped relationship between DBP and dementia, and a linear relationship between BPI and dementia. These results underscore the importance of considering DBP and BPI in BP management strategies for older adults to potentially prevent or delay dementia onset.

Low Intake of Total Antioxidant Nutrients as a Risk Factor for Incident Dementia in Older Adults: The Shanghai Aging Study

INTRODUCTION

Previous longitudinal studies reported the impact of antioxidant nutrients (ANs) on cognitive impairment in the older population, but the conclusions were inconsistent. This study aimed to verify the hypothesis that dietary intake of total AN was associated with incident dementia among older individuals.

METHODS

Community residents without dementia aged ≥60 years were prospectively followed up for an average of 5.2 years in the Shanghai Aging Study. At baseline, daily intakes of total dietary AN (the sum of carotene, vitamin C, vitamin E, lutein, and flavonoids) and energy were calculated based on an interviewer-administered food frequency questionnaire measuring the dietary intake over the past 1 year for each participant. A battery of neuropsychological tests was used to evaluate cognitive function, and a consensus diagnosis of dementia was made according to the DSM-IV criteria at baseline and follow-up.

RESULTS

Among 1,550 dementia-free participants, 135 (8.7%) incident dementia cases were identified during the average of 5.2 years of follow-up. Participants with low AN intake (<112 mg/day) had a significantly higher risk of incident dementia than those with high AN intake (≥112 mg/day) (hazard ratio 1.87, 95% confidence interval 1.26-2.77) after adjusting for age, gender, education, obesity, APOE-ε4, hypertension, diabetes, depression, baseline Mini-Mental State Examination score, and total energy intake. The significant association of total AN intake with incident dementia was only found in individuals ≥70 years.

CONCLUSION

Low total AN intake may be a risk factor for incident dementia among older adults. Maintaining sufficient AN intake may be beneficial against age-related cognitive decline.

Hearing Loss and Cognitive Impairment Among Community-Dwelling Older Adults - Liaoning, Henan, and Guangdong Provinces, China, 2019-2020

What is already known about this topic?

Many studies have shown that hearing loss (HL) is a risk factor for cognitive decline and dementia, but there are still limited studies on this association among Chinese older adults.

What is added by this report?

Based on the results of pure-tone audiometry tests, HL is associated with cognitive impairment in community-dwelling older adults. The odds ratios (ORs) were 1.23 (1.08-1.40) for mild HL, 1.55 (1.32-1.82) for moderate HL, and 1.87 (1.47-2.39) for severe or profound HL.

What are the implications for public health practice?

Enhanced public awareness of hearing protection is important for preventing cognitive impairment. It is advocated to promote the screening of HL and cognitive function assessment in elderly health examinations or management in primary care services.

Resistance and Resilience to Alzheimer's Disease

Dementia is a significant public health crisis; the most common underlying cause of age-related cognitive decline and dementia is Alzheimer's disease neuropathologic change (ADNC). As such, there is an urgent need to identify novel therapeutic targets for the treatment and prevention of the underlying pathologic processes that contribute to the development of AD dementia. Although age is the top risk factor for dementia in general and AD specifically, these are not inevitable consequences of advanced age. Some individuals are able to live to advanced age without accumulating significant pathology (resistance to ADNC), whereas others are able to maintain cognitive function despite the presence of significant pathology (resilience to ADNC). Understanding mechanisms of resistance and resilience will inform therapeutic strategies to promote these processes to prevent or delay AD dementia. This article will highlight what is currently known about resistance and resilience to AD, including our current understanding of possible underlying mechanisms that may lead to candidate preventive and treatment interventions for this devastating neurodegenerative disease.

The association between household and family composition and mental health of the elderly: mediating role of lifestyle

BACKGROUND

Mental health in the elderly has multiple determinants, and studies indicate household and family composition, economic status, and family support are key factors. However, these are difficult to modify, and better lifestyle for the elderly can be a possible intervention. The current study examined the mediating role of lifestyle in the association between these three types of the household and family composition (living alone, living with a spouse, and living with children) and mental health in older adults.

METHODS

We studied 5,407 participants (58.7% female, age 45 + years) from the Beijing Aging Brain Rejuvenation Initiative Project. All participants underwent a battery of examinations to measure degree loneliness, depression, and global cognitive function. We also surveyed personal lifestyles. We used a mediation analysis to determine the relative contribution of each lifestyle factor on mental health outcomes.

RESULTS

Older adults living alone rarely participated in mental and social activities and often had irregular diets; those adults living with children spent most of their time caring for grandchildren and had irregular eating and sleeping schedules; those living with a spouse often engaged in a variety of leisure activities and had the best life habits. Mediation analyses showed that dietary and sleeping irregularity partially mediated the negative effects of living alone on mental health, and were moderated by age and gender.

CONCLUSIONS

Living with a spouse was associated with benefits for the mental health of middle-aged and older adults (especially older and female individuals), through modifying better lifestyles than those of individuals with the other two types of the household and family composition.

Association between ambient fine particular matter components and subsequent cognitive impairment in community-dwelling older people: a prospective cohort study from eastern China

BACKGROUND

Fine particular matter (PM2.5) has been associated with dementia, but limited information is available regarding the association between PM2.5 components and dementia.

AIMS

We aimed to identify the major components of PM2.5 that affect cognitive function to further investigate its mechanism of action, and develop a prevention strategy for dementia.

METHODS

In this study, we included 7804 participants aged ≥ 60 years recruited from seven counties in Zhejiang province, eastern China. The participants completed the baseline survey between 2014 and 2015, and were followed up until the end of 2020. We adopted single-component robust Poisson regression models for analyses, and estimated relative risks and 95% confidence intervals describing associations between the chemical constituents of PM2.5 exposure and incident cognitive impairment in those who were free from cognitive impairment at baseline.

RESULTS

Significantly positive associations were observed between sulfate, nitrate, ammonium, and organic matter in PM2.5 and incident cognitive impairment across different exposure periods; the relative risks of 10-year exposure before enrollment ranged from 1.01 to 1.02. However, we did not find a significant association between black carbon and cognitive impairment. The point estimates of the relative risk values did not change substantially after performing the sensitivity analyses.

CONCLUSIONS

Our findings strengthen the idea that long-term exposure to PM2.5 mass and its chemical components is associated with an elevated risk of incident cognitive impairment among older adults.

Cognitive impairment and associated factors among patients with diabetes mellitus in Africa: a systematic review and meta-analysis

Background

Inappropriate management of blood sugar in patients with diabetes mellitus leads to micro-vascular and macro-vascular complications, subsequently leading to high morbidity and mortality rates. In addition, diabetes independently increases the occurrence of cognitive impairment complicated by dementia. Scientific evidence on the magnitude of cognitive impairment will provide a sound basis for the determination of healthcare needs and the planning of effective healthcare services. Despite this, there are no comprehensive data on the prevalence and associated factors of cognitive impairment among patients with diabetes in Africa.

Methods

To identify relevant articles for this review, we searched PubMed, Cochrane Library, Science Direct, African Journals Online, and Google Scholar. After extraction, the data were imported into Stata software version 11 (Stata Corp., TX, USA) for further analysis. The random-effects model, specifically the DerSimonian and Laird (D+L) pooled estimation method, was used due to the high heterogeneity between the included articles. Begg's and Egger's regression tests were used to determine the evidence of publication bias. Sub-group analyses and sensitivity analyses were also conducted to handle heterogeneity.

Results

The pooled prevalence of cognitive impairment among patients with diabetes in Africa is found to be 43.99% (95% CI: 30.15-57.83, p < 0.001). According to our analysis, primary level of education [pooled odds ratio (POR) = 6.08, 95% CI: 3.57-10.36, I 2 = 40.7%], poorly controlled diabetes mellitus (POR = 5.85, 95% CI: 1.64-20.92, I 2 = 87.8%), age above 60 years old (POR = 3.83, 95% 95% CI: 1.36-10.79, I 2 = 63.7%), and diabetes duration greater than 10 years (POR = 1.13; 95% CI: 1.07-1.19, I 2 = 0.0%) were factors associated with cognitive impairment among patients with diabetes.

Conclusion

Based on our systematic review, individuals with diabetes mellitus exhibit a substantial prevalence rate (43.99%) of cognitive impairment. Cognitive impairment was found to be associated with factors such as primary level of education, poorly controlled diabetes mellitus, age above 60 years, and diabetes duration greater than 10 years. Developing suitable risk assessment tools is crucial to address uncontrolled hyperglycemia effectively.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier CRD42024561484.

Associations of Heavy Metals with Cognitive Function: An Epigenome-Wide View of DNA Methylation and Mediation Analysis

OBJECTIVE

Exposure to heavy metals has been reported to be associated with impaired cognitive function, but the underlying mechanisms remain unclear. This pilot study aimed to identify key heavy metal elements associated with cognitive function and further explore the potential mediating role of metal-related DNA methylation.

METHODS

Blood levels of arsenic, cadmium, lead, copper, manganese, and zinc and genome-wide DNA methylations were separately detected in peripheral blood in 155 older adults. Cognitive function was evaluated using the Mini-Mental State Examination (MMSE). Least absolute shrinkage and selection operator penalized regression and Bayesian kernel machine regression were used to identify metals associated with cognitive function. An epigenome-wide association study examined the DNA methylation profile of the identified metal, and mediation analysis investigated its mediating role.

RESULTS

The MMSE scores showed a significant decrease of 1.61 (95% confidence interval [CI]: -2.64, -0.59) with each 1 standard deviation increase in ln-transformed arsenic level; this association was significant in multiple-metal models and dominated the overall negative effect of 6 heavy metal mixture on cognitive function. Seventy-three differentially methylated positions were associated with blood arsenic (p < 1.0 × 10-5). The methylation levels at cg05226051 (annotated to TDRD3) and cg18886932 (annotated to GAL3ST3) mediated 24.8% and 25.5% of the association between blood arsenic and cognitive function, respectively (all p < 0.05).

INTERPRETATION

Blood arsenic levels displayed a negative association with the cognitive function of older adults. This finding shows that arsenic-related DNA methylation alterations are critical partial mediators that may serve as potential biomarkers for further mechanism-related studies. ANN NEUROL 2024;96:87-98.

Serum TRPA1 mediates the association between olfactory function and cognitive function

Background

Olfactory dysfunction was associated with poorer cognition. However, the association between transient receptor potential cation channel subfamily A member 1 (TRPA1) and cognitive function have not been studied. This study aimed to evaluate the mediation effect of TRPA1 on the association between olfactory and cognitive function among Chinese older adults.

Methods

We recruited 121 participants with cognitive impairment (CI) and 135 participants with normal cognition (NC) from a memory clinic and the "Shanghai Aging Study." Olfactory identification of each participant was measured by the Sniffin' Sticks Screening Test 12 (SSST-12). Serum TRPA1 were quantified using the Enzyme-Linked Immunosorbent Assay. The mediation effects of TRPA1 on the association between olfactory function and cognitive function were explored using mediation analysis.

Results

The CI group had a significantly higher proportion of the high level of serum TRPA1 (58.7%) than the NC group (42.2%) (p = 0.0086). After adjusted for gender, age, and years of education, mediation analysis verified that TRPA1 partially mediated the association between SSST-12 and Mini Mental State Examination (MMSE). It also verified that TRPA1 partially mediated the association between the identification of peppermint and MMSE.

Conclusion

Our study emphasizes the mediation role of TRPA1 in the relationship between olfactory and cognitive function among older adults. Further research is necessary to explore the mechanism of TRPA1 on the relationship between olfactory and cognitive decline.

Factors associated with intrinsic capacity impairment in hospitalized older adults: a latent class analysis

BACKGROUND

Intrinsic capacity (IC) is proposed by the World Health Organization (WHO) to promote healthy aging. Although some studies have examined the factors influencing IC, few studies have comprehensively confirmed lifestyle factors on IC, especially IC impairment patterns. The present study aimed to identify the patterns of IC impairment and explore the lifestyle and other factors associated with different patterns of IC impairment.

METHODS

This cross-sectional study was conducted in a Chinese geriatric hospital. IC was evaluated in five domains according to the recommendations of WHO: cognition, locomotion, vitality, sensory and psychological domains. The sociodemographic and health-related characteristics of participants were assessed.The health promoting lifestyle was evaluated using the Health-Promoting Lifestyle Profile-II scale, including nutrition, health responsibility, interpersonal relationships, physical activity, spiritual growth and stress management. We applied latent class analysis to identify IC impairment patterns and compared basic activities of daily living, instrumental activities of daily living, frailty, quality of life and falls among different IC impairment patterns. Multinomial logistic regression analysis was conducted to identify factors influencing the IC impairment patterns.

RESULTS

Among 237 participants included, the latent class analysis identified three patterns of IC impairment: 44.7% high IC (Class 1), 31.2% intermediate IC mainly locomotor impairment (Class 2) and 24.1% low IC mainly cognitive impairment (Class 3). Older adults in class 1 had the best function ability and quality of life, while class 3 had the highest levels of disability and frailty, the poorest quality of life and a higher prevalence of falls. Compared with class 1, older adults with advanced age (OR = 22.046, 95%CI:1.735-280.149), osteoporosis (OR = 3.377, 95%CI:1.161-9.825), and lower scores in physical activity (OR = 0.842, 95%CI:0.749-0.945), stress management (OR = 0.762, 95%CI:0.585-0.993) and social support (OR = 0.897, 95%CI:0.833-0.965) were more likely to belong to the class 2. Simultaneously, compared with class 1, older adults with advanced age (OR = 104.435, 95%CI:6.038-1806.410), stroke (OR = 3.877, 95%CI:1.172-12.823) and lower scores in physical activity (OR = 0.784, 95%CI:0.667-0.922) and social support (OR = 0.909, 95%CI:0.828-0.998) were more likely to be class 3. In addition, compared with class 2, older adults with a lower score in nutrition (OR = 0.764, 95%CI:0.615-0.950) were more likely to belong to the class 3.

CONCLUSIONS

This study provides evidence that there are heterogeneous IC impairment patterns in older adults and identifies various associated factors in each pattern, including age, stroke, osteoporosis, social support and lifestyle behaviors such as nutrition, physical activity and stress management. It informs stakeholders on which modifiable factors should be targeted through public health policy or early intervention to promote IC and healthy aging in older adults.

Association of physical performance with cognitive impairment in middle-aged to older haemodialysis patients: a multicentre cross-sectional observational study

OBJECTIVE

To determine the prevalence of cognitive impairment (CI) among middle-aged to older patients receiving maintenance haemodialysis (MHD) and to investigate the potential association between CI and physical performance.

METHODS

This cross-sectional observational study enrolled participants aged 55-85 years who received MHD. Cognitive status was assessed using the Mini Mental State Examination (MMSE). Physical performance was measured by hand grip strength, the Timed Up and Go Test (TUGT) and the 4-m walking speed. Sociodemographic, clinical and laboratory parameters were recorded for each patient.

RESULTS

The study included 592 patients (363 males); and of these, 126 (21.3%) were diagnosed with CI. Compared with patients with normal cognitive function, those with CI were significantly older and had significantly longer dialysis duration, lower educational level, higher Malnutrition Inflammation Score, higher depression and higher Charlson Comorbidity Index score. After adjustment for covariates, multiple regression analysis suggested that grip strength (odds ratio [OR] = 0.959, 95% confidence interval [CI] = 0.924, 0.996) and 4-m walking speed (OR = 0.161, 95% CI = 0.070, 0.368) were protective factors. TUGT (OR = 1.037, 95%CI = 1.003, 1.071) was a risk factor.

CONCLUSION

Physical performance was correlated with CI and might be a significant indicator for the early identification of CI in middle-aged to older MHD patients.

Differential influences of rest tremor on brain fiber architecture in essential tremor and Parkinson's disease

BACKGROUND

Rest tremor is a movement disorder commonly found in diseases like Parkinson's disease (PD) and essential tremor (ET). Rest tremor typically shows slower progression in PD, but more severe progression in ET. However, the underlying white matter organization of rest tremor behind PD and ET remains unclear.

METHODS

This study included 57 ET patients (40 without rest tremor (ETWR), 17 with rest tremor (ETRT)), 68 PD patients (34 without rest tremor (PDWR), 34 with rest tremor (PDRT)), and 62 normal controls (NC). Fixel-based analysis was used to evaluate the structural changes of white matter in rest tremor in these different diseases.

RESULTS

The fiber-bundle cross-section (FC) of the right non-decussating dentato-rubro-thalamic tract and several fibers outside the dentato-rubro-thalamic pathway in ETWR were significantly higher than that in NC. The fiber density and cross-section of the left nigro-pallidal in PDWR is significantly lower than that in NC, while the FC of bilateral nigro-pallidal in PDRT is significantly lower than that in NC.

CONCLUSION

ET patients with pure action tremor showed over-activation of fiber tracts. However, when superimposed with rest tremor, ET patients no longer exhibited over-activation of fiber tracts, but rather showed a trend of fiber tract damage. Except for the nigro-pallidal degeneration in all PD, PDRT will not experience further deterioration in fiber organization. These results provide important insights into the unique effects of rest tremor on brain fiber architecture in ET and PD.

Reading the mind in the eyes in patients with idiopathic REM sleep behavior disorder

OBJECTIVES

Idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) is characterized by vocalizations, jerks, and motor behaviors during REM sleep, often associated with REM-related dream content, which is considered a prodromal stage of α-synucleinopathy. The results of the Reading the Mind in the Eyes (RME) reflecting affective Theory of Mind (ToM) are inconsistent in α-synucleinopathy. The present study tried to investigate the RME in patients with iRBD.

METHODS

A total of 35 patients with iRBD and 26 healthy controls were included in the study. All participants were administered the RME and the cognitive assessments according to a standard procedure. The patients with iRBD were further divided into two groups (high or low RME) according to the scores of the RME (> 21, or ≤ 20).

RESULTS

The patients with iRBD had worse scores on cognitive tests compared with healthy controls involving global cognitive screening, memory, and visuospatial abilities (p < 0.05), but the scores of the RME were similar between the two groups (20.83 ± 3.38, 20.58 ± 3.43) (p ˃ 0.05). Patients with low RME had more obvious cognitive impairments than healthy controls. After applying Bonferroni correction for multiple tests, the low REM group only performed worse on the Sum of trials 1 to 5 and delayed recall of the RAVLT compared with the healthy control group (p < 0.001, = 0.002). The RME correlated with the scores of cognitive tests involving executive function, attention, memory, and visuospatial function.

CONCLUSIONS

The changes in RME had a relationship with cognitive impairments, especially memory, in patients with iRBD.

Parallel-Forms Reliability and Minimal Detectable Change of the Four Telerehabilitation Version Mobility-Related Function Scales in Stroke Survivors

OBJECTIVE

To investigate the parallel-forms reliability, minimal detectable change with 95% confidence interval (MDC95), and feasibility of the 4 telerehabilitation version mobility-related function scales: Fugl-Meyer Assessment-lower extremity subscale (Tele-FMA-LE), Berg Balance Scale (Tele-BBS), Tinetti Performance Oriented Mobility Assessment-Gait subscale (Tele-POMA-G), and Rivermead Mobility Index (Tele-RMI).

DESIGN

Reliability and agreement study and cross-sectional study.

SETTING

Medical center.

PARTICIPANTS

Stroke survivors' ability to independently walk 3 meters with assistive devices, age of ≥18 years for participants and their partners, stable physical condition, and absence of cognitive impairment (N=60).

INTERVENTIONS

Not applicable.

MAIN OUTCOMES MEASURES

Parallel-forms reliability and MDC95 of Tele-FMA-LE, Tele-BBS, Tele-POMA-G, and Tele-RMI.

RESULTS

No significant differences (P>.05) were observed among the mean scores of the telerehabilitation version and face-to-face version mobility-related function scales. Intraclass correlation coefficients (ICCs) indicated good reliability for most scales, with Tele-FMA-LE, Tele-BBS, and Tele-RMI scores achieving values of 0.81, 0.78, and 0.84. Tele-POMA-G scores demonstrated moderate reliability (ICC=0.72). Weighted kappa (κw) showed good-to-excellent reliability for most individual items (κw>0.60). The MDCs of the Tele-FMA-LE, Tele-BBS, Tele-POMA-G, and Tele-RMI were 5.84, 8.10, 2.74, and 1.31, respectively. Bland-Altman analysis showed adequate agreement between tele-assessment and face-to-face assessment for all scales. The 5 dimensions affirm the robust feasibility of tele-assessment: assessment time, subjective fatigue perception, overall preference, participant satisfaction, and system usability.

CONCLUSIONS

The study demonstrates good parallel-forms reliability, MDC, and promising feasibility of the 4 telerehabilitation version mobility-related function scales (Tele-FMA-LE, Tele-BBS, Tele-POMA-G, and Tele-RMI) in survivors of stroke.

Leisure activities as reserve mediators of the relationship between loneliness and cognition in aging

Previous studies have found that loneliness affects cognitive functions in older persons. However, the influence of loneliness on different cognitive fields and the internal mechanism of the relationship are unclear. A total of 4772 older persons aged above 50 years (Mean = 65.31, SD = 6.96, 57.7% female) were included in this study. All the participants completed the characteristics scale, as well as the loneliness scale, leisure activity scale, and cognitive function tests in six domains. The results showed that 17.6% of participants had high loneliness, while 16.7% of participants had low loneliness. Associations were observed between higher levels of loneliness and lower scores in general cognitive ability, memory, and executive functions. Mediation analysis suggested that leisure activities, encompassing mental, physical, and social activities, were associated with cognitive functions in the context of loneliness. These results indicate that leisure activities may play a significant role in the relationship between loneliness and cognitive functions in older adults. The study highlights the importance of considering leisure activities in this demographic to potentially mitigate the adverse cognitive effects associated with loneliness.

Community screening for dementia among older adults in China: a machine learning-based strategy

BACKGROUND

Dementia is a leading cause of disability in people older than 65 years worldwide. However, diagnosing dementia in its earliest symptomatic stages remains challenging. This study combined specific questions from the AD8 scale with comprehensive health-related characteristics, and used machine learning (ML) to construct diagnostic models of cognitive impairment (CI).

METHODS

The study was based on the Shenzhen Healthy Ageing Research (SHARE) project, and we recruited 823 participants aged 65 years and older, who completed a comprehensive health assessment and cognitive function assessments. Permutation importance was used to select features. Five ML models using BalanceCascade were applied to predict CI: a support vector machine (SVM), multilayer perceptron (MLP), AdaBoost, gradient boosting decision tree (GBDT), and logistic regression (LR). An AD8 score ≥ 2 was used to define CI as a baseline. SHapley Additive exPlanations (SHAP) values were used to interpret the results of ML models.

RESULTS

The first and sixth items of AD8, platelets, waist circumference, body mass index, carcinoembryonic antigens, age, serum uric acid, white blood cells, abnormal electrocardiogram, heart rate, and sex were selected as predictive features. Compared to the baseline (AUC = 0.65), the MLP showed the highest performance (AUC: 0.83 ± 0.04), followed by AdaBoost (AUC: 0.80 ± 0.04), SVM (AUC: 0.78 ± 0.04), GBDT (0.76 ± 0.04). Furthermore, the accuracy, sensitivity and specificity of four ML models were higher than the baseline. SHAP summary plots based on MLP showed the most influential feature on model decision for positive CI prediction was female sex, followed by older age and lower waist circumference.

CONCLUSIONS

The diagnostic models of CI applying ML, especially the MLP, were substantially more effective than the traditional AD8 scale with a score of ≥ 2 points. Our findings may provide new ideas for community dementia screening and to promote such screening while minimizing medical and health resources.

Longitudinal analysis of the mediating role of self-perception of aging in the relationship between frailty and intrinsic capacity: A cross-lagged mediation model

OBJECTIVES

The causal relationship between intrinsic capacity and frailty in older adults, as well as the underlying temporal mechanisms, remained poorly understood. The study aimed to investigate the causal association between intrinsic capacity and frailty while exploring the potential mediating role of self-perception of aging.

MEASUREMENTS

A survey was conducted with a sample of 429 participants who completed measures of intrinsic capacity, self-perception of aging, and frailty at baseline and were followed for one year. The relationships between these variables were assessed using an autoregressive cross-lagged model.

RESULTS

The study found reciprocal associations between intrinsic capacity and frailty (p < 0.01). Furthermore, the results indicated that self-perception of aging partially mediated the effect of frailty at baseline (T1) on intrinsic capacity at one-year follow-up (T2) (β = -0.02, confidence interval: [-0.055, -0.004]). However, the reverse causation was not observed.

CONCLUSIONS AND IMPLICATIONS

This study demonstrates a bidirectional causal relationship between intrinsic capacity and frailty in older adults. Self-perception of aging plays a significant mediating role in this relationship. Older adults with a worse level of frailty should be made aware of the potentially vicious cycle related to self-perception of aging, which can negatively affect their intrinsic capacity. Maintaining a positive self-perception of aging may help preserve physical and psychological reserves, maintain intrinsic capacity, and slow the decline of frailty.

Effect of the duration of hypertension on white matter structure and its link with cognition

The relation between hypertension (HTN) and cognition has been reported inclusive results, which may be affected by disease duration. Our study aimed to examine the influence of HTN duration on cognition and its underlying white matter (WM) changes including macrostructural WM hyperintensities (WMH) and microstructural WM integrity. A total of 1218 patients aged ≥55 years with neuropsychological assessment and a subgroup of 233 people with imaging data were recruited and divided into 3 groups (short duration: <5 years, medium duration: 5-20 years, long duration: >20 years). We found that greater HTN duration was preferentially related to worse executive function (EF), processing speed (PS), and more severe WMH, which became more significant during long duration stage. The reductions in WM integrity were evident at the early stage especially in long-range association fibers and then scattered through the whole brain. Increasing WMH and decreasing integrity of specific tracts consistently undermined EF. Furthermore, free water imaging method greatly enhanced the sensitivity in detecting HTN-related WM alterations. These findings supported that the neurological damaging effects of HTN is cumulative and neuroimaging markers of WM at macro- and microstructural level underlie the progressive effect of HTN on cognition.

Discontinuity of deep medullary veins in SWI is associated with deep white matter hyperintensity volume and cognitive impairment in cerebral small vessel disease

BACKGROUND

Discontinuation of the deep medullary veins (DMVs) may be an early imaging marker for identifying cognitive impairment caused by cerebral small vessel disease (CSVD). However, this method lacks mechanistic exploration. We aimed to investigate whether the DMV score is related to CSVD imaging markers and cognitive impairment in patients with CSVD.

METHODS

This retrospective study included patients with CSVD who completed DMV score and cognition (e.g., MMSE, MoCA) assessments, and underwent MRI scanning (T2-FLAIR for white matter hyperintensities (WMH) volume, T1-weighted MRI for brain parenchymal fractions (BPF) analysis, and SWI for assessment of DMV score). The CSVD imaging markers were quantitatively assessed using the AccuBrain® system. We assessed the diagnostic value of neuroimaging biomarkers for detecting CSVD-related cognitive impairment. In addition, we explored the relationship between the DMV score, CSVD imaging markers, and cognition using mediation analysis.

RESULTS

Ninety-four patients with CSVD were divided into a cognitive impairment group (n = 39) and a non-cognitive impairment group (n = 55). Higher DMV scores, larger WMH volumes, and smaller BPF were observed in the cognitive impairment group than those in the non-cognitive impairment group. Receiver operating characteristics (ROC) analysis revealed that the discovery value of the integration of patient age, BPF, whole WMH volume, and DMV score for cognitive impairment was 0.742, with a sensitivity and specificity of 79.5 % and 61.5 %, respectively. Mediation analysis showed mediation by WMH and BPF in the relationship between DMV score and cognitive impairment (all P < 0.05).

LIMITATIONS

This study did not evaluate the DMV score in subregions according to DMV anatomy.

CONCLUSIONS

The DMV score is significantly associated with cognitive impairment in patients with CSVD, and this association is mediated through WMH and BPF.

The effects of dietary diversity on health status among the older adults: an empirical study from China

BACKGROUND

Dietary diversity is an indicator of nutrient intake among the elderly. Previous researches have primarily examined dietary diversity and the risks with chronic and infectious disease and cognitive impairment, limited evidence shows the association between dietary diversity and the overall health status of specific populations with a heterogeneity analysis. This study aimed to probe the effects of dietary diversity on health status among Chinese older adults.

METHODS

There were 5740 sample participants aged 65 and above selected from the Chinese Longitudinal Healthy Longevity Survey, among which 3334 samples in 2018 wave and 2406 samples in 2011 wave. Dietary diversity was assessed by Dietary Diversity Score ranged from 0 to 9, the higher the score, the better dietary diversity. Health status was assessed into healthy, impaired and dysfunctional state by three indicators: Activities of Daily Living, Instrument Activities of Daily Living and Mini-Mental State Examination. Multinomial logistic regression was employed to assess the effects of dietary diversity on the health status among the elderly. Heterogeneity analysis between different groups by age was further discussed.

RESULTS

Older adults with better dietary diversity are in better health status, the mean dietary diversity score for healthy group was higher than that of impaired and dysfunctional groups (In 2018 wave, the scores were 6.54, 6.26 and 5.92, respectively; and in 2011 wave, they were 6.38, 5.93 and 5.71, respectively). Heterogeneity analysis shows that the younger groups tend to have more diversified dietary and be in better health status. Dietary diversity was more significantly associated with health status of the younger elderly (OR, 1.22, 95% CI, 1.04-1.44, p < 0.05) than the older elderly (OR, 1.01, 95% CI, 0.37-2.78, p > 0.05) in 2018 wave; and in 2011 wave, dietary diversity was more significantly related to health status among the younger elderly (OR, 1.62, 95% CI, 1.26-2.08, p < 0.001) than the older elderly (OR, 0.08, 95%CI, 0.31-1.94, p > 0.05).

CONCLUSIONS

Better dietary diversity has positive effects on health status and is more significantly related to the younger elderly than the older elderly. So interventions including available dietary diversity assessment, variety of dietary assistance services in daily life, keeping nutrient digestion and absorption capacity for the venerable age might benefit to ensure the effects of dietary diversity on health status among older adults especially in maintaining intrinsic ability and physical function. In addition, healthy lifestyle should also be recommended.

Altered resting-state brain oscillation and the associated cognitive impairments in late-life depression with different depressive severity: An EEG power spectrum and functional connectivity study

OBJECTIVE

Cognitive impairments are prevalent in late-life depression (LLD). However, it remains unclear whether there are concurrent brain oscillation alterations in resting condition across varying level of depression severity. This cross-sectional study aims to investigate the characteristics of altered resting-state oscillations, including power spectrum and functional connectivity, and their association with the cognitive impairments in LLD with different depression severity.

METHODS

A total of 65 patients with LLD and 40 elder participants without depression were recruited. Global cognition and subtle cognitive domains were evaluated. A five-minute resting-state electroencephalography (EEG) was conducted under eyes-closed conditions. Measurements included the ln-transformed absolute power for power spectrum analysis and the weighted phase lag index (wPLI) for functional connectivity analysis.

RESULTS

Attentional and executive dysfunction were exhibited in Moderate-Severe LLD group. Enhanced posterior upper gamma power was observed in both LLD groups. Additionally, enhanced parietal and fronto-parietal/occipital theta connectivity were observed in Moderate-Severe LLD group, which were associated with the attentional impairment.

LIMITATIONS

Limitations include a small sample size, concomitant medication use, and a relatively higher proportion of females.

CONCLUSIONS

Current study observed aberrant brain activity patterns in LLD across different levels of depression severity, which were linked to cognitive impairments. The altered posterior brain oscillations may be trait marker of LLD. Moreover, cognitive impairments and associated connectivity alterations were exhibited in moderate-severe group, which may be a state-like marker of moderate-to severe LLD. The study deepens understanding of cognitive impairments with the associated oscillation changes, carrying implications for neuromodulation targets in LLD.

DCP: A pipeline toolbox for diffusion connectome

The brain structural network derived from diffusion magnetic resonance imaging (dMRI) reflects the white matter connections between brain regions, which can quantitatively describe the anatomical connection pattern of the entire brain. The development of structural brain connectome leads to the emergence of a large number of dMRI processing packages and network analysis toolboxes. However, the fully automated network analysis based on dMRI data remains challenging. In this study, we developed a cross-platform MATLAB toolbox named "Diffusion Connectome Pipeline" (DCP) for automatically constructing brain structural networks and calculating topological attributes of the networks. The toolbox integrates a few developed packages, including FSL, Diffusion Toolkit, SPM, Camino, MRtrix3, and MRIcron. It can process raw dMRI data collected from any number of participants, and it is also compatible with preprocessed files from public datasets such as HCP and UK Biobank. Moreover, a friendly graphical user interface allows users to configure their processing pipeline without any programming. To prove the capacity and validity of the DCP, two tests were conducted with using DCP. The results showed that DCP can reproduce the findings in our previous studies. However, there are some limitations of DCP, such as relying on MATLAB and being unable to fixel-based metrics weighted network. Despite these limitations, overall, the DCP software provides a standardized, fully automated computational workflow for white matter network construction and analysis, which is beneficial for advancing future human brain connectomics application research.

The impact of kidney function on plasma neurofilament light and phospho-tau 181 in a community-based cohort: the Shanghai Aging Study

BACKGROUND

The blood-based biomarkers are approaching the clinical practice of Alzheimer's disease (AD). Chronic kidney disease (CKD) has a potential confounding effect on peripheral protein levels. It is essential to characterize the impact of renal function on AD markers.

METHODS

Plasma phospho-tau181 (P-tau181), and neurofilament light (NfL) were assayed via the Simoa HD-X platform in 1189 dementia-free participants from the Shanghai Aging Study (SAS). The estimated glomerular filter rate (eGFR) was calculated. The association between renal function and blood NfL, P-tau181 was analyzed. An analysis of interactions between various demographic and comorbid factors and eGFR was conducted.

RESULTS

The eGFR levels were negatively associated with plasma concentrations of NfL and P-tau181 (B = - 0.19, 95% CI - 0.224 to - 0.156, P < 0.001; B = - 0.009, 95% CI - 0.013 to -0.005, P < 0.001, respectively). After adjusting for demographic characteristics and comorbid diseases, eGFR remained significantly correlated with plasma NfL (B = - 0.010, 95% CI - 0.133 to - 0.068, P < 0.001), but not with P-tau181 (B = - 0.003, 95% CI - 0.007 to 0.001, P = 0.194). A significant interaction between age and eGFR was found for plasma NfL (Pinteraction < 0.001). In participants ≥ 70 years and with eGFR < 60 ml/min/1.73 m2, the correlation between eGFR and plasma NfL was significantly remarkable (B = - 0.790, 95% CI - 1.026 to - 0,554, P < 0.001).

CONCLUSIONS

Considering renal function and age is crucial when interpreting AD biomarkers in the general aging population.

Associations between cardiometabolic multimorbidity and cerebrospinal fluid biomarkers of Alzheimer's disease pathology in cognitively intact adults: the CABLE study

BACKGROUND

Cardiometabolic multimorbidity is associated with an increased risk of dementia, but the pathogenic mechanisms linking them remain largely undefined. We aimed to assess the associations of cardiometabolic multimorbidity with cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) pathology to enhance our understanding of the underlying mechanisms linking cardiometabolic multimorbidity and AD.

METHODS

This study included 1464 cognitively intact participants from the Chinese Alzheimer's Biomarker and LifestylE (CABLE) database. Cardiometabolic diseases (CMD) are a group of interrelated disorders such as hypertension, diabetes, heart diseases (HD), and stroke. Based on the CMD status, participants were categorized as CMD-free, single CMD, or CMD multimorbidity. CMD multimorbidity is defined as the coexistence of two or more CMDs. The associations of cardiometabolic multimorbidity and CSF biomarkers were examined using multivariable linear regression models with demographic characteristics, the APOE ε4 allele, and lifestyle factors as covariates. Subgroup analyses stratified by age, sex, and APOE ε4 status were also performed.

RESULTS

A total of 1464 individuals (mean age, 61.80 years; age range, 40-89 years) were included. The markers of phosphorylated tau-related processes (CSF P-tau181: β = 0.165, P = 0.037) and neuronal injury (CSF T-tau: β = 0.065, P = 0.033) were significantly increased in subjects with CMD multimorbidity (versus CMD-free), but not in those with single CMD. The association between CMD multimorbidity with CSF T-tau levels remained significant after controlling for Aβ42 levels. Additionally, significantly elevated tau-related biomarkers were observed in patients with specific CMD combinations (i.e., hypertension and diabetes, hypertension and HD), especially in long disease courses.

CONCLUSIONS

The presence of cardiometabolic multimorbidity was associated with tau phosphorylation and neuronal injury in cognitively normal populations. CMD multimorbidity might be a potential independent target to alleviate tau-related pathologies that can cause cognitive impairment.

Cholinergic basal forebrain system degeneration underlies postural instability/gait difficulty and attention impairment in Parkinson's disease

BACKGROUND AND PURPOSE

The specific pathophysiological mechanisms underlying postural instability/gait difficulty (PIGD) and cognitive function in Parkinson's disease (PD) remain unclear. Both postural and gait control, as well as cognitive function, are associated with the cholinergic basal forebrain (cBF) system.

METHODS

A total of 84 PD patients and 82 normal controls were enrolled. Each participant underwent motor and cognitive assessments. Diffusion tensor imaging was used to detect structural abnormalities in the cBF system. The cBF was segmented using FreeSurfer, and its fiber tract was traced using probabilistic tractography. To provide information on extracellular water accumulation, free-water fraction (FWf) was quantified. FWf in the cBF and its fiber tract, as well as cortical projection density, were extracted for statistical analyses.

RESULTS

Patients had significantly higher FWf in the cBF (p < 0.001) and fiber tract (p = 0.021) than normal controls, as well as significantly lower cBF projection in the occipital (p < 0.001), parietal (p < 0.001) and prefrontal cortex (p = 0.005). In patients, a higher FWf in the cBF correlated with worse PIGD score (r = 0.306, p = 0.006) and longer Trail Making Test A time (r = 0.303, p = 0.007). Attentional function (Trail Making Test A) partially mediated the association between FWf in the cBF and PIGD score (indirect effect, a*b = 0.071; total effect, c = 0.256; p = 0.006).

CONCLUSIONS

Our findings suggest that degeneration of the cBF system in PD, from the cBF to its fiber tract and cortical projection, plays an important role in cognitive-motor interaction.

Illiterate Addenbrooke's Cognitive Examination-III in Three Indian Languages: An Adaptation and Validation Study

BACKGROUND

Literacy is an important factor that predicts cognitive performance. Existing cognitive screening tools are validated only in educated populations and are not appropriate for older adults with little or no education leading to poor performance on these tests and eventually leading to misdiagnosis. This challenge for clinicians necessitates a screening tool suitable for illiterate or low-literate older individuals.

OBJECTIVES

The objective was to adapt and validate Addenbrooke's Cognitive Examination-III (ACE-III) for screening general cognitive functions in illiterate and low-literate older populations in the Indian context in three languages.

METHOD

The Indian illiterate ACE-III was systematically adapted by modifying the original items of the Indian literate ACE-III to assess the cognitive functions of illiterates and low-literates with the consensus of an expert panel of professionals working in the area of dementia and related disorders. A total of 180 illiterate or low-literate participants (84 healthy-controls, 50 with dementia, and 46 with mild cognitive impairment [MCI]) were recruited from three different centers speaking Bengali, Hindi, and Kannada to validate the adapted version.

RESULTS

The optimal cut-off score for illiterate ACE-III to distinguish controls from dementia in all 3 languages was 75. The optimal cut-off scores in distinguishing between controls and MCI ranged from 79 to 82, with a sensitivity ranging from 93% to 99% and a specificity ranging from 72% to 99%.

CONCLUSION

The test is found to have good psychometric properties and is a reliable cognitive screening tool for identifying dementia and MCI in older adults with low educational backgrounds in the Indian context.

Controversial Past, Splendid Present, Unpredictable Future: A Brief Review of Alzheimer Disease History

Background: The concept of Alzheimer disease (AD)-since its histological discovery by Alzheimer to the present day-has undergone substantial modifications. Methods: We conducted a classical narrative review of this field with a bibliography selection (giving preference to Medline best match). Results: The following subjects are reviewed and discussed: Alzheimer's discovery, Kraepelin's creation of a new disease that was a rare condition until the 1970's, the growing interest and investment in AD as a major killer in a society with a large elderly population in the second half of the 20th century, the consolidation of the AD clinicopathological model, and the modern AD nosology based on the dominant amyloid hypothesis among many others. In the 21st century, the development of AD biomarkers has supported a novel biological definition of AD, although the proposed therapies have failed to cure this disease. The incidence of dementia/AD has shown a decrease in affluent countries (possibly due to control of risk factors), and mixed dementia has been established as the most frequent etiology in the oldest old. Conclusions: The current concept of AD lacks unanimity. Many hypotheses attempt to explain its complex physiopathology entwined with aging, and the dominant amyloid cascade has yielded poor therapeutic results. The reduction in the incidence of dementia/AD appears promising but it should be confirmed in the future. A reevaluation of the AD concept is also necessary.