Education and cognitive reserve in old age

Connectivity between default mode and frontoparietal networks mediates the association between global amyloid-β and episodic memory

Βeta-amyloid (Aβ) is a neurotoxic protein that deposits early in the pathogenesis of preclinical Alzheimer's disease. We aimed to identify network connectivity that may alter the negative effect of Aβ on cognition. Following assessment of memory performance, resting-state fMRI, and mean cortical PET-Aβ, a total of 364 older adults (286 with clinical dementia rating [CDR-0], 59 with CDR-0.5 and 19 with CDR-1, mean age: 74.0 ± 6.4 years) from the OASIS-3 sample were included in the analysis. Across all participants, a partial least squares regression showed that lower connectivity between posterior medial default mode and frontoparietal networks, higher within-default mode, and higher visual-motor connectivity predict better episodic memory. These connectivities partially mediate the effect of Aβ on episodic memory. These results suggest that connectivity strength between the precuneus cortex and the superior frontal gyri may alter the negative effect of Aβ on episodic memory. In contrast, education was associated with different functional connectivity patterns. In conclusion, functional characteristics of specific brain networks may help identify amyloid-positive individuals with a higher likelihood of memory decline, with implications for AD clinical trials.

Associations between objectively measured sleep parameters and cognition in healthy older adults: A meta-analysis

Multiple studies have examined associations between sleep and cognition in older adults, but a majority of these depend on self-reports on sleep and utilize cognitive tests that assess overall cognitive function. The current meta-analysis involved 72 independent studies and sought to quantify associations between objectively measured sleep parameters and cognitive performance in healthy older adults. Both sleep macrostructure (e.g., sleep duration, continuity, and stages) and microstructure (e.g., slow wave activity and spindle activity) were evaluated. For macrostructure, lower restlessness at night was associated with better memory performance (r = 0.43, p = 0.02), while lower sleep onset latency was associated with better executive functioning (r = 0.28, p = 0.03). Greater relative amount of N2 and REM sleep, but not N3, positively correlated with cognitive performance. The association between microstructure and cognition in older adults was marginally significant. This relationship was moderated by age (z = 0.07, p < 0.01), education (z = 0.26, p = 0.03), and percentage of female participants (z = 0.01, p < 0.01). The current meta-analysis emphasizes the importance of considering objective sleep measures to understand the relationship between sleep and cognition in healthy older adults. These results also form a base from which researchers using wearable sleep technology and measuring behavior through computerized testing tools can evaluate their findings.

Cognitive evaluation in Parkinson's disease: applying the Movement Disorder Society recommendations in a population with a low level of formal education

BACKGROUND

 The diagnosis of cognitive disorders in Parkinson disease (PD) can be very challenging. Aiming at establishing uniform and reliable diagnostic procedures, the International Parkinson's Disease and Movement Disorder Society (MDS) commissioned task forces to delineate diagnostic criteria for mild cognitive impairment (MCI) and dementia in PD.

OBJECTIVES

 To investigate the applicability of the MDS recommendations for cognitive evaluation in a Brazilian sample of patients with PD with low levels of formal education.

METHODS

 A total of 41 patients with PD were subjected to a comprehensive neuropsychological evaluation based on tests proposed by the MDS, which included the Mini-Mental State Examination, the Mattis Dementia Rating Scale (MDRS), the Trail Making Test (TMT) parts A and B, in addition to language and memory skills assessment. Neuropsychiatric and daily functioning features were also evaluated. Spearman correlation analyses were used to evaluate the association between the scores obtained in the cognitive scales and demographic/clinical variables.

RESULTS

 Although none of the participants had a formal diagnosis of dementia, 50% presented some degree of cognitive impairment when considering the results of the MDRS. Of note, a noticeable number of patients was not able to complete the full neuropsychological assessment. The TMT part B was the most difficult task, being completed by only 22 participants (54%). As expected, the greater the educational level, the better the performance on the cognitive tests. Better motor function was also associated with better scores in cognition.

CONCLUSIONS

 Adopting strict inclusion/exclusion criteria and a comprehensive clinical evaluation, we found remarkable limitations for the MDS recommendations when individuals with low educational levels are considered. A revision of the current guidelines is necessary considering differences among populations, especially related to formal education.

Changes in executive function in the Canadian longitudinal study on aging over 3-years: A focus on social determinants of health

Maintaining executive functions, including planning, inhibition, and decision-making skills, is important for autonomy and activities of daily living. There is a growing body of evidence linking social determinants and cognitive aging, but less is known about the potential role of social determinants in changes in executive functioning over time. Using data from the Canadian Longitudinal Study on Aging (CLSA), a large cohort of mid-aged and older adults, we examined changes in executive function over a 3-year period. Specifically, we focused on the role of social determinants (i.e., social positioning, social support, education) in explaining these changes. Executive function was measured at baseline and follow-up 3 years later using the Mental Alteration Test (MAT). We computed a reliable change index (RCI) and used a multiple linear regression model to examine the associations between known correlates and change in executive function over the 3-year period (n = 29,344). Older age, higher household income, and greater educational attainment predicted declines in executive function. Health factors (e.g., depression symptoms, physical activity levels) and many social determinants (sexual orientation, gender identity, race, and perceived social standing) were not associated with change in executive function. These results suggest that social determinants of health may be related to initial differences in cognitive functioning (i.e., cross-sectional differences) rather than more rapid cognitive aging.

The Mediating Roles of Neurobiomarkers in the Relationship Between Education and Late-Life Cognition

BACKGROUND

The mediating roles of neuropathologies and neurovascular damage in the relationship between early-life education and later-life cognitive function are unknown.

OBJECTIVE

To examine whether Alzheimer's and neurovascular biomarkers mediate the relationships between education and cognitive functions.

METHODS

Data were from 537 adults aged 55-94 in the Alzheimer's Disease Neuroimaging Initiative 3. We tested whether the relationships between education (continuous, years) and cognitive function (memory, executive functioning, and language composites) were mediated by neuroimaging biomarkers (hippocampal volumes, cortical gray matter volumes, meta-temporal tau PET standard uptake value ratio, and white matter hyperintensity volumes). Models were adjusted for age, race, sex/gender, cardiovascular history, body mass index, depression, and Apolipoprotein E-ɛ4 status.

RESULTS

Hippocampal volumes and white matter hyperintensities partially mediated the relationships between education and cognitive function across all domains (6.43% to 15.72% mediated). The direct effects of education on each cognitive domain were strong and statistically significant.

CONCLUSIONS

Commonly measured neurobiomarkers only partially mediate the relationships between education and multi-domain cognitive function.

The Early Stage of Abnormal Aging: Cognitive Impairment

Cognitive impairment has become an important aspect affecting the health and quality of life of middle-aged and elderly people, which is defined as the difficulty of thought processing and leads to memory loss, difficulties making decisions, the inability to concentrate, and difficulties learning. The process of cognitive ability decline with age goes through subjective cognitive impairment (SCI) to mild cognitive impairment (MCI). There is abundant evidence supporting the link between cognitive impairment and several modifiable risk factors, such as physical activity, social activity, mental activity, higher education, and management of cardiovascular risk factors (diabetes, obesity, smoking, hypertension, and obesity). Meanwhile, these factors also provide a new perspective for the prevention of cognitive impairment and dementia.

High lifelong cognitive reserve prolongs disability-free survival: The role of cognitive function

INTRODUCTION

The association between cognitive reserve (CR) and survival with independence is unknown. We examined whether lifelong CR accumulation is associated with disability-free survival and explored the extent to which cognitive function mediates this association.

METHODS

Within the Rush Memory and Aging Project, 1633 dementia- and disability-free participants were followed annually for up to 22 years. Lifelong CR including education, early-/mid-/late-life cognitive activities, and late-life social activity was assessed and tertiled.

RESULTS

CR score was dose-dependently associated with disability/death (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.93-0.99). Compared to low CR, the HR (95% CI) of disability/death was 0.82 (0.70-0.95) for high CR. The median disability-free survival time was prolonged by 0.99 (95% CI 0.28-1.71) years for participants with high CR. Cognitive function mediated 35.7% of the association between CR and disability-free survival.

DISCUSSION

High lifelong CR was associated with prolonged disability-free survival. Cognitive function mediates about one-third of this association. Our findings underscore the importance of CR for healthy aging.

Association Between Cognitive Performance and Nutritional Status: Analysis From LASI-DAD

Malnutrition in low- and middle-income countries causes cognitive decline and other health problems. Harmonized Diagnostic Assessment of Dementia for Longitudinal Aging Study in India (LASI DAD) is an extensive study on late-life cognition and dementia. This study examines the link between nutrition and cognitive abilities in older adults using data from the LASI DAD. We conducted descriptive statistics on nutritional parameters (body-mass index, waist-hip ratio, and Mini-Nutritional Assessment), cognitive functions, and socio-demographic variables in 2,892 adults aged ≥60 years. Cognitive domains assessed included delayed recall, orientation, language, executive function, abstract reasoning, and attention. Cognitive impairment was defined as impaired performance in two or more domains. Mean age was 69.3 ± 7.1 years, 52.9% were female, and 57.5% were illiterate. Low body-mass index (adjusted OR: 1.88, p < .001), at risk of malnutrition (adjusted OR: 1.89, p < .001) and malnourished (adjusted OR: 2.86, p < .001) on Mini-Nutritional Assessment were associated with the presence of cognitive impairment. Better cognitive performance was associated with increased body mass index (adjusted OR: 0.74, p-.03), hemoglobin (adjusted OR: 0.91, p-.006), and serum albumin (adjusted OR: 0.38, p < .001). This study shows that nutritional status assessed by anthropometric measures and blood markers is strongly linked to cognitive performance in older adults.

Arrhythmia and other modifiable risk factors in incident dementia and MCI among elderly individuals with low educational levels in Taiwan

Introduction

There is increasing evidence that arrhythmia is a risk factor for dementia; however, it appears that arrhythmia affects the cognitive function of individuals differentially across age groups, races, and educational levels. Demographic differences including educational level have also been found to moderate the effects of modifiable risk factors for cognitive decline.

Methods

This study recruited 1,361 individuals including a group of cognitively unimpaired (CU) individuals, a group of patients with mild cognitive impairment (MCI), and a group of patients with dementia with low education levels. The participants were evaluated in terms of modifiable risk factors for dementia, including arrhythmia and neuropsychiatric symptoms.

Results

Cox proportional hazard regression models revealed that among older MCI patients (>75 years), those with arrhythmia faced an elevated risk of dementia. Among younger MCI patients, those taking anti-hypertensive drugs faced a relatively low risk of dementia. Among younger MCI patients, male sex and higher educational level were associated with an elevated risk of dementia. Among CU individuals, those with coronary heart disease and taking anti-lipid compounds faced an elevated risk of MCI and those with symptoms of depression faced an elevated risk of dementia.

Discussion

The risk and protective factors mentioned above could potentially be used as markers in predicting the onset of dementia in clinical settings, especially for individuals with low educational levels.

Midlife occupational cognitive requirements protect cognitive function in old age by increasing cognitive reserve

Introduction

Several lifestyle factors promote protection against Alzheimer's disease (AD) throughout a person's lifespan. Although such protective effects have been described for occupational cognitive requirements (OCR) in midlife, it is currently unknown whether they are conveyed by brain maintenance (BM), brain reserve (BR), or cognitive reserve (CR) or a combination of them.

Methods

We systematically derived hypotheses for these resilience concepts and tested them in the population-based AgeCoDe cohort and memory clinic-based AD high-risk DELCODE study. The OCR score (OCRS) was measured using job activities based on the O*NET occupational classification system. Four sets of analyses were conducted: (1) the interaction of OCR and APOE-ε4 with regard to cognitive decline (N = 2,369, AgeCoDe), (2) association with differentially shaped retrospective trajectories before the onset of dementia of the Alzheimer's type (DAT; N = 474, AgeCoDe), (3) cross-sectional interaction of the OCR and cerebrospinal fluid (CSF) AD biomarkers and brain structural measures regarding memory function (N = 873, DELCODE), and (4) cross-sectional and longitudinal association of OCR with CSF AD biomarkers and brain structural measures (N = 873, DELCODE).

Results

Regarding (1), higher OCRS was associated with a reduced association of APOE-ε4 with cognitive decline (mean follow-up = 6.03 years), consistent with CR and BR. Regarding (2), high OCRS was associated with a later onset but subsequently stronger cognitive decline in individuals converting to DAT, consistent with CR. Regarding (3), higher OCRS was associated with a weaker association of the CSF Aβ42/40 ratio and hippocampal volume with memory function, consistent with CR. Regarding (4), OCR was not associated with the levels or changes in CSF AD biomarkers (mean follow-up = 2.61 years). We found a cross-sectional, age-independent association of OCRS with some MRI markers, but no association with 1-year-change. OCR was not associated with the intracranial volume. These results are not completely consistent with those of BR or BM.

Discussion

Our results support the link between OCR and CR. Promoting and seeking complex and stimulating work conditions in midlife could therefore contribute to increased resistance to pathologies in old age and might complement prevention measures aimed at reducing pathology.

Cognitive decline and alcohol consumption in the aging population-A longitudinal analysis of the Survey of Health, Ageing and Retirement in Europe

BACKGROUND

Prevalence of cognitive decline and dementia is rising globally, with more than 10 million new cases every year. These conditions cause a significant burden for individuals, their caregivers, and health care systems. As no causal treatment for dementia exists, prevention of cognitive decline is of utmost importance. Notably, alcohol is among the most significant modifiable risk factors for cognitive decline.

METHODS

Longitudinal data across 15 years on 6,967 individuals of the Survey of Health, Ageing and Retirement in Europe were used to analyze the effect of alcohol consumption and further modifiable (i.e., smoking, depression, and educational obtainment) and non-modifiable risk factors (sex and age) on cognitive functioning (i.e., memory and verbal fluency). For this, a generalized estimating equation linear model was estimated for every cognitive test domain assessed.

RESULTS

Consistent results were revealed in all three regression models: A nonlinear association between alcohol consumption and cognitive decline was found-moderate alcohol intake was associated with overall better global cognitive function than low or elevated alcohol consumption or complete abstinence. Furthermore, female sex and higher educational obtainment were associated with better cognitive function, whereas higher age and depression were associated with a decline in cognitive functioning. No significant association was found for smoking.

CONCLUSION

Our data indicate that alcohol use is a relevant risk factor for cognitive decline in older adults. Furthermore, evidence-based therapeutic concepts to reduce alcohol consumption exist and should be of primary interest in prevention measures considering the aging European population.

Education, but not occupation, is associated with cognitive impairment: The role of cognitive reserve in a sample from a low-to-middle-income country

INTRODUCTION

Education, and less frequently occupation, has been associated with lower dementia risk in studies from high-income countries. We aimed to investigate the association of cognitive impairment with education and occupation in a low-middle-income country sample.

METHODS

In this cross-sectional study, cognitive function was assessed by the Clinical Dementia Rating sum of boxes (CDR-SOB). We investigated the association of occupation complexity and education with CDR-SOB using adjusted linear regression models for age, sex, and neuropathological lesions.

RESULTS

In 1023 participants, 77% had < 5 years of education, and 56% unskilled occupations. Compared to the group without education, those with formal education had lower CDR-SOB (1-4 years:β $\beta \;$ = -0.99, 95% confidence interval [CI] = -1.85; -0.14, P = .02; ≥5 years:β $\beta \;$ = -1.42, 95% CI = -2.47; -0.38, P = .008). Occupation complexity and demands were unrelated to cognition.

DISCUSSION

Education, but not occupation, was related to better cognitive abilities independent of the presence of neuropathological insults.

Quantifying longitudinal cognitive resilience to Alzheimer's disease and other neuropathologies

INTRODUCTION

Cognitive resilience (CR) has been defined as the continuum of better (or worse) than expected cognition, given the degree of neuropathology. To quantify this concept, existing approaches focus on either cognitive level at a single time point or slopes of cognitive decline.

METHODS

In a prospective study of 1215 participants, we created a continuous measure of CR defined as the mean of differences between estimated person-specific and marginal cognitive levels over time, after accounting for neuropathologies.

RESULTS

Neuroticism and depressive symptoms were associated with all CR measures (P-values < .012); as expected, cognitive activity and education were only associated with the cognitive-level approaches (P-values < .0002). However, compared with the existing CR measures focusing on a single measure or slopes of cognition, our new measure yielded stronger relations with risk factors.

DISCUSSION

Defining CR based on the longitudinal differences between person-specific and marginal cognitive levels is a novel and complementary way to quantify CR.

Research on nonstroke dementia screening and cognitive function prediction model for older people based on brain atrophy characteristics

BACKGROUND

Brain atrophy is an important feature in dementia and is meaningful to explore a brain atrophy model to predict dementia. Using machine learning algorithm to establish a dementia model and cognitive function model based on brain atrophy characteristics is unstoppable.

METHOD

We acquired 157 dementia and 156 normal old people.s clinical information and MRI data, which contains 44 brain atrophy features, including visual scale assessment of brain atrophy and multiple linear measurement indexes and brain atrophy index. Five machine learning models were used to establish prediction models for dementia, general cognition, and subcognitive domains.

RESULTS

The extreme Gradient Boosting (XGBoost) model had the best effect in predicting dementia, with a sensitivity of 0.645, a specificity of 0.839, and the area under curve (AUC) of 0.784. In this model, the important brain atrophy features for predicting dementia were temporal horn ratio, cella media index, suprasellar cistern ratio, and the thickness of the corpus callosum genu.

CONCLUSION

For nonstroke elderly people, the machine learning model based on clinical head MRI brain atrophy features had good predictive value for dementia, general cognitive impairment, immediate memory impairment, word fluency disorder, executive dysfunction, and visualspatial disorder.

Resting-state functional connectivity alteration in elderly patients with knee osteoarthritis and declined cognition: An observational study

OBJECTIVE

This study is designed to investigate the brain function changed regions in elderly patients with knee osteoarthritis (KOA) and to explore the relationship between neuropsychological tests and resting-state functional magnetic resonance imaging (rs-fMRI) network to clarify the possible mechanism underlying cognitive changes in KOA patients.

MATERIALS AND METHODS

Fifty-two patients aged ≥ 65 with KOA and twenty-two healthy-matched controls were recruited in this study. All participants were given rs-fMRI check. We used graph theory analysis to characterize functional connectivity (FC) and topological organization of the brain structural network. The relationship between FC values, topological properties, and the neuropsychological test scores was analyzed.

RESULTS

Compared with the controls, fourteen edges with lower functional connectivity were noted in the KOA group. Local efficiency and small-worldness of KOA patients decreased compared to the healthy controls. No significant alterations of nodal topological properties were found between the two groups. There was a significant positive correlation between the AVLT-H (L) and the internetwork of default mode network (DMN) (left/right orbitofrontal Superior cortex) and limbic/cortical areas (left/right caudate, right amygdala). AVLT-H(L) was positively correlated with small-worldness and local efficiency.

CONCLUSION

The results indicated that for elderly KOA patients with declined cognition, topological properties, FC between DMN and subcortical limbic network related regions are significantly decreased compared to healthy controls. These alterations demonstrated a significant correlation with the neuropsychological test scores.

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.

Properties of the Cognitive Function Battery for the MIND Diet Intervention to Prevent Alzheimer's Disease

OBJECTIVE

To evaluate the properties of the cognitive battery used in the MIND Diet Intervention to Prevent Alzheimer's Disease. The MIND Diet Intervention is a randomized control trial to determine the relative effectiveness of the MIND diet in slowing cognitive decline and reducing brain atrophy in older adults at risk for Alzheimer's dementia.

METHODS

The MIND cognitive function battery was administered at baseline to 604 participants of an average age of 70 years, who agreed to participate in the diet intervention study, and was designed to measure change over time. The battery included 12 cognitive tests, measuring the 4 cognitive domains of executive function, perceptual speed, episodic memory, and semantic memory. We conducted a principal component analysis to examine the consistency between our theoretical domains and the statistical performance of participants in each domain. To further establish the validity of each domain, we regressed the domain scores against a late-life cognitive activity score, controlling for age, race, sex, and years of education.

RESULTS

Four factors emerged in the principal component analyses that were similar to the theoretical domains. In regression equations, we found the expected associations with age, education, and late-life cognitive activity with each of the four cognitive domains.

CONCLUSIONS

These results indicate that the MIND cognitive battery is a comprehensive and valid battery of four separate domains of cognitive function that can be used in diet intervention trials for older adults.

Effect of cognitive reserve on amnestic mild cognitive impairment due to Alzheimer’s disease defined by fluorodeoxyglucose-positron emission tomography

This study aimed to investigate the effect of cognitive reserve (CR) on the rate of cognitive decline and cerebral glucose metabolism in amnestic mild cognitive impairment (MCI) using the Study on Diagnosis of Early Alzheimer’s Disease-Japan (SEAD-J) dataset. The patients in SEAD-J underwent cognitive tests and fluorodeoxyglucose-positron emission tomography (FDG-PET). MCI to be studied was classified as amnestic MCI due to Alzheimer’s disease (AD) with neurodegeneration. A total of 57 patients were visually interpreted as having an AD pattern (P1 pattern, Silverman’s classification). The 57 individuals showing the P1 pattern were divided into a high-education group (years of school education ≥13, N = 18) and a low-education group (years of school education ≤12, N = 39). Voxel-based statistical parametric mapping revealed more severe hypometabolism in the high-education group than in the low-education group. Glucose metabolism in the hippocampus and temporoparietal area was inversely associated with the years of school education in the high- and low-education groups (N = 57). General linear mixed model analyses demonstrated that cognitive decline was more rapid in the high-education group during 3-year follow-up. These results suggest that the cerebral glucose metabolism is lower and cognitive function declines faster in patients with high CR of amnestic MCI due to AD defined by FDG-PET.

Associations of digital neuro-signatures with molecular and neuroimaging measures of brain resilience: The altoida large cohort study

Background

Mixed results in the predictive ability of traditional biomarkers to determine cognitive functioning and changes in older adults have led to misdiagnosis and inappropriate treatment plans to address mild cognitive impairment and dementia among older adults. To address this critical gap, the primary goal of the current study is to investigate whether a digital neuro signature (DNS-br) biomarker predicted global cognitive functioning and change over time relative among cognitively impaired and cognitive healthy older adults. The secondary goal is to compare the effect size of the DNS-br biomarker on global cognitive functioning compared to traditional imaging and genomic biomarkers. The tertiary goal is to investigate which demographic and clinical factors predicted DNS-br in cognitively impaired and cognitively healthy older adults.

Methods

We conducted two experiments (Study A and Study B) to assess DNS for brain resilience (DNS-br) against the established FDG-PET brain imaging signature for brain resilience, based on a 10 min digital cognitive assessment tool. Study A was a semi-naturalistic observational study that included 29 participants, age 65+, with mild to moderate mild cognitive impairment and AD diagnosis. Study B was also a semi-naturalistic observational multicenter study which included 496 participants (213 mild cognitive impairment (MCI) and 283 cognitively healthy controls (HC), a total of 525 participants-cognitively healthy (n = 283) or diagnosed with MCI (n = 213) or AD (n = 29).

Results

DNS-br total score and majority of the 11 DNS-br neurocognitive subdomain scores were significantly associated with FDG-PET resilience signature, PIB ratio, cerebral gray matter and white matter volume after adjusting for multiple testing. DNS-br total score predicts cognitive impairment for the 80+ individuals in the Altoida large cohort study. We identified a significant interaction between the DNS-br total score and time, indicating that participants with higher DNS-br total score or FDG-PET in the resilience signature would show less cognitive decline over time.

Conclusion

Our findings highlight that a digital biomarker predicted cognitive functioning and change, which established biomarkers are unable to reliably do. Our findings also offer possible etiologies of MCI and AD, where education did not protect against cognitive decline.

Sleep duration, genetic susceptibility, and Alzheimer's disease: a longitudinal UK Biobank-based study

BACKGROUND

Alzheimer's disease (AD) is the most frequently occurring type of dementia. Concurrently, inadequate sleep has been recognized as a public health epidemic. Notably, genetic and environmental factors are now considered contributors to AD progression.

OBJECTIVE

To assess the association between sleep duration, genetic susceptibility, and AD.

METHODS AND RESULTS

Based on 483,507 participants from the UK Biobank (UKB) with an average follow-up of 11.3 years, there was a non-linear relationship between AD incidence and sleep duration (P for non-linear < 0.001) by restricted cubic splines (RCS). Sleep duration was categorized into short sleep duration (< 6 h/night), normal sleep duration (6-9 h/night), and long sleep duration (> 9 h/night). No statistically significant interaction was identified between sleep duration and the AD-GRS (Alzheimer's disease genetic risk score, P for interaction = 0.45) using Cox proportional risk model. Compared with the participants who had a low AD-GRS and normal sleep duration, there was associated with a higher risk of AD in participants with a low AD-GRS and long sleep duration (HR = 3.4806; 95% CI 2.0011-6.054, p < 0.001), participants with an intermediate AD-GRS and long sleep duration (HR = 2.0485; 95% CI 1.3491-3.1105, p < 0.001), participants with a high AD-GRS and normal sleep duration (HR = 1.9272; 95% CI 1.5361-2.4176, p < 0.001), and participants with a high AD-GRS and long sleep duration (HR = 5.4548; 95% CI 3.1367-9.4863, p < 0.001).In addition, there was no causal association between AD and sleep duration using Two Sample Mendelian randomization (MR).

CONCLUSION

In the UKB population, though there was no causal association between AD and sleep duration analyzed using Two Sample MR, long sleep duration (> 9 h/night) was significantly associated with a higher risk of AD, regardless of high, intermediate or low AD-GRS. Prolonged sleep duration may be one of the clinical predictors of a higher risk of AD.

Glucose metabolism patterns: A potential index to characterize brain ageing and predict high conversion risk into cognitive impairment

Exploring individual hallmarks of brain ageing is important. Here, we propose the age-related glucose metabolism pattern (ARGMP) as a potential index to characterize brain ageing in cognitively normal (CN) elderly people. We collected 18F-fluorodeoxyglucose (18F-FDG) PET brain images from two independent cohorts: the Alzheimer's Disease Neuroimaging Initiative (ADNI, N = 127) and the Xuanwu Hospital of Capital Medical University, Beijing, China (N = 84). During follow-up (mean 80.60 months), 23 participants in the ADNI cohort converted to cognitive impairment. ARGMPs were identified using the scaled subprofile model/principal component analysis method, and cross-validations were conducted in both independent cohorts. A survival analysis was further conducted to calculate the predictive effect of conversion risk by using ARGMPs. The results showed that ARGMPs were characterized by hypometabolism with increasing age primarily in the bilateral medial superior frontal gyrus, anterior cingulate and paracingulate gyri, caudate nucleus, and left supplementary motor area and hypermetabolism in part of the left inferior cerebellum. The expression network scores of ARGMPs were significantly associated with chronological age (R = 0.808, p < 0.001), which was validated in both the ADNI and Xuanwu cohorts. Individuals with higher network scores exhibited a better predictive effect (HR: 0.30, 95% CI: 0.1340 ~ 0.6904, p = 0.0068). These findings indicate that ARGMPs derived from CN participants may represent a novel index for characterizing brain ageing and predicting high conversion risk into cognitive impairment.

A Study of Dementia Prediction Models Based on Machine Learning with Survey Data of Community-Dwelling Elderly People in China

BACKGROUND

For community-dwelling elderly individuals without enough clinical data, it is important to develop a method to predict their dementia risk and identify risk factors for the formulation of reasonable public health policies to prevent dementia.

OBJECTIVE

A community elderly survey data was used to establish machine learning prediction models for dementia and analyze the risk factors.

METHODS

In a cluster-sample community survey of 9,387 elderly people in 5 subdistricts of Wuxi City, data on sociodemographics and neuropsychological self-rating scales for depression, anxiety, and cognition evaluation were collected. Machine learning models were developed to predict their dementia risk and identify risk factors.

RESULTS

The random forest model (AUC = 0.686) had slightly better dementia prediction performance than logistic regression model (AUC = 0.677) and neural network model (AUC = 0.664). The sociodemographic data and psychological evaluation revealed that depression (OR = 3.933, 95% CI = 2.995-5.166); anxiety (OR = 2.352, 95% CI = 1.577-3.509); multiple physical diseases (OR = 2.486, 95% CI = 1.882-3.284 for three or above); "disability, poverty or no family member" (OR = 1.859, 95% CI = 1.337-2.585) and "empty nester" (OR = 1.339, 95% CI = 1.125-1.595) in special family status; "no spouse now" (OR = 1.567, 95% CI = 1.118-2.197); age older than 80 years (OR = 1.645, 95% CI = 1.335-2.026); and female (OR = 1.214, 95% CI = 1.048-1.405) were risk factors for suspected dementia, while a higher education level (OR = 0.365, 95% CI = 0.245-0.546 for college or above) was a protective factor.

CONCLUSION

The machine learning models using sociodemographic and psychological evaluation data from community surveys can be used as references for the prevention and control of dementia in large-scale community populations and the formulation of public health policies.

MoCA 7.1: Multicenter Validation of the First Italian Version of Montreal Cognitive Assessment

Background:

The early detection of neurocognitive disorders, especially when mild, is a key issue of health care systems including the Italian Dementia National Plan. The Mini-Mental State Examination (MMSE), i.e., the reference screening tool for dementia in Italian Memory Clinics, has low sensitivity in detecting mild cognitive impairment (MCI) or mild dementia.

Objective:

Availability of a 10-minute screening test sensitive to MCI and mild dementia, such as the Montreal Cognitive Assessment (MoCA), is relevant in the field. This study presents initial validity and reliability data for the Italian version of MoCA 7.1 that is being collected as part of a large ongoing longitudinal study to evaluate the rate of incident MCI and dementia in older adults.

Methods:

MoCA 7.1 and MMSE were administered to cognitive impaired patients (n = 469; 214 with MCI, 255 with dementia; mean age: 75.5; 52% females,) and healthy older adults (n = 123, mean age: 69.7, 64 % females).

Results:

Test-retest (0.945, p < 0.001) and inter-rater (0.999, p < 0.001) reliability of MoCA 7.1, assessed on randomly selected participants with normal cognition, MCI, dementia, were significant. MoCA 7.1 showed adequate sensitivity (95.3%) and specificity (84.5%) in detecting MCI compared to MMSE (sensitivity: 53.8%; specificity: 87.5%). The Area Under the Curve of MoCA 7.1 was significantly greater than that of MMSE (0.963 versus 0.742). MoCA 7.1 showed similar results in detecting both MCI and dementia.

Conclusion:

MoCA 7.1 is a reliable and useful tool that can aid in the diagnosis of MCI and dementia in the Italian population.

Dynamic modeling of practice effects across the healthy aging-Alzheimer’s disease continuum

Standardized tests of learning and memory are sensitive to changes associated with both aging and superimposed neurodegenerative diseases. Unfortunately, repeated behavioral test administration can be confounded by practice effects (PE), which may obscure declines in level of abilities and contribute to misdiagnoses. Growing evidence, however, suggests PE over successive longitudinal measurements may differentially predict cognitive status and risk for progressive decline associated with aging, mild cognitive impairment (MCI), and dementia. Thus, when viewed as a reflection of neurocognitive plasticity, PE may reveal residual abilities that can add to our understanding of age- and disease-related changes in learning and memory. The present study sought to evaluate differences in PE and verbal recall in a clinically characterized aging cohort assessed on multiple occasions over 3 years. Participants included 256 older adults recently diagnosed as cognitively unimpaired (CU; n = 126), or with MCI of amnestic (n = 65) or non-amnestic MCI (n = 2085), and multi-domain amnestic dementia of the Alzheimer’s type (DAT; n = 45). We applied a continuous time structural equation modeling (ctsem) approach to verbal recall performance on the Hopkins Verbal Learning Test in order to distinguish PE from individual occasion performance, coupled random changes, age trends, and differing measurement quality. Diagnoses of MCI and dementia were associated with lower recall performance on all trials, reduced PE gain per occasion, and differences in non-linear dynamic parameters. Practice self-feedback is a dynamic measure of the decay or acceleration in PE process changes over longitudinal occasions. As with PE and mean recall, estimated practice self-feedback followed a gradient from positive in CU participants to null in participants with diagnosed MCI and negative for those with dementia diagnoses. Evaluation of sensitivity models showed this pattern of variation in PE was largely unmodified by differences in age, sex, or educational attainment. These results show dynamic modeling of PE from longitudinal performance on standardized learning and memory tests can capture multiple aspects of behavioral changes in MCI and dementia. The present study provides a new perspective for modeling longitudinal change in verbal learning in clinical and cognitive aging research.

Episodic Memory and Executive Function Are Differentially Affected by Retests but Similarly Affected by Age in a Longitudinal Study of Normally-Aging Older Adults

Episodic memory and executive function are two cognitive domains that have been studied extensively in older adults and have been shown to decline in normally-aging older individuals. However, one of the problems with characterizing cognitive changes in longitudinal studies has been separating effects attributable to normal aging from effects created by repeated testing or practice. In the present study, 166 people aged 65 and older were enrolled over several years and tested at least 3 times at variable intervals (M = 3.2 yrs). The cognitive measures were composite scores. Each composite was made up of five neuropsychological tests, previously identified through factor analysis. For one pair of composite scores, variance attributable to age was removed from each subtest through regression analyses before z-scores were computed, creating two age-corrected composites. A second pair of composites were not age-corrected. Using linear mixed-effects models, we first explored retest effects for each cognitive domain, independent of age, using the age-corrected composites. We then modeled aging effects using the age-uncorrected composites after subtracting out retest effects. Results indicated significant retest effects for memory but not for executive function, such that memory performance improved across the three testing sessions. When these practice effects were removed from the age-uncorrected data, effects of aging were evident for both executive and memory function with significant declines over time. We also explored several individual difference variables including sex, IQ, and age at the initial testing session and across time. Although sex and IQ affected performance on both cognitive factors at the initial test, neither was related to practice effects, although young-older adults tended to benefit from practice to a greater extent than old-older adults. In addition, people with higher IQs showed slower age-related declines in memory, but no advantages in executive function. These findings suggest that (a) aging affects both memory and executive function similarly, (b) higher IQ, possibly reflecting cognitive reserve, may slow age-related declines in memory, and (c) practice through repeated testing enhances performance in memory particularly in younger-older adults, and may therefore mask aging effects if not taken into account.

Gender differences in cognitive reserve: implication for subjective cognitive decline in women

BACKGROUND

Subjective Cognitive Decline (SCD) is a self-experienced decline in cognitive capacity with normal performance on standardized cognitive tests, showing to increase risk of Alzheimer's Disease (AD). Cognitive reserve seems to influence the progression from SCD to Mild Cognitive Impairment (MCI) and to AD. The aim of our study was to investigate gender differences in cognitive reserve evaluating how sex might modulate the role of cognitive reserve on SCD.

METHODS

We included 381 SCD patients who underwent clinical evaluation, neuropsychological assessment, evaluation of premorbid intelligence by the Test di Intelligenza Breve (TIB), cognitive complaints by the Memory Assessment Clinics Questionnaire (MAC-Q), and apolipoprotein E (APOE) genotyping.

RESULTS

The proportion between women and men was significantly different (68.7% [95% CI 63.9-73.4 vs 31.4%, 95% CI 26.6-36.0]). Women were younger than men at onset of SCD and at the baseline visit (p = 0.021), had lower years of education (p = 0.007), lower TIB scores (p < 0.001), and higher MAC-Q scores (p = 0.012). TIB was directly associated with age at onset of SCD in both women and men, while years of education was inversely associated with age at onset only in women. Multivariate analysis showed that sex influences TIB independently from years of education. TIB was directly associated with MAC-Q in men.

CONCLUSIONS

Sex interacts with premorbid intelligence and education level in influencing the age at onset and the severity of SCD. As the effect of education was different between men and women, we speculated that education might act as a minor contributor of cognitive reserve in women.

Cognition and Cognitive Reserve in Cochlear Implant Recipients

At present, dementia is a hot topic. Hearing loss is considered to be a modifiable risk factor for cognitive decline. The underlying mechanism remains unclear and might be mediated by socioeconomic and psychosocial factors. Cochlear implantation has been shown not only to restore auditory abilities, but also to decrease mental distress and to improve cognitive functions in people with severe hearing impairment. However, the promising results need to be confirmed. In a prospective single-center study, we tested the neurocognitive abilities of a large group of 71 subjects with bilateral severe hearing impairment with a mean age of 66.03 (SD = 9.15) preoperatively and 6, 12, and 24 months after cochlear implantation using a comprehensive non-auditory computer-based test battery, and we also assessed the cognitive reserve (CR) [Cognitive Reserve Index (CRI)], health-related quality of life (QoL) (Nijmegen Cochlear Implant Questionnaire), and depression (Geriatric Depression Scale-15). Cognitive functions significantly increased after 6 months in attention (p = 0.00004), working memory (operation span task; p = 0.002), and inhibition (p = 0.0002); and after 12 months in recall (p = 0.003) and verbal fluency (p = 0.0048), and remained stable up to 24 months (p ≥ 0.06). The CR positively correlated with cognitive functions pre- and post-operatively (both p < 0.005), but postoperative improvement in cognition was better in subjects with poor CR (p = 0.003). Depression had only a slight influence on one subtest. No correlation was found among cognitive skills, quality of life, and speech perception (each p ≥ 0.05). Cochlear implantation creates an enriched environment stimulating the plasticity of the brain with a global positive impact on neurocognitive functions, especially in subjects with poor preoperative cognitive performance and low cognitive reserve.

How Welfare Regimes Moderate the Associations Between Cognitive Aging, Education, and Occupation

OBJECTIVES

Previous studies have shown the importance of individual markers of cognitive reserve, such as education and occupation, for cognitive health in old age. However, there has been only little investigation so far on how this relationship varies across contexts.

METHODS

We analyzed data from the Survey of Health, Ageing, and Retirement in Europe, using second-order latent growth models, to assess the moderating role of welfare regimes on the relationship between education and occupation skill level in explaining overall cognitive functioning and decline in old age. Our sample includes 13 European countries using data from 5 regular waves of the survey (2004-2007 and 2011-2015) and 2 retrospective ones (2008-2009 and 2017). Cognitive functioning was modeled as a latent variable measured by immediate and delayed recall, verbal fluency, and numeracy.

RESULTS

74,193 participants were included from the survey. Our analysis showed that the association of education with cognition was weaker overall in Scandinavian countries, but stronger in Southern European countries, relative to Bismarckian ones. However, educational differences in the decline of cognition were more pronounced only in Scandinavian compared to Bismarckian countries. Additionally, higher-skilled occupations in Scandinavian countries had better overall functioning compared to the same occupations in Bismarckian countries, but there was no difference in the decline in cognitive functioning.

DISCUSSION

Our findings indicate that the associations of cognitive functioning and its decline with individuals' cognitive reserve markers (education and occupational skill level) vary according to welfare regimes, showing the importance of contextual factors in cognitive aging processes.

Elder abuse/mistreatment and associated covariates in India: results from the Longitudinal Aging Study in India wave 1, 2017-2018

OBJECTIVES

Elder abuse has significant adverse consequences for the overall health and well-being of the elderly, including premature mortality. Using cross-sectional data, we assessed the prevalence of elder abuse in India, its variation across states, and associated factors.

METHODS

Nationally representative data from the first wave of the Longitudinal Aging Study in India were analyzed. Bivariate and multivariate analyses were used to study the prevalence, state variations, and associated factors of elder abuse.

RESULTS

Overall, 5.2% of elderly adults (≥60 years) had experienced abuse in the year prior to the survey and 3% had experienced abuse within their own household. Verbal abuse or disrespect was the most common form of abuse. Considerable variation was observed in the prevalence of elder abuse across states and union territories, with the highest prevalence observed in Bihar (11.6%) and Karnataka (10.1%). In regression analysis, education level emerged as a protective factor against elder abuse, particularly among women. Older adults who lived alone, had functional limitations, had multiple morbidities, and had been hospitalized in the past year were more likely to experience abuse. Older adults who experienced abuse were 2 times more likely to experience depressive symptoms.

CONCLUSIONS

Cross-state variation in the prevalence of elder abuse and subgroup differences suggest that state-specific interventions and essential monitoring of older adults with functional limitations, chronic diseases, and recent hospitalization can further reduce the prevalence and consequences of elder abuse in India.

Comparing the Effects of Two Cardiovascular Health Factors on Working Memory Capacity in Healthy Aging: Separate and Combined Effects of Arterial Elasticity and Physical Fitness

OBJECTIVES

Arterial elasticity and physical fitness are 2 important cardiovascular health factors that influence cognition in older adults. Working memory capacity (WMC), a core component underlying cognitive aging across many cognitive domains, may be affected by individual differences in cardiovascular health in older adults. This study aims to identify in older adults: (a) separate and combined effects of these 2 cardiovascular health factors on WMC and (b) which of the 2 factors is more critical in influencing WMC.

METHODS

WMC in 89 healthy older adults was assessed by 2 complex span tasks. Arterial elasticity was assessed by pulse pressure (PsP). Physical fitness was measured by an established proxy of VO2 max (MET). Effects of PsP and MET on WMC were evaluated via step-wise regressions.

RESULTS

After controlling for age, sex, and education, PsP and MET were separately predictive of WMC in older adults. Together, the combined effect of PsP and MET was more predictive of WMC than fitness alone, but not more than PsP alone. Mediation analysis indicates that the relationship between MET and WMC was completely mediated by PsP.

DISCUSSION

This study innovatively demonstrates that though arterial elasticity and physical fitness separately predict WMC, the former completely mediates the relationship between fitness and WMC. This suggests that biologically based cardiovascular health factors like arterial elasticity are crucial individual difference variables that should be measured and monitored in cognitive aging studies as well as in physical interventions that are designed to improve cognition in healthy aging.

Is Old Age Just a Number in Language Skills? Language Performance and Its Relation to Age, Education, Gender, Cognitive Screening, and Dentition in Very Old Finnish Speakers

PURPOSE

This study reports on how very old (VO) Finnish people without dementia perform in the Western Aphasia Battery (WAB) and two verbal fluency tasks and which demographic factors predict the performance.

METHOD

The study included fifty 80- to 100-year-old community-dwelling Finnish speakers with no dementing illnesses or speech-language disabilities, who completed the WAB and two verbal fluency tasks. Multifactorial statistical analyses with recursive partitioning were carried out to determine the significant predictors out of five predictor variables (age, gender, education, dentition, and Mini-Mental State Examination [MMSE]) for four response variables (WAB Aphasia Quotient [AQ], Language Quotient [LQ], semantic, and phonemic word fluencies).

RESULTS

Overall, individual variation was notable in VO speakers. All predictor variables were statistically significantly associated with one or more of the language skills. Age was the most significant predictor; the critical age of 85-86 years was associated with a decline in WAB-AQ and semantic fluency. Poor dentition and the MMSE score both predicted a decline in WAB-LQ and phonemic fluency. A high level of education was positively associated with the skills of the best-performing individuals in WAB-AQ, WAB-LQ, and semantic fluency.

CONCLUSIONS

VO age is a significant factor contributing to language performance. However, a younger age, a good cognitive performance, intact teeth, and a higher educational level also seem to have a preservative power as regards language skills. Gender differences should be interpreted with caution. The results of this study provide culture- and language-specific normative data, which aids in differentiating typical aging from the signs of acute or degenerative neuropathology to ensure appropriate medical and therapeutic interventions.

Relationships between enriching early life experiences and cognitive function later in life are mediated by educational attainment

The study of how engagement in enriching cognitive, physical and social activities in childhood impacts cognitive function decades later will advance our understanding of how modifiable lifestyle activities promote cognition across the lifespan. 88 healthy older adults (aged 60-80 years) returned a retrospective questionnaire regarding their participation in seven lifestyle activities (musical instrument playing, language learning, sport participation, art/dance lessons, scouting, volunteering, family vacations) before age 13 years. After controlling for current age, educational attainment, socioeconomic status of the mother and current engagement in lifestyle activities, a greater number of activities were significantly associated with better vocabulary abilities, episodic memory and fluid intelligence. The relationships with vocabulary and fluid intelligence were mediated by educational attainment. We postulate that engagement in a higher number of enriching early life activities is a reflection of both one's sociocontextual environment and engagement with that environment. This engagement leads to attributes relevant for educational aspirations/attainment, ultimately contributing to factors that have a lifespan impact on cognitive function.

The effect of Alzheimer's disease risk factors on brain aging in normal Chineses: Cognitive aging and cognitive reserve

Aging has been recognized as a major driving force of the Alzheimer's disease's (AD) progression, however, the relationship between brain aging and AD is still unclear. There is also a lack of studies investigating the influence of AD risk factors on brain aging in cognitively normal people. Here, the "Brain Age Gap Estimation" (BrainAGE) framework was applied to investigate the effects of AD risk factors on individual brain aging. Across a total of 165 cognitively normal elderly subjects, although no significant difference was observed in the BrainAGE scores among the three groups, AD risk dose (i.e., the number of AD risk factors) is tend to associated with an increased BrainAGE scores (high-risk > middle risk > low risk). Female exhibited more advanced brain aging (P = 0.004), and higher education years were associated with preserved brain aging (P < 0.001). APOE-ɛ4 (P = 0.846) and family history (FH) of dementia (P = 0.209) did not increase BrainAGE scores. When comparing 52 aMCI patients with 38 cognitively normal controls from ADNI dataset, aMCI patients showed significantly increased BrainAGE scores. BrainAGE scores were negatively correlated with CSF Aβ42 levels in the aMCI group (r = -0.275, P = 0.048). With an accuracy of 68.9%, BrainAGE outperformed APOE-ɛ4 and hippocampus gray matter volume (GMV) in predicting aMCI. In conclusion, AD is independently associated with structural changes in the brain that reflect advanced aging. Potentially, BrainAGE combined with APOE-ɛ4 and hippocampus GMV could be used as a pre-screening tool in early-stage AD.

Long-term prognosis and educational determinants of brain network decline in older adult individuals

Older adults with lower education are at greater risk for dementia. It is unclear which brain changes lead to these outcomes. Longitudinal imaging-based measures of brain structure and function were examined in adult individuals (baseline age, 45-86 years; two to five visits per participant over 1-9 years). College degree completion differentiates individual-based and neighborhood-based measures of socioeconomic status and disadvantage. Older adults (~65 years and over) without a college degree exhibit a pattern of declining large-scale functional brain network organization (resting-state system segregation) that is less evident in their college-educated peers. Declining brain system segregation predicts impending changes in dementia severity, measured up to 10 years past the last scan date. The prognostic value of brain network change is independent of Alzheimer's disease (AD)-related genetic risk (APOE status), the presence of AD-associated pathology (cerebrospinal fluid phosphorylated tau, cortical amyloid) and cortical thinning. These results demonstrate that the trajectory of an individual's brain network organization varies in relation to their educational attainment and, more broadly, is a unique indicator of individual brain health during older age.

Influence of Cognitive Reserve on Cognitive Trajectories: Role of Brain Pathologies

BACKGROUND AND OBJECTIVES

Evidence on the association of cognitive reserve (CR) with the cognitive trajectories is limited. We aimed to examine the influence of CR indicator on domain-specific cognitive trajectories taking brain pathologies into account.

METHODS

Within the Rush Memory and Aging Project, 1,697 participants without dementia (mean age 79.6 years) were followed up to 21 years. CR indicator encompassing education, early-life, mid-life, and late-life cognitive activities and late-life social activity was ascertained at baseline and categorized as tertiles (lowest, middle, and highest). Global cognition, episodic memory, semantic memory, working memory, visuospatial ability, and perceptual speed were assessed annually with 19 tests, from which composite scores were derived. During the follow-up, 648 participants died and underwent autopsies to evaluate brain pathologies. Data were analyzed using linear mixed-effect models.

RESULTS

Among the participants, the score of the CR indicator ranged from -8.00 to 5.74 (mean 0.00 ± 2.23). In multi-adjusted mixed-effect models, compared to the lowest CR, the highest was related to a slower decline in global cognition (β = 0.028, 95% confidence interval [CI] 0.012-0.043), episodic memory (β = 0.028, 95% CI 0.010-0.047), and working memory (β = 0.019, 95% CI 0.005-0.033) during the follow-up. In brain pathologic data analysis, the association of the highest CR with cognitive function changes remained significant among participants with high Alzheimer disease pathology or gross infarcts.

DISCUSSION

High CR indicator is associated with preserved global cognitive function, episodic memory, and working memory, even in the presence of brain pathologies. Our findings highlight the important role of high CR accumulation in the prevention of cognitive decline.

Reducing Your Risk of Alzheimer's Dementia: Building a Better Brain as We Age

Alzheimer' dementia is a large and growing public health problem. Of utmost importance for limiting the impact of the disease on society is the prevention of dementia, that is, delay onset either by years whereby death ensues prior to dementia onset. The Religious Orders Study and the Rush Memory and Aging Project are two harmonized cohort studies of aging and dementia that include organ donation at death. Ongoing since 1994 and 1997, respectively, we published on the association of numerous experiential, psychological, and medical risk factors for dementia, many of which are potentially modifiable. Here, selected findings are reviewed based on a presentation at the 2020 National Academy of Neuropsychology given virtually in Chicago in October of 2020.

Meta-analysis of the effects of game types and devices on older adults-video game interaction: Implications for video game training on cognition

Video game training can effectively improve the cognition of older adults. However, whether video game types and game devices influence the training effects of video games remains controversial. This meta-analysis aimed to access and evaluate the effects of video game types and game devices in video game training on the cognition of older adults. Interestingly, results indicated that mouse/keyboard was superior over other video game devices on perceptual-motor function. The effect size (Hedge's g) for perceptual-motor function decreased by 1.777 and 1.722 when the video game training device changed from mouse/keyboard to driving simulator and motion controller. The effects of cognitive training game and conventional video game were moderated by session length. More well-designed studies are required to clarify the unique efficacy of video game types and devices for older adults with video game training.

The histone code in dementia: Transcriptional and chromatin plasticity fades away

With the aging of the population, Alzheimer's disease and other forms of dementia represent major challenges for health care systems globally. To date, the molecular mechanisms underlying the pathophysiology of dementia remain elusive, with a consequent negative impact in developing efficient disease modifiers. New exciting findings suggest that modulation of the histone code may influence transcriptional networks at the root of neuronal plasticity and cognitive performance. Although most of the current conclusions require further mechanistic evidence, it appears that chromatin perturbations actually correlate with Alzheimer's disease onset and progression. Thus, a better understanding of the epigenetic contribution to normal brain function and dementia pathogenesis may help to identify new epigenetic targets for the inhibition of disease trajectories associated with cognitive decline.

Cognitive Reserve Characteristics and Occupational Performance Implications in People with Mild Cognitive Impairment

The Cognitive Reserve hypothesis suggests that there are individual differences in the ability to cope with the pathologic changes in Alzheimer's Disease. The proportion of elderly individuals has increased in recent years; this increase emphasizes the importance of early detection of mild cognitive impairment and the promotion of healthy ageing. The purpose of our study is to characterize cognitive reserve and occupational performance implications in people with mild cognitive impairment. 125 patients with mild cognitive impairment were enrolled. The Montreal Cognitive Assessments (MoCA) was used to evaluate cognitive status and the Cognitive Reserve Index Questionnaire (CRIq) as an indicator of cognitive reserve. Higher level of education was associated with higher MoCA scores (r = 0.290, p = 0.001). Positive significant correlations were observed between MoCA and total CRIq (r = 0.385, p < 0.001) as well as its three sub-domains, education (r = 0.231, p = 0.010), working activity (r = 0.237, p = 0.008) and leisure time (r = 0.319, p < 0.001). This study findings provide the importance of considering socio-behavioral factors in cognitive status. This research helps to describe the importance of engaging occupationally along the whole life-course as a potential protective factor in ageing, and includes a perspective of occupational therapy regarding the hypothesis of cognitive reserve.

Positive Effects of Education on Cognitive Functioning Depend on Clinical Status and Neuropathological Severity

Background: Variability in cognitive functions in healthy and pathological aging is often explained by educational attainment. However, it remains unclear to which extent different disease states alter protective effects of education. We aimed to investigate whether protective effects of education on cognition depend on (1) clinical diagnosis severity, and (2) the neuropathological burden within a diagnosis in a memory clinic setting. Methods: In this cross-sectional study, we included 108 patients with subjective cognitive decline [SCD, median age 71, IQR (66-78), 43% men], 190 with mild cognitive impairment [MCI, median age 78, IQR (73-82), 44% men], and 245 with Alzheimer's disease dementia (AD) [median age 80, IQR (76-84), 35% men]. We combined visual ratings of hippocampal atrophy, global atrophy, and white matter hyperintensities on MRI into a single neuropathology score. To investigate whether the contribution of education to cognitive performance differed across SCD, MCI, and AD, we employed several multiple linear regression models, stratified by diagnosis and adjusted for age, sex, and neurodegeneration. We re-ran each model with an additional interaction term to investigate whether these effects were influenced by neuropathological burden for each diagnostic group separately. False discovery rate (FDR) corrections for multiple comparisons were applied. Results: We observed significant positive associations between education and performance for global cognition and executive functions (all adjusted p-values < 0.05). As diagnosis became more severe, however, the strength of these associations decreased (all adjusted p-values < 0.05). Education related to episodic memory only at relatively lower levels of neuropathology in SCD (β = -0.23, uncorrected p = 0.02), whereas education related to episodic memory in those with higher levels of neuropathology in MCI (β = 0.15, uncorrected p = 0.04). However, these interaction effects did not survive FDR-corrections. Conclusions: Altogether, our results demonstrated that positive effects of education on cognitive functioning reduce with diagnosis severity, but the role of neuropathological burden within a particular diagnosis was small and warrants further investigation. Future studies may further unravel the extent to which different dimensions of an individual's disease severity contribute to the waxing and waning of protective effects in cognitive aging.

Association Between Central and Peripheral Age-Related Hearing Loss and Different Frailty Phenotypes in an Older Population in Southern Italy

Importance

The association between age-related hearing loss (ARHL) and physical or cognitive frailty has been poorly explored. These associations could define new perspectives for delaying frailty-related processes in older age.

Objective

To examine whether peripheral ARHL and age-related central auditory processing disorder (CAPD) are independently associated with physical or cognitive frailty.

Design, Setting, and Participants

This cross-sectional study analyzed registry data from December 31, 2014, on 1929 older (≥65 years) participants of the Salus in Apulia Study (Southern Italy) who underwent audiologic, physical, and neuropsychological assessment. Data analysis was performed from December 12, 2019, to January 4, 2020.

Main Outcomes and Measures

Prevalence of peripheral ARHL in older individuals with physical and/or cognitive frailty and those without frailty assessed using the Fried criteria (physical) and the Mini-Mental State Examination (cognitive). Multivariable logistic regression models were used to assess associations of audiologic variables with frailty phenotype.

Results

Data from 1929 participants (mean [SD] age, 73.6 [6.3] years; 974 male [50.5%]) were eligible for the analyses. The prevalence of peripheral ARHL was higher in the physical frailty group (96 [26.6%]) than in the nonfrail group (329 [21.0%]) (difference, 5.61 percentage points; 95% CI, 0.63-10.59 percentage points) and in the cognitive frailty group (40 [38.8%]) than in the nonfrail group (385 [21.1%]) (difference, 17.75 percentage points; 95% CI, 8.2-27.3 percentage points). Age-related CAPD was more prevalent in the physical frailty group (62 [17.2%]) than in the nonfrail group (219 [14.0%]) (difference, 3.21 percentage points; 95% CI, -1.04 to 7.46 percentage points) and in the cognitive frailty group (28 [27.2%]) than in the nonfrail group (253 [13.9%]) (difference, 13.33 percentage points; 95% CI, 4.10-22.21 percentage points). In the multivariable models, age-related CAPD was associated with cognitive frailty in the fully adjusted model (odds ratio [OR], 1.889; 95% CI, 1.094-3.311). There was also an inverse association between the unitary increase in Synthetic Sentence Identification With the Ipsilateral Competitive Message scores, indicating a lower likelihood of this disorder, and cognitive frailty (OR, 0.989; 95% CI, 0.988-0.999). Peripheral ARHL was associated with cognitive frailty only in the partially adjusted model (OR, 1.725; 95% CI, 1.008-2.937).

Conclusions and Relevance

In this cross-sectional study of 1929 participants, age-related CAPD was independently associated with cognitive frailty. Whether the management of ARHL may help prevent the development of different frailty phenotypes or improve their clinical consequences should be addressed in longitudinal studies and, eventually, well-designed randomized clinical trials.

Prevalence of dementia and cognitive impairment with no dementia in a primary care setting in southern Brazil

BACKGROUND

Cognitive decline is a common condition, but is still underrepresented in studies conducted in developing countries.

OBJECTIVE

To calculate the prevalence of cognitive decline and depression in an elderly community-dwelling population in a city in southern Brazil.

METHODS

We calculated the prevalences of dementia, cognitive impairment with no dementia (CIND) and symptoms of depression in an elderly population relying on the public healthcare system. This epidemiological study in Pelotas, Brazil, was conducted within the primary care setting. It included 299 older adults (mean age = 69.75 ± 7.6 years) who presented low levels of education (mean = 4.16 ± 3.17 years of education). They underwent cognitive screening and their medical records were analyzed.

RESULTS

Among these older adults, 142 (47.5%) presented cognitive decline: 104 (34.8%) matching the cognitive criteria for CIND and 38 (12.7%) matching the cognitive criteria for dementia. Among all the individuals who completed the cognitive screening, 141 (48.4%) were positive for symptoms of depression, of whom 99 (34%) did not have any previous diagnosis in their medical records.

CONCLUSION

There was high prevalence of cognitive impairment among these older adults in a primary care setting. A large number of older adults were found to have symptoms of depression without any diagnosis.

Cognitive Activity and Onset Age of Incident Alzheimer Disease Dementia

OBJECTIVE

To test the hypothesis that higher level of cognitive activity predicts older age at dementia onset in Alzheimer disease (AD) dementia.

METHODS

As part of a longitudinal cohort study, 1,903 older persons without dementia at enrollment reported their frequency of participation in cognitively stimulating activities. They had annual clinical evaluations to diagnose dementia and AD, and the deceased underwent neuropathologic examination. In analyses, we assessed the relation of baseline cognitive activity to age at diagnosis of incident AD dementia and to postmortem markers of AD and other dementias.

RESULTS

During a mean of 6.8 years of follow-up, 457 individuals were diagnosed with incident AD at a mean age of 88.6 (SD 6.4, range 64.1-106.5) years. In an extended accelerated failure time model, higher level of baseline cognitive activity (mean 3.2, SD 0.7) was associated with older age at AD dementia onset (estimate 0.026; 95% confidence interval 0.013-0.039). Low cognitive activity (score 2.1, 10th percentile) was associated with a mean onset age of 88.6 years compared to a mean onset age of 93.6 years associated with high cognitive activity (score 4.0, 90th percentile). Results were comparable in subsequent analyses that adjusted for potentially confounding factors. In 695 participants who died and underwent a neuropathologic examination, cognitive activity was unrelated to postmortem markers of AD and other dementias.

CONCLUSION

A cognitively active lifestyle in old age may delay the onset of dementia in AD by as much as 5 years.

Bilingualism as a protective factor in aphasia

BACKGROUND

Bilingualism may affect the profile of cognitive disturbances associated with stroke. Its impact on aphasia severity, however, is in need of substantiation.

AIMS

To determine the relationship between bilingualism and vascular aphasia severity.

METHODS

This is an observational cross-sectional study conducted on people with post-stroke aphasia. Our sample included 155 monolingual and 53 bilingual vascular aphasia patients. They were selected in a neurological hospital in Kolkata (West Bengal, India).

RESULTS

The Bengali version of Western Aphasia Battery (BWAB) was used in this study. Aphasia severity was compared between monolingual and bilingual participants. The overall difference in the mean aphasia quotient (AQ) between bilingual and monolingual participants was statistically significant (p = 0.009). It was also found that in bilingual participants, aphasia was less severe in certain subgroups, namely: higher lesion volume, male gender, and sub-cortical stroke, while in none of the subgroups a monolingual advantage was documented.

CONCLUSION

Current results suggest that bilingualism represents a protective factor in vascular aphasia; this effect is observed particularly in some aphasia subgroups.

Increasingly capable at the ripe old age? Cognitive abilities from 2004 to 2013 in Germany, Spain, and Sweden

Background

Life expectancy is increasing in most high-income countries, but gains in life years are maximized if spent in good health and if cognitive abilities are maintained until old age. Age-related decline of cognitive abilities does nevertheless occur, but the pace of decline is decisive. This was the starting point for our study that aims to examine cohort effects of cognitive aging in women and men in Germany, Spain and Sweden by analyzing changes from 2004 to 2013 by estimating cohort effects within age groups starting from the age of 50 years.

Methods

A cohort study was conducted that was based on data of the surveys 2004 (N = 6,081) and 2013 (N = 8,650) from the Survey of Health, Ageing and Retirement in Europe (SHARE). The analyses were based on data of female and male respondents aged 50 years and older. Age-specific means of verbal fluency and delayed recall from the German, Spanish and Swedish samples were the cognitive domains considered in the study.

Results

In both domains of cognitive ability the achievements in the later surveys were higher than in the earlier ones. This was found in all countries, abut achievement levels increased markedly in the German and the Spanish samples, while the scores of the Swedish samples were not significantly different.

While the highest scores were found for Sweden, Germany ranked in the middle and the lowest scores were found in the Spanish samples. Over time, the scores of the German samples approached those of Sweden.

Conclusions

From the first to the second survey, improvements of older adults’ cognitive abilities were found for all countries considered. This may indicate improvements of the underlying educational systems, but also increasingly stimulating general living conditions.

The effects of education on cognition in older age: Evidence from genotyped Siblings

A growing literature has sought to tie educational attainment with later-life cognition and Alzheimer's disease outcomes. This paper leverages sibling comparisons in educational attainment as well as genetic predictors (polygenic scores) for cognition, educational attainment, and Alzheimer's disease to estimate effects of educational attainment on cognition in older age in the United Kingdom. We find that the effects of education on cognition are confounded by family background factors (~40%) and by genetics (<10%). After adjustments, we continue to find large effects of education. College graduates have cognition scores that are approximately 0.75 SD higher than those who report no credentials. We also find evidence that educational effects on cognition are smaller for those with high polygenic scores for Alzheimer's disease.

Neurocognitive Impairment After Hematopoietic Stem Cell Transplant for Hematologic Malignancies: Phenotype and Mechanisms

Hematopoietic stem cell transplant (HSCT) plays a central role in the treatment of hematologic cancers. With the increasing survival of patients after HSCT, survivorship issues experienced by this population have become an important outcome. Cognitive impairment is an established sequela of HSCT, with studies to date establishing its presence, associated risk factors, and clinical phenotype. There are multiple potential contributors to cognitive impairment after HSCT. Efforts are ongoing to further characterize its clinical phenotype, associated biomarkers, and biologic underpinnings. A fundamental knowledge of post-HSCT cognitive impairment is of value for all clinicians who interface with this population, and further academic efforts are needed to more fully understand the impact of this cancer treatment on brain health. IMPLICATIONS FOR PRACTICE: As survival outcomes after hematopoietic stem cell transplant (HSCT) improve, an awareness of the post-treatment challenges faced by this population has become central to its care. HSCT can have a sustained and broad impact on brain health, causing cognitive dysfunction, fatigue, disturbed mood, and sleep. In affected patients, autonomy, return to work, relationships, and quality of life may all be affected. A fundamental fluency in this area is important for clinicians interfacing with HSCT survivors, facilitating the identification and management of cognitive dysfunction and concurrent symptom clusters, and stimulating interest in these sequelae as areas for future clinical research.

A coordinated analysis of the associations among personality traits, cognitive decline, and dementia in older adulthood

There are individual differences in the rates of cognitive decline across later adulthood. Personality traits are among the factors that may account for these differences. The current project investigated whether personality traits were associated with trajectories of cognitive decline, and whether the associations were different before and after dementia diagnosis. The data was analyzed using linear mixed effects regression. Across study aims is a focus on replicability and generalizability. Each question was addressed in four independent longitudinal studies (EAS, MAP, ROS, SATSA), then meta-analyzed, providing estimates of replicability. Results indicated that low neuroticism and high openness were associated with total cognitive function. We detected evidence for cognitive decline in all four samples, and openness was associated with decline post dementia diagnosis.