Progression from normal cognition to mild cognitive impairment in a diverse clinic-based and community-based elderly cohort

The Effect of Temporal Persistence of Loneliness on Dementia: A Longitudinal Analysis From the Hunter Community Study

OBJECTIVES

Loneliness is common and becoming a public health concern. Although there is the clear evidence of the variable effect of temporal differences in loneliness (transient/situational and persistent/chronic) on health, their effect on dementia risk is unclear. This study aims to assess the effect of transient/situational and persistent/chronic loneliness on dementia risk.

METHOD

Participants aged 55 years and older from the Hunter Community Study were recruited. Loneliness was measured using a single item measure. Dementia was defined as per International Classification of Disease-10 (ICD 10) codes. The Fine-Gray subdistribution hazard model was performed to calculate dementia risk.

RESULTS

Of 1968 total participants with mean age of 66 years, (3%) 57 developed dementia and (7%) 135 died over the mean follow up of 10 years. Both persistent/chronic and transient/situational loneliness significantly increased the risk of all cause dementia in adjusted models (HR 2.74, 95% CI 1.11-6.88, p 0.03 and HR 2.35, 95% CI 1.21-4.55, p 0.01 respectively) with mean time to event of 9.7 years. Feeling lonely below the age of 70 years elevated the risk of dementia in later life (HR 4.01, 95% CI 1.40-11.50, p 0.01).

CONCLUSIONS

Loneliness (both persistent/chronic and transient/situational) was associated with increased risk of all cause dementia, especially if loneliness was experienced before the age of 70 years. These results suggest that promoting coping strategies for loneliness especially in persons 70 years and younger may play a role in preventing dementia.

Modifiable risk factors for mild cognitive impairment among cognitively normal community-dwelling older adults: A systematic review and meta-analysis

Although numerous studies have investigated modifiable risk factors for mild cognitive impairment (MCI) among community-dwelling seniors, no meta-analysis has summarized these findings. Five databases were searched from January 1, 2000, to December 30, 2023. The protocol was registered with PROSPERO. Data were extracted and reported following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant meta-analyses of modifiable risk factors were performed. The evidence of each factor was assessed by the GRADE for cohort studies. Of 16,651 citations, 87 studies involving 225,584 community-dwelling seniors were included. Fourteen meta-analyses involving 20 studies with 44,199 participants were performed. The analyses revealed low-to-moderate-quality evidence supporting that diabetes, 2 or more comorbidities, anxiety, apathy, depressive symptoms, and physical frailty were risk factors for incident MCI in older adults. Conversely, hypertension, agitation, and irritability might not be risk factors. Additionally, moderate-quality evidence supports the protective effect of engaging in cognitive-demanding activities on the onset of MCI. Collectively, this study constitutes the first extensive compilation of evidence regarding the various risk factors for the development of MCI in older adults. Our findings hold significant potential to guide the formulation of prevention and management strategies to either prevent or potentially reverse the onset of MCI.

Prevalence of and Annual Conversion Rates to Mild Cognitive Impairment and Dementia: Prospective, Longitudinal Study of an Essential Tremor Cohort

OBJECTIVE

Despite recent attention to cognitive impairment in essential tremor, few studies examine rates of conversion to diagnoses of mild cognitive impairment and dementia. Development of dementia in essential tremor is associated with loss of functional ability and a doubling of mortality rate. This prospective, longitudinal study comprehensively reports the prevalence and incidence of, and the annual rates of conversion to, mild cognitive impairment and dementia in an essential tremor cohort.

METHODS

Patients underwent detailed cognitive assessments and were assigned diagnoses of normal cognition, mild cognitive impairment, or dementia. There were 222 patients at baseline (mean age = 79.3 ± 9.7 years), and 177 patients participated in follow-up evaluations at 18, 36, 54, and 72 months (mean years of observation = 5.1 ± 1.7). Data were compared to those of historical controls and Parkinson disease patients.

RESULTS

The cumulative prevalence of dementia and average annual conversion rate of mild cognitive impairment to dementia were 18.5% and 12.2%, nearly three times higher than rates in the general population, and approximately one half the magnitude of those reported for Parkinson disease patients. The cumulative prevalence of mild cognitive impairment (26.6%) was almost double that of the general population, but less than that in Parkinson disease populations.

INTERPRETATION

We present the most complete exposition of the longitudinal trajectory of cognitive impairment in an essential tremor cohort yet presented. The prevalence of and conversion rates to dementia in essential tremor fall between those associated with the natural course of aging and the more pronounced rates observed in Parkinson disease. ANN NEUROL 2024;95:1193-1204.

Psychometric Evaluation of a Tablet-Based Tool to Detect Mild Cognitive Impairment in Older Adults: Mixed Methods Study

BACKGROUND

With the rapid aging of the global population, the prevalence of mild cognitive impairment (MCI) and dementia is anticipated to surge worldwide. MCI serves as an intermediary stage between normal aging and dementia, necessitating more sensitive and effective screening tools for early identification and intervention. The BrainFx SCREEN is a novel digital tool designed to assess cognitive impairment. This study evaluated its efficacy as a screening tool for MCI in primary care settings, particularly in the context of an aging population and the growing integration of digital health solutions.

OBJECTIVE

The primary objective was to assess the validity, reliability, and applicability of the BrainFx SCREEN (hereafter, the SCREEN) for MCI screening in a primary care context. We conducted an exploratory study comparing the SCREEN with an established screening tool, the Quick Mild Cognitive Impairment (Qmci) screen.

METHODS

A concurrent mixed methods, prospective study using a quasi-experimental design was conducted with 147 participants from 5 primary care Family Health Teams (FHTs; characterized by multidisciplinary practice and capitated funding) across southwestern Ontario, Canada. Participants included health care practitioners, patients, and FHT administrative executives. Individuals aged ≥55 years with no history of MCI or diagnosis of dementia rostered in a participating FHT were eligible to participate. Participants were screened using both the SCREEN and Qmci. The study also incorporated the Geriatric Anxiety Scale-10 to assess general anxiety levels at each cognitive screening. The SCREEN's scoring was compared against that of the Qmci and the clinical judgment of health care professionals. Statistical analyses included sensitivity, specificity, internal consistency, and test-retest reliability assessments.

RESULTS

The study found that the SCREEN's longer administration time and complex scoring algorithm, which is proprietary and unavailable for independent analysis, presented challenges. Its internal consistency, indicated by a Cronbach α of 0.63, was below the acceptable threshold. The test-retest reliability also showed limitations, with moderate intraclass correlation coefficient (0.54) and inadequate κ (0.15) values. Sensitivity and specificity were consistent (63.25% and 74.07%, respectively) between cross-tabulation and discrepant analysis. In addition, the study faced limitations due to its demographic skew (96/147, 65.3% female, well-educated participants), the absence of a comprehensive gold standard for MCI diagnosis, and financial constraints limiting the inclusion of confirmatory neuropsychological testing.

CONCLUSIONS

The SCREEN, in its current form, does not meet the necessary criteria for an optimal MCI screening tool in primary care settings, primarily due to its longer administration time and lower reliability. As the number of digital health technologies increases and evolves, further testing and refinement of tools such as the SCREEN are essential to ensure their efficacy and reliability in real-world clinical settings. This study advocates for continued research in this rapidly advancing field to better serve the aging population.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/25520.

Development and validation of cognitive ageing risk score (CARS) for early detection of subtle cognitive deficits in older people

BACKGROUND

Early cognitive deficits commonly seen in older people have not been well defined and managed in primary care. The objectives are (1) to develop and validate a new risk score to estimate the risk of dementia in Chinese older population; and (2) to evaluate the use of risk score in conjunction with cognitive screening in detecting early cognitive deficits in community older people.

METHODS

A development cohort of 306 cognitive healthy older adults aged 60 or above were followed for 6 years. A CARS was constructed using the estimated coefficients of risk factors associated with dementia at follow up. Validation was carried out in another five-year cohort of 383 older adults. The usefulness of CARS in detecting early cognitive deficits was evaluated.

RESULTS

Risk factors include older age, male gender, low level of education, poorly controlled diabetes, prolonged sleep latency, fewer mind body or light exercise, loneliness, and being apolipoprotein e4 carriers. A cutoff of CARS at -1.3 had a sensitivity of 83.9% and a specificity of 75.4% to predict dementia. The area under curve was 82.5% in the development cohort. Early cognitive deficits were characterized by impaired retention (p <.001, 95% CI 0.2-0.9) and attention (p =.012, 95% CI 0.1-0.8).

CONCLUSION

The CARS can be used as a standard risk assessment of dementia or in conjunction with a computerized cognitive screening to evaluate a full cognitive profile for detecting early cognitive deficits. The result put forward the integration of risk algorithm into smart healthcare system to provide personalized lifestyle interventions.

Estimating Dementia Onset: AT(N) Profiles and Predictive Modeling in Mild Cognitive Impairment Patients

BACKGROUND

Mild Cognitive Impairment (MCI) usually precedes the symptomatic phase of dementia and constitutes a window of opportunities for preventive therapies.

OBJECTIVES

The objective of this study was to predict the time an MCI patient has left to reach dementia and obtain the most likely natural history in the progression of MCI towards dementia.

METHODS

This study was conducted on 633 MCI patients and 145 subjects with dementia through 4726 visits over 15 years from Alzheimer Disease Neuroimaging Initiative (ADNI) cohort. A combination of data from AT(N) profiles at baseline and longitudinal predictive modeling was applied. A data-driven approach was proposed for categorical diagnosis prediction and timeline estimation of cognitive decline progression, which combined supervised and unsupervised learning techniques.

RESULTS

A reduced vector of only neuropsychological measures was selected for training the models. At baseline, this approach had high performance in detecting subjects at high risk of converting from MCI to dementia in the coming years. Furthermore, a Disease Progression Model (DPM) was built and also verified using three metrics. As a result of the DPM focused on the studied population, it was inferred that amyloid pathology (A+) appears about 7 years before dementia, and tau pathology (T+) and neurodegeneration (N+) occur almost simultaneously, between 3 and 4 years before dementia. In addition, MCI-A+ subjects were shown to progress more rapidly to dementia compared to MCI-A- subjects.

CONCLUSION

Based on proposed natural histories and cross-sectional and longitudinal analysis of AD markers, the results indicated that only a single cerebrospinal fluid sample is necessary during the prodromal phase of AD. Prediction from MCI into dementia and its timeline can be achieved exclusively through neuropsychological measures.

Cognitive and functional evolution in older adults with and without intellectual disability using a multicomponent intervention: A prospective longitudinal study

BACKGROUND

The global population is experiencing accelerated biopsychosocial aging. Cognitive impairment is frequently associated with functional impairment in basic and instrumental daily living activities. To maintain optimal cognitive and functional functioning, health professionals recommend that older adults participate in cognitive training.

AIMS

This study examines the cognitive and functional evolution of older adults with and without Intellectual Disability and the factors associated with favourable evolution following the intervention of a multicomponent programme based on the human occupational model and the person-centred care model.

METHODS AND PROCEDURES

247 people participated. Descriptive and univariate analyses were performed to examine baseline data. The Wilcoxon paired samples test was used to compare cognitive and functional evolution one year after the intervention. Linear regression was used to detect factors predicting favourable evolution.

OUTCOMES AND RESULTS

Both populations improved cognitively. There was no change in basic activities of daily living. There was an improvement in instrumental activities of daily living in the group with Intellectual Disability. None of the variables collected was a predictor of greater improvement.

CONCLUSIONS AND IMPLICATIONS

This study demonstrated that older people with Intellectual Disability who have supports to cope with this life stage can improve their cognitive and functional abilities.

Stress, depression, and risk of dementia - a cohort study in the total population between 18 and 65 years old in Region Stockholm

BACKGROUND

Chronic stress and depression are potential risk factors for mild cognitive impairment and dementia, including Alzheimer disease. The aim was to investigate whether any such risk is additive.

METHODS

Cohort study including 1 362 548 people (665 997 women, 696 551 men) with records in the Region Stockholm administrative healthcare database (VAL). Exposure was a recorded ICD-10 diagnosis of chronic stress, depression, or both, recorded in 2012 or 2013. Outcome was a diagnosis of Alzheimer disease, other dementia, or mild cognitive impairment recorded from 2014 through 2022. Odds ratios with 99% confidence intervals (CI) adjusted for age, sex, neighborhood socioeconomic status, diabetes, and cardiovascular disorders were calculated.

RESULTS

During the exposure period, 4 346 patients were diagnosed with chronic stress, 40 101 with depression, and 1 898 with both. The average age at baseline was around 40 years in all groups. In the fully adjusted model, the odds ratio of Alzheimer disease was 2.45 (99% CI 1.22-4.91) in patients with chronic stress, 2.32 (99% CI 1.85-2.90) in patients with depression, and 4.00 (99% CI 1.67-9.58) in patients with chronic stress and depression. The odds ratio of mild cognitive impairment was 1.87 (99% CI 1.20-2.91) in patients with chronic stress, 2.85 (99% CI 2.53-3.22) in patients with depression, and 3.87 (99% CI 2.39-6.27) in patients with both. When other dementia was analyzed, the odds ratio was significant only in patients with depression, 2.39 (99% CI 1.92-2.96).

CONCLUSIONS

Documented chronic stress increased the risk of mild cognitive impairment and Alzheimer disease. The same was seen with depression. The novel finding is the potential additive effect of chronic stress to depression, on risk of MCI and AD.

Primary outcome from the augmenting cognitive training in older adults study (ACT): A tDCS and cognitive training randomized clinical trial

BACKGROUND

There is a need for effective interventions to stave off cognitive decline in older adults. Cognitive training has variably produced gains in untrained tasks and daily functioning. Combining cognitive training with transcranial direct current stimulation (tDCS) may augment cognitive training effects; however, this approach has yet to be tested on a large-scale.

OBJECTIVE

This paper will present the primary findings of the Augmenting Cognitive Training in Older Adults (ACT) clinical trial. We hypothesize that receiving active stimulation with cognitive training will result in greater improvements on an untrained fluid cognition composite compared to sham following intervention.

METHODS

379 older adults were randomized, and 334 were included in intent-to-treat analyses for a 12-week multidomain cognitive training and tDCS intervention. Active or sham tDCS was administered at F3/F4 during cognitive training daily for two weeks then weekly for 10 weeks. To assess the tDCS effect, we fitted regression models for changes in NIH Toolbox Fluid Cognition Composite scores immediately following intervention and one year from baseline controlling for covariates and baseline scores.

RESULTS

Across the entire sample, there were improvements in NIH Toolbox Fluid Cognition Composite scores immediately post-intervention and one year following baseline; however, there were no significant tDCS group effects at either timepoint.

CONCLUSIONS

The ACT study models rigorous, safe administration of a combined tDCS and cognitive training intervention in a large sample of older adults. Despite potential evidence of near-transfer effects, we failed to demonstrate an additive benefit of active stimulation. Future analyses will continue to assess the intervention's efficacy by examining additional measures of cognition, functioning, mood, and neural markers.

Representativeness of samples enrolled in Alzheimer's disease research centers

To generalize findings on the mechanisms and prognosis in Alzheimer's disease and related dementias (ADRD), it is critical for ADRD research to be representative of the population. Sociodemographic and health characteristics across ethnoracial groups included in the National Alzheimer's Coordinating Center sample (NACC) were compared to the nationally representative Health and Retirement Study (HRS).

Baseline NACC data (n = 36,639) and the weighted 2010 HRS wave (N = 52,071,840) were included. We assessed covariate balance by calculating standardized mean differences across harmonized covariates (i.e., sociodemographic, health).

NACC participants were older, more educated, with worse subjective memory and hearing, but endorsed fewer depressive symptoms compared to HRS participants. While all racial and ethnic groups in NACC differed from HRS participants in the same way overall, these differences were further amplified between racial and ethnic groups.

NACC participants do not represent the U.S. population in key demographic and health factors, which differed by race and ethnicity.

HIGHLIGHTS

We examined selection factors included in NACC studies compared to a nationally representative sample.Selection factors included demographic and health factors and self-reported memory concerns.Results suggest that NACC participants are not representative of the U.S. population.Importantly, selection factors differed across racial and ethnic groups.Findings are suggestive of selection bias within NACC studies.

Cognitive Impairment and the Associated Factors Among Older People in Rural Central Tanzania

AIM

This study examined the profile of cognitive impairment and associated factors among older people in rural central Tanzania.

METHODS

We conducted a cross-sectional study involving 462 community-dwelling older adults. We performed cognitive, psychosocial, and clinical assessments and face-to-face interviews with all older adults. Descriptive, bivariate and multivariate linear regression analyses were performed to determine the participant's cognitive performance and the associated factors.

RESULTS

The mean cognitive score on the Identification and Intervention for Dementia in Elderly Africans cognitive test was 11.04 (SD=2.89). Per the proposed cut-off scores to define probable and possible dementia, 13.2% of the population had probable dementia and another 13.9% had possible dementia. Increase in age was associated with poor cognitive performance (β=-0.076, 95% CI=-0.109 to -0.043, P<0.001); whereas male sex (β=0.989, 95% CI=0.333 to 1.645, P=0.003), higher educational attainment (β=2.575, 95% CI=0.557 to 4.594, P=0.013) and performance in instrumental activities of daily living (β=0.552, 95% CI=0.376 to 0.729, P<0.001) were associated with higher cognitive performance.

DISCUSSION

Older people in rural settings of central Tanzania have poor cognitive functions and are at high risk of further cognitive decline. Preventive and therapeutic programs for the affected older people are warranted to prevent further decline and maintain quality of life.

Classification and prediction of cognitive trajectories of cognitively unimpaired individuals

Objectives

Efforts to prevent Alzheimer's disease (AD) would benefit from identifying cognitively unimpaired (CU) individuals who are liable to progress to cognitive impairment. Therefore, we aimed to develop a model to predict cognitive decline among CU individuals in two independent cohorts.

Methods

A total of 407 CU individuals from the Alzheimer's Disease Neuroimaging Initiative (ADNI) and 285 CU individuals from the Samsung Medical Center (SMC) were recruited in this study. We assessed cognitive outcomes by using neuropsychological composite scores in the ADNI and SMC cohorts. We performed latent growth mixture modeling and developed the predictive model.

Results

Growth mixture modeling identified 13.8 and 13.0% of CU individuals in the ADNI and SMC cohorts, respectively, as the "declining group." In the ADNI cohort, multivariable logistic regression modeling showed that increased amyloid-β (Aβ) uptake (β [SE]: 4.852 [0.862], p < 0.001), low baseline cognitive composite scores (β [SE]: -0.274 [0.070], p < 0.001), and reduced hippocampal volume (β [SE]: -0.952 [0.302], p = 0.002) were predictive of cognitive decline. In the SMC cohort, increased Aβ uptake (β [SE]: 2.007 [0.549], p < 0.001) and low baseline cognitive composite scores (β [SE]: -4.464 [0.758], p < 0.001) predicted cognitive decline. Finally, predictive models of cognitive decline showed good to excellent discrimination and calibration capabilities (C-statistic = 0.85 for the ADNI model and 0.94 for the SMC model).

Conclusion

Our study provides novel insights into the cognitive trajectories of CU individuals. Furthermore, the predictive model can facilitate the classification of CU individuals in future primary prevention trials.

A systematic review and meta-analysis of the prevalence and correlation of mild cognitive impairment in sarcopenia

Sarcopenia is a progressive skeletal muscle disorder involving the loss of muscle mass and function, associated with an increased risk of disability and frailty. Though its prevalence in dementia has been studied, its occurrence in mild cognitive impairment (MCI) has not been well established. As MCI is often a prelude to dementia, our study aims to investigate the prevalence of MCI among individuals with sarcopenia and to also ascertain whether sarcopenia is independently associated with MCI. The Cochrane Library, PubMed, Ovid, Embase and Web of Science were systematically searched for articles on MCI and/or sarcopenia published from inception to 1 February 2022. We reviewed the available literature on the number of individuals with MCI and/or sarcopenia and calculated odds ratios (ORs) of sarcopenia in MCI and MCI in sarcopenia, respectively. Statistical analyses were performed using the meta package in Stata, Version 12.0. A total of 13 studies and 27 428 patients were included in our analysis. The pooled prevalence of MCI in participants with sarcopenia was 20.5% (95% confidence interval [CI]: 0.140-0.269) in a total sample of 2923 cases with a high level of heterogeneity (P < 0.001; I²  = 95.4%). The overall prevalence of sarcopenia with MCI was 9.1% (95% CI: 0.047-0.134, P < 0.001; I²  = 93.0%). For overall ORs, there were 23 364 subjects with a mean age of 73 years; the overall adjusted OR between MCI and sarcopenia was 1.46 (95% CI: 1.31-1.62). Slight heterogeneity in both adjusted ORs (P = 0.46; I²  = 0%) was noted across the studies. The prevalence of MCI is relatively high in patients with sarcopenia, and sarcopenia may be a risk factor for MCI.

Subjective Functional Difficulties and Subjective Cognitive Decline in Older-Age Adults: Moderation by Age Cohorts and Mediation by Mentally Unhealthy Days

Background and Objectives: Despite the expected positive association between subjective functional difficulties (SFD) and subjective cognitive decline (SCD), their mediation by mentally unhealthy days (MUDs) is under-studied. Moreover, few SCD studies have examined affective reactivity to functional difficulties by age cohort. This study examined the mediation effect of MUDs on the association between SFD and SCD by age cohorts' moderation among older adults. Methods: Using a cross-sectional design approach, we used the 2019 BRFSS dataset on 13,377 older adults aged 65 to ≥80 (44% males and 56% females). Results: The bias-corrected percentile bootstrap with 5000 samplings revealed that MUDs partially mediate the relationship between SFD and SCD (14.12% mediation effect), controlling depressive symptoms, education, income levels, and race. Age cohorts moderated the relationship between SFD and SCD and between SFD and SCD but not between MUDs and SCD. The predictive effects of the path from SFD to MUDs and from MUDs to SCD were stronger in the younger-old (65-69) than the middle-old (70-79) and oldest-old (≥80) age cohorts. Worse SCD was associated with being Asian, in female older adults, and in those with lower education and income levels. Conclusions: These findings extend the chronic stress theory predictions that accentuated emotional vulnerability to subjective functional difficulties may magnify SCD, particularly in the younger-old age group. By implication, preventive SCD interventions should seek to support younger-old adults in their activities of daily life for successful aging transitioning into older-age cohorts.

Comparison of Brain Amyloid Deposition and Cortical Glucose Metabolism Between Clinic- and Community-Based Cohort

BACKGROUND

The differences in positron emission tomography (PET) imaging among older adults with mild cognitive impairment (MCI), according to the recruitment source, remain unclear.

OBJECTIVE

To investigate the differences in brain amyloid deposition and cortical glucose metabolism according to recruitment source among older adults with MCI.

METHODS

Participants in the clinic-based MCI cohort, who were referred to Oita University Hospital for cognitive decline, consisted of 90 adults with MCI. The community-based MCI cohort, which participated in a prospective cohort study, consisted of 118 adults with MCI. Participants underwent cognitive function evaluation, 11C-Pittsburgh compound B (PiB)-PET, and 18F-fluorodeoxyglucose (FDG)-PET. The prevalence of amyloid positivity and mean PiB and FDG uptake values were compared between the cohorts. Moreover, a voxel-by-voxel group study was performed to determine the areas with significant differences between the clinic- and community-based MCI cohorts.

RESULTS

The prevalence of amyloid positivity and mean PiB uptake value in the clinic-based MCI cohort were significantly higher than those in the community-based MCI cohort (p < 0.001 and p < 0.001, respectively). The mean FDG uptake value in the clinic-based MCI cohort was significantly lower than that in the community-based MCI cohort (p < 0.001). SPM 8 analysis showed significantly increased PiB uptake in the precuneus and parietotemporal lobe and significantly decreased FDG uptake in the posterior cingulate in the clinic-based MCI cohort compared to the community-based MCI cohort.

CONCLUSION

The prevalence and severity of amyloid pathology in older adults with MCI varied depending on the recruitment source.

Machine learning based multi-modal prediction of future decline toward Alzheimer's disease: An empirical study

Alzheimer's disease (AD) is a neurodegenerative condition that progresses over decades. Early detection of individuals at high risk of future progression toward AD is likely to be of critical significance for the successful treatment and/or prevention of this devastating disease. In this paper, we present an empirical study to characterize how predictable an individual subjects' future AD trajectory is, several years in advance, based on rich multi-modal data, and using modern deep learning methods. Crucially, the machine learning strategy we propose can handle different future time horizons and can be trained with heterogeneous data that exhibit missingness and non-uniform follow-up visit times. Our experiments demonstrate that our strategy yields predictions that are more accurate than a model trained on a single time horizon (e.g. 3 years), which is common practice in prior literature. We also provide a comparison between linear and nonlinear models, verifying the well-established insight that the latter can offer a boost in performance. Our results also confirm that predicting future decline for cognitively normal (CN) individuals is more challenging than for individuals with mild cognitive impairment (MCI). Intriguingly, however, we discover that prediction accuracy decreases with increasing time horizon for CN subjects, but the trend is in the opposite direction for MCI subjects. Additionally, we quantify the contribution of different data types in prediction, which yields novel insights into the utility of different biomarkers. We find that molecular biomarkers are not as helpful for CN individuals as they are for MCI individuals, whereas magnetic resonance imaging biomarkers (hippocampus volume, specifically) offer a significant boost in prediction accuracy for CN individuals. Finally, we show how our model's prediction reveals the evolution of individual-level progression risk over a five-year time horizon. Our code is available at https://github.com/batuhankmkaraman/mlbasedad.

Rhythmic Physical Activity and Global Cognition in Older Adults with and without Mild Cognitive Impairment: A Systematic Review

Growing evidence suggests that rhythmic physical activity (PA) improves cognitive function in both persons with normal brain aging and with cognitive impairment. This study aims to conduct a systematic review of randomized controlled trials assessing the effects of rhythmic PA over global cognition in older adults with and without mild cognitive impairment. Different keywords related to the topic and Boolean operators were used in the Web of Science, PubMed, and Scopus databases. A total of 11 articles that met the inclusion criteria were analyzed; all of them assessed global cognition using either the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA) or the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Five studies showed beneficial effects over global cognition. All studies had at least one experimental group with rhythmic training, and the interventions evidenced a great diversity of rhythmic stimuli, as well as a varied frequency, duration and type of activities. The heterogeneity of the protocols could be the reason for the mixed findings. Future studies with more precise exercise prescriptions are needed to establish whether rhythmic PA has beneficial effects on global cognition.

High-Density Lipoprotein Changes in Alzheimer's Disease Are APOE Genotype-Specific

High-density lipoproteins (HDL) play a critical role in cholesterol homeostasis. Apolipoprotein E (APOE), particularly the E4 allele, is a significant risk factor for Alzheimer's disease but is also a key HDL-associated protein involved in lipid transport in both the periphery and central nervous systems. The objective was to determine the influence of the APOE genotype on HDL function and size in the context of Alzheimer's disease. HDL from 194 participants (non-demented controls, mild cognitive impairment, and Alzheimer's disease dementia) were isolated from the plasma. The HDL cholesterol efflux capacity (CEC), lecithin-cholesterol acyltransferase (LCAT) activity, and particle diameter were measured. Neuropsychological test scores, clinical dementia rating, and magnetic resonance imaging scores were used to determine if cognition is associated with HDL function and size. HDL CEC and LCAT activity were reduced in APOE3E4 carriers compared to APOE3E3 carriers, regardless of diagnosis. In APOE3E3 carriers, CEC and LCAT activity were lower in patients. In APOE3E4 patients, the average particle size was lower. HDL LCAT activity and particle size were positively correlated with the neuropsychological scores and negatively correlated with the clinical dementia rating. We provide evidence for the first time of APOE genotype-specific alterations in HDL particles in Alzheimer's disease and an association between HDL function, size, and cognitive function.

Categorical predictive and disease progression modeling in the early stage of Alzheimer's disease

BACKGROUND

A preclinical stage of Alzheimer's disease (AD) precedes the symptomatic phases of mild cognitive impairment (MCI) and dementia, which constitutes a window of opportunities for preventive therapies or delaying dementia onset.

NEW METHOD

We propose to use categorical predictive models based on survival analysis with longitudinal data which are capable of determining subsets of markers to classify cognitively unimpaired (CU) subjects who progress into MCI/dementia or not. Subsequently, the proposed combination of markers was used to construct disease progression models (DPMs), which reveal long-term pathological trajectories from short-term clinical data. The proposed methodology was applied to a population recruited by the ADNI.

RESULTS

A very small subset of standard MRI-based data, CSF markers and cognitive measures was used to predict CU-to-MCI/dementia progression. The longitudinal data of these selected markers were used to construct DPMs using the algorithms of growth models by alternating conditional expectation (GRACE) and the latent time joint mixed effects model (LTJMM). The results show that the natural history of the proposed cognitive decline classifies the subjects well according to the clinical groups and shows a moderate correlation between the conversion times and their estimates by the algorithms.

COMPARISON WITH EXISTING METHODS

Unlike the training of the DPM algorithms without preselection of the markers, here, it is proposed to construct and evaluate the DPMs using the subsets of markers defined by the categorical predictive models.

CONCLUSIONS

The estimates of the natural history of the proposed cognitive decline from GRACE were more robust than those using LTJMM. The transition from normal to cognitive decline is mostly associated with an increase in temporal atrophy, worsening of clinical scores and pTAU/Aβ. Furthermore, pTAU/Aβ, Everyday Cognition score and the normalized volume of the entorhinal cortex show alterations of more than 20% fifteen years before the onset of cognitive decline.

Characterizing Cognition in Everyday Life of Older Adults With Subjective Cognitive Decline

Subjective cognitive decline (SCD), the subjective experience of worsening cognition with no objective cognitive impairment, poses a heightened risk for dementia. This study aimed to characterize cognition in the everyday life of people with SCD, is crucial for understanding and preventing further functional and cognitive decline. One hundred and thirty-five older adults (age 70.7±6.7) with SCD were assessed using functional-cognition measures: Multifactorial Memory Questionnaire (MMQ), Behavior Rating Inventory of Executive Function–Adult version (BRIEF-A), and Multiple Errands Test (MET). The resulted showed that older adults with SCD reported lower memory satisfaction (Hedges’s g = 0.41) on the MMQ, and worse metacognition on the BRIEF-A (Hedges’s g = 0.63) compared with published normative data. They completed an average of only 6/12 required tasks on the MET. The findings show functional difficulties related to SCD and inform the development of occupational therapy intervention for this population.

A Systematic review of smartphone and tablet use by older adults with and without cognitive impairment

Background and Objectives

A systematic review was conducted to explore the use of smartphones and tablet computers as cognitive and memory aids by older adults with and without cognitive impairment, specifically the effects of smartphone and tablet use on participants’ cognition and memory, and the barriers and facilitators to smartphone and tablet use for cognitive and memory support.

Research Design and Methods

A systematic search of 6 key databases found 11,895 citations published between 2010 and 2021. Studies were included if they involved community-dwelling older adults with or without cognitive impairment arising from acquired brain injury, mild cognitive impairment, or dementia, and if they evaluated everyday smartphone or tablet device use for cognition, memory, or activities of daily living.

Results

A total of 28 papers were included in the narrative synthesis. There was some evidence that the use of smartphones and tablets could aid cognitive function in older adults without cognitive impairment, particularly executive function and processing speed. There was modest evidence that smartphone and tablet use could support memory in both older adults without cognitive impairment and those with acquired brain injury and dementia.

Discussion and Implications

Smartphones and tablets were seen by users as acceptable, enjoyable, and nonstigmatizing alternatives to conventional assistive technology devices; however, current use of smartphone and tablet devices is hindered by the digital literacy of older adults, a lack of accommodation for older adult users’ motor and sensory impairments, and a lack of input from clinicians and researchers. Much of the evidence presented in this review derives from case studies and small-scale trials of smartphone and tablet training interventions. Further research is needed into older adults’ use of smartphones and tablets for cognitive support before and after the onset of cognitive impairment in order to develop effective evidence-based smart technology cognition and memory aids.

Automated Classification of Normal Control and Early-Stage Dementia Based on Activities of Daily Living (ADL) Data Acquired from Smart Home Environment

With the global trend toward an aging population, the increasing number of dementia patients and elderly living alone has emerged as a serious social issue in South Korea. The assessment of activities of daily living (ADL) is essential for diagnosing dementia. However, since the assessment is based on the ADL questionnaire, it relies on subjective judgment and lacks objectivity. Seven healthy seniors and six with early-stage dementia participated in the study to obtain ADL data. The derived ADL features were generated by smart home sensors. Statistical methods and machine learning techniques were employed to develop a model for auto-classifying the normal controls and early-stage dementia patients. The proposed approach verified the developed model as an objective ADL evaluation tool for the diagnosis of dementia. A random forest algorithm was used to compare a personalized model and a non-personalized model. The comparison result verified that the accuracy (91.20%) of the personalized model was higher than that (84.54%) of the non-personalized model. This indicates that the cognitive ability-based personalization showed encouraging performance in the classification of normal control and early-stage dementia and it is expected that the findings of this study will serve as important basic data for the objective diagnosis of dementia.

Effectiveness of psychosocial interventions among older adults with mild cognitive impairment: a systematic review and meta-analysis

OBJECTIVES

This review aimed to examine available evidence concerning the effectiveness of psychosocial interventions in improving memory, executive function, depression and activities of daily living (ADL) in older adults with MCI.

METHODS

Eight electronic databases were used to conduct a comprehensive literature search for published and unpublished studies. A primary outcome was cognitive function, including memory and executive function. Secondary outcomes were depression and ADL. Two researchers independently appraised quality of included studies and extracted data. Meta-analysis, heterogeneity test, subgroup analysis and sensitivity analyses were performed.

RESULTS

Ten studies (out of 1,265 records) were included in this review. Psychosocial interventions contributed to a significant improvement in memory, not executive function, depression and ADL. Subgroup analyses suggested that interventions with a longer duration, more therapeutic sessions, and individual format had larger effect sizes. Strategies found to enhance memory entailed behavior modification and activation, memory training, visual imagery, storytelling, memory aids, journaling, and exercise.

CONCLUSION

Healthcare providers may offer psychosocial interventions to client with MCI in clinical settings. Higher quality trials should be conducted to increase solid evidence in this domain.

Compensatory and Lifestyle-Based Brain Health Program for Subjective Cognitive Decline: Self-Implementation versus Coaching

Although recent studies have explored the potential of multidomain brain health programs, there is a dearth of literature on operationalizing this research to create a clinical treatment program specifically for subjective cognitive decline (SCD). Patients seen by geriatricians in primary care and by behavioral neurology services at our institution presenting with SCD were recruited via a patient-appropriate flyer. After all participants had a 1-h brain health consultation with a neuropsychologist and were provided with program materials, they were randomized to attend a 10-week intervention designed to support program implementation (N = 10) or the control group of implementing the program on their own (N = 11). The program included (1) a calendar-based executive and memory support system for compensatory training and (2) training in healthy lifestyle. There were no significant differences between groups for any outcomes. Participants across both groups showed significant improvements with moderate effect sizes in compensatory strategy use, anxiety symptoms, and daily functioning, which were sustained through 6-month follow-up. They also increased physical activity by the end of the intervention period but did not sustain this through 6-month follow-up. Our pilot study demonstrates preliminary feasibility of a cognitive compensatory and lifestyle-based brain health program. Additional research is recommended to further develop two potentially scalable implementation strategies—coaching and self-implementation after brief consultation.

The Impact of Study Setting on Clinical Characteristics in Older Chinese Adults with Subjective Cognitive Decline: Baseline Investigation of Convenience and Population-Based Samples

Background

Subjective cognitive decline (SCD) is the earliest symptom stage of Alzheimer's disease (AD). Previous studies have shown that the study setting is an important influence factor of SCD. However, the effect of this factor among a Chinese population with SCD is not clear. Here, we aim to compare the clinical characteristics of SCD between a convenience and a population-based sample in China.

Methods

We included a convenience sample of 212 SCD subjects and a population-based sample of 110 SCD subjects. We performed univariate analysis to evaluate the between-group differences in sociodemographic characteristics, neuropsychological performance, psychiatric conditions, different cognitive domains, and the SCD-plus criteria. Multiple linear regression model was established, adjusted for sex, age, and education, and compared the neuropsychological performance between the groups.

Results

The convenience sample had more years of education, a higher family history of dementia, and higher neuropsychological and anxiety depression score than the population-based sample. Using sex, age, education, group as the independent variables, and neuropsychological score as the dependent variable, multiple linear regression model was established; a statistically significant neuropsychological score difference (MoCA-B, AVLT-H-N4, AVLT-H-N5, AVLT-H-N7, AFT, and STT-B) was found between the two samples. In the SCD cognitive domains, the population-based sample had more complaints about declines in their language and planning domains. For SCD-plus criteria in memory domain, the convenience sample had more complaints, worry, and cognitive decline within the last 5 years, along with medical help-seeking.

Conclusion

There were some different characteristics among SCD individuals between convenience samples and population-based samples in China.

Use of in-home activity monitoring technologies in older adult veterans with mild cognitive impairment: The impact of attitudes and cognition

BACKGROUND

As researchers incorporate in-home technologies to identify and track changes in older adults' cognitive and daily functioning that could lead to early interventions, the attitudes of older adults across the continuum from normal cognitive aging to mild cognitive impairment (MCI) must be assessed to ensure technology adoption and adherence in each unique group.

OBJECTIVE

This exploratory pilot study incorporated both quantitative and qualitative approaches to examine mild cognitive impairment (MCI) and cognitively intact older adults' attitudes (i.e., usability, acceptability, digital readiness, barriers) and adherence to in-home technologies after undergoing 7 months of in-home activity monitoring.

METHOD

Participants were 30 older adult veterans who were classified as cognitively intact (n = 15) or having mild cognitive impairment (MCI) (n = 15) and participated in a longitudinal aging and technology study that monitored their physical activity and computer use.

RESULTS

While MCI older adults endorsed reduced digital readiness (p =.041) and required more in-home technology maintenance visits (p =.041) from staff as compared to cognitively intact older adults, there was no difference in adherence to the study technology (p >.05). Usability and acceptability attitudes in the entire sample predicted adherence to the physical activity monitoring technology employed in the study (p =.008).

CONCLUSION

Findings highlight the potential gap between technology developers and older adult end users, and technologies designed specifically for older adults with MCI should be developed with direct input from older adults with MCI to promote usability and long-term adoption in this clinical population. Larger studies are needed to replicate and increase the generalizability of the current findings.

Functional Differences Found in the Elderly Living in the Community

Introduction: Successful aging lies in cognitive and functional maintenance, and in the optimal performance of daily tasks that keep the elderly free of disability and dependence. However, there is little evidence for functional differences for gender and age, and how cognitive and physical demands in past working lives can affect them, to design more personalized occupational therapy interventions to prevent functional and cognitive impairment. Method: This observational descriptive study evaluated 367 older adults living in a community with subjective memory complaints and scored between 24 and 35 with the Spanish version of the “Mini-Mental State Examination (MEC-35)”. Basic activities of daily living (BADL) were studied with the Barthel Index, while instrumental ADL (IADL) were examined with the Lawton–Brody scale. Functional differences for gender, age, and physico-mental occupation were examined. Results: The significant differences found for gender indicated that men did better in BADL (p = 0.026) and women better performed IADL (p < 0.001). Differences between age groups suggest that the younger group (aged 64–75) obtained better results for BADL (p = 0.001) and IADL (p < 0.001). For physico-mental occupation, statistically significant differences were found only in IADL for mental (p = 0.034) and physical occupation (p = 0.005). Conclusions: Gender, age, and the cognitive and physical demands of occupational stages, can be important predictors of cognitive and functional impairment. These results can be generalized to other health centers in the province and to other Spanish Autonomous Communities because their socio-demographic variables are similar. It would be interesting to carry out multimodal personalized interventions that consider the factors that might affect functional impairment to preserve personal autonomy.

Occupational performance issues in older adults with subjective cognitive decline

PURPOSE

To describe and categorize difficulties in daily activities of older adults with subjective cognitive decline (SCD) compared to individuals with mild cognitive impairment (MCI).

METHODS

Deductive quantitative content analysis was used to classify reported issues in the performance of meaningful daily activities, in older adults with SCD (n = 67; age= 70 ± 6.3) or MCI (n = 42; age= 72 ± 6.6). The occupational performance issues were identified using the Canadian Occupational Performance Measure, a semi-structured interview, and categorised using the International Classification of Functioning, Disability and Health (ICF).

RESULTS

Both groups identified issues in all nine ICF "Activities and Participation" domains, with no significant group effects on seven of them. The most frequently affected "Activities and Participation" domains in both groups were "Self-care" (e.g. exercise and diet); "Community, social and civic life" (e.g. social-leisure activities); and "General tasks and demands" (e.g. time management). Over 90% of the issues in both groups were described in the context of difficulties in "Mental functions" (e.g. memory and higher-level cognitive functions).

CONCLUSIONS

Older adults with SCD, although independent, identified a variety of daily activities that they are not performing satisfactorily, remarkably similar in nature to the occupational performance issues described by older adults with MCI.Implications for RehabilitationOlder adults with SCD identified difficulties in performing social and leisure activities, maintaining healthy lifestyle behaviours, and managing multiple daily tasks.The daily challenges described by older adults with SCD are similar in nature to those identified by those with MCI.Older adults with SCD and MCI describe their daily challenges are related not only to memory problems, but also to executive dysfunction.Interventions for older adults with SCD should aim to improve self-identified problems in everyday functioning.

Amyloid Plaques and Symptoms of Depression Links to Medical Help-Seeking due to Subjective Cognitive Decline

Background:

Subjective cognitive decline (SCD) is associated with an increased risk of Alzheimer’s disease (AD). However, patients reporting SCD to their general practitioner are not always referred to a memory clinic.

Objective:

To investigate whether prior history of medical help-seeking is associated with AD biomarker abnormality, worse cognitive performance, and/or depressive symptoms in SCD.

Methods:

We compared levels of cerebrospinal fluid (CSF) Aβ_1 - 42, cognitive performance, and depressive symptoms (15-item Geriatric Depression Scale, GDS-15) between healthy controls (n = 88), SCD with a history of medical help seeking (SCD-HS, n = 67), and SCD non help-seekers (SCD-NHS, n = 44). Cases with evidence of amyloid plaques (CSF Aβ_1 - 42 ≤708 ng/l) and symptoms of depression (GDS-15≥6) were determined in both SCD groups.

Results:

The SCD-HS group had lower CSF Aβ_1 - 42 (p < 0.01), lower word list learning and memory recall (p < 0.0001), and an increased level of depressive symptoms (p < 0.0001) compared to controls and SCD-NHS cases. The SCD-HS group had more cases with symptoms of depression (n = 12, 18%) and amyloid plaques (n = 18, 27%) compared to SCD-NHS (n = 1, 2% and n = 7, 16%, respectively). None of the SCD-HS cases and only one SCD-NHS case had concurrent symptoms of depression and amyloid plaques. The SCD-HS cases showed equal word list learning and memory performance regardless of amyloid status or symptoms of depression.

Conclusion:

Medical help-seeking in SCD is associated with an increased risk of AD pathology or symptoms of depression. However, subtle memory deficits are seen in SCD help-seekers, also without amyloid plaques or symptoms of depression.

Early prevention of cognitive impairment in the community population: The Beijing Aging Brain Rejuvenation Initiative

Facing considerable challenges associated with aging and dementia, China urgently needs an evidence-based health-care system for prevention and management of dementia. The Beijing Aging Brain Rejuvenation Initiative (BABRI) is a community-based cohort study initiated in 2008 that focuses on asymptomatic stages of dementia, aims to develop community-based prevention strategies for cognitive impairment, and provides a platform for scientific research and clinical trials. Thus far, BABRI has recruited 10,255 participants (aged 50 and over, 60.3% female), 2021 of whom have been followed up at least once at a 2- or 3-year interval. This article presents aims and study design of BABRI; summarizes preliminary behavioral and neuroimaging findings on mild cognitive impairment (MCI) and results of clinical trials on MCI; and discusses issues concerning early prevention in community, MCI diagnosis methods, and applications of database of aging and dementia. BABRI is proposed to build a systematic framework on brain health in old age.

Disease progression modelling from preclinical Alzheimer's disease (AD) to AD dementia

To characterize the course of Alzheimer’s disease (AD) over a longer time interval, we aimed to construct a disease course model for the entire span of the disease using two separate cohorts ranging from preclinical AD to AD dementia. We modelled the progression course of 436 patients with AD continuum and investigated the effects of apolipoprotein E ε4 (APOE ε4) and sex on disease progression. To develop a model of progression from preclinical AD to AD dementia, we estimated Alzheimer’s Disease Assessment Scale-Cognitive Subscale 13 (ADAS-cog 13) scores. When calculated as the median of ADAS-cog 13 scores for each cohort, the estimated time from preclinical AD to MCI due to AD was 7.8 years and preclinical AD to AD dementia was 15.2 years. ADAS-cog 13 scores deteriorated most rapidly in women APOE ε4 carriers and most slowly in men APOE ε4 non-carriers (p < 0.001). Our results suggest that disease progression modelling from preclinical AD to AD dementia may help clinicians to estimate where patients are in the disease course and provide information on variation in the disease course by sex and APOE ε4 status.

Functional reserve: The residual variance in instrumental activities of daily living not explained by brain structure, cognition, and demographics

OBJECTIVE

Cognitive reserve is a concept that explains individual differences in resilience to brain pathology and susceptibility to poor late-life cognitive outcomes. We evaluate the analogous concept of "Functional Reserve," defined as the difference between observed functional abilities and those predicted by brain structure, cognitive performance, and demographics. This study aims to validate the construct of functional reserve by testing its utility in predicting clinical outcomes and exploring its predictors.

METHOD

Longitudinal data collected annually for up to 7 years from 1,084 older adults (ndementia = 163; nMCI = 333; nCN = 523) were analyzed. Functional reserve was operationalized as the residual variance in the Lawton-Brody Instrumental Activities of Daily Living (IADL) Scale after accounting for demographics (sex/gender, race, ethnicity, education), neuropathology (gray matter, hippocampal, and white matter hyperintensity volumes), and cognition (executive function, verbal episodic memory, semantic memory, and spatial function). Structural equation models estimated (a) functional reserve's associations with 7-year changes in clinical diagnosis and disease severity and (b) predictors of functional reserve.

RESULTS

Functional reserve was lower in dementia versus cognitively normal individuals. Higher baseline functional reserve was associated with lower concurrent dementia severity and slower clinical progression and attenuated the association of cognition with concurrent dementia severity. Physical function and apathy were the strongest predictors of functional reserve.

CONCLUSIONS

Results provide preliminary validation of functional reserve for explaining individual differences in susceptibility to IADL dysfunction independent of neuropathology, cognition, and demographics. Physical functioning and apathy are promising modifiable intervention targets to enhance functional reserve in the context of brain atrophy and cognitive decline. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Subtle executive deficits are associated with higher brain amyloid burden and lower cortical volume in subjective cognitive decline: the FACEHBI cohort

To determine whether lower performance on executive function tests in subjective cognitive decline (SCD) individuals are associated with higher levels of brain amyloid beta (Aβ) deposition and regional volumetric reduction in areas of interest for Alzheimer’s disease (AD). 195 individuals with SCD from the FACEHBI study were assessed with a neuropsychological battery that included the following nine executive function tests: Trail Making Test A and B (TMTA, TMTB), the Rule Shift Cards subtest of BADS, the Automatic Inhibition subtest of the Syndrom Kurz Test (AI-SKT), Digit Span Backwards and Similarities from WAIS-III, and the letter, semantic, and verb fluency tests. All subjects underwent an 18F-Florbetaben positron emission tomography (FBB-PET) scan to measure global standard uptake value ratio (SUVR), and a magnetic resonance imaging (MRI). A multiple regression analysis, adjusted for age, was carried out to explore the association between global SUVR and performance on executive tests. Then, on those tests significantly associated with amyloid burden, a voxel-based morphometry (VBM) analysis was carried out to explore their correlates with grey matter volume. Multiple regression analysis revealed a statistically significant association between Aβ deposition and performance on one of the executive tests (the AI-SKT). Moreover, VBM analysis showed worse AI-SKT scores were related to lower volume in bilateral hippocampus and left inferior frontal regions. In conclusion, in SCD individuals, worse automatic inhibition ability has been found related to higher cerebral Aβ deposition and lower volume in the hippocampus and frontal regions. Thus, our results may contribute to the early detection of AD in individuals with SCD.

Digital biomarker-based individualized prognosis for people at risk of dementia

Background

Research investigating treatments and interventions for cognitive decline fail due to difficulties in accurately recognizing behavioral signatures in the presymptomatic stages of the disease. For this validation study, we took our previously constructed digital biomarker‐based prognostic models and focused on generalizability and robustness of the models.

Method

We validated prognostic models characterizing subjects using digital biomarkers in a longitudinal, multi‐site, 40‐month prospective study collecting data in memory clinics, general practitioner offices, and home environments.

Results

Our models were able to accurately discriminate between healthy subjects and individuals at risk to progress to dementia within 3 years. The model was also able to differentiate between people with or without amyloid neuropathology and classify fast and slow cognitive decliners with a very good diagnostic performance.

Conclusion

Digital biomarker prognostic models can be a useful tool to assist large‐scale population screening for the early detection of cognitive impairment and patient monitoring over time.

Predictors of Quality of Life among Older People with Mild Cognitive Impairment Attending Urban Primary Care Clinics

OBJECTIVES

To study the prevalence of Mild Cognitive Impairment (MCI) among older people attending primary care clinics and its predictors of QOL.

METHODS

A cross-sectional study was conducted at two primary care clinics in Kuala Lumpur, Malaysia, recruiting 271 participants by utilizing the universal sampling method. Every patient who attended both the clinics during the study period and met the inclusion and exclusion criteria were approached and briefed about the study. Patients who gave consent were recruited as study participants. Information on sociodemographic, medical condition, and lifestyle behaviors were obtained. The Montreal Cognitive Assessment (MoCA) was used to screen for MCI at a score < 23. The World Health Organization Quality of Life-BREF (WHOQOL-BREF) questionnaire was used to evaluate QOL.

RESULTS

Prevalence of MCI was 27.3%. Lower QOL scores were found in the physical (67.3 ± 1.4), psychological (67.3 ± 1.4), social (66.9 ± 1.6) and environmental (71.3 ± 1.3) domains among participants with MCI. Among them, predictors of QOL were depression in the physical domain, age and stroke in the psychological domain, presence of other types of disorders in the social domain and diabetes and stroke in the environmental domain.

CONCLUSIONS

MCI was prevalent among study participants and were associated with poorer QOL in all domains of QOL. A better understanding of predictors of QOL in older people with MCI is deemed important.

CLINICAL IMPLICATION

Routine cognitive screening at primary care clinics will facilitate early recognition of MCI and facilitates referral to memory clinics for further assessment and treatment.

Feasibility of In-Home Sensor Monitoring to Detect Mild Cognitive Impairment in Aging Military Veterans: Prospective Observational Study

BACKGROUND

Aging military veterans are an important and growing population who are at an elevated risk for developing mild cognitive impairment (MCI) and Alzheimer dementia, which emerge insidiously and progress gradually. Traditional clinic-based assessments are administered infrequently, making these visits less ideal to capture the earliest signals of cognitive and daily functioning decline in older adults.

OBJECTIVE

This study aimed to evaluate the feasibility of a novel ecologically valid assessment approach that integrates passive in-home and mobile technologies to assess instrumental activities of daily living (IADLs) that are not well captured by clinic-based assessment methods in an aging military veteran sample.

METHODS

Participants included 30 community-dwelling military veterans, classified as healthy controls (mean age 72.8, SD 4.9 years; n=15) or MCI (mean age 74.3, SD 6.0 years; n=15) using the Clinical Dementia Rating Scale. Participants were in relatively good health (mean modified Cumulative Illness Rating Scale score 23.1, SD 2.9) without evidence of depression (mean Geriatrics Depression Scale score 1.3, SD 1.6) or anxiety (mean generalized anxiety disorder questionnaire 1.3, SD 1.3) on self-report measures. Participants were clinically assessed at baseline and 12 months later with health and daily function questionnaires and neuropsychological testing. Daily computer use, medication taking, and physical activity and sleep data were collected via passive computer monitoring software, an instrumented pillbox, and a fitness tracker watch in participants' environments for 12 months between clinical study visits.

RESULTS

Enrollment began in October 2018 and continued until the study groups were filled in January 2019. A total of 201 people called to participate following public posting and focused mailings. Most common exclusionary criteria included nonveteran status 11.4% (23/201), living too far from the study site 9.4% (19/201), and having exclusionary health concerns 17.9% (36/201). Five people have withdrawn from the study: 2 with unanticipated health conditions, 2 living in a vacation home for more than half of the year, and 1 who saw no direct benefit from the research study. At baseline, MCI participants had lower Montreal Cognitive Assessment (P<.001) and higher Functional Activities Questionnaire (P=.04) scores than healthy controls. Over seven months, research personnel visited participants' homes a total of 73 times for technology maintenance. Technology maintenance visits were more prevalent for MCI participants (P=.04) than healthy controls.

CONCLUSIONS

Installation and longitudinal deployment of a passive in-home IADL monitoring platform with an older adult military veteran sample was feasible. Knowledge gained from this pilot study will be used to help develop acceptable and effective home-based assessment tools that can be used to passively monitor cognition and daily functioning in older adult samples.

Subjective cognitive decline and subsequent dementia: a nationwide cohort study of 579,710 people aged 66 years in South Korea

Background

Subjective cognitive decline (SCD) is a potential risk factor for dementia. We aimed to investigate the association between SCD and subsequent dementia in a nationwide population-based cohort in South Korea.

Methods

This cohort included 579,710 66-year-old adults who were followed for a total of 3,870,293 person-years (average 6.68 ± 1.33 years per person). All subjects completed a questionnaire about subjective memory impairment, the Pre-screening Korean Dementia Screening Questionnaire (KDSQ-P), which included a validated 5-item derivative, and were determined to have SCD based on a single question assessing memory decline. Depressive symptoms were assessed in all subjects using a 3-item modified geriatric depression scale. Hazard ratios were estimated using the Cox proportional hazards model and compared between subjects with and without SCD.

Results

Compared to subjects without SCD, those with SCD were more likely to develop dementia (incidence per 1000 person-years: non-SCD, 5.66; SCD, 8.59). After adjusting for potential confounding factors, the risk of subsequent dementia significantly increased in subjects with SCD, with an adjusted hazard ratio (aHR) of 1.38 (95% confidence interval [CI] 1.34 to 1.41). The risk of subsequent dementia was greatly increased in subjects with higher KDSQ-P scores (aHR = 2.77, 95% CI 2.35 to 3.27). A significant association between SCD and dementia was observed in both depressive and non-depressive symptom groups (aHR = 1.50, 95% CI 1.42 to 1.57 in subjects with depressive symptoms; aHR = 1.33, 95% CI 1.29 to 1.37 in subjects without depressive symptoms; P = 0.001).

Conclusions

In this population of 66-year-old individuals, SCD was significantly associated with an increased risk of subsequent dementia. This association was found in both depressive and non-depressive groups, with an increased risk of dementia in the presence of depressive symptoms. Our findings suggest that SCD indicates a risk for dementia. Further studies are needed to delineate potential approaches to preventing the development of dementia in individuals with SCD.

Changes in Activity Participation Among Older Adults With Subjective Cognitive Decline or Objective Cognitive Deficits

Participation in daily activities is crucial for healthy aging. There is limited research on participation of older adults with subjective cognitive decline (SCD), defined as the experience of cognitive deficits with no evidence of objective cognitive deficits. Therefore, this study examined perceived changes in participation in this population, and compared it to perceived changes reported by individuals with objective cognitive deficits. The study aimed to: (1) examine the reported changes in activity participation of older with SCD; (2) investigate differences in the reported changes in participation between individuals with SCD and those with mild or severe objective cognitive deficits; (3) examine the relationship between activity participation, subjective memory, and objective cognitive status; and (4) explore whether subjective memory explains additional variance in activity participation after accounting for age and objective cognitive deficits. Participants were 115 older adults (60+), divided into three groups based on their Montreal Cognitive Assessment (MoCA) scores: (1) SCD (MoCA≥26; n = 66); (2) mild objective cognitive deficits (MoCA = 20-25; n = 34); and (3) severe objective cognitive deficits (MoCA ≤ 19; n = 15). The Activity Card Sort was used to measure participation in instrumental activities of daily living, social, and leisure activities. The Multifactorial Memory Questionnaire-Ability subscale was used to assess subjective memory. We found that individuals with SCD, mild cognitive deficits and severe cognitive deficits reported participation withdrawal to a level of 80, 70, and 58% of their past participation, respectively. A significant between group difference was found on participation [χ2(2) = 16.44, p < 0.01], with the SCD group reporting higher participation than the other two groups. Participation significantly correlated with both cognitive status (r = 0.40, p < 0.01) and subjective memory (r = 0.45, p < 0.05). A regression analysis revealed that subjective memory contributed significantly to the explained variance in participation, beyond that accounted for by objective cognitive deficits and age. Our findings demonstrate the important role of subjective memory problems in activity participation of older adults, even in the absence of objective cognitive deficits.

Characterizing functional alterations in instrumental activities of daily living using latent class analysis: a population-based study (NEDICES)

Background and Objectives: The existence of different patterns of functional impairment in older adults has scarcely been addressed. This research investigates major patterns of functional impairment based on Pfeffer's Functional Activity Questionnaire (FAQ).Research Design and Methods: The participants come from NEDICES (Neurological Disorders in Central Spain), a prospective population-based cohort study. A total of 3837 individuals without dementia who completed the Spanish version of the FAQ was selected. Latent Class Analysis (LCA) was carried out to examine potential cluster subgroups based on FAQ responses.Results: The FAQ showed good internal consistency (Cronbach's alpha: 0.86) and moderate correlation (r = -.40) with cognitive performance on the Mini-Mental State Examination (MMSE-37). The response patterns revealed the presence of three latent classes: absence of functional alteration (Class 1), established functional alteration (Class 2), and minimal functional alteration (Class 3). Moreover, the probability of resolving Items 2 ('shopping alone for…'), 3 ('heating water…'), 4 ('preparing a balanced meal'), and 9 ('travelling out of neighbourhood…') was close to 0% for Class 2 membership, while those with the lowest probability of resolution for Class 3 were Items 2 and 9. Items 3 and 4 were the best to discriminate between different grades of functional alterations (Class 2 vs. Class 3).Discussion and Implications: Our findings indicate that the combination of overall FAQ score and item response pattern may help to classify individuals with different subtypes of functional impairment. The Spanish version of the FAQ is a useful tool for detection of functional impairment in older adults.

Association between enrollment factors and incident cognitive impairment in Blacks and Whites: Data from the Alzheimer's Disease Center

INTRODUCTION

We examined the influence of enrollment factors demonstrated to differ by race on incident mild cognitive impairment and dementia using Alzheimer's Disease Center data.

METHODS

Differences in rates of incident impairment between non-Latino Whites and Blacks (n = 12,242) were examined with age-at-progression survival models. Models included race, sex, education, source of recruitment, health factors, and family history of dementia.

RESULTS

No significant race differences in progression were observed in cognitively unimpaired participants. In those with mild cognitive impairment at baseline, Whites evidenced greater risk for progression than Blacks. Enrollment factors, for example, referral source, were significantly related to progression.

DISCUSSION

The finding that Blacks demonstrated lower rate of progression than Whites is contrary to the extant literature. Nested-regression analyses suggested that selection-related factors, differing by race, may account for these findings and influence our ability to accurately estimate risk for progression. It is potentially problematic to make racial comparisons using Alzheimer's Disease Center data sets.

Risk factors for predicting progression from normal cognition to mild cognitive impairment: protocol for a systematic review and meta-analysis of cohort studies

INTRODUCTION

Mild cognitive impairment (MCI) often represents the earliest stage of Alzheimer's disease. There has been considerable research investigating specific risk factors regarding the progression from normal cognition to MCI. However, different studies have come to different conclusions on the impact of particular risk factors. Therefore, it is necessary to conduct a meta-analysis of the risk factors that predict cognitive disruption in individuals based on associations with MCI.

METHODS AND ANALYSIS

We will search seven electronic databases without time limit, including MEDLINE, EMBASE, The Cochrane Library, Web of Science, China National Knowledge Infrastructure, the Wan Fang Database and China Biology Medicine. Two researchers will independently screen for eligibility and perform data extraction. Data were extracted from cohort studies meeting the inclusive criteria according to the Newcastle Ottawa Scale (NOS) methods. A third member of the research team will be contacted when a consensus cannot be reached. Any disagreement will be settled by consensus. The NOS will be used to assess the quality of the studies. All analyses were performed using Stata V.15.1.

ETHICS AND DISSEMINATION

We will report this review in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis statement. We will disseminate our findings through a publication in a peer-reviewed journal. This systematic review does not require ethical approval as no primary data are collected.

PROSPERO REGISTRATION NUMBER

CRD42018109099.

A 'Framingham-like' Algorithm for Predicting 4-Year Risk of Progression to Amnestic Mild Cognitive Impairment or Alzheimer's Disease Using Multidomain Information

BACKGROUND

There are no agreed-upon variables for predicting progression from unimpaired cognition to amnestic mild cognitive impairment (aMCI), or from aMCI to Alzheimer's disease (AD).

OBJECTIVE

Use ADNI data to develop a 'Framingham-like' prediction model for a 4-year period.

METHODS

We developed models using the strongest baseline predictors from six domains (demographics, neuroimaging, CSF biomarkers, genetics, cognitive tests, and functional ability). We chose the best predictor from each domain, which was dichotomized into more versus less harmful.

RESULTS

There were 224 unimpaired individuals and 424 aMCI subjects with baseline data on all predictors, of whom 37 (17% ) and 150 (35% ) converted to aMCI and AD, respectively, during 4 years of follow-up. For the unimpaired, CSF tau/Aβ ratio, hippocampal volume, and a memory score predicted progression. For those aMCI at baseline, the same predictors plus APOE4 status and functional ability predicted progression. Demographics and family history were not important predictors for progression for either group. The fit statistic was good for the unimpaired-aMCI model (C-statistic 0.80) and very good for the aMCI-AD model (C-statistic 0.91). Among the unimpaired, those with no harmful risk factors had a 4-year predicted 2% risk of progression, while those with the most harmful risk factors had a predicted 35% risk. The aMCI subjects with no harmful risk factors had a predicted 1% risk of progression those with all six harmful risk factors had a predicted 90% risk.

CONCLUSION

Our parsimonious model accurately predicted progression from unimpaired to aMCI with three variables, and from aMCI to AD with five variables.

The effect of ApoE ε4 on longitudinal brain region-specific glucose metabolism in patients with mild cognitive impairment: a FDG-PET study

While the ApoE ε4 allele is a known risk factor for mild cognitive impairment (MCI) and Alzheimer's disease, brain region specific effects remain elusive. In this study, we investigate whether the ApoE ε4 allele exhibits brain region specific effects in longitudinal glucose uptake among patients with MCI from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Preprocessed FDG PET images, MRIs, and demographic information were downloaded from the ADNI database. An iterative reblurred Van Cittertiteration method was used for partial volume correction (PVC) on all PET images. Structural MRIs were used for PET spatial normalization and region of interest (ROI) definition in standard space. Longitudinal changes in ROI FDG standardized uptake value ratio (SUVR) relative to cerebellum in 24 ApoE ε4 carriers and 24 age-matched ApoE ε4 non-carriers were measured for up to 84-months (median 72 months, SD = 11.2 months) and compared using a generalized linear mixed effects model controlling for gender, education, baseline age, and follow-up period. Additionally, voxelwise analysis was performed by implementing a paired t-test comparing matched baseline and 72 month FDG SUVR images in ApoE carriers and non-carriers separately. Results with PVC were compared with ones from non-PVC based analysis. After applying PVC, the superior fontal, parietal, lateral temporal, medial temporal, caudate, thalamus, and post-cingulate, and amygdala regions had greater longitudinal decreases in FDG uptake in ApoE ε4 carriers with MCI compared to non-carriers with MCI. Similar forebrain and limbic clusters were found through voxelwise analysis. Compared to the PVC based analysis, fewer significant ApoE-associated regions and clusters were found in the non-PVC based PET analysis. Our findings suggest that the ApoE ε4 genotype is associated with a longitudinal decline in glucose uptake in 8 forebrain and limbic brain regions in the context of MCI. In conclusion, this 84-months longitudinal FDG PET study demonstrates a novel ApoE ε4-associated brain-region specific glucose metabolism pattern in patients with MCI. Partial volume correction improved FDG PET quantification.

Use of an Alzheimer's disease polygenic risk score to identify mild cognitive impairment in adults in their 50s

Early identification of younger, non-demented adults at elevated risk for Alzheimer's disease (AD) is crucial because the pathological process begins decades before dementia onset. Toward that end, we showed that an AD polygenic risk score (PRS) could identify mild cognitive impairment (MCI) in adults who were only in their 50s. Participants were 1176 white, non-Hispanic community-dwelling men of European ancestry in the Vietnam Era Twin Study of Aging (VETSA): 7% with amnestic MCI (aMCI); 4% with non-amnestic MCI (naMCI). Mean age was 56 years, with 89% <60 years old. Diagnosis was based on the Jak-Bondi actuarial/neuropsychological approach. We tested six P-value thresholds (0.05-0.50) for single nucleotide polymorphisms included in the ADPRS. After controlling for non-independence of twins and non-MCI factors that can affect cognition, higher PRSs were associated with significantly greater odds of having aMCI than being cognitively normal (odds ratios (ORs) = 1.36-1.43 for thresholds P < 0.20-0.50). The highest OR for the upper vs. lower quartile of the ADPRS distribution was 3.22. ORs remained significant after accounting for APOE-related SNPs from the ADPRS or directly genotyped APOE. Diabetes was associated with significantly increased odds of having naMCI (ORs = 3.10-3.41 for thresholds P < 0.05-0.50), consistent with naMCI having more vascular/inflammation components than aMCI. Analysis of sensitivity, specificity, and negative and positive predictive values supported some potential of ADPRSs for selecting participants in clinical trials aimed at early intervention. With participants 15+ years younger than most MCI samples, these findings are promising with regard to efforts to more effectively treat or slow AD progression.

Mind the gaps: What we don't know about cognitive impairment in essential tremor

INTRODUCTION

Although the hallmark feature of essential tremor (ET) is tremor, there is growing appreciation that cognitive impairment also occurs, including increased prevalence of mild cognitive impairment (MCI) and increased prevalence and incidence of dementia. With emerging knowledge of ET-cognitive impairment, come fundamental questions regarding its course, bases, predictors and clinical outcomes. Studies in the general population and in Parkinson's disease (PD), a related movement disorder, offer a starting point from which to begin filling these clinically important knowledge gaps.

METHODS

A PubMed search (June 2018) identified articles for this review.

RESULTS

Much of our knowledge of cognitive impairment in ET is of the static condition (e.g., prevalence of cognitive impairment in ET), with nearly no information on its bases, predictors and dynamics (i.e., course, and clinical outcomes). In PD, where such data have been published, rates of cognitive decline and conversion to MCI/dementia are higher than in the general population. Predictors of cognitive change in PD and the general population have also been identified, yet they only partially overlap one another.

CONCLUSION

The predictors and dynamics of cognitive impairment have been investigated fairly extensively in the general population, to a somewhat lesser extent in PD, and are emerging only now in ET. We suggest that longitudinal studies specific to ET are needed, and we outline variables to be considered in these investigations. Increased knowledge of ET-cognitive impairment will facilitate meaningful counseling of patients and their families.

Is function in instrumental activities of daily living a useful feature in predicting Alzheimer's disease dementia in subjective cognitive decline?

OBJECTIVE

Subjective cognitive decline (SCD), the earliest symptom in preclinical Alzheimer's disease (AD), is insufficient to identify individuals at risk for AD dementia. Therefore, we aimed to investigate whether function in instrumental activities of daily living (IADL) contributes to identification.

METHODS

We analysed data of cognitively unimpaired participants of the prospective German Study on Ageing, Cognition, and Dementia in Primary Care Patients (AgeCoDe) and its extension, the Study on Needs, Health Service Use, Costs and Health-related Quality of Life in a Large Sample of Oldest-old Primary Care Patients (AgeQualiDe), collected over 10.5 years. Development of AD dementia was quantified as incidence rates (IRs) per 1000 person-years. Cox regression was used to assess the association of SCD and IADL function in regard to incident AD dementia.

RESULTS

Of 1467 included individuals, 792 (54.0%) reported SCD at baseline. Impaired IADL were present in 50 (3.4%) individuals. IR for AD dementia was highest in individuals with SCD and impaired IADL (49.7; 95% CI, 24.8-99.3). Unadjusted and adjusted Cox analyses revealed an increased AD dementia risk for individuals with SCD and impaired IADL (uHR = 6.1; 95% CI, 2.9-13.0; P < 0.001; aHR = 2.5; 95% CI, 1.1-5.7; P < 0.05).

CONCLUSIONS

Consistent with the SCD concept, IADL function was largely well preserved in the majority of individuals with SCD. However, if difficulties in IADL were present, risk for AD dementia was increased. Therefore, screening for IADL impairment could serve as an economically viable indicator to assess AD dementia risk above and beyond SCD.

Association among handgrip strength, body mass index and decline in cognitive function among the elderly women

Background

The association between handgrip strength combined with body mass index (BMI) and cognitive impairment has not been thoroughly examined. We aimed to investigate whether the relationship between handgrip strength and risk of cognitive impairment is altered by the presence of obesity in older women.

Methods

A total of 544 older women aged over 65 years without cognitive impairment from the Korean Longitudinal Study of Aging (KLoSA) were included in the study. Handgrip strength was classified in a binary manner (weak or strong) or in tertiles and obesity was defined as a BMI ≥ 25 kg/m², in accordance with the Asia-Pacific World Health Organization criteria. Incident cognitive impairment was defined as a Korean Mini-mental State Examination (K-MMSE) score of less than 24 after eight years of follow-up.

Results

Strong handgrip strength was associated with reduced likelihood of developing cognitive impairment compared to weak handgrip strength in obese women (adjusted odds ratio, aOR 0.23, 95% confidence interval, CI 0.08–0.66). The highest tertile of handgrip strength was associated with reduced risk of incident cognitive impairment (aOR 0.16, 95% CI 0.04–0.70), compared to the lowest tertile of handgrip strength in obese women, with a significant linear trend (p for trend = 0.016). Furthermore, the highest tertile of handgrip strength was significantly associated with smaller decline in K-MMSE scores compared to the lowest tertile of handgrip strength in obese women (p value = 0.009). There was no association between handgrip strength and incident cognitive impairment in non-obese women.

Conclusions

Strong handgrip strength was associated with reduced risk of cognitive impairment among obese women, but not in non-obese women. Handgrip strength may be a simple and useful marker for predicting future cognitive impairment among obese women.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0918-9) contains supplementary material, which is available to authorized users.

Cognitive composite score association with Alzheimer's disease plaque and tangle pathology

BACKGROUND

Cognitive composite scores are used as the primary outcome measures for Alzheimer's disease (AD) prevention trials; however, the extent to which these composite measures correlate with AD pathology has not been fully investigated. Since many on-going AD prevention studies are testing therapies that target either amyloid or tau, we sought to establish an association between a cognitive composite score and the underlying pathology of AD.

METHODS

Data from 192 older deceased and autopsied persons from the Rush Religious Order Study were used in this study. All participants were classified at their initial evaluations with a clinical diagnosis of no cognitive impairment (NCI). Of these individuals, 105 remained NCI at the time of their death while the remaining 87 progressed to mild cognitive impairment (MCI) or AD. A cognitive composite score composed of eight cognitive tests was used as the outcome measure. Individuals were classified into groups based on Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropathological diagnosis and Braak stage.

RESULTS

The rate of annualized composite score decline was significantly greater for the high CERAD (p < 0.001, d = 0.56) and Braak (p < 0.001, d = 0.55) groups compared with the low CERAD and Braak groups, respectively. Mixed-model repeated measure (MMRM) analyses revealed a significantly greater difference in composite score change from baseline for the high CERAD group relative to the low CERAD group after 5 years (Δ = -2.74, 95% confidence interval (CI) -5.01 to -0.47; p = 0.02). A similar analysis between low and high Braak stage groups found no significant difference in change from baseline (Δ = -0.69, 95% CI -3.03 to 1.66; p = 0.56).

CONCLUSIONS

These data provide evidence that decreased cognitive composite scores were significantly associated with increased AD pathology and provide support for the use of cognitive composite scores in AD prevention trials.