Age-Stratified Prevalence of Mild Cognitive Impairment and Dementia in European Populations: A Systematic Review

Cognitive Impairment Related to Chronic Kidney Disease Is Associated with a Decreased Abundance of Membrane-Bound Klotho in the Cerebral Cortex

Cognitive impairment (CI) is a complication of chronic kidney disease (CKD) that is frequently observed among patients. The aim of this study was to evaluate the potential crosstalk between changes in cognitive function and the levels of Klotho in the brain cortex in an experimental model of CKD. To induce renal damage, Wistar rats received a diet containing 0.25% adenine for six weeks, while the control group was fed a standard diet. The animals underwent different tests for the assessment of cognitive function. At sacrifice, changes in the parameters of mineral metabolism and the expression of Klotho in the kidney and frontal cortex were evaluated. The animals with CKD exhibited impaired behavior in the cognitive tests in comparison with the rats with normal renal function. At sacrifice, CKD-associated mineral disorder was confirmed by the presence of the expected disturbances in the plasma phosphorus, PTH, and both intact and c-terminal FGF23, along with a reduced abundance of renal Klotho. Interestingly, a marked and significant decrease in Klotho was observed in the cerebral cortex of the animals with renal dysfunction. In sum, the loss in cerebral Klotho observed in experimental CKD may contribute to the cognitive dysfunction frequently observed among patients. Although further studies are required, Klotho might have a relevant role in the development of CKD-associated CI and represent a potential target in the management of this complication.

Forecasted Dementia Prevalence in Portugal (2020-2080)

Dementia is a global public health challenge, and its impact on Portugal is yet unclear. This study forecasts dementia prevalence in Portugal until 2080. Using the Gonçalves-Pereira et al (2021) method, we estimated dementia cases among older adults (≥65 years) in the community. Applying age-sex specific prevalence rates of the Gonçalves-Pereira study to population projections for Portugal between 2020-2080, based on the 10/66 Dementia Research Group criteria (10/66 DRG) and the Diagnostic and Statistical Manual of Mental Disorders IV criteria (DSM-IV), to Portugal's population projections (2020-2080) under various growth scenarios (low, medium, and high). We anticipate a more than 2-fold increase in dementia prevalence from 2020 to 2080, both for 10/66 DRG [2.1%-5.0%] and DSM-IV [.8%-2.0%]. By 2080, those aged ≥80 years are projected to constitute 75.0% (vs 59.0% in 2020) of all dementia cases, particularly affecting women. Addressing dementia growth in Portugal calls for a comprehensive global response, while country-level estimates facilitate informed public health planning, policy-making, and resource allocation.

Prevalence and risk factors of mild cognitive impairment in a tertiary care setting in Turkey

BACKGROUND

Mild cognitive impairment (MCI) is an intermediate stage between healthy cognition and dementia, particularly Alzheimer's disease. There is limited information on the prevalence of MCI among older Turkish adults. This study aimed to determine the prevalence and risk factors of MCI in Turkey.

MATERIAL AND METHODS

A cross-sectional study was conducted with community-dwelling older people who were admitted to a tertiary geriatric outpatient clinic. Information on demographics and clinical variables was obtained. We used a neuropsychological battery to assess the cognitive domains in each subject. Participants who fell below 1.5 standard deviations on 1 or more of the 5 cognitive tests were considered MCI and were classified as either single domain MCI and multiple domain MCI. Risk factors were determined using univariate and multivariate logistic regression analyses.

RESULTS

A total of 259 participants were enrolled in this study. The mean age was 74.0 years (SD 7.1 years), 54% were women, and 48.3% had a low level of education (≤ 5 years). The overall prevalence of MCI was 52.1%, with 27.8% for single domain MCI and 24.3% for multiple domain MCI. The prevalence of MCI increased with age: 16.4% aged 65-74 years, 32.0% aged 75-84 years, and 40.9% ≥ 85 years. Advanced age and low educational level were risk factors for both single domain MCI (OR = 1.07; 95% CI: 1.02-1.13; p = 0.003 and OR = 3.18; 95% CI:1.7-6.1; p < 0.001) and multiple domain MCI (OR = 1.1; 95% CI:1.1-1.2; p < 0.001 and adjusted OR = 11.9; 95% CI:5.1-27.8; p < 0.001).

CONCLUSION

MCI was common in older Turkish people admitted to a tertiary hospital, especially in those with advanced age and low educational level.

Prevalence and associated factors of mild cognitive impairment among middle-aged and older adults: Results of the first phase of Ardakan Cohort Study on Aging

Background and Aims

Data on mild cognitive impairment (MCI) in low- to middle-income countries are still being determined, despite the fact that most future older adults are expected to reside in these regions. This study aimed to investigate the prevalence and associated factors of MCI in Iran.

Methods

A cross-sectional study was conducted on 4938 community-dwelling subjects aged 50 years or above in the first wave of the Ardakan Cohort Study on Aging. MCI was evaluated using the Mini-Mental State Examination (MMSE) and the Abbreviated Mental Test Score (AMTS) in literate and illiterate individuals. The relationship between factors associated with the odds of MCI was assessed through logistic regression.

Results

The prevalence of MCI among all participants, the literates and illiterates, was 15.8%, 6.3%, and 36.4%, respectively. It was found that failure to accomplish any of the MMSE or AMTS items was significantly related to MCI (p < 0.001). Age ([odds ratio (OR): 1.05; p < 0.001 in the literates], [OR: 1.06; p < 0.001 in the illiterates]), sex (OR: 0.13; p < 0.001 in the illiterates), history of stroke ([OR: 2.86; p = 0.006 in the literates], [OR: 2.04; p = 0.045 in the illiterates]), and depression ([OR: 1.87; p < 0.001 in the literates], [OR: 1.41; p = 0.008 in the illiterates]) were significantly associated with MCI.

Conclusion

This study highlights the significant associations between age, education, depression, stroke, and MCI in Iranian participants. These findings emphasize the need for targeted interventions in low-literacy populations, mental health screening, and stroke prevention strategies to mitigate the burden of MCI and enhance cognitive health.

Loss-of-Set and Strategy Application on the Menu Task: An Exploratory Study

Background. The Menu Task (MT) is an occupational therapy screening measure designed to identify people in need of functional cognitive (FC) assessment. Purpose. To explore whether test-taker strategy selection on the MT is clinically informative. Methods. Using a cross-sectional design we administered assessments of FC including the MT and the After MT interview, cognitive screening measures, and self-report instrumental activities of daily living assessment to a convenience sample of 55 community-dwelling adults. After MT interviews responses were qualitatively characterized as (a) loss of set (e.g., not recognizing that food preferences are irrelevant to task performance), (b) calorie counting, or (c) planning. Findings. Loss of set was associated with poorer performance on most study measures, calorie counting was associated with superior performance on most study measures, and no differences were observed relating to planning. Implications. Determining the test-takers approach to the MT adds information to that provided by the MT itself.

Usability testing of the first prototype of the Memento system: a technological device to promote an independent living in people with dementia

PURPOSE

Assistive technologies have the potential for supporting people with memory complaints in their daily life. User-centered interaction design research helps developers to create systems that are suitable for users. The aim of this work is to describe the methodology and the results of the usability test for the first Memento prototype involving users.

MATERIALS AND METHODS

In each country, 5 subjects with different levels of cognitive reserve and technical proficiency were enrolled in Italy, Austria and Spain, respectively (15 subjects; 6 M; 9 F, age 72.8 ± 10.8 years, MMSE score 25.6 ± 1.6). Observation methods, performance metrics and the System Usability Scale were used to collect data.

RESULTS

The results are presented in terms of design, technical problems, target-group-related challenges and usability perception from the participant perspective. Suggestions for improvement were pointed out by the users. Considering the usability scores interpretation, the first prototype was classified as "OK" and "Good" by users.

CONCLUSIONS

The results of the Lab Trials provide important information on usability and the users' needs in order to improve the Memento prototype and to create a final system to be evaluated during the Field Trials phase of the project.Implication for rehabilitationThe MEMENTO project mission is to improve the quality of life of people in the early and middle stages of dementia, by supporting the management of daily activities that are usually affected by the loss of memory and cognition. The Lab Trial phase is essential to have feedback on the usability of the Memento prototype to allow a better understanding of users' needs and expectations.

Current Challenges in the Diagnosis of Progressive Neurocognitive Disorders: A Critical Review of the Literature and Recommendations for Primary and Secondary Care

Screening for early symptoms of cognitive impairment enables timely interventions for patients and their families. Despite the advances in dementia diagnosis, the current nosography of neurocognitive disorders (NCDs) seems to overlook some clinical manifestations and predictors that could contribute to understanding the conversion from an asymptomatic stage to a very mild one, eventually leading to obvious disease. The present review examines different diagnostic approaches in view of neurophysiological and neuropsychological evidence of NCD progression, which may be subdivided into: (1) preclinical stage; (2) transitional stage; (3) prodromal or mild stage; (4) major NCD. The absence of univocal criteria and the adoption of ambiguous or narrow labels might complicate the diagnostic process. In particular, it should be noted that: (1) only neuropathological hallmarks characterize preclinical NCD; (2) transitional NCD must be assessed through proactive neuropsychological protocols; (3) prodromal/mild NCDs are based on cognitive functional indicators; (4) major NCD requires well-established tools to evaluate its severity stage; (5) insight should be accounted for by both patient and informants. Therefore, the examination of evolving epidemiological and clinical features occurring at each NCD stage may orient primary and secondary care, allowing for more targeted prevention, diagnosis, and/or treatment of both cognitive and functional impairment.

Effect of indoor air quality on the association of long-term exposure to low-level air pollutants with cognition in older adults

BACKGROUND

How indoor air quality affects the temporal associations of long-term exposure to low-level air pollutants with cognition remains unclear.

METHODS

This cohort study (2011-2019) included 517 non-demented older adults at baseline with four repeated cognitive assessments. The time-varying exposure to PM2.5, PM10, NO2, SO2, CO, and O3 was estimated for each participant from 1994 to 2019. Indoor air quality was determined by ventilation status and daily indoor time. Generalized linear mixed models were used to analyze the association of air pollutants, indoor air quality, and cognition adjusting for important covariates.

RESULTS

Over time, per 2.97 μg/m3 (i.e., an interquartile range) increment of PM2.5 was associated with the poor performance of memory (Z score of a cognitive test, βˆ:-0.14), attention (βˆ:-0.13), and executive function (βˆ:-0.20). Similarly, per 2.05 μg/m3 increase in PM2.5-10 was associated with poor global cognition [adjusted odds ratio (aOR): 1.48, βˆ:-0.28], attention (βˆ:-0.07), and verbal fluency (βˆ:-0.09); per 4.94 μg/m3 increase in PM10 was associated with poor global cognition (aOR: 1.78; βˆ:-0.37). In contrast, per 2.74 ppb increase in O3 was associated with better global cognition (βˆ:0.36 to 0.47). These associations became more evident in participants with poor ventilation or short daily indoor time (<12.5 h/day). For global cognition, the exposure to a 10-μg/m3 increment in PM2.5, PM2.5-10, and PM10 corresponded to 1.4, 5.8, and 2.8 years of aging, respectively.

CONCLUSION

This study demonstrated how indoor air quality in areas using clean fuels differentially affected the associations of long-term exposure to low-level air pollutants with cognition. Tightening air quality standards may help prevent dementia.

Global prevalence of mild cognitive impairment among older adults living in nursing homes: a meta-analysis and systematic review of epidemiological surveys

Mild cognitive impairment (MCI) is the early stage of cognitive impairment between the expected cognitive decline of normal aging and the more serious decline of dementia. This meta-analysis and systematic review explored the pooled global prevalence of MCI among older adults living in nursing homes and its relevant factors. The review protocol was registered in INPLASY (INPLASY202250098). PubMed, Web of Science, Embase, PsycINFO, and CINAHL databases were systematically searched from their respective inception dates to 8 January 2022. The inclusion criteria were made based on the PICOS acronym, as follows: Participants (P): Older adults living in nursing homes; Intervention (I): not applicable; Comparison (C): not applicable; Outcome (O): prevalence of MCI or the data can generate the prevalence of MCI according to study-defined criteria; Study design (S): cohort studies (only baseline data were extracted) and cross-sectional studies with accessible data published in a peer-reviewed journal. Studies involving mixed resources, reviews, systematic reviews, meta-analyses, case studies, and commentaries were excluded. Data analyses were performed using Stata Version 15.0. Random effects model was used to synthesize the overall prevalence of MCI. An 8-item instrument for epidemiological studies was used to assess the quality of included studies. A total of 53 articles were included involving 376,039 participants with a mean age ranging from 64.42 to 86.90 years from 17 countries. The pooled prevalence of MCI in older adults in nursing homes was 21.2% (95% CI: 18.7-23.6%). Subgroup and meta-regression analyses revealed that the screening tools used were significantly associated with MCI prevalence. Studies using the Montreal Cognitive Assessment (49.8%) had a higher prevalence of MCI than those using other instruments. No significant publication bias was found. Several limitations warrant attention in this study; for example, significant heterogeneity between studies remained and some factors associated with the prevalence of MCI were not examined due to insufficient data. Adequate screening measures and allocation of resources are needed to address the high global prevalence of MCI among older adults living in nursing homes.

Mechanisms and Clinical Manifestations of Cognitive Decline in Atrial Fibrillation Patients: Potential Implications for Preventing Dementia

Atrial fibrillation (AF) patients face an approximate 1.5-fold increased risk of cognitive decline compared with the general population. Among poststroke AF patients, the risk of cognitive decline is even higher with an estimated threefold increase. This article provides a narrative review on the current evidence and highlights gaps in knowledge and areas for future research. Although earlier studies hypothesized that the association between AF and cognitive decline is mainly a consequence of previous ischemic strokes, more recent evidence also suggests such an association in AF patients without a history of clinical stroke. Because AF and cognitive decline mainly occur among elderly individuals, it is not surprising that both entities share multiple risk factors. In addition to clinically overt ischemic strokes, silent brain infarcts and other brain injury are likely mechanisms for the increased risk of cognitive decline among AF patients. Oral anticoagulation for stroke prevention in AF patients with additional stroke risk factors is one of the only proven therapies to prevent brain injury. Whether a broader use of oral anticoagulation, or more intense anticoagulation in some patients are beneficial in this context needs to be addressed in future studies. Although direct studies are lacking, it is reasonable to recommend optimal treatment of comorbidities and risk factors for the prevention of cognitive decline and dementia.

Metabolic syndrome and cognition: A systematic review across cognitive domains and a bibliometric analysis

The aim of this review is to investigate the association between metabolic syndrome (MetS) and cognitive decline in distinct cognitive domains, and to perform a complementary study description through the bibliometric analysis. PubMed and Scopus databases were searched from inception to 15 December 2021 to identify longitudinal studies that examined the association of MetS with incident decline, in order to prevent reverse causality. The Preferred Reporting Items for Systematic Review and Meta-Analysis checklist was used to conduct the present systematic review. Thirty studies were included and results were analyzed across the cognitive domains of global cognition, memory, executive functions, attention, visuoconstructive abilities, and language. The majority of the studies reviewed did not report statistically significant results for most cognitive domains investigated, and decline in specific cognitive domains was not consistently associated with the presence of MetS. Meta-analyses were not conducted due to the high degree of between-study heterogeneity regarding the MetS definitions, the cognitive domains examined, the specific tests used for each cognitive domain and the different measures of association used. Bibliometric analysis revealed that most studies are conducted by research teams from USA and China, and that cognitive tasks that reflect real-life abilities are rarely examined. Future studies should employ larger sample sizes, longer follow-up periods, a global consensus for MetS definition and standardized tests of the above mentioned cognitive domains as well as problem-solving tasks with high sensitivity and specificity to clarify the impact of MetS on cognition and its underlying mechanisms.

Efficacy of mindfulness-based interventions in cognitive function in the elderly people: a systematic review and meta-analysis

OBJECTIVES

The main objective was to determine the efficacy of Mindfulness-Based Interventions in improving the cognitive function of older adults (healthy adults or adults with mild cognitive impairment).

METHODS

A search was conducted in 4 databases. The effect sizes were extracted to perform a meta-analysis of the cognitive functions, as well as subgroup meta-analyses according to each domain: attention, memory and executive function.

RESULTS

The meta-analysis of cognitive functions showed an average effect size of g = .07, 95% CI [-.013; .160], p = .09, with the following values for each domain: g = .02, 95% CI [-.167; .204] for attention; g = .06, 95% CI [-.148; .262] for memory; and g = .14, 95% CI [-.042; .329] for executive function.

CONCLUSION

The MBI had a null global effect. The attention and memory results showed a null effect size and a small effect size was found for executive function. The methodological quality of the studies, however, was poor, so the results need to be interpreted with caution.

The prevalence of mild cognitive impairment in Latin America and the Caribbean: a systematic review and meta-analysis

OBJECTIVES

The population of Latin America and Caribbean (LAC) is ageing rapidly, presenting the highest prevalence rates of dementia in the world. Mild cognitive impairment (MCI) is an intermediate condition between normal ageing, Alzheimer's disease, and related dementias. We conducted a systematic review to evaluate the prevalence of MCI in LAC countries and explore factors associated with MCI (i.e. age, sex/gender, and education).

METHOD

A database search was conducted in September 2020 using PubMed, Web of Science, Scopus, Lilacs, SciELO, EMBASE, and medRxiv for population- or community-based studies, published in English, Spanish, or Portuguese.

RESULTS

From 2,155 screened studies, we selected reports including subjects with a precise diagnosis of MCI. A total of 11 studies met the inclusion criteria, adding up to 20,220 participants in nine countries: Brazil, Mexico, Argentina, Colombia, Peru, Cuba, Dominican Republic, Venezuela, and Costa Rica. Estimates for all-type MCI prevalence ranged from 6.8% to 25.5% and amnestic MCI between 3.1% and 10.5%. Estimates differed by age and education, with oldest and lower-educated adults presenting higher MCI prevalence.

CONCLUSION

This first systematic review of the prevalence of MCI discusses the population strata with the highest potential to benefit from dementia risk reduction interventions in LAC countries.

Further Validation of the Menu Task: Functional Cognition Screening for Older Adults

Occupational therapists need a brief tool to identify the potential for functional cognitive deficits leading to impaired occupational performance. The objective is to establish the sensitivity and specificity, concurrent and known-group validity of the Menu Task by comparison with performance on the Weekly Calendar Planning Activity (WCPA). Using a cross-sectional design, we administered the Menu Task and the WCPA to a community-dwelling convenience sample of 287 adults aged from 55 to 93 years. The receiver operating characteristic (ROC) analysis estimated sensitivity and specificity. Concurrent and known-group construct validity was examined by comparing scores on the Menu Task with the WCPA scores. As a result, a new cutoff score of 9 was established for the Menu Task (area under the curve [AUC] = 0.80, sensitivity = 0.89, 95% confidence interval [CI] = [0.73, 0.97]; specificity = 0.58, 95% CI = [0.52, 0.64]). Both concurrent and construct validity were supported. The Menu Task demonstrates sensitivity to functional cognitive impairments in a community sample.

The Predictive Value of Anticholinergic Burden Measures in Relation to Cognitive Impairment in Older Chronic Complex Patients

Anticholinergic burden (AB) is related to cognitive impairment (CI) and older complex chronic patients (OCCP) are more susceptible. Our objective was to evaluate the predictive value of ten anticholinergic scales to predict a potential CI due to anticholinergic pharmacotherapy in OCCP. An eight-month longitudinal multicentre study was carried out in a cohort of OCCP, in treatment with at least one anticholinergic drug and whose cognition status had been evaluated by Pfeiffer test twice for a period of 6-15 months. CI was considered when the Pfeiffer test increased 2 or more points. AB was detected using ten scales included on the Anticholinergic Burden Calculator. An ROC curve analysis was performed to assess the discriminative capacity of the scales to predict a potential CI and the cut-off point of AB that obtains better validity indicators. 415 patients were included (60.2% female, median age of 85 years (IQR = 11)). 190 patients (45.8%) manifested CI. Only the DBI (Drug Burden Index) showed statistically significant differences in the median AB between patients without CI and with CI (0.5 (1.00) vs. 0.67 (0.65), p = 0.006). At the ROC curve analysis, statistically significant values were obtained only with the DBI (AUC: 0.578 (0.523-0.633), p = 0.006). The cut-off point with the greatest validity selected for the DBI was an AB of 0.41 (moderate risk) (sensitivity = 81%, specificity = 36%, PPV = 51%). The DBI is the scale with the greatest discriminatory power to detect OCCP at risk of CI and the best cut-off point is a load value of 0.41.

Standardised results of the Montreal Cognitive Assessment (MoCA) for neurocognitive screening in a Chilean population

INTRODUCTION

Population ageing poses a challenge for countries in preventing and detecting neurodegenerative disorders. The Montreal Cognitive Assessment (MoCA), a short, simple, valid, and reliable screening test, assesses general cognitive status, and is useful in public health contexts. This study aims to normalise and standardise the MoCA test for the Chilean population.

METHOD

We performed a descriptive, correlational validation study of the MoCA test, using a sample including 526 healthy individuals of both sexes, aged between 18 and 90 years, from the north, centre, and south of Chile. We analysed the effects of age, education level, and sex on MoCA performance.

RESULTS

Age and education level had a significant impact on general cognitive performance, as determined by MoCA score. Age, education, and sex account for 1%-7% of variance. The mean (standard deviation) score for the total sample was 24.04 (3.22), whereas the normal range originally defined for the instrument is 26-30 points. Older adults with less formal education presented poorer results and lower cognitive performance. We propose a protocol for evaluating results by percentiles and scores for different age ranges, and an individual normalised scalar score.

DISCUSSION

We present normative data for the MoCA test in the Chilean population, and propose cut-off points for different age ranges to discriminate normal cognitive performance from neurocognitive disorders; results are adjusted for education level. This proposal would assist in the use of the test and reduce the rate of false positives.

Risk of conversion from mild cognitive impairment to dementia in low- and middle-income countries: A systematic review and meta-analysis

Introduction

With no treatment for dementia, there is a need to identify high risk cases to focus preventive strategies, particularly in low‐ and middle‐income countries (LMICs) where the burden of dementia is greatest. We evaluated the risk of conversion from mild cognitive ompairment (MCI) to dementia in LMICs.

Methods

Medline, Embase, PsycINFO, and Scopus were searched from inception until June 30, 2020. The search was restricted to observational studies, conducted in population‐based samples, with at least 1 year follow‐up. There was no restriction on the definition of MCI used as long as it was clearly defined. PROSPERO registration: CRD42019130958.

Results

Ten thousand six hundred forty‐seven articles were screened; n = 11 retained. Of the 11 studies, most were conducted in China (n = 7 studies), with only two studies from countries classified as low income. A qualitative analysis of n = 11 studies showed that similar to high‐income countries the conversion rate to dementia from MCI was variable (range 6.0%–44.8%; average follow‐up 3.7 years [standard deviation = 1.2]). A meta‐analysis of studies using Petersen criteria (n = 6 studies), found a pooled conversion rate to Alzheimer's disease (AD) of 23.8% (95% confidence interval = 15.4%–33.4%); approximately one in four people with MCI were at risk of AD in LMICs (over 3.0–5.8 years follow‐up). Risk factors for conversion from MCI to dementia included demographic (e.g., age) and health (e.g., cardio‐metabolic disease) variables.

Conclusions

MCI is associated with high, but variable, conversion to dementia in LMICs and may be influenced by demographic and health factors. There is a notable absence of data from low‐income settings and countries outside of China. This highlights the urgent need for research investment into aging and dementia in LMIC settings. Being able to identify those individuals with cognitive impairment who are at highest risk of dementia in LMICs is necessary for the development of risk reduction strategies that are contextualized to these unique settings.

The Relationship Between Low-Density Lipoprotein Cholesterol and Progression of Mild Cognitive Impairment: The Influence of rs6859 in PVRL2

Background: Genome-wide association studies have identified many Alzheimer’s disease (AD) genetic-risk single nucleotide polymorphisms (SNPs) and indicated the important role of the cholesterol/lipid metabolism pathway in AD pathogenesis. This study aims to investigate the effects of cholesterol and genetic risk factors on progression of mild cognitive impairment (MCI) to AD.

Methods: We prospectively followed 316 MCI participants aged ≥50 years with a baseline cholesterol profile and SNP genotyping data for 4.5 years on average in a sub-cohort of the Shanghai Aging Study. Total cholesterol, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol in serum were measured at baseline. SNP genotyping was performed using a MassARRAY system. At follow-up, consensus diagnosis of incident dementia and AD were established based on medical, neurological, and neuropsychological examinations. Cox regression models were used to assess the association of cholesterol and SNP with incident AD.

Results: The AG/AA genotypes of PVRL2 rs6859 were significantly associated with increased incident AD in MCI participants, compared with GG genotype (adjusted hazard ratio [HR] 2.75, 95% confidence interval [CI] 1.32–5.76, p = .007, false discovery rate–adjusted p = .030). In PVRL2 rs6859 AG/AA carriers, each-1 mmol/L higher level of LDL-C was significantly associated with a 48% decreased risk of AD (adjusted HR 0.52, 95%CI 0.33–0.84, p = .007). Consistent results were obtained when using LDL-C as the categorical variable (P for trend = 0.016).

Conclusion: The relationship between LDL-C and progression of MCI may be influenced by genetic variants.

The Prevalence of Amnestic and Non-Amnestic Mild Cognitive Impairment and Its Association with Different Lifestyle Factors in a South Italian Elderly Population

Mild Cognitive Impairment (MCI) is a transition stage between normal aging and dementia and can be useful to monitor the cognitive status of people at risk of dementias. Our aims were to investigate the prevalence of amnestic and non-amnestic MCI in a South Italian elderly population, and to identify socio-demographic, clinical and lifestyle factors associated with MCI. A cross-sectional retrospective population study on 839 community-dwelling participants over 60 years of age was carried out. Elderly people were administered a brief neuropsychological screening to identify their cognitive and functional status, and a questionnaire to investigate several socio-demographic, clinical, and lifestyle factors. Prevalence estimate for MCI was 12.0% (95% CI: 10.0–14.5%), for amnestic MCI was 7.4% (95% CI: 5.8–9.4%), and for non-amnestic MCI was 4.6% (95% CI: 3.4–6.4%), for people older than 60 years of age. Logistic regression models, corrected for age, sex, and education, revealed a significant association of MCI with the following factors: age, education, intellectual activities, and topographical disorientation. On the other hand, education, clinical factors (e.g., depression level and perceived physical pain), lifestyle factors (e.g., smoking, alcohol, and leisure/productive activities), dietary habits, quality of life, and self-reported topographical disorientation were non-significantly associated with MCI. Prevalence estimates and the association of MCI and its subtypes with risk and protective factors were discussed in comparison with the most recent systematic reviews and meta-analyses.

"Is It Removed During Dialysis?"-Cognitive Dysfunction in Advanced Kidney Failure-A Review Article

Cognitive impairment is independently associated with kidney disease and increases in prevalence with declining kidney function. At the stage where kidney replacement therapy is required, with dialysis or transplantation, cognitive impairment is up to three times more common, and can present at a younger age. This is not a new phenomenon. The cognitive interactions of kidney disease are long recognized from historical accounts of uremic encephalopathy and so-called "dialysis dementia" to the more recent recognition of cognitive impairment in those undergoing kidney replacement therapy (KRT). The understanding of cognitive impairment as an extra-renal complication of kidney failure and effect of its treatments is a rapidly developing area of renal medicine. Multiple proposed mechanisms contribute to this burden. Advanced vascular aging, significant multi-morbidity, mood disorders, and sleep dysregulation are common in addition to the disease-specific effects of uremic toxins, chronic inflammation, and the effect of dialysis itself. The impact of cognitive impairment on people living with kidney disease is vast ranging from increased hospitalization and mortality to decreased quality of life and altered decision making. Assessment of cognition in patients attending for renal care could have benefits. However, in the context of a busy clinical service, a pragmatic approach to assessing cognitive function is necessary and requires consideration of the purpose of testing and resources available. Limited evidence exists to support treatments to mitigate the degree of cognitive impairment observed, but promising interventions include physical or cognitive exercise, alteration to the dialysis treatment and kidney transplantation. In this review we present the history of cognitive impairment in those with kidney failure, and the current understanding of the mechanisms, effects, and implications of impaired cognition. We provide a practical approach to clinical assessment and discuss evidence-supported treatments and future directions in this ever-expanding area which is pivotal to our patients' quality and quantity of life.

Processing speed is affected by early impairment in kidney function in the general elder population

Background

Chronic kidney disease, cardiovascular disease, and cognitive dysfunction are common in the elder population. There is evidence of a connection between these conditions, possibly by a shared vascular pathogenesis. Processing speed is commonly impaired in cerebrovascular disease.

Methods

The data was obtained from the population based study “Good aging in Skåne” (GÅS), and included 905 individuals (mean age = 68 years). We investigated the impact of impaired kidney function at baseline on the development of dementia, MCI, and impairment in specific cognitive domains at follow up 6 years later, using logistic regression models. Impaired kidney function was defined as GFR < 60 ml/min/1,73 m². GFR was estimated from creatinine and cystatin C, using the CKD-EPI formula. Function in the cognitive domains learning and memory, language, complex attention, executive function, perceptual-motor, as well as meta-memory, and global cognitive function, was assessed using a neuropsychological test battery consisting of 12 tests. We compared the test results from follow up, with the results obtained at baseline, using linear regression models in order to assess changes in performance in cognitive domains.

Results

At follow up, 14 and 158 participants had developed dementia and MCI, respectively. We did not find evidence that moderately impaired eGFR at baseline increased the odds of dementia or MCI. A decline in processing speed was associated with impaired kidney function.

Conclusions

The effect on processing speed could represent early vascular implications on cognition. Even at moderately impaired kidney function, overview of cardiovascular risk factors could potentially prevent further cognitive impairment.

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.

Does older subjective age predict poorer cognitive function and higher risk of dementia in middle-aged and older adults?

As a biopsychosocial marker of aging, subjective age (i.e., the age individuals feel regardless of their actual age) was related to many health issues in the elderly. The purpose of this study is to investigate whether subjective age is associated with subsequent cognition and dementia risk in middle-aged and older adults. Samples were drawn from the English Longitudinal Study of Ageing (ELSA). Participants reported their subjective ages at the baseline (2004/2005), and their cognitive functions were measured after 10 years (2014/2015). Newly diagnosed dementias were recorded between 2006/2007 to 2014/2015. Overall, 6,475 adults aged 50 years or older were included in the current analyses. The relationship between subjective age reported at baseline and cognition assessed ten years later was modeled using multiple linear regression models. Compared to participants who reported a younger subjective age, those who reported an older subjective age were more likely to have poorer cognition after ten years (β = -0.705, P = .002 for memory, β = -1.567, P = .001 for executive function). A Cox proportional hazard regression model suggested that older subjective age was an independent risk factor for incident dementia (HR = 1.737, 95% CI =1.060-2.848). Other than chronological age, subjective age could also be considered as an important predictor for the development of cognitive dysfunction.

Prevalence and Risk of Mild Cognitive Impairment in Low and Middle-Income Countries: A Systematic Review

Background: Mild cognitive impairment (MCI) is a cognitive state associated with increased risk of dementia. Little research on MCI exists from low-and middle-income countries (LMICs), despite high prevalence of dementia in these settings. Objective: This systematic review aimed to review epidemiological reports to determine the prevalence of MCI and its associated risk factors in LMICs. Methods: Medline, Embase, and PsycINFO were searched from inception until November 2019. Eligible articles reported on MCI in population or community-based studies from LMICs and were included as long as MCI was clearly defined. Results: 5,568 articles were screened, and 78 retained. In total, n = 23 different LMICs were represented; mostly from China (n = 55 studies). Few studies were from countries defined as lower-middle income (n = 14), low income (n = 4), or from population representative samples (n = 4). There was large heterogeneity in how MCI was diagnosed; with Petersen criteria the most commonly applied (n = 26). Prevalence of amnesic MCI (aMCI) (Petersen criteria) ranged from 0.6%to 22.3%. Similar variability existed across studies using the International Working Group Criteria for aMCI (range 4.5%to 18.3%) and all-MCI (range 6.1%to 30.4%). Risk of MCI was associated with demographic (e.g., age), health (e.g., cardio-metabolic disease), and lifestyle (e.g., social isolation, smoking, diet and physical activity) factors. Conclusion: Outside of China, few MCI studies have been conducted in LMIC settings. There is an urgent need for population representative epidemiological studies to determine MCI prevalence in LMICs. MCI diagnostic methodology also needs to be standardized. This will allow for cross-study comparison and future resource planning.

Trends in Dementia and Mild Cognitive Impairment Prevalence and Incidence in German General and Specialist Practices Between 2015 and 2019

BACKGROUND

The number of patients with dementia is forecast to grow continuously. However, there are indications that the incidence and prevalence is falling in high-income countries.

OBJECTIVE

To examine whether any effects of declining incidence and prevalence rates of dementia and mild cognitive impairment (MCI) were evident in Germany between 2015 and 2019.

METHODS

The analysis was based on 797 general and 132 specialists (neurological/psychiatric) practices and included 10.1 million patients aged 18 years and older who visited between January 2014 and December 2019 one of the practitioners. The prevalence and incidence of dementia and MCI were demonstrated descriptively.

RESULTS

Between 2015 and 2019, the prevalence (incidence) of dementia decreased from 2.18%(0.44%) in 2015 to 2.07%(0.35%) in 2019. A relatively large decrease in the prevalence (incidence) of dementia was observed in patients aged 80 and older, at -1.47%(-0.62%), compared to younger patients, at -0.40%(-0.18%). By contrast, the prevalence and incidence of MCI have remained constant over the years (0.19%to 0.22%and 0.06%, respectively). Overall, the number of patients diagnosed with dementia decreased slightly by 1%while the number of patients diagnosed with MCI increased by 17%.

CONCLUSION

Our results confirmed the reduction in the prevalence and incidence of dementia and revealed a decrease in the number of patients with dementia despite continued demographic changes. Future studies are warranted to determine whether the results are caused by changing risk and lifestyle factors or changes in medical diagnosis and treatment behavior of the practitioners.

Association Between Dietary Fish and PUFA Intake in Midlife and Dementia in Later Life: The JPHC Saku Mental Health Study

BACKGROUND

The relationship between midlife dietary habits and risk of dementia remains unclear.

OBJECTIVE

To investigate the association between dietary fish and n-3 polyunsaturated fatty acid (PUFA) consumption in midlife and risk of dementia in later life.

METHODS

This population-based cohort study assessed food frequency (average intake in 1995 and 2000) and cognition (2014-2015) in 1,127 participants (aged 45-64 in 1995). We used logistic regression analyses to calculate odds ratios (ORs) for dementia and mild cognitive impairment (MCI) diagnoses for consumption quartiles of fish, PUFA-rich fish, total n-3 PUFAs, total n-6 PUFAs, types of PUFAs, and n-3/n-6 PUFA ratio. Estimated ORs were adjusted for age; sex; education; smoking status; alcohol consumption frequency; physical activity; histories of cancer, myocardial infarction, and diabetes mellitus; and depression.

RESULTS

Significantly reduced risks of dementia over non-dementia (MCI plus cognitively normal) were observed in the second (OR = 0.43 (95% CI = 0.20-0.93)), third (OR = 0.22 (95% CI = 0.09-0.54)), and highest quartiles (OR = 0.39 (95% CI = 0.18-0.86)) for fish; the third (OR = 0.39 (95% CI = 0.16-0.92)) and highest quartiles (OR = 0.44 (95% CI = 0.19-0.98)) for eicosapentaenoic acid (EPA); the second (OR = 0.39 (95% CI = 0.18-0.84)), third (OR = 0.30 (95% CI = 0.13-0.70)), and highest quartiles (OR = 0.28 (95% CI = 0.12-0.66)) for docosahexaenoic acid (DHA); and the third (OR = 0.36 (95% CI = 0.16-0.85)) and highest quartiles (OR = 0.42 (95% CI = 0.19-0.95)) for docosapentaenoic acid (DPA).

CONCLUSION

High intake of fish in midlife might aid in preventing dementia.

Predementia constructs: Mild cognitive impairment or mild neurocognitive disorder? A narrative review

BACKGROUND

Predementia is a heuristic umbrella concept to classify older adults with cognitive impairment who do not suffer dementia. Many diagnostic entities have been proposed to address this concept, but most of them have not had widespread acceptance.

AIMS

To review clinical definitions, epidemiologic data (prevalence, incidence) and rate of conversion to dementia of the main predementia constructs, with special interest in the two most frequently used: mild cognitive impairment (MCI) and minor neurocognitive disorder (miNCD).

METHODS

We have selected in three databases (MEDLINE, Web of Science and Google scholar) the references from inception to 31 December 2019 of relevant reviews, population and community-based surveys, and clinical series with >500 participants and >3 years follow-up as the best source of evidence.

MAIN RESULTS

The history of predementia constructs shows that MCI is the most referred entity. It is widely recognized as a clinical syndrome harbinger of dementia of several etiologies, mainly MCI due to Alzheimer's disease. The operational definition of MCI has shortcomings: vagueness of its requirement of "preserved independence in functional abilities" and others. The recent miNCD construct presents analogous difficulties. Current data indicate that it is a stricter predementia condition, with lower prevalence than MCI, less sensitivity to cognitive decline and, possibly, higher conversion rate to dementia.

CONCLUSIONS

MCI is a widely employed research and clinical entity. Preliminary data indicate that the clinical use of miNCD instead of MCI requires more scientific evidence. Both approaches have common limitations that need to be addressed.

Standardized results of the Montreal Cognitive Assessment (MoCA) for neurocognitive screening in a Chilean population

INTRODUCTION

Population ageing poses a challenge for countries in preventing and detecting neurodegenerative disorders. The Montreal Cognitive Assessment (MoCA), a short, simple, valid, and reliable screening test, assesses general cognitive status, and is useful in public health contexts. This study aims to normalise and standardise the MoCA test for the Chilean population.

METHOD

We performed a descriptive, correlational validation study of the MoCA test, using a sample including 526 healthy individuals of both sexes, aged between 18 and 90 years, from the north, centre, and south of Chile. We analysed the effects of age, education level, and sex on MoCA performance.

RESULTS

Age and education level had a significant impact on general cognitive performance, as determined by MoCA score. Age, education, and sex account for 1-7% of variance. The mean (standard deviation) score for the total sample was 24.04 (3.22), whereas the normal range originally defined for the instrument is 26-30 points. Older adults with less formal education presented poorer results and lower cognitive performance. We propose a protocol for evaluating results by percentiles and scores for different age ranges, and an individual normalised scalar score.

DISCUSSION

We present normative data for the MoCA test in the Chilean population, and propose cut-off points for different age ranges to discriminate normal cognitive performance from neurocognitive disorders; results are adjusted for education level. This proposal would assist in the use of the test and reduce the rate of false positives.

Prevalence of Cognitive Complaints and Impairment in Patients with Chronic Subdural Hematoma and Recovery after Treatment: A Systematic Review

Chronic subdural hematoma (CSDH) is a frequently occurring neurological disease associated with older age and use of anticoagulants. Symptoms vary from headaches to coma, but cognitive deficits can also be present. However, exact prevalence and severity of cognitive deficits in CSDH are still unknown. In this systematic review, we aim to assess cognitive status of patients with CSDH, at presentation and after treatment. PubMed, Embase and PsycInfo were searched for articles concerning cognition in CSDH. We divided cognitive changes into subjective cognitive deficit (cognitive complaints [CC]) and objective cognitive deficit (cognitive impairment [CI]). Two reviewers independently selected studies for inclusion and subsequently extracted data. Quality assessment was done by means of the Newcastle-Ottawa Scale. Reported prevalence of CC and CI was pooled with random effects meta-analysis. Out of 799 identified references, 22 met inclusion criteria. Twenty-one articles reported on prevalence of CC/CI and one study reported solely on CSDH patients with cognitive deficit. Estimated pooled prevalence of both CC and CI in CSDH at presentation was 45% (95% confidence interval [CI]: 36-54%). Four studies concerned a prospective evaluation of the effect of surgical treatment on cognition. These proved to be of fair to good quality after quality assessment. The estimated pre-treatment prevalence of objectified cognitive impairment was 61% (95% CI: 51-70%) decreasing to 18% (95% CI: 8-32%) post-surgery. From this review it can be concluded that CC and CI are very common in CSDH, with a tendency to improve after treatment. Therefore, we underline the importance of increased attention to cognitive status of these patients, with proper testing methods and treatment-testing intervals.

The effect of resistance training on sleep in Chinese older adults: A randomized controlled trial

Sleep disturbances affect approximately half of the older adult population and add additional risks of developing Alzheimer's disease. This study is to test the effects of a 12-week resistance training (RT) program on sleep in older adults residing in an assisted living facility in China. A total of 62 eligible participants were randomly assigned to RT (n = 31) or control group (n = 31). Participants in RT group participated in three 1-hour moderate intensity RT sessions per week for 12 weeks (at least 48 h between sessions). In the overall sample, sleep efficiency increased (P < 0.01), wake after sleep onset (P < 0.01) decreased in participants in RT group at post-intervention, compared to control group. Similar results were found in participants with mild cognitive impairment (MCI). The findings support that RT improves sleep efficiency and decreases sleep fragmentation in older adults in general and in those with MCI.

Cognitive function and its transitions in predicting all-cause mortality among urban community-dwelling older adults

BACKGROUND

Cognitive impairment is accompanied with high rates of comorbid conditions, leading ultimately to death. Few studies examine the relation between cognitive transition and mortality, especially in Asian population. This study evaluated baseline cognition and cognitive transition in relation to all-cause mortality among community-dwelling older adults.

METHODS

We conducted a community-based prospective cohort study among 921 participants of Taichung Community Health Study for Elders in 2009. Cognitive function was evaluated by the Mini-Mental State Examination. Cognitive impairment was considered if the total score is less than 27, 24, and 21 for a participant's educational level of more than 6 years, equal or less than 6 years, and illiteracy, respectively. One-year transition in cognitive function was obtained among 517 individuals who were assessed in both 2009 and 2010. Mortality was followed up until 2016. Cox proportional hazards models were applied to estimate the adjusted hazard ratios of mortality for baseline cognitive impairment and one-year transition in cognitive status.

RESULTS

After a follow-up of 6.62 years, 160 deaths were recorded. The multivariate adjusted hazard ratio (95% confidence interval) for baseline cognitive impairment was 2.08 (1.43, 3.01). Significantly increased mortality risk was observed for cognitively impaired-normal and impaired-impaired subgroups over 1 year as compared with those who remained normal [2.87 (1.25, 6.56) and 3.79 (1.64, 8.73), respectively]. The area under the receiver operating characteristic curves demonstrated that baseline cognition and one-year cognitive transition had no differential predictive ability for mortality. Besides, there was an interaction of cognitive impairment and frailty, with an additive mortality risk [5.41 (3.14, 9.35)] for the elders who presented with both.

CONCLUSION

Baseline cognitive impairment rather than one-year progression is associated with mortality in a six-year follow-up on older adults.

The European medical information framework: A novel ecosystem for sharing healthcare data across Europe

INTRODUCTION

The European medical information framework (EMIF) was an Innovative Medicines Initiative project jointly supported by the European Union and the European Federation of Pharmaceutical Industries and Associations, that generated a common technology and governance framework to identify, assess and (re)use healthcare data, to facilitate real-world data research. The objectives of EMIF included providing a unified platform to support a wide range of studies within two verification programmes-Alzheimer's disease (EMIF-AD), and metabolic consequences of obesity (EMIF-MET).

METHODS

The EMIF platform was built around two main data-types: electronic health record data and research cohort data, and the platform architecture composed of a set of tools designed to enable data discovery and characterisation. This included the EMIF catalogue, which allowed users to find relevant data sources, including the data-types collected. Data harmonisation via a common data model were central to the project especially for population data sources. EMIF also developed an ethical code of practice to ensure data protection, patient confidentiality and compliance with the European Data Protection Directive, and GDPR.

RESULTS

Currently 18 population-based disease agnostic and 60 cohort-based Alzheimer's data partners from across 14 countries are contained within the catalogue, and this will continue to expand. The work conducted in EMIF-AD and EMIF-MET includes standardizing cohorts, summarising baseline characteristics of patients, developing diagnostic algorithms, epidemiological studies, identifying and validating novel biomarkers and selecting potential patient samples for pharmacological intervention.

CONCLUSIONS

EMIF was designed to provide a sustainable model as demonstrated by the sustainability plans for EMIF-AD. Although network-wide studies using EMIF were not conducted during this project to evaluate its sustainability, learning from EMIF will be used in the follow-on IMI-2 project, European Health Data and Evidence Network (EHDEN). Furthermore, EMIF has facilitated collaborations between partners and continues to promote a wider adoption of principles, technology and architecture through some of its continued work.

The Secure Anonymised Information Linkage databank Dementia e-cohort (SAIL-DeC)

Introduction

The rising burden of dementia is a global concern, and there is a need to study its causes, natural history and outcomes. The Secure Anonymised Information Linkage (SAIL) Databank contains anonymised, routinely-collected healthcare data for the population of Wales, UK. It has potential to be a valuable resource for dementia research owing to its size, long follow-up time and prospective collection of data during clinical care.

Objectives

We aimed to apply reproducible methods to create the SAIL dementia e-cohort (SAIL-DeC). We created SAIL-DeC with a view to maximising its utility for a broad range of research questions whilst minimising duplication of effort for researchers.

Methods

SAIL contains individual-level, linked primary care, hospital admission, mortality and demographic data. Data are currently available until 2018 and future updates will extend participant follow-up time. We included participants who were born between 1st January 1900 and 1st January 1958 and for whom primary care data were available. We applied algorithms consisting of International Classification of Diseases (versions 9 and 10) and Read (version 2) codes to identify participants with and without all-cause dementia and dementia subtypes. We also created derived variables for comorbidities and risk factors.

Results

From 4.4 million unique participants in SAIL, 1.2 million met the cohort inclusion criteria, resulting in 18.8 million person-years of follow-up. Of these, 129,650 (10%) developed all-cause dementia, with 77,978 (60%) having dementia subtype codes. Alzheimer's disease was the most common subtype diagnosis (62%). Among the dementia cases, the median duration of observation time was 14 years.

Conclusion

We have created a generalisable, national dementia e-cohort, aimed at facilitating epidemiological dementia research.

Circular pOlyethylene drape in preVEntion of suRgical site infection (COVER trial): study protocol for a randomised controlled trial

INTRODUCTION

Surgical site infection (SSI) after abdominal surgery remains a significant cause of morbidity and is associated with an increased socioeconomic burden and a reduced quality of life. Circular wound protectors have been expected to reduce the risk of SSI, but previous studies reported conflicting results on their protective effects. The purpose of this study was to evaluate the efficacy of circular wound protectors in reducing SSI in open abdominal surgery.

METHODS AND ANALYSIS

The circular pOlyethylen drape in preVEntion of suRgical site infection (COVER) trial investigates whether the application of a dual-ring circular plastic wound protector reduces the rate of SSI in patients undergoing elective or emergent open abdominal surgery related to the gastrointestinal tract, regardless of the type of wound classified by the Centers for Disease Control. The COVER trial is a multicentre, randomised controlled clinical trial with two parallel arms-one using a dual-ring wound protector with circular polyethylene drape and the other using conventional surgical dressing gauze. The primary outcome will measure the rate of SSI within 30 days after surgery in two groups. Statistical analysis of the primary end point will be based on the intention-to-treat population. The sample size was determined to achieve a study power of 80% with 95% two-sided confidence limits. Considering a dropout rate of up to 5%, a total of 458 patients, 229 patients in each group, will be enrolled in this study.

ETHICS AND DISSEMINATION

The trial protocol and informed consent document have been reviewed and approved by the institutional review board at each participating centre. Written informed consent will be obtained from each study participant. The clinical outcomes of this trial will be submitted to an international peer-reviewed journal and presented at international conferences.

TRIAL REGISTRATION NUMBER

NCT03170843.

Impaired kidney function is associated with lower cognitive function in the elder general population. Results from the Good Aging in Skåne (GÅS) cohort study

BACKGROUND

A possible connection on vascular basis between impaired kidney function and cognitive dysfunction has been suggested in previous studies. Contradictory results regarding specific cognitive domains have been reported. The aim for this study was to investigate the association between kidney function and specific cognitive domains.

METHODS

In this cross-sectional design, data from the general population based cohort study "Good aging in Skåne" (GÅS) was used. The sample included 2931 subjects ages 60 to 93 randomly selected from the southern part of Sweden. Estimated glomerular filtration rate (eGFR) for both creatinine and cystatine C was calculated using the chronic kidney disease epidemiology collaboration (CKD-EPI) equation. The subjects underwent a test battery of neuropsychological tests assessing global cognitive function, learning and memory, language, complex attention, executive function, perceptual motor and meta-memory. Adjustments were made for age, sex, education and country of origin.

RESULTS

After adjustment for demographic variables, impaired kidney function was associated with 0.41 points worse result in MMSE, 0.56 points worse result in recognition, 0.66 points worse result in word fluency, 0.45 points worse result in digit cancellation, 0.99 points worse result in pattern comparison, and 3.71 s longer time to finish TMT B-A. Associations to cognitive function was also noted for mildly impaired kidney function defined as eGFR 45- < 60 ml/min/1,73m². No association was found between kidney function and meta-memory.

CONCLUSIONS

Impaired kidney function as well as the severity of impaired kidney function is associated with impairment in learning and memory, language, complex attention, executive function and global cognitive function, but not meta-memory.

Effects on cognition of 20-day anodal transcranial direct current stimulation over the left dorsolateral prefrontal cortex in patients affected by mild cognitive impairment: a case-control study

BACKGROUND

Mild cognitive impairment (MCI) is a common disorder affecting as much as 15% of the elderly population. Transcranial direct current stimulation (tDCS) is a non-invasive technique of neuromodulation that has proven to influence performance in different cognitive domains.

OBJECTIVE/HYPOTHESIS

We investigated the effects on cognition of 20-day anodal tDCS in 17 MCI patients compared with 17 matched MCI patients.

METHODS

Patients underwent neuropsychological evaluation at baseline and then were randomly assigned to the anodal or sham group. The tDCS protocol consisted in 20 min, 5 days per week (up to a total of 20 days), of 2-mA anodal stimulation over the left dorsolateral prefrontal cortex (DLPFC). The location of anodal electrode was chosen in accordance with previous reports which relate anodal stimulation of this site with cognitive enhancement. At the end of the last day of stimulation, a second neuropsychological evaluation was performed. We compared baseline and post-stimulation neuropsychological results in the anodal vs sham group using repeated measures ANOVA as a statistical analysis test.

RESULTS

At follow-up, patients exposed to anodal stimulation showed improvement in episodic verbal memory (p < 0.001) and figure naming test (p < 0.01), in a general index of cognitive function (Brief Mental Deterioration Battery) (p < 0.0001) and in a mood measurement test (Beck Depression Inventory) (p < 0.01).

CONCLUSION

Anodal tDCS could be a useful tool to improve cognitive symptoms in MCI although more evidence is needed to understand the exact underlying mechanisms. Confirmation of its potential benefits in MCI would be significant.

Adaptation and validation into Portuguese language of the six-item cognitive impairment test (6CIT)

BACKGROUND

The six-item cognitive impairment test (6CIT) is a brief cognitive screening tool that can be administered to older people in 2-3 min.

OBJECTIVE

To adapt the 6CIT for the European Portuguese and determine its psychometric properties based on a sample recruited from several contexts (nursing homes; universities for older people; day centres; primary health care units).

METHOD

The original 6CIT was translated into Portuguese and the draft Portuguese version (6CIT-P) was back-translated and piloted. The accuracy of the 6CIT-P was assessed by comparison with the Portuguese Mini-Mental State Examination (MMSE). A convenience sample of 550 older people from various geographical locations in the north and centre of the country was used.

RESULTS

The test-retest reliability coefficient was high (r = 0.95). The 6CIT-P also showed good internal consistency (α = 0.88) and corrected item-total correlations ranged between 0.32 and 0.90. Total 6CIT-P and MMSE scores were strongly correlated. The proposed 6CIT-P threshold for cognitive impairment is ≥10 in the Portuguese population, which gives sensitivity of 82.78% and specificity of 84.84%. The accuracy of 6CIT-P, as measured by area under the ROC curve, was 0.91.

CONCLUSION

The 6CIT-P has high reliability and validity and is accurate when used to screen for cognitive impairment.

Hospital admissions 2000-2014: A retrospective analysis of 288 096 events in patients with dementia

INTRODUCTION

Dementia is a leading cause of disability worldwide. It is associated with an increased risk of hospitalization, imposing a significant burden on healthcare systems. The evidence on the long-term evolution of this issue and broadly on healthcare systems is currently limited. This study aims to describe the hospitalizations of people who received a diagnosis of dementia admitted to public general hospitals in a western European country with universal health coverage, over more than a decade.

METHODS

This retrospective observational study analyzed all inpatient episodes from 2000 to 2014 with a primary or secondary diagnosis of dementia using a national hospitalization database from mainland Portuguese public hospitals.

RESULTS

A total of 288 096 hospital admissions were registered. Hospitalization rates increased 4.7 times throughout the study period. Pneumonia and urinary tract infections were the most frequent main diagnoses, while dementia itself was the cause of admission in a minority (6.8%) of cases. Cerebrovascular disease, diabetes without chronic complications, and congestive heart failure were the most prevalent comorbidities; 5.9% of patients with dementia admitted to hospital underwent a surgical procedure, orthopedic surgeries being the most frequent. The median length of hospital stay was 8.0 days, and in-hospital mortality rate was 16.1%.

CONCLUSIONS

Dementia patients represent a significant amount of hospital admissions. Most leading causes of hospital admissions are preventable if timely diagnosed and could be effectively managed in the outpatient setting. These findings may be useful for healthcare resource planning and allocation. Further research should drive evidence-based reorganization of health care systems.

The smartphone in the memory clinic: A study of patient and care partner's utilisation habits

Smartphones have potential as cognitive aids for adults with cognitive impairments. However, little is known about how patients and their care partners utilise smartphones in their day-to-day lives. We collected self-reported smartphone utilisation data from patients referred for neuropsychological evaluations (N = 53), their care partners (N = 44), and an Amazon Mechanical Turk control sample (N = 204). Patient participants were less likely to own a smartphone than controls, with increasing age associated with less utilisation of smartphone features in all groups. Of the patients who owned smartphones, spontaneous use of cognitive aid features (e.g., reminders and calendars) occurred on only a monthly-to-weekly basis; by comparison, patients reported utilising social/general features (e.g., email and internet) on a weekly-to-daily basis. Individuals referred for geriatric cognitive disorder evaluations were less likely to own and use smartphones than individuals referred for other reasons. Care partners reported using their smartphones more frequently than control group adults, with 55% of care partners endorsing utilising their device in caring for the patient. Building upon existing smartphone use habits to increase the use of cognitive aid features may be a feasible intervention for some patients, and including care partners in such interventions is encouraged.

Occupational Attainment as Risk Factor for Progression from Mild Cognitive Impairment to Alzheimer's Disease: A CREDOS Study

High occupational attainment has been known as a marker of cognitive reserve. Previous studies in the general population have shown that high occupational attainment is associated with reduced risk of Alzheimer's disease (AD). However, few studies have assessed the effect of occupational attainment on the clinical course of mild cognitive impairment (MCI). In this study, we evaluated whether individuals with high occupational attainment show more frequent progression from MCI to AD. Participants (n = 961) with MCI were recruited from a nationwide, hospital-based multi-center cohort, and were followed for up to 60 months (median: 17.64, interquartile range [12.36, 29.28]). We used Cox regression for competing risks to analyze the effect of occupational attainment on development of AD, treating dementia other than AD as a competing risk. Among the 961 individuals with MCI, a total of 280 (29.1%) converted to dementia during the follow-up period. The risk of progression to AD was higher in the individuals with high occupational attainment after controlling for potential confounders (hazard ratio = 1.83, 95% confidence interval = 1.25-2.69, p = 0.002). High occupational attainment in individuals with MCI is an independent risk factor for higher progression rate of MCI to AD. This result suggests that the protective effect of high occupational attainment against cognitive decline disappears in the MCI stage, and that careful assessment of occupational history can yield important clinical information for prognosis in individuals with MCI.

Preoperative Cognitive Performance and Postoperative Delirium Are Independently Associated With Future Dementia in Older People Who Have Undergone Cardiac Surgery: A Longitudinal Cohort Study

OBJECTIVE

To investigate if postoperative delirium was associated with the development of dementia within 5 years after cardiac surgery.

DESIGN

Longitudinal cohort study.

SETTING

Cardiothoracic Division, Umeå University Hospital, Sweden.

PATIENTS

Patients aged 70 years old or older (n = 114) scheduled for routine cardiac procedures with cardiopulmonary bypass without documented dementia were enrolled in 2009.

INTERVENTION

Structured assessments were performed preoperatively, 1 and 4 days after extubation, and 1, 3, and 5 years postoperatively.

MEASUREMENTS AND MAIN RESULTS

Patients were assessed comprehensively, including cognitive and physical function, coexisting medical conditions, demographic characteristics, and medications. Diagnoses of delirium, depression, and dementia were made according to Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision criteria. During the 5-year period, 30 of 114 participants (26.3%) developed dementia. Postoperative delirium had occurred in 87% of those who later developed dementia. A multivariable logistic regression model showed a lower preoperative Mini-Mental State Examination score (p < 0.001; odds ratio, 0.68; 95% CI, 0.54-0.84) and the occurrence of postoperative delirium (p = 0.002; odds ratio, 7.57; 95% CI, 2.15-26.65) were associated with dementia occurrence.

CONCLUSIONS

Our findings suggest that older patients with reduced preoperative cognitive functions or who develop postoperative delirium are at risk of developing dementia within 5 years after cardiac surgery. Cognitive functions should be screened for preoperatively, those who develop postoperative delirium should be followed up to enable early detection of dementia symptoms, and management should be implemented.

Dementia prevalence and incidence in a federation of European Electronic Health Record databases: The European Medical Informatics Framework resource

INTRODUCTION

The European Medical Information Framework consortium has assembled electronic health record (EHR) databases for dementia research. We calculated dementia prevalence and incidence in 25 million persons from 2004 to 2012.

METHODS

Six EHR databases (three primary care and three secondary care) from five countries were interrogated. Dementia was ascertained by consensus harmonization of clinical/diagnostic codes. Annual period prevalences and incidences by age and gender were calculated and meta-analyzed.

RESULTS

The six databases contained 138,625 dementia cases. Age-specific prevalences were around 30% of published estimates from community samples and incidences were around 50%. Pooled prevalences had increased from 2004 to 2012 in all age groups but pooled incidences only after age 75 years. Associations with age and gender were stable over time.

DISCUSSION

The European Medical Information Framework initiative supports EHR data on unprecedented number of people with dementia. Age-specific prevalences and incidences mirror estimates from community samples in pattern at levels that are lower but increasing over time.

Prevalence of DSM-5 Mild Neurocognitive Disorder in Dementia-Free Older Adults: Results of the Population-Based LIFE-Adult-Study

OBJECTIVE

The DSM-5 introduces mild neurocognitive disorder (miNCD) as a syndrome that recognizes the potential clinical importance of acquired cognitive deficits being too mild to qualify for diagnosis of dementia. We provide new empirical data on miNCD including total, age-, and sex-specific prevalence rates; number and types of neurocognitive domains being impaired; and diagnostic overlap with the well-established mild cognitive impairment (MCI) concept.

DESIGN

Cross-sectional results of an observational cohort study (LIFE-Adult-Study).

SETTING

General population.

PARTICIPANTS

A total of 1,080 dementia-free individuals, aged 60-79 years.

MEASUREMENTS

We calculated weighted point prevalence rates with confidence intervals (95% CI) for miNCD and analyzed diagnostic overlap between miNCD and MCI by calculating overall percentage agreement and Cohen's kappa coefficient.

RESULTS

Weighted total prevalence of miNCD was 20.3% (95% CI: 17.8-23.0). Prevalence was similar in both sexes, but significantly higher in older age. Two-thirds (66.2%) of the individuals with miNCD showed impairment restricted to only one out of six possible neurocognitive domains. Learning and memory was the most frequently (38.3%) impaired domain in all miNCD-cases, followed by social cognition (26.1%). Analysis of diagnostic overlap with MCI yielded an overall agreement of 98.6% and a kappa of 0.959.

CONCLUSIONS

By considering all six predefined neurocognitive domains, our study observed a substantial proportion of dementia-free older adults having miNCD. Provision of information on the underlying etiology/ies may be of prime importance in future studies aiming at evaluating the clinical relevance of the miNCD syndrome.

Dietary Diversity and Cognitive Function among Elderly People: A Population-Based Study

OBJECTIVES

To explore associations of dietary diversity with cognitive function among Chinese elderly.

DESIGN

This cross-sectional study was conducted in 2011-2012, data were analyzed using multiple linear regression and logistic regression models.

SETTING

community-based setting in the 23 provinces in China.

SUBJECTS

8,571 elderly participants, including 2984 younger elderly aged 65-79 and 5587 oldest old aged 80+ participated in this study.

MEASUREMENT

Intake frequencies of food groups was collected and dietary diversity (DD) was assessed based on the mean of DD score. Cognitive function was assessed using the Chinese version of Mini-Mental State Examination (MMSE), and cognitive impairment was defined using education-based cutoffs. Information about socio-demographics, lifestyles, resilience and health status was also collected.

RESULTS

Poor dietary diversity was significantly associated with cognitive function, with β (95% CI) of -0.11(-0.14, -0.08) for -log (31-MMSE score) and odds ratio (95% CI) of 1.29 (1.14, 1.47) for cognitive impairment. Interaction effect of age with DD was observed on cognitive impairment (P interaction=0.018), but not on -log (31-MMSE score) (P interaction=0.08). Further separate analysis showed that poor DD was significantly associated with increased risk of cognitive impairment in the oldest old (p<0.01), with odds ratio (95% CI) of 1.34 (1.17, 1.54), while not in the younger elderly (p>0.05), with OR (95% CI) being 1.09 (0.80, 1.47) in the fully adjusted model. Similar results were obtained when DD was categorized into four groups.

CONCLUSIONS

Poor dietary diversity was associated with worse global cognitive function among Chinese elderly, and particularly for the oldest old. This finding would be very meaningful for prevention of cognitive impairment.