Prevalence of dementia and mild cognitive impairment in a Bulgarian urban population

Development and validation of a risk prediction model for mild cognitive impairment in elderly patients with type 2 diabetes mellitus

BACKGROUND

The prevalence of mild cognitive impairment (MCI) is steadily increasing among elderly people with type 2 diabetes (T2DM). This study aimed to create and validate a predictive model based on a nomogram.

METHODS

This cross-sectional study collected sociodemographic characteristics, T2DM-related factors, depression, and levels of social support from 530 older adults with T2DM. We used LASSO regression and multifactorial logistic regression to determine the predictors of the model. The performance of the nomogram was evaluated using calibration curves, receiver operating characteristics (ROC), and decision curve analysis (DCA).

RESULTS

The nomogram comprised age, smoking, physical activity, social support, depression, living alone, and glycosylated hemoglobin. The AUC for the training and validation sets were 0.914 and 0.859. The DCA showed good clinical applicability.

CONCLUSIONS

This predictive nomogram has satisfactory accuracy and discrimination. Therefore, the nomogram can be intuitively and easily used to detect MCI in elderly adults with T2DM.

Alcohol Consumption and Mild Cognitive Impairment: A Mendelian Randomization Study from Rural China

Alcohol consumption has been associated with the risk of mild cognitive impairment (MCI) in observational studies. The result is inconsistent and whether the association is causal remains unknown. To examine the causal effect of alcohol consumption on MCI in rural China, this study used a cross-sectional dataset that included 1966 observations collected in rural China, of which 235 observations’ genotyping were collected. All participants accepted the MCI evaluation using Mini-Cog and were asked about the participants’ alcohol consumption behavior. The causal effect of alcohol consumption on MCI was investigated by Mendelian randomization (MR) of genetic variation in the aldehyde dehydrogenase 2 (ALDH2 rs671) gene. The risk of MCI in Chinese rural areas was 43%. Alcohol consumption was causally associated with a higher risk of MCI under MR design. Parameter estimates of drinking or not (b = 0.271, p = 0.007, 95% CI = 0.073 to 0.469), drinking frequency during the past 30 days (b = 0.016, p = 0.003, 95% CI = 0.005 to 0.027), and the weekly ethanol consumption (b = 0.132, p = 0.004, 95% CI = 0.042 to 0.223) were all positive and statistically significant at the 5% level. In conclusion, there was a high risk of MCI in rural China, and alcohol consumption was causally associated with a higher risk of MCI.

The complex burden of determining prevalence rates of mild cognitive impairment: A systematic review

Mild cognitive impairment (MCI) is a syndrome characterized by a decline in cognitive performance greater than expected for an individual's age and education level, but that does not interfere much with daily life activities. Establishing the prevalence of MCI is very important for both clinical and research fields. In fact, in a certain percentage of cases, MCI represents a prodromal condition for the development of dementia. Accordingly, it is important to identify the characteristics of MCI that allow us to predict the development of dementia. Also, initial detection of cognitive decline can allow the early implementation of prevention programs aimed at counteracting or slowing it down. To this end, it is important to have a clear picture of the prevalence of MCI and, consequently, of the diagnostic criteria used. According to these issues, this systematic review aims to analyze MCI prevalence, exploring the methods for diagnosing MCI that determine its prevalence. The review process was conducted according to the PRISMA statement. Three thousand one hundred twenty-one international articles were screened, and sixty-six were retained. In these studies, which involved 157,035 subjects, the prevalence of MCI ranged from 1.2 to 87%. The review results showed a large heterogeneity among studies due to differences in the subjects' recruitment, the diagnostic criteria, the assessed cognitive domains, and other methodological aspects that account for a higher range of MCI prevalence. This large heterogeneity prevents drawing any firm conclusion about the prevalence of MCI.

Initial Adaptation of the General Cognitive Assessment Battery by Cognifit™ for Bulgarian Older Adults

BACKGROUND

Online neuropsychological assessment batteries may facilitate the screening of cognitive functions in older adults and could be useful for early diagnosis and detection of cognitive impairments.

OBJECTIVE

The primary aim of this study was to assess the psychometric qualities of an online multi-domain cognitive assessment battery (General Cognitive Assessment Battery (GCAB) by Cognifit™) applied for the first time in Bulgaria.

METHODS

A total of 20 healthy older adults (6 male and 14 female, aged 60-82) completed the GCAB as well as the Mini-Mental State Examination (MMSE) and the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropsychological battery. Descriptive statistics were used to describe the demographic characteristics of the sample and the scores on the GCAB and the CERAD battery. The internal consistency of the GCAB was evaluated using item analysis and measured with Cronbach's alpha. The concurrent validity of the GCAB was assessed with respect to the CERAD using Spearman's r after verifying the linear relationship between the GCAB and CERAD scores.

RESULTS

The GCAB showed good concurrent validity when compared with the corresponding CERAD tests. The correlation coefficients ranged from 0.67 for working memory to 0.47 for short-term auditory memory. We found very good reliability of the GCAB, with the inter-class correlation coefficient higher than 0.8 for all cognitive domains. There were no significant correlations between MMSE and GCAB scores.

CONCLUSION

The GCAB was found to be valid for the cognitive screening of Bulgarian healthy older adults and may provide an adequate assessment of their cognitive status. The GCAB showed good concurrent validity when compared with the CERAD battery, measuring similar cognitive constructs. Further work is necessary to explore its validity and reliability.

Prevalence of Dementia in Older Adults in Central and Eastern Europe: A Systematic Review and Meta-Analysis

Data on dementia prevalence in Europe are primarily based on studies from Western Europe. Central and Eastern European countries differ from Western European countries in their average income and other socioeconomic and health factors that are relevant for dementia risk. We, therefore, conducted a systematic review of population-based studies on prevalence of dementia in Central and Eastern Europe. We searched in electronic databases from the date of inception up to July 2019, updated in October 2020. We hand-searched references of included articles and contacted experts in each country to identify further articles. We combined studies by meta-analysis where possible. Ten population-based studies (n = 30,268) met inclusion criteria. We meta-analysed seven studies (n = 11,994). The selected studies were conducted across 5 countries with no studies identified for the vast majority of countries in this region. Prevalence of all-cause dementia was 6.7% (95% CI 5.1–8.2) in those aged 60 or over, and 7.1% (95% CI 5.1–9.2) in those aged 65 and over. Prevalence rates were similar to those in Western Europe, but are increasing over time, compared with the patterns of reduction in age-specific prevalence in Western Europe.

Inhibitors of Cholinesterases in Pharmacology: the Current Trends

Inhibitors of cholinesterases are a wide group of low molecular weight compounds with a significant role in the current pharmacology. Besides the pharmacological importance, they are also known as toxic compounds like military nerve agents. In the pharmacology, drugs for Alzheimer disease, myasthenia gravis and prophylaxis of poisoning by nerve agents can be mentioned as the relevant applications. Besides this, anti-inflammation and antiphrastic drugs are other pharmacological applications of these inhibitors. This review is focused on a survey of cholinesterase inhibitors with known or expected pharmacological impact and indications of their use. Recent literature with comments is provided here as well.

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.

Establishment of a Risk Prediction Model for Mild Cognitive Impairment among Elderly Chinese

BACKGROUND

Mild cognitive impairment (MCI) is a transitional stage of cognitive function between normal aging and dementia. Substantial variations in the prevalence of MCI in different countries have been studied including China. In this study, we established a prediction system to assess the risk of MCI among the elderly in China.

METHODS

The Rothman-Keller model was conducted on the basis of the risk factors of MCI obtained by the combined results of a meta-analysis. The accuracy of the model was verified using actual population data.

RESULTS

A total of 1826 subjects as a verification set were enrolled in this study in February 2019. There were statistically significant differences in the combined results of 10 risk factors including hypertension, diabetes, educational level, hyperlipidemia, smoking, physical exercise, living alone, stroke, drinking and heart disease (P<0.05). The area under the curve (AUC) of the actual data and the predictive results of this model was 0.859 (95%CI: 0.812-0.906, P<0.05), the sensitivity was 86.6% and the specificity was 76.5%.

CONCLUSIONS

This model performs an effective prediction that may be applied to the primary prevention for patients with MCI, helping to reduce the risk of MCI.

Dementia care in the Danube Region. A multi-national expert survey

BACKGROUND

Dementia is a particularly severe societal challenge in several countries of the Danube Region due to higher-than-average increment in population longevity, disproportionate increase of the old-age dependency ratio, and selective outward migration of health care professionals. A survey was conducted among dementia experts to obtain a deeper understanding of the dementia care structures and services in this geographical area, and to identify the educational needs of health care professionals, and the availability of assistive technology.

SUBJECTS AND METHODS

A standardized questionnaire was sent out to 15 leading dementia experts/clinicians in 10 Danube Region countries inquiring about professional groups involved in dementia care, availability and reimbursement of services, inclusion of dementia in professional education and training, acceptability of Internet-based education, and availability of assistive technology. The authors are the survey respondents.

RESULTS

The majority of individuals with dementia receive care in the community rather than in institutions. The roles of medical specialties are disparate. General practitioners usually identify dementia symptoms while specialists contribute most to clinical diagnosis and treatment. Health care professionals, particularly those who work closely with patients and carers, have limited access to dementia-specific education and training. The greatest need for dementia-specific education is seen for general practitioners and nurses. An Internet-based education and skill-building program is considered to be equivalent to traditional face-to-face but offer advantages in terms of convenience of access. Assistive technology is available in countries of the Danube Region but is significantly underused.

CONCLUSION

Dementia care in the Danube Region can be improved by an educational and skill-building program for health care professionals who work in the frontline of dementia care. Such a program should also attempt to enhance interdisciplinary and intersectorial collaboration, to intensify the interaction between primary care and specialists, and to promote the implementation of assistive technology.

A Systematic Review and Meta-Analysis on the Prevalence of Dementia in Europe: Estimates from the Highest-Quality Studies Adopting the DSM IV Diagnostic Criteria

BACKGROUND

Dementia, including Alzheimer's disease (AD), is one of the most burdensome medical conditions. Usually, the reviews that aim at calculating the prevalence of dementia include estimates from studies without assessing their methodological quality. Alzheimer's Disease International (ADI) proposed a score to assess the methodological quality of population-based studies aimed at estimating the prevalence of dementia. During the last three years, the European Commission has funded three projects (Eurodem, EuroCoDe, and ALCOVE) in order to estimate the prevalence of dementia in Europe.

OBJECTIVE

The aim of this study was to perform a systematic review and meta-analysis of data on the prevalence of dementia in Europe derived from studies that included only subjects with a diagnosis of dementia according to the DSM IV criteria, and that had a high quality score according to ADI criteria.

METHODS

We considered the studies selected by the two projects EuroCoDe (1993-2007) and Alcove (2008-2011), and we performed a new bibliographic search. For the systematic review, we only selected the subset of articles that included subjects with a diagnosis of dementia according to the DSM IV criteria. The studies were qualitatively assessed using the ADI tool.

RESULTS

The meta-analysis considered 9 studies that were carried out in Europe between 1993 and 2018 including a total of 18,263 participants, of which 2,137 were diagnosed with dementia. The prevalence rate standardized for age and sex resulted 7.1%.

DISCUSSION

This is the first systematic review on the prevalence of dementia in Europe considering only high-quality studies adopting the same diagnostic criteria (i.e., DSM IV).

Prevalence of mild cognitive impairment and its subtypes in community-dwelling residents aged 65 years or older in Guangzhou, China

BACKGROUND

Prevalence of mild cognitive impairment (MCI) has been reported substantial variations, and mostly in Western countries. Less is known about MCI in the south of China. The study is to estimate the prevalence of MCI and its subtypes in residents aged 65year or older in community-dwelling residents of Guangzhou, China.

METHODS

The study was a community-based, cross-sectional study conducted in rural and urban areas of Guangzhou between April and October 2009. Eight communities were randomly selected using a cluster sampling method. Each elderly was interviewed with Montreal Cognitive Assessment, the Mini-Mental state examination, Auditory Verbal Learning Test, the Clinical Dementia Rating scale et al. MCI was classified as amnestic MCI (a-MCI) or nonamnestic MCI (na-MCI).

RESULTS

2427 individuals were contacted, but in-person interviews were conducted with 2111 participants. 299 participants with MCI were identified. The prevalence of MCI, a-MCI and na-MCI was 14.2%, 12.2%, 2.0% respectively. The prevalence of MCI and a-MCI increased with age, decreased with education level, and was higher in rural areas than in urban areas. The difference of prevalence of MCI and a-MCI between women with men wasn't statistically significant(MCIχ2=1.0, OR 0.9, 95%CI=0.6-1.2; a-MCIχ2=1.0, OR 0.9, 95%CI=0.6-1.2), when controlling for education by logistic regression analysis.

CONCLUSIONS

The results suggest that 14.2% of elderly individuals are affected by MCI in Guangzhou, China. And MCI was dominated by a-MCI. The prevalence of MCI and a-MCI increased with age, decreased with education level, and was higher in the rural population compared to the urban population.

Prevalence of Dementia, Depression, and Mild Cognitive Impairment in a Rural Area of the Island of Crete, Greece

The studies on the prevalence of dementia, depression, and mild cognitive impairment (MCI) in Greece are sparse and show major variations of prevalence depending on geographical areas, nutritional habits, and the way of living. The aim of this door-to-door study was to find the prevalence of dementia, depression, and MCI in a rural Greek population. Four hundred and forty-three individuals older than 61years following the application of specific criteria were diagnosed with: normal cognition, depression, MCI with and without depression, and dementia with and without depression. Four diagnostic methods were used, 2 of which included Mungas correction for age and education. After Mungas adjustment, the results were as follows-depression: 33.9%; MCI: 15.3%; MCI with depression: 8.6%; dementia: 2.0%; and dementia with depression: 7.2%. Dementia is less prevalent compared to global data and other Greek areas. Mild cognitive impairment is more prevalent than dementia. High percentages of depression may be related to low education.

Prevalence of mild cognitive impairment in an urban community in China: a cross-sectional analysis of the Shanghai Aging Study

BACKGROUND

Substantial variations in the prevalence of mild cognitive impairment (MCI) have been reported, although mostly in Western countries. Less is known about MCI in the Chinese population.

METHODS

We clinically and neuropsychologically evaluated 3141 community residents ≥60 years of age. Diagnoses of MCI and its subtypes were made using standard criteria via consensus diagnosis.

RESULTS

Among 2985 nondemented individuals, 601 were diagnosed with MCI, resulting in a prevalence of 20.1% for total MCI, 13.2% for amnestic MCI (aMCI), and 7.0% for non-amnestic MCI (naMCI). The proportions of MCI subtypes were: aMCI single domain (SD), 38.9%; aMCI multiple domains (MD), 26.5%; naMCI-SD, 25.0%; and naMCI-MD, 9.6%. The prevalence of aMCI-MD increased rapidly with age in women APOE ε4 carriers (from 60 to 69 years to ≥80 years, 3.1%-33.3%, P < .001).

CONCLUSIONS

Our findings suggest that 20% of Chinese elderly are affected by MCI. Prospective studies in China are needed to examine progression to dementia and related risk factors.

The prevalence and incidence of dementia with Lewy bodies: a systematic review of population and clinical studies

BACKGROUND

Dementia with Lewy bodies (DLB) is increasingly recognized as a common cause of dementia in older people. However, its true frequency remains unclear, with previous studies reporting a prevalence range from zero to 22.8% of all dementia cases. This review aimed to establish the population prevalence and incidence for DLB and to compare this to its prevalence in secondary care settings.

METHOD

A literature review of all relevant population and clinical studies was conducted using PubMed. Additional references from papers found during that process were added to this.

RESULTS

DLB accounted for 4.2% of all diagnosed dementias in the community. In secondary care this increased to 7.5%. The incidence of DLB was 3.8% of new dementia cases. There was a significant increase in DLB diagnoses when using the revised (2005) International Consensus Criteria (ICC) for DLB compared to the original (1996) criteria.

CONCLUSIONS

DLB currently accounts for around one in 25 dementia cases diagnosed in the community and one in 13 cases in secondary care. The significantly higher rates of DLB in secondary care may reflect enhanced diagnostic accuracy in specialist settings and/or the increased morbidity and carer burden of the DLB syndrome compared to other dementias. However, the true prevalence is likely to be much higher because DLB diagnoses are often missed, although there is evidence that new criteria aid case identification.