Estimating Bidirectional Transitions and Identifying Predictors of Mild Cognitive Impairment

Dissecting the clinical and pathological prognosis of MCI patients who reverted to normal cognition: a longitudinal study

BACKGROUND

Controversy existed in the prognosis of reversion from mild cognitive impairment (MCI) to normal cognition (NC). We aim to depict the prognostic characteristics of cognition, neuroimaging, and pathology biomarkers, as well as the risk of Alzheimer's disease (AD) dementia for MCI reverters.

METHODS

A total of 796 non-demented participants (mean age = 73.3 years, female = 54.4%, MCI = 55.7%), who were divided into MCI reverters (n = 109), stable MCI (n = 334), and stable NC (n = 353) based on 2-year diagnosis changes, were subsequently followed up for 6 years. Cox proportional hazard regression models were applied to assess the AD dementia hazard. Linear mixed-effect models were used to evaluate the differences in changing rates of cognitive scores, brain volumes, brain metabolism, and AD biomarkers among three groups.

RESULTS

The 2-year MCI reversion rate was 18.17%. MCI reversion was associated with an 89.6% lower risk of AD dementia (HR = 0.104, 95% confidence interval = [0.033, 0.335], p < 0.001) than stable MCI. No significant difference in incident AD risk was found between MCI reverters and stable NC (p = 0.533). Compared to stable MCI, reverters exhibited slower decreases in cognitive performance (false discovery rate corrected p value [FDR-Q] < 0.050), brain volumes (FDR-Q < 0.050), brain metabolism (FDR-Q < 0.001), and levels of cerebrospinal fluid β-amyloid1-42 (FDR-Q = 0.008). The above-mentioned differences were not found between MCI reverters and stable NC (FDR-Q > 0.050).

CONCLUSIONS

Reversion from MCI to NC predicts a favorable prognosis of pathological, neurodegenerative, and cognitive trajectory.

The prevalence and influencing factors of reversion from mild cognitive impairment to normal cognition: A systemic review and meta-analysis

OBJECTIVE

The aim was to investigate the pooled prevalence of reversion from mild cognitive impairment (MCI) to normal cognition people, and the influencing factors for reversion.

METHODS

PubMed, Embase, Web of Science, The Cochrane Library, Wanfang Database, China Knowledge Resource Integrated Database (CNKI), Weipu Database, SinoMed were systematically searched from the inception to June 1, 2023. Participants were diagnosis as MCI adults.

RESULTS

In total, 4075 studies were screened and data from 48 studies involving 31876 subjects were used in meta-analysis. The pooled prevalence of reversion from MCI to normal cognition was 31%. The following risk factors were associated with the reversion from MCI to normal cognition: education (low to high), age, Mini-Mental State Examination (MMSE), Functional Activities Questionnaire (FAQ), Auditory Verbal Learning Test (AVLT) delay recall test, Apolipoprotein E (APOE) positive, multiple domain impaired, live along, depression, doing house work daily/exercise once a week.

CONCLUSIONS

The study shows the pooled prevalence of reversion from MCI to normal cognition was high, and there are controllable factors. Understanding the controllable factors of reversion from MCI to normal cognition can provide the clinicians with the theoretical basis for the management and treatment of the patients.

A point-based cognitive impairment scoring system for southeast Asian adults

BACKGROUND

Cognitive impairment is a growing concern in Southeast Asian populations, where the burden of cerebrovascular disease (CeVD) is high. Currently, there is no point-based scoring system for identifying cognitive impairment in these populations.

OBJECTIVE

To develop and validate a simple point-based Cognitive Impairment Scoring System (CISS) for identifying individuals with cognitive impairment no dementia (CIND) and concomitant CeVD in Southeast Asian populations.

DESIGN

A cross-sectional study using data from two population-based studies.

SETTING

Community-based setting in Southeast Asia.

PARTICIPANTS

1,511 Southeast Asian adults (664 with CIND, 44.0 %).

MEASURES

Two CISS measures were developed: a basic measure including 11 easily assessable risk factors, and an extended measure incorporating seven additional neuroimaging markers. Performance was evaluated using receiver operating characteristic analysis (AUC) and calibration plots.

RESULTS

The AUC for CISS-basic and CISS-extended were 0.81 (95 %CI, 0.76-0.86) and 0.85 (95 %CI, 0.81-0.89), respectively. Calibration plots indicated satisfactory fit for both the basic measure (p=0.82) and the extended measure (p=0.17). The basic measure included age, gender, ethnicity, education, systolic blood pressure, BMI, smoking history, diabetes, hyperlipidemia, stroke history, and mild/moderate depression. The extended measure added neuroimaging markers of CeVD and brain atrophy.

CONCLUSION

The CISS provides a quick, objective, and clinically relevant tool for assessing cognitive impairment risk in Southeast Asian populations. The basic measure is suitable for initial community-based screenings, while the extended measure offers higher specificity for probable diagnosis. This point-based system enables rapid estimation of cognitive status without requiring complex calculations, potentially improving early detection and management of cognitive impairment in clinical practice.

The prognosis of mild cognitive impairment: A systematic review and meta-analysis

INTRODUCTION

Knowledge gaps remain about the prognosis of mild cognitive impairment (MCI). Conversion rates to dementia vary widely, and reversion to normal cognition has gained attention. This review updates evidence on MCI conversion risk and probability of stability and reversion.

METHODS

We searched databases for studies on MCI prognosis with ≥3 years of follow-up, established criteria for MCI and dementia, and performed a meta-analysis using a random-effects model to assess conversion risk, reversion, and stability probability. Meta-regressions identified sources of heterogeneity and guided subgroup analysis.

RESULTS

From 89 studies (mean follow-up: 5.2 years), conversion risk was 41.5% (38.3%-44.7%) in clinical and 27.0% (22.0%-32.0%) in population-based studies, with Alzheimer's dementia as the most common outcome. Stability rates were 49.3% (clinical) and 49.8% (population). Reversion was 8.7% (clinical) and 28.2% (population).

DISCUSSION

Our findings highlight higher conversion in clinical settings and 30% reversion in population studies, calling for sustainable care pathway development.

Highlights

Prognosis for mild cognitive impairment (MCI) varies by setting; dementia risk is higher and the probability of reversion is lower in clinical-based studies.In both clinical and population settings, cognitive stability is ≈50%.A reorganization of health services could ensure sustainable care for individuals with MCI.Significant heterogeneity in MCI studies impacts data interpretation; follow-up length is crucial.Long-term prognosis studies on MCI in low- and middle-income countries are urgently needed.

Association between childhood parental literacy and late-life cognitive function: The Guangzhou Biobank Cohort Study

OBJECTIVES

Evidence on the associations of childhood parental education with late-life cognitive function remains inconsistent. Additionally, studies focusing on dimensions of cognitive function are scarce, with none from China. Therefore, we examined the associations of childhood parental education with late-life cognitive function and it's dimensions and investigated potential interactions.

STUDY DESIGN

A cross-sectional study.

METHODS

Participants were included from the third phase of Guangzhou Biobank Cohort Study. Mini-Mental State Examination (MMSE), Delayed 10-Word Recall Test (DWRT), and childhood parental literacy (could read or write) were collected. Multivariate linear and logistic regression were used.

RESULTS

Among 8891 participants aged ≥50 years, compared with those whose childhood parents could not read/write, those with only the father, only the mother, or both parents able to read/write during childhood had higher scores on the MMSE and its dimensions, and lower odds of mild cognitive impairment (MCI). The coefficients (β) and 95 % confidence intervals (CI) for scores of MMSE were 1.25 (1.10, 1.41), 1.36 (0.86, 1.86), and 2.05 (1.89, 2.21) respectively; the odds ratios and 95 % CIs for MCI were 0.38 (0.33, 0.45), 0.35 (0.18, 0.67), and 0.15 (0.12, 0.19) respectively. More pronounced effects were found in women, those aged ≥60, those with ≤ primary education, and in those whose childhood parents could read/write. Socioeconomic position mediated the association. Cognitive functions of attention and calculation in children of only fathers who could read/write (β = 0.43, 95%CI: 0.35, 0.50) and memory in children of only mothers who could read/write (β = 0.34, 95%CI: 0.16, 0.51) were associated with better outcomes. Consistent results were also found using scores from the DWRT.

CONCLUSIONS

Childhood parental literacy was associated with late-life cognitive function and it's dimensions, which mediated by socioeconomic position. Specifically, having only a father or only a mother who could read/write during childhood was associated with better cognitive function in attention/calculation and memory, respectively. These results add new evidence to support strategies for elderly cognitive health care.

Socioeconomic inequalities linked to the transitioning to neurocognitive disorders and mortality

Research on socioeconomic position (SEP) and mild neurocognitive impairment, considered a transient state between normal cognitive function and dementia is limited. The purpose of this study was to determine the role of SEP in transitioning between different cognitive states and mortality risk. Using nationally representative English data and utilising a multistate model association between SEP and the risk of transitioning from no cognitive impairment (NOCI) to Cognitive impairment no dementia (CIND), dementia and death were investigated. The potential reverse transition from CIND to NOCI was also explored. The probabilities of transitioning between cognitive states and time spent in each state differed significantly between those with lower and higher levels of SEP. Higher wealth was associated with a reverse transition from CIND to NOCI [HR = 1.56, CI (1.42,1.72)]. Socioeconomic advantage might protect against the progression to the early stages of neurocognitive disorders (CIND) and facilitate the potential reversion from mild cognitive impairment to a healthy cognitive state in later life. Lower levels of education affect the risk of mortality after the onset of dementia.

Elevated circulating levels of GFAP associated with reduced volumes in hippocampal subregions linked to mild cognitive impairment among community-dwelling elderly individuals

Objective

Cerebrospinal fluid biomarkers are challenging to use for diagnosing mild cognitive impairment (MCI) in large populations, and there is an urgent need for new blood biomarkers. The aim of this study is to investigate whether astrocyte activation is correlated with hippocampal atrophy, and to assess the potential of glial fibrillary acidic protein (GFAP) as a biomarker for diagnosing MCI among community-dwelling older individuals.

Methods

This cross-sectional study included 107 older adults. The levels of GFAP in serum were measured, and the volumetric assessment of gray matter within hippocampal subregions was conducted using Voxel-Based Morphometry (VBM). The relationship between hippocampal subregion volume and blood biomarkers were analyzed using partial correlation. The effectiveness of blood biomarkers in differentiating MCI was assessed using a receiver operating characteristic (ROC) curve.

Results

We found that serum GFAP levels were significantly elevated in the MCI group compared to the cognitively normal (CN) group. Additionally, individuals with MCI exhibited a reduction gray matter volume in specific hippocampal subregions. Notably, the right dentate gyrus (DG) and right cornu ammonis (CA) subregions were found to be effective for distinguishing MCI patients from CN individuals. Serum levels of GFAP demonstrate a sensitivity of 65.9% and a specificity of 75.6% in differentiating patients with MCI from CN individuals.

Conclusion

Specific atrophy within hippocampal subregions has been observed in the brains of community-dwelling elderly individuals. Elevated levels of circulating GFAP may serve as a sensitive peripheral biomarker indicative of hippocampal-specific cognitive alterations in patients with MCI.

Correlation Between Cognitive Impairment and Lenticulostriate Arteries: A Clinical and Radiomics Analysis

Lenticulostriate arteries (LSA) are potentially valuable for studying vascular cognitive impairment. This study aims to investigate correlations between cognitive impairment and LSA through clinical and radiomics features analysis. We retrospectively included 102 patients (mean age 62.5±10.3 years, 60 males), including 58 with mild cognitive impairment (MCI) and 44 with moderate or severe cognitive impairment (MSCI). The MRI images of these patients were subjected to z-score preprocessing, manual regions of interest (ROI) outlining, feature extraction (pyradiomics), feature selection [max-relevance and min-redundancy (mRMR), least absolute shrinkage and selection operator (LASSO), and univariate analysis], model construction (multivariate logistic regression), and evaluation [receiver operating characteristic curve (ROC), decision curve analysis (DCA), and calibration curves (CC)]. In the training dataset (71 patients, 44 MCI) and the test dataset (31 patients, 17 MCI), the area under curve (AUC) of the combined model (training 0.88 [95% CI 0.78, 0.97], test 0.76 [95% CI 0.6, 0.93]) was better than that of the clinical model and the radiomics model. The DCA results demonstrated the highest net yield of the combined model relative to the clinical and radiomics models. In addition, we found that LSA total vessel count (0.79 [95% CI 0.08, 1.59], P = 0.038) and wavelet.HLH_glcm_MCC (-1.2 [95% CI -2.2, -0.4], P = 0.008) were independent predictors of MCI. The model that combines clinical and radiomics features of LSA can predict MCI. Besides, LSA vascular parameters may serve as imaging biomarkers of cognitive impairment.

Depressive symptom mediates the association between the number of chronic diseases and cognitive impairment: a multi-center cross-sectional study based on community older adults

Objective

The purpose of this study was to understand the relationship between the multiple chronic conditions (MCC), mental health and cognitive function of older adults in the community, and to propose a hypothesis that depressive symptom mediate the number of chronic diseases and cognitive impairment in older adults.

Method

Participants aged 65 years and older from 35 communities in 14 cities in Guangxi, China were recruited. The residents' depressive symptom (PHQ-9) and cognitive status (AD-8) were evaluated, Chi-square test was used to explore the effects of different socio-demographic characteristics on depressive symptom and cognitive impairment. Pearson correlation analysis and the process model 4 were used to explore the relationship between the number of chronic diseases, depressive symptom and cognitive impairment.

Result

A total of 11,582 older adults were included in our analysis. The rate of MCC reaching 26.53%. Hypertension combined with diabetes accounts for the highest proportion of two chronic diseases (13.2%). Among the combination of three chronic diseases, the highest incidence of coexisting hypertension combined with cervical/lumbar spondylosis, and rheumatoid arthritis (7.1%). In this study, depression symptoms accounted for 12.9% of older adults aged 65 and above, and cognitive impairment accounted for 27.4%. Female, older age, reside in urban areas, lower educational levels, no spouse, live alone, and MCC were risk factors for depressive symptom and cognitive impairment in older adults (P<0.05). Depressive symptom had a mediating effect in the number of chronic diseases and cognitive impairment, and the mediating effect (1.109) accounted for 44.13% of the total effect (0.247).

Conclusion

The mental health of the older adult needs to be taken seriously, and improving depressive symptom can reduce the occurrence of cognitive impairment in older patients with MCC to a certain extent.

Predicting the reversion from mild cognitive impairment to normal cognition based on magnetic resonance imaging, clinical, and neuropsychological examinations

BACKGROUND

Reversion from mild cognitive impairment (MCI) to normal cognition (NC) is not uncommon and indicates a better cognitive trajectory. This study aims to identify predictors of MCI reversion and develop a predicting model.

METHOD

A total of 391 MCI subjects (mean age = 74.3 years, female = 61 %) who had baseline data of magnetic resonance imaging, clinical, and neuropsychological measurements were followed for two years. Multivariate logistic analyses were used to identify the predictors of MCI reversion after adjusting for age and sex. A stepwise backward logistic regression model was used to construct a predictive nomogram for MCI reversion. The nomogram was validated by internal bootstrapping and in an independent cohort.

RESULT

In the training cohort, the 2-year reversion rate was 19.95 %. Predictors associated with reversion to NC were higher education level (p = 0.004), absence of APOE4 allele (p = 0.001), larger brain volume (p < 0.005), better neuropsychological measurements performance (p < 0.001), higher glomerular filtration rate (p = 0.035), and lower mean arterial pressure (p = 0.060). The nomogram incorporating five predictors (education, hippocampus volume, the Alzheimer's Disease Assessment Scale-Cognitive score, the Rey Auditory Verbal Learning Test-immediate score, and mean arterial pressure) achieved good C-indexes of 0.892 (95 % confidence interval [CI], 0.859-0.926) and 0.806 (95 % CI, 0.709-0.902) for the training and validation cohort.

LIMITATION

Observational duration is relatively short; The predicting model warrant further validation in larger samples.

CONCLUSION

This prediction model could facilitate risk stratification and early management for the MCI population.

Association between Life's Essential 8 and cognitive function: insights from NHANES 2011-2014

Introduction

Life's Essential 8 (LE8) is prompted by the American Heart Association (AHA) to assess cardiovascular health. The association between LE8 and cognitive function in America is unknown. Our study was to investigate the association of LE8 with cognitive function in general adults.

Materials and methods

A total of 2,301 participants were enrolled in the National Health and Nutrition Examination Surveys (NHANES). LE8 scores (range 0-100) were obtained from measurements based on American Heart Association definitions, divided into health behavior and health factor scores. Cognitive function was assessed by three tests including the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), Animal fluency test (AFT), and Digit Symbol Substitution test (DSST). The multivariable linear regression analysis explored the associations between LE8 and cognitive function. Smooth curve fitting was explored using restricted cubic splines. The inflection point was determined by the two-piecewise linear regression.

Results

In the multivariable linear regression model with full adjustment for confounding variables, AFT scores were 1.2 points higher in participants with LE8 scores >80 than in those with LE8 scores <50 (high LE8 score group: β = 1.20, 95% CI 0.37, 2.03), and 3.32 points higher in DSST (high LE8 score group: β = 3.32, 95% CI 1.24, 5.39). Although high LE8 scores show a Negative association with high CERAD, we found a significant association between higher LE8 scores and higher CERAD when LE8 scores were higher than 82.5 (β = 0.21 95%CI 0.04, 0.39, p-value = 0.0179).

Conclusion

Our study highlighted a positive association between Life's Essential 8 and cognitive function in older adults.

Screening strategies and dynamic risk prediction models for Alzheimer's disease

BACKGROUND

Characterizing the progression from Mild cognitive impairment (MCI) to Alzheimer's disease (AD) is essential for early AD prevention and targeted intervention. Our goal was to construct precise screening schemes for individuals with different risk of AD and to establish prognosis models for them.

METHODS

We constructed a retrospective cohort by reviewing individuals with baseline diagnosis of MCI and at least one follow-up visits between November 2005 and May 2021. They were stratified into high-risk and low-risk groups with longitudinal cognitive trajectory. Then, we established a screening framework and obtained optimal screening strategies for two risk groups. Cox and random survival forest (RSF) models were developed for dynamic prognosis prediction.

RESULTS

In terms of screening strategies, the combination of Clinical Dementia Rating Sum of Boxes (CDRSB) and hippocampus volume was recommended for the high-risk MCI group, while the combination of Alzheimer's Disease Assessment Scale Cognitive 13 items (ADAS13) and FAQ was recommended for low-risk MCI group. The concordance index (C-index) of the Cox model for the high-risk group was 0.844 (95% CI: 0.815-0.873) and adjustments for demographic information and APOE ε4. The RSF model incorporating longitudinal ADAS13, FAQ, and demographic information and APOE ε4 performed for the low-risk group.

CONCLUSION

This precise screening scheme will optimize allocation of medical resources and reduce the economic burden on individuals with low risk of MCI. Moreover, dynamic prognosis models may be helpful for early identification of individuals at risk and clinical decisions, which will promote the secondary prevention of AD.

Neutrophil-Mediated Progression of Mild Cognitive Impairment to Dementia

Cognitive impairment is a serious condition that begins with amnesia and progresses to cognitive decline, behavioral dysfunction, and neuropsychiatric impairment. In the final stage, dysphagia and incontinence occur. There are numerous studies and developed drugs for cognitive dysfunction in neurodegenerative diseases, such as Alzheimer's disease (AD); however, their clinical effectiveness remains equivocal. To date, attempts have been made to overcome cognitive dysfunction and understand and delay the aging processes that lead to degenerative and chronic diseases. Cognitive dysfunction is involved in aging and the disruption of inflammation and innate immunity. Recent reports have indicated that the innate immune system is prevalent in patients with AD, and that peripheral neutrophil markers can predict a decline in executive function in patients with mild cognitive impairment (MCI). Furthermore, altered levels of pro-inflammatory interleukins have been reported in MCI, which have been suggested to play a role in the peripheral immune system during the process from early MCI to dementia. Neutrophils are the first responders of the innate immune system. Neutrophils eliminate harmful cellular debris via phagocytosis, secrete inflammatory factors to activate host defense systems, stimulate cytokine production, kill pathogens, and regulate extracellular proteases and inhibitors. This review investigated and summarized the regulation of neutrophil function during cognitive impairment caused by various degenerative diseases. In addition, this work elucidates the cellular mechanism of neutrophils in cognitive impairment and what is currently known about the effects of activated neutrophils on cognitive decline.

Motoric cognitive risk syndrome trajectories and incident dementia over 10 years

Background

Motoric Cognitive Risk (MCR) syndrome is a high-risk state for adverse health outcomes in older adults characterised by measured slow gait speed and self-reported cognitive complaints. The recent addition to the Lothian Birth Cohort 1936 of robust dementia outcomes enabled us to assess the prognostic value of MCR for dementia and explore the various trajectories of participants diagnosed with MCR.

Methods

We classified 680 community-dwelling participants free from dementia into non-MCR or MCR groups at mean [SD] age 76.3 [0.8] years. We used Cox and competing risk regression methods, adjusted for potential confounders, to evaluate the risk of developing all-cause incident dementia over 10 years of follow-up. Secondarily, we followed the trajectories for individuals with and without MCR at baseline and categorised them into subgroups based on whether MCR was still present at the next research wave, three years later.

Results

The presence of MCR increased the risk of incident dementia (adjusted HR 2.34, 95%CI 1.14-4.78, p = 0.020), as did fewer years of education and higher depression symptoms. However, MCR has a heterogenous progression trajectory. The MCR progression subgroups each have different prognostic values for incident dementia.

Conclusion

MCR showed similar prognostic ability for dementia in a Scottish cohort as for other populations. MCR could identify a target group for early interventions of modifiable risk factors to prevent incident dementia. This study illustrates the heterogeneous nature of MCR progression. Exploring the underlying reasons will be important work in future work.

Advances in amyloid-targeting monoclonal antibodies for Alzheimer's disease: clinical and public health issues

INTRODUCTION

Alzheimer's disease (AD) is a major global public health challenge. To date, no treatments have been shown to stop the underlying pathological processes. The cerebral accumulation of amyloid-beta (Ab) is still considered as the primum movens of AD and disease-modifying treatments targeting Ab are reaching - or have already reached - clinical practice.

AREAS COVERED

The authors explore the main advancements from Aβ-targeting monoclonal antibodies (mAbs) for the treatment of AD. From a public health perspective, they address ethically relevant issues such as the benevolence and non-maleficence principles. They report on the potential biological and clinical benefits of these drugs, discussing minimal clinically important differences (MCID) and other relevant outcomes. They examine the short- and long-term effects of amyloid-related imaging abnormalities (ARIA), and explore the differences between eligibility criteria in clinical trials, appropriate use recommendations, and prescribing information content. In doing so, they contextualize the discussion on the disagreements among different regulatory authorities.

EXPERT OPINION

Although anti-β-amyloid monoclonal antibodies may be effective in selected scenarios, non-negligible knowledge gaps and implementation limits persist. Overcoming these gaps can no longer be postponed if we are to ensure the principles of Quality of Care for patients with cognitive impairment who would be eligible for this class of drugs.