APOE and mild cognitive impairment: the Framingham Heart Study

Comparison of genetic and health risk factors for mild cognitive impairment and Alzheimer's disease between Hispanic and non-Hispanic white participants

INTRODUCTION

The influence of apolipoprotein E (APOE) genotype on mild cognitive impairment (MCI) and Alzheimer's disease (AD) is well studied in the non-Hispanic white (NHW) population but not in the Hispanic population. Additionally, health risk factors such as hypertension, stroke, and depression may also differ between the two populations.

METHODS

We combined three data sets (National Alzheimer's Coordinating Center [NACC], Alzheimer's Disease Neuroimaging Initiative [ADNI], Health and Aging Brain Study: Health Disparities [HABS-HD]) and compared risk factors for MCI and AD between Hispanic and NHW participants, with a total of 24,268 participants (11.1% Hispanic).

RESULTS

APOEε4 was associated with fewer all-cause MCI cases in Hispanic participants (Hispanic odds ratio [OR]: 1.114; NHW OR: 1.453), and APOEε2 (Hispanic OR: 1.224; NHW OR: 0.592) and depression (Hispanic OR: 2.817; NHW OR: 1.847) were associated with more AD cases in Hispanic participants.

DISCUSSION

APOEε2 may not be protective for AD in Hispanic participants and Hispanic participants with depression may face a higher risk for AD.

HIGHLIGHTS

GAAIN allows for discovery of data sets to use in secondary analyses. APOEε2 was not protective for AD in Hispanic participants. APOEε4 was associated with fewer MCI cases in Hispanic participants. Depression was associated with more AD cases in Hispanic participants.

Neuropsychiatric Symptoms and In Vivo Alzheimer's Biomarkers in Mild Cognitive Impairment

BACKGROUND

Neuropsychiatric symptoms (NPS) carry an increased risk of progression from mild cognitive impairment (MCI) to Alzheimer's disease (AD). There is a need to understand how to integrate NPS into the paradigm outlined in the 2018 NIA-AA Research Framework.

OBJECTIVE

To evaluate a prediction model of MCI-AD progression using a collection of variables, including NPS, cognitive testing, apolipoprotein E4 status (APOE4), imaging and laboratory AD biomarkers.

METHODS

Of 300 elderly subjects, 219 had stable MCI and 81 MCI-AD progression over a 5-year follow-up. NPS were measured using the Neuropsychiatric Inventory (NPI). A multivariate Cox Proportional Hazards Regression Analysis assessed the effects of APOE4, baseline NPI, baseline CSF amyloid-β, phosphorylated and total tau, baseline AD-signature MRI biomarker, baseline memory and executive function on MCI-AD progression.

RESULTS

27% progressed to dementia (median follow-up = 43 months). NPS were found in stable MCI (62.6%) and MCI-AD converters (70.3%). The Cox model exhibited a good fit (p < 0.001), and NPS (HR = 1.033, p = 0.027), phosphorylated tau (HR = 1.011, p = 0.025), total tau (HR = 1.005, p = 0.024), AD-signature MRI biomarker (HR = 0.111, p = 0.002), executive function (HR = 0.727, p = 0.045), and memory performance (HR = 0.387, p < 0.001) were significantly associated with dementia.

CONCLUSIONS

NPS may inform dementia risk assessment in conjunction with cognitive testing and imaging and laboratory AD biomarkers. NPS is independently associated with the risk of MCI-dementia progression, over and beyond the contributions of CSF biomarkers.

Mild cognitive impairment among rural-dwelling older adults in China: A community-based study

BACKGROUND

Epidemiological studies of mild cognitive impairment (MCI) and subtypes of MCI have rarely focused on rural residents in China.

METHODS

This population-based study included 5068 participants (age ≥60 years) who were living in rural communities. We defined MCI, amnestic MCI (aMCI), and non-amnestic MCI (naMCI) following the Petersen's criteria that integrated neuropsychological assessments with in-person clinical evaluations.

RESULTS

The overall prevalence of MCI, aMCI, and naMCI was 26.48%, 22.30%, and 4.18%, respectively. The prevalence of MCI increased with age. The adjusted odds ratio (OR) of MCI was 0.71 (95% confidence interval [CI] 0.61 to 0.82) for primary school (vs. illiteracy), 0.30 (0.24 to 0.39) for middle school or above, 1.35 (1.09 to 1.67) for being farmers, 0.65 (0.54 to 0.78) for alcohol consumption, 1.43 (1.20 to 1.70) for stroke history, and 1.14 (0.95 to 1.36) for any apolipoprotein E (APOE) ε4 allele (vs ε3/ε3).

CONCLUSIONS

MCI affects over one-fourth of rural older adults in China. Overall MCI was associated with demographic factors, non-alcohol consumption, and stroke, but not with APOE genotype and cardiometabolic factors.

Type 2 Diabetes Mellitus as a Risk Factor for Alzheimer’s Disease: Review and Meta-Analysis

Alzheimer’s disease is the most common type of dementia, reaching 60–80% of case totals, and is one of the major global causes of the elderly population’s decline in functionality concerning daily life activities. Epidemiological research has already indicated that, in addition to several others metabolic factors, diabetes mellitus type 2 is a risk factor of Alzheimer’s disease. Many molecular pathways have been described, and at the same time, there are clues that suggest the connection between type 2 diabetes mellitus and Alzheimer’s disease, through specific genes, autophagy, and even inflammatory pathways. A systematic review with meta-analysis was conducted, and its main goal was to reveal the multilevel connection between these diseases.

Genetic Effects of NDUFAF6 rs6982393 and APOE on Alzheimer’s Disease in Chinese Rural Elderly: A Cross-Sectional Population-Based Study

Purpose

To investigate the associations of genotypes of NDUFAF6 rs6982393 and APOE and their combined genotypes with the risk of Alzheimer’s disease (AD) and mild cognitive impairment (MCI) in Chinese rural elderly.

Methods

This cross-sectional population-based study included 5096 older adults (age ≥60 years, 57.1% female). Genotypes of NDUFAF6 rs6982393 and APOE were detected using the multiple-polymerase chain reaction amplification. We diagnosed AD following the criteria of Diagnostic and Statistical Manual of Mental Disorders, the fourth edition and diagnosed MCI following the Petersen’s criteria MCI. Data were analyzed using the logistic regression model.

Results

The overall prevalence of AD and MCI was 3.57% (95% confidence interval [CI]: 0.040, 0.053) and 22.65% (95% CI: 0.223, 0.247), separately. The TT versus CC/CT genotype of NDUFAF6 rs6982393 was related to a higher risk of AD with the multi-adjusted odds ratio (95% CI) being 1.61 (1.02, 2.54) in the total sample, 3.36 (1.48, 7.60) in those aged 60–69, and 1.24 (0.71, 2.17) in those aged 70 years and above. The interaction between genotype of NDUFAF6 rs6982393 with age groups (60–69 versus ≥70 years) was significant on the risk of AD. The presence of APOE ε4 was not significantly associated with the risk of AD. Carrying both NDUFAF6 TT and APOE ε4 was related to a higher risk of AD with the multi-adjusted odds ratio (95% CI) being 2.69 (1.10, 2.56). In addition, there was no significant association between the above genotypes and MCI.

Conclusion

In Chinese rural elderly, the TT versus CT/CC genotype of NDUFAF6 rs6982393 was associated with an increased likelihood of AD; such an association only existed among young-old adults. Carrying both NDUFAF6 rs6982393-TT and APOE ε4 was related to a higher risk of AD. This finding highlights the importance of considering age and combined genotype in studying the genetic profiles of AD.

Human microRNA (miR-20b-5p) modulates Alzheimer's disease pathways and neuronal function, and a specific polymorphism close to the MIR20B gene influences Alzheimer's biomarkers

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with loss of cognitive, executive, and other mental functions, and is the most common form of age-related dementia. Amyloid-β peptide (Aβ) contributes to the etiology and progression of the disease. Aβ is derived from the amyloid-β precursor protein (APP). Multiple microRNA (miRNA) species are also implicated in AD. We report that human hsa-miR20b-5p (miR-20b), produced from the MIR20B gene on Chromosome X, may play complex roles in AD pathogenesis, including Aβ regulation. Specifically, miR-20b-5p miRNA levels were altered in association with disease progression in three regions of the human brain: temporal neocortex, cerebellum, and posterior cingulate cortex. In cultured human neuronal cells, miR-20b-5p treatment interfered with calcium homeostasis, neurite outgrowth, and branchpoints. A single-nucleotide polymorphism (SNP) upstream of the MIR20B gene (rs13897515) associated with differences in levels of cerebrospinal fluid (CSF) Aβ1-42 and thickness of the entorhinal cortex. We located a miR-20b-5p binding site in the APP mRNA 3'-untranslated region (UTR), and treatment with miR-20b-5p reduced APP mRNA and protein levels. Network analysis of protein-protein interactions and gene coexpression revealed other important potential miR-20b-5p targets among AD-related proteins/genes. MiR-20b-5p, a miRNA that downregulated APP, was paradoxically associated with an increased risk for AD. However, miR-20b-5p also reduced, and the blockade of APP by siRNA likewise reduced calcium influx. As APP plays vital roles in neuronal health and does not exist solely to be the source of "pathogenic" Aβ, the molecular etiology of AD is likely to not just be a disease of "excess" but a disruption of delicate homeostasis.

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.

Mild cognitive impairment: when nutrition helps brain energy rescue-a report from the EuGMS 2020 Congress

BACKGROUND

Mild cognitive impairment (MCI) is characterized by a decline in cognition and mainly affects older individuals above the age of 60. The global incidence of MCI varies, but it is often underdiagnosed and untreated. There is a distinct lack of approved pharmacologic options to treat MCI. There is, however, evidence to support the efficacy of nutritional interventions, such as ketogenic supplements/diets, which offer ketones as an alternative energy source to brain cells. This article explores the effect of ketones on metabolic activity in the brain and the mechanisms by which ketogenic medium-chain triglycerides (kMCTs) induce ketosis in patients with MCI.

KEY TAKEAWAYS

This article reviews the effect of ketogenic supplements/diets on brain metabolism, including evidence supporting the efficacy of ketones as an efficient fuel for the brain. It discusses the use of oral nutritional ketogenic supplements, with particular reference to the 6-month randomized controlled BENEFIC trial, which showed that consumption of a kMCT drink, BrainXpert Energy Complex, improved cognitive performance in individuals with MCI compared with placebo.

CONCLUSION

While there is a need for more long-term studies, results from the BENEFIC trial revealed the benefits of a brain-specific ketogenic supplement, as a nutritional intervention, on cognitive performance in individuals with MCI.

A profile of brain reserve in adults at genetic risk of Alzheimer's disease

INTRODUCTION

The apolipoprotein E (APOE) ε4 allele is the greatest genetic risk factor for Alzheimer's disease (AD). Our aim was to identify the structural brain measures that mitigate the negative effect of APOE ε4 on cognition, which would have implications for AD diagnosis and treatment trial selection.

METHODS

A total of 742 older adults (mean age: 70.1 ± 8.7 years) were stratified by APOE status and classified as cognitively normal (CDR 0) or with very mild dementia (CDR 0.5). Regional brain volume and cognitive performance were measured.

RESULTS

There were significant interactions between APOE and CDR on the left precuneus and on bilateral superior frontal volumes. These regions were preserved in CDR-0 ε3/ε4 and ε4/ε4 carriers but were reduced in CDR-0.5 ε3/ε4 and ε4/ε4 carriers, compared to their respective ε3/ε3 counterparts. Educational attainment predicted greater brain reserve.

DISCUSSION

This pattern of preserved brain structure in cognitively normal ε4 carriers with comprised medial temporal volume is consistent with the theory of brain reserve.

Peripheral Blood Biomarkers Coupled with the Apolipoprotein E4 Genotype Are Strongly Associated with Semantic and Episodic Memory Impairments in Elderly Subjects with Amnestic Mild Cognitive Impairment and Alzheimer's Disease

BACKGROUND

The Apolipoprotein E4 (ApoE4) genotype is strongly associated with Alzheimer's disease (AD), although the presence of the ApoE4 allele alone is not sufficient to explain AD. The pathophysiology of amnestic mild cognitive impairment (aMCI) remains unclear.

OBJECTIVE

This study aims to examine associations between peripheral blood biomarkers coupled with ApoE4 and episodic and semantic memory.

METHODS

The CERAD battery was completed and various biomarkers were assayed in 60 subjects with aMCI, 60 with AD, and 62 healthy controls.

RESULTS

Deficits in semantic and episodic memory were significantly predicted by anion gap and bicarbonate, albumin, and glucose coupled with ApoE4. Furthermore, these peripheral biomarkers interacted with ApoE to predict greater memory impairments.

CONCLUSIONS

Peripheral blood biomarkers may interact with pathways related to ApoE4 to predict greater semantic and episodic memory impairments, thus contributing to the pathophysiology of aMCI and AD. Our data suggest that the transition from aMCI to AD could at least in some cases be associated with significant interactions between ApoE4 and those peripheral blood biomarkers.

Nuances in Alzheimer's Genetic Risk Reveal Differential Predictions of Non-demented Memory Aging Trajectories: Selective Patterns by APOE Genotype and Sex

BACKGROUND

Apolipoprotein E (APOE) is a prominent genetic risk factor for Alzheimer's disease (AD) and a frequent target for associations with non-demented and cognitively impaired aging. APOE offers a unique opportunity to evaluate two dichotomous comparisons and selected gradations of APOE risk. Some evidence suggests that APOE effects may differ by sex and emerge especially in interaction with other AD-related biomarkers (e.g., vascular health).

METHODS

Longitudinal trajectories of non-demented adults (n = 632, 67% female, Mage = 68.9) populated a 40-year band of aging. Focusing on memory performance and individualized memory trajectories, a sequence of latent growth models was tested for predictions of (moderation between) APOE and pulse pressure (PP) as stratified by sex. The analyses (1) established robust benchmark PP effects on memory trajectories, (2) compared predictions of alternative dichotomous groupings (ε4- vs ε4+, ε2- vs ε2+), and (3) examined precision-based predictions by disaggregated APOE genotypes.

RESULTS

Healthier (lower) PP was associated with better memory performance and less decline. Therefore, all subsequent analyses were conducted in the interactive context of PP effects and sex stratification. The ε4-based dichotomization produced no differential genetic predictions. The ε2-based analyses showed sex differences, including selective protection for ε2-positive females. Exploratory follow-up disaggregated APOE genotype analyses suggested selective ε2 protection effects for both homozygotic and heterozygotic females.

CONCLUSION

Precision analyses of AD genetic risk will advance the understanding of underlying mechanisms and improve personalized implementation of interventions.

Impact of Apolipoprotein E gene polymorphism during normal and pathological conditions of the brain across the lifespan

The central nervous system (CNS) is the cellular substrate for the integration of complex, dynamic, constant, and simultaneous interactions among endogenous and exogenous stimuli across the entire human lifespan. Numerous studies on aging-related brain diseases show that some genes identified as risk factors for some of the most common neurodegenerative diseases - such as the allele 4 of APOE gene (APOE4) for Alzheimer's disease (AD) - have a much earlier neuro-anatomical and neuro-physiological impact. The impact of APOE polymorphism appears in fact to start as early as youth and early-adult life. Intriguingly, though, those same genes associated with aging-related brain diseases seem to influence different aspects of the brain functioning much earlier actually, that is, even from the neonatal periods and earlier. The APOE4, an allele classically associated with later-life neurodegenerative disorders as AD, seems in fact to exert a series of very early effects on phenomena of neuroplasticity and synaptogenesis that begin from the earliest periods of life such as the fetal ones.We reviewed some of the findings supporting the hypothesis that APOE polymorphism is an early modifier of various neurobiological aspects across the entire human lifespan - from the in-utero to the centenarian life - during both normal and pathological conditions of the brain.

Effect of apolipoprotein E ε4 allele on the progression of cognitive decline in the early stage of Alzheimer's disease

INTRODUCTION

Possession of the apolipoprotein E (APO E) ε4 allele advances amyloid β (Aβ) deposition and symptomatic onset of Alzheimer's disease (AD), whereas its effect on the rate of cognitive decline remained controversial. We examined the effects of APOE ε4 allele on cognition in biomarker-confirmed late mild cognitive impairment (LMCI) and mild AD subjects in the Japanese Alzheimer's Disease Neuroimaging Initiative (J-ADNI) and North American ADNI (NA-ADNI).

METHODS

The "early AD" (ie, combined LMCI and mild AD) cohort of 649 subjects from J-ADNI and NA-ADNI were selected based on positivity of Aβ confirmed by amyloid positron emission tomography (PET) or cerebrospinal fluid testing. The rates of cognitive decline in the Mini Mental State Examination (MMSE), the Clinical Dementia Rating Sum of Boxes (CDR-SB), and the Alzheimer's Disease Assessment Scale-cognitive subscale 13 (ADAS-Cog) from baseline were examined using mixed-effects model. The effect of ε4 on time to conversion to dementia was also analyzed in LMCI using the Kaplan-Meier estimator and log-rank test.

RESULTS

The rates of cognitive decline were not significantly different between ε4 carriers and ε4 non-carriers in the total early AD cohort, which were affected neither by region nor by the number of ε4 alleles. In LMCI, ε4 carriers showed almost the same progression rates as ε4 non-carriers, except for a significantly faster decline in MMSE (P = .0282). Time to conversion to demenita was not significantly different between ε4 carriers and ε4 non-carriers. In ε4-positive mild AD, the rates of decline in MMSE (P = .003) and CDR-SB (P = .0071) were slower than those in ε4 non-carriers.

DISCUSSION

The APOE ε4 allele had little effect on the rates of cognitive decline in the overall biomarker-confirmed early AD, regardless of region and number of ε4 alleles, with a slight variability in different clinical stages, the ε4 allele being slightly accelerative in LMCI, while decelerative in mild AD.

M1 muscarinic receptor is a key target of neuroprotection, neuroregeneration and memory recovery by i-Extract from Withania somnifera

Memory loss is one of the most tragic symptoms of Alzheimer's disease. Our laboratory has recently demonstrated that 'i-Extract' of Ashwagandha (Withania somnifera) restores memory loss in scopolamine (SC)-induced mice. The prime target of i-Extract is obscure. We hypothesize that i-Extract may primarily target muscarinic subtype acetylcholine receptors that regulate memory processes. The present study elucidates key target(s) of i-Extract via cellular, biochemical, and molecular techniques in a relevant amnesia mouse model and primary hippocampal neuronal cultures. Wild type Swiss albino mice were fed i-Extract, and hippocampal cells from naïve mice were treated with i-Extract, followed by muscarinic antagonist (dicyclomine) and agonist (pilocarpine) treatments. We measured dendritic formation and growth by immunocytochemistry, kallikrein 8 (KLK8) mRNA by reverse transcription polymerase chain reaction (RT-PCR), and levels of KLK8 and microtubule-associated protein 2, c isoform (MAP2c) proteins by western blotting. We performed muscarinic receptor radioligand binding. i-Extract stimulated an increase in dendrite growth markers, KLK8 and MAP2. Scopolamine-mediated reduction was significantly reversed by i-Extract in mouse cerebral cortex and hippocampus. Our study identified muscarinic receptor as a key target of i-Extract, providing mechanistic evidence for its clinical application in neurodegenerative cognitive disorders.

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.

Analysis of pleiotropic genetic effects on cognitive impairment, systemic inflammation, and plasma lipids in the Health and Retirement Study

Variants associated with modulation of c-reactive protein (CRP) and plasma lipids have been investigated for polygenic overlap with Alzheimer's disease risk variants. We examined pleiotropic genetic effects on cognitive impairment conditioned on genetic variants (SNPs) associated with systemic inflammation as measured by CRP and with plasma lipids using data from the Health and Retirement Study. SNP enrichment was observed for cognitive impairment conditioned on the secondary phenotypes of plasma CRP and lipids. Fold enrichment of 100%-800% was observed for increasingly stringent p-value thresholds for SNPs associated with cognitive impairment conditional on plasma CRP, 80%-800% for low-density lipoprotein, and 80%-600% for total cholesterol. Significant associations (false discovery rate Q ≤ 0.05) between cognitive impairment, conditional with either CRP, low-density lipoprotein, or total cholesterol, were found for the locus on chromosome 19 that contains the APOE, TOMM40, APOC1, and PVRL2 genes. Relative numbers of significant SNPs in each of the genes differed by the conditional associations with the secondary phenotypes. Biological interpretation of both the genetic pleiotropy results and the individual genome-wide association results showed that the variants and proximal genes identified are involved in multiple pathological processes including cholesterol metabolism, inflammation, and mitochondrial transport. These findings are potentially important for Alzheimer's disease risk prediction and development of novel therapeutic approaches.

Neck Circumference, Brain Imaging Measures, and Neuropsychological Testing Measures

BACKGROUND

Perivascular fat may have direct effects on local vascularity. Neck fat is associated with carotid intimal thickness, a predictor of brain aging outcomes. This study investigated whether neck circumference, an estimation of neck fat, has unique associations with brain aging outcomes.

METHODS

The study sample (n = 2082, 53.5% women, mean age 60.9 years) was derived from Framingham Heart Study participants with brain magnetic resonance imaging (MRI) and neuropsychological (NP) test measures. Multivariable-adjusted regressions examined cross-sectional associations of neck circumference with brain MRI and NP test measures. Models were also constructed with waist circumference and body mass index (BMI) as exposures.

RESULTS

A 1 standard deviation (2.8 cm [women]; 2.9 cm [men]) increment in neck circumference was associated with lower total cerebral brain volume (β = -.22, P = .0006) and lower frontal brain volume (β = -.55, P < .0001). However, a similar association was observed for both waist circumference and BMI. There were no associations between neck circumference and NP test measures after full covariate adjustment.

CONCLUSIONS

There were no unique associations between neck circumference and brain MRI or NP measures. Consistent with prior observations, all adiposity measures showed associations with more adverse brain MRI and NP measures, suggesting a global association of generalized adiposity.

Mild cognitive decline. A position statement of the Cognitive Decline Group of the European Innovation Partnership for Active and Healthy Ageing (EIPAHA)

INTRODUCTION

Mild cognitive impairment (MCI) is a term used to describe a level of decline in cognition which is seen as an intermediate stage between normal ageing and dementia, and which many consider to be a prodromal stage of neurodegeneration that may become dementia. That is, it is perceived as a high risk level of cognitive change. The increasing burden of dementia in our society, but also our increasing understanding of its risk factors and potential interventions, require diligent management of MCI in order to find strategies that produce effective prevention of dementia.

AIM

To update knowledge regarding mild cognitive impairment, and to bring together and appraise evidence about the main features of clinical interest: definitions, prevalence and stability, risk factors, screening, and management and intervention.

METHODS

Literature review and consensus of expert opinion.

RESULTS AND CONCLUSION

MCI describes a level of impairment in which deteriorating cognitive functions still allow for reasonable independent living, including some compensatory strategies. While there is evidence for some early risk factors, there is still a need to more precisely delineate and distinguish early manifestations of frank dementia from cognitive impairment that is less likely to progress to dementia, and furthermore to develop improved prospective evidence for positive response to intervention. An important limitation derives from the scarcity of studies that take MCI as an endpoint. Strategies for effective management suffer from the same limitation, since most studies have focused on dementia. Behavioural changes may represent the most cost-effective approach.