Prevalence, distribution, and impact of mild cognitive impairment in Latin America, China, and India: a 10/66 population-based study

LncRNA 51A: A promising diagnostic biomarker for assessing cognitive decline in occupationally exposed aluminum workers

OBJECTIVE

To assess the diagnostic utility of lncRNA 51 A in detecting cognitive decline among aluminum-exposed workers occupationally.

METHODS

921 male workers from an aluminum manufacturing facility underwent cognitive assessments, measurement of plasma aluminum levels and quantification of lncRNA 51 A levels. Receiver Operating Characteristic (ROC) curves were constructed to assess the diagnostic potential of lncRNA 51 A. Bayesian network model was utilized to predict the likelihood of cognitive decline among the study population.

RESULTS

Significant differences in lncRNA 51 A levels, plasma aluminum concentration and MMSE scores were observed between cognitive normal and decline groups. The lncRNA 51 A expression was negatively correlated with MMSE scores. The area under the curve (AUC) was 0.894, with 89.3 % sensitivity and 73.9 % specificity. The Bayesian network model indicated varying probabilities of cognitive decline based on lncRNA 51 A expression levels.

CONCLUSION

Plasma lncRNA 51 A shows potential as an excellent biomarker for cognitive decline diagnosis in aluminum-exposed workers.

Considerations for the use of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) in cross-country comparisons of cognitive aging and dementia

INTRODUCTION

Informant reports are a critical component of dementia diagnoses, but the comparability of informant reports across countries is not well understood.

METHODS

We compared the performance of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) using population-representative surveys in the United States (N = 3183), England (N = 1050), and India (N = 4047).

RESULTS

Analyses of regression splines and comparisons of model fit showed strong associations between IQCODE and objective cognition at low cognitive functioning in the United States and England; in India, the association was weaker but consistent over the range of cognition. Associations between IQCODE score and informant generation (analysis of variance [ANOVA] p = 0.001), caregiver status (p < 0.001), and years known by the informant (p = 0.015) were different across countries after adjusting for objective cognition.

DISCUSSION

In India, the IQCODE was less sensitive to impairments at the lowest levels of cognitive functioning. Country-specific adjustments to IQCODE scoring based on informant characteristics may improve cross-national comparisons.

HIGHLIGHTS

Associations between IQCODE and cognitive testing were similar in the United States and England but differed in India. In India, the IQCODE may be less sensitive to impairments among those with low cognition and no education. Informant characteristics may differentially impact informant reports of decline across countries. Adjustments or culturally sensitive adaptations may improve cross-national comparability.

Prevalence, severity and impacts of breathlessness in Indian adults: An exploratory, nationally representative, cross-sectional online survey

There are no known estimates of the prevalence, severity and impacts from breathlessness in low- and middle-income countries. This study aimed to explore the prevalence, severity, self-attributed underlying conditions and impacts of breathlessness limiting exertion in community-dwelling adults in India. This exploratory, population-based online survey recruited a pre-planned sample of 3,000 adult respondents stratified by age, sex and rurality (quotas as per the 2011 Indian National Census). Measures included: demographics; breathlessness limiting exertion (modified Medical Research [mMRC] scale); health-related quality of life (EQ-5D-5L); and disability (World Health Organisation's Disability Assessment Schedule 2.0 12-item questionnaire [WHODAS-12]). Respondents (n = 3,046) had a mean age of 38 years (SD 15); 57% were male, 59% lived in rural areas and 33% had completed 12th grade. Breathlessness limiting exertion (mMRC ≥1) was reported by 44%, mostly attributed to poor nutrition (28%), lung conditions excluding tuberculosis (17%) or anaemia (13%). Compared to those without breathlessness, a higher proportion of people with breathlessness (mMRC ≥1) reported problems across all EQ-5D-5L dimensions. Most people reporting breathlessness (81%) indicated the symptom had adversely affected their normal activities. Disability scores (WHODAS-12 total and individual domains) increased as breathlessness worsened. To conclude, in India, conservative estimates indicate 626 million people live with breathlessness of whom 52 million people live with severe breathlessness. The symptom is associated with poorer health-related quality of life and marked disability, including reduced ability to perform daily activities.

The Relationship Between Apathy and Cognitive Impairment Among Hispanic/Latin Americans: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses Systematic Review

OBJECTIVES

The primary aim was to evaluate apathy assessment measures in relation to cognitive impairment among Hispanic/Latin Americans.

METHODS

A systematic review on the relationship between apathy and cognitive impairment among Hispanic/Latin Americans across normal aging and neurocognitive disorders was conducted according to preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines and using APA PsycInfo, Embase, and PubMed databases. Inclusion criteria required (1) a sample of English or Spanish-speaking adults ages 18 years and older, (2) with measures of apathy, (3) assessment of cognitive functioning or diagnosis of neurocognitive disorder, (4) with at least 18.5% Hispanic/Latin American represented in the sample.

RESULTS

Only 14 papers met criteria to be included in this review. Of the 12 cross-sectional studies, 9 demonstrated significant associations between increased apathy and cognitive impairment, 1 demonstrated a descriptive difference between apathy and cognitive status (ie, no hypothesis test conducted), while 2 demonstrated null effects. These cross-sectional studies consisted of community and clinic samples of participants across North and South America. Two longitudinal studies conducted in North America demonstrated non-significant associations of apathy with cognitive status.

CONCLUSIONS

The Neuropsychiatric Inventory (NPI) and Neuropsychiatric Inventory Questionnaire (NPI-Q) apathy subscales were the most used measures for apathy in this review (85.7% of included studies). However, validity evidence from a review of apathy measures has warranted caution against the use of the NPI outside the context of screening for apathy. This potential measurement bias with Hispanic/Latin Americans apathy research limits conclusions drawn from the present review.

Translation and Adaptation of Cognistat in Hindi Language: For Computerized Evaluation of Cognitive Functioning

OBJECTIVE

Cognitive assessment is a crucial element of the mental health screening process. However, there is a lack of culturally appropriate cognitive screening tools for the Hindi-speaking aging population in India. We aimed to translate and culturally tailor the English version of the computerized Cognistat test for the Hindi-speaking aging population.

METHOD

The computer-based Cognistat Assessment System was culturally adapted for the North Indian Hindi-speaking population. Participants with mild cognitive impairment (MCI) (n = 30), depression (n = 30), and healthy control (n = 30) groups between the age range of 50 and 83 years were assessed using the translated version of the tool. The group differences were analyzed using analysis of variance, multivariate analysis of variance, Tukey's post hoc analysis for continuous variables, and Fisher's exact test for categorical variables. The correlation between the Cognistat domains was analyzed using Pearson's correlation, and test reliability was assessed using Cronbach's alpha.

RESULTS

The MCI group had significantly lower scores as compared with the depression and control groups on orientation, language, repetition, and calculation domain tasks. For attention and construction tasks, the MCI group had lower scores than the control group. MCI group scores were significantly lower than the control group on naming domain. The Hindi version of the test was reliable for the Hindi-speaking aging population.

CONCLUSIONS

Cognistat Hindi can be used by trained healthcare professionals with Hindi-speaking populations for culturally tailored primary evaluation of cognitive difficulties. Future research should focus on further validation and assessment of its properties.

Prevalence of DSM-5 mild and major neurocognitive disorder in India: Results from the LASI-DAD

INTRODUCTION

India, with its rapidly aging population, faces an alarming burden of dementia. We implemented DSM-5 criteria in large-scale, nationally representative survey data in India to characterize the prevalence of mild and major Neurocognitive disorder.

METHODS

The Harmonized Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD) (N = 4,096) is a nationally representative cohort study in India using multistage area probability sampling methods. Using neuropsychological testing and informant reports, we defined DSM-5 mild and major neurocognitive disorder, reported its prevalence, and evaluated criterion and construct validity of the algorithm using clinician-adjudicated Clinical Dementia Ratings (CDR)®.

RESULTS

The prevalence of mild and major neurocognitive disorder, weighted to the population, is 17.6% and 7.2%. Demographic gradients with respect to age and education conform to hypothesized patterns. Among N = 2,390 participants with a clinician-adjudicated CDR, CDR ratings and DSM-5 classification agreed for N = 2,139 (89.5%) participants.

DISCUSSION

The prevalence of dementia in India is higher than previously recognized. These findings, coupled with a growing number of older adults in the coming decades in India, have important implications for society, public health, and families. We are aware of no previous Indian population-representative estimates of mild cognitive impairment, a group which will be increasingly important in coming years to identify for potential therapeutic treatment.

Prevalence, cognitive characteristics, and influencing factors of amnestic mild cognitive impairment among older adults residing in an urban community in Chengdu, China

Objective

Dementia is a significant public health concern, and mild cognitive impairment (MCI) serves as a transitional stage between normal aging and dementia. Among the various types of MCI, amnestic MCI (aMCI) has been identified as having a higher likelihood of progressing to Alzheimer's dimension. However, limited research has been conducted on the prevalence of aMCI in China. Therefore, the objective of this study is to investigate the prevalence of aMCI, examine its cognitive characteristics, and identify associated risk factors.

Methods

In this cross-sectional study, we investigated a sample of 368 older adults aged 60 years and above in the urban communities of Chengdu, China. The participants underwent a battery of neuropsychological assessments, including the Mini-Mental State Examination (MMSE), the Clinical Dementia Rating (CDR), Auditory Verbal Learning Test (AVLT), Wechsler's Logical Memory Task (LMT), Boston Naming Test (BNT) and Trail Making Test Part A (TMT-A). Social information was collected by standard questionnaire. Multiple logistic regression analysis was utilized to screen for the risk and protective factors of aMCI.

Results

The data analysis included 309 subjects with normal cognitive function and 59 with aMCI, resulting in a prevalence of 16.0% for aMCI. The average age of participants was 69.06 ± 7.30 years, with 56.0% being females. After controlling for age, gender and education, the Spearman partial correlation coefficient between various cognitive assessments and aMCI ranged from -0.52 for the long-term delayed recall scores in AVLT to 0.19 for the time-usage scores in TMT-A. The results indicated that all cognitive domains, except for naming scores (after semantic cue of BNT) and error quantity (in TMT-A), showed statistically significant associations with aMCI. Furthermore, the multiple logistic regression analysis revealed that older age (OR = 1.044, 95%CI: 1.002~1.087), lower educational level, and diabetes (OR = 2.450, 95%CI: 1.246~4.818) were risk factors of aMCI.

Conclusion

This study found a high prevalence of aMCI among older adults in Chengdu, China. Individuals with aMCI exhibited lower cognitive function in memory, language, and executive domains, with long-term delayed recall showing the strongest association. Clinicians should prioritize individuals with verbal learning and memory difficulties, especially long-term delayed recall, in clinical practice.

Cognitive performance and all-cause mortality in community dwellers of Amerindian ancestry living in rural Ecuador: A population-based, longitudinal prospective study

OBJECTIVE

There is limited information on mortality risk in individuals with cognitive impairment living in rural Latin America. In this study, we assess the association between cognitive impairment and all-cause mortality in adults of Amerindian ancestry living in rural Ecuador.

PATIENTS AND METHODS

Middle-aged and older adults enrolled in the population-based Three Villages Study cohort were followed prospectively in order to estimate mortality risk according to their baseline cognitive performance as determined by the Montreal Cognitive Assessment (MoCA). Results were adjusted for demographics, level of education, traditional cardiovascular risk factors, symptoms of depression, severe tooth loss, and oily fish intake (factors previously associated with mortality in the study population).

RESULTS

Analysis included 1022 individuals followed for an average of 7.8 ± 3.4 years. Mean MoCA score was 21.2 ± 5.4 points (median: 22 points), with 334 (32.7%) individuals showing cognitive impairment, as evidenced by a MoCA score ≤ 19 points (the cutoff for poor cognitive performance based on previous studies in the same population). A total of 150 (14.7%) individuals died during the follow-up. Crude mortality rate was 2.87 per 100 person-years (95% C.I.: 2.08 - 3.96). For individuals with normal cognition, the mortality rate was 1.21 (95% C.I.: 0.92 - 1.50) while for those with cognitive impairment the rate increased to 3.48 (95% C.I.: 2.73 - 4.23). A multivariate Cox-proportional hazards model, confirmed that individuals with cognitive impairment had a significantly higher mortality risk than those without cognitive impairment (HR: 1.52; 95% C.I.: 1.05 - 2.18).

CONCLUSIONS

Cognitive impairment is associated with mortality in the study population.

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.

Prevalence of Mild Cognitive Impairment in Southern Regions of Colombia

Background

Recent reports suggest that by 2050 there will be an increase of around 310% of cases affected by dementia in Latin American countries. A previous study in a Southern region reported one of the highest prevalences of dementia in Latin America.

Objective

To investigate the prevalence of mild cognitive impairment associated with low education, rurality, and demographic characteristics.

Methods

A cross-sectional study recruited a community-dwelling sample of 823 adults from rural and urban areas of two Southern provinces of Colombia from 2020-2022. Participants were assessed with a neuropsychological protocol validated in Colombia. To obtain general and region-specific prevalence rates, age, sex, schooling, and socioeconomic level were considered and controlled for.

Results

Most of the participants reported low education and socioeconomic level, the participation of women was higher. It was determined that the prevalence of mild cognitive impairment (MCI) was 53.6%, with 56.6% in the province of Caquetá followed by 51.9% in the province of Huila. The amnestic MCI represented 42.6%, the amnestic multi-domain was 39%, the non-amnestic 16.55%, and the non-amnestic multi-domain 1.81%. Our participants reported comorbidities such as diabetes and hypertension. We also observed a relationship between exposure to pesticides and MCI.

Conclusions

We observed one of the highest prevalences of MCI in Latin America reported to date. Variables such as age, gender, and education proved risk factors for MCI in the explored regions. Our findings are very much in line with recent studies that highlight the influence of non-canonical risk factors of dementia in underrepresented countries from Latin America.

Epidemiology of neurocognitive disorders in adults from urban-marginalized areas: a door-to-door population-based study in Puente Piedra, Lima, Peru

Background

In Latin America (LA), the prevalence of dementia is expected to triple to 150 million people by 2050. The 2020 Lancet Commission report identified several modifiable dementia risk factors, yet few social and environmental factors, most relevant to vulnerable regions of LA, were highlighted in this report. We sought to assess the epidemiology of neurocognitive disorders (NCD) in Puente Piedra, one of the most socially and economically vulnerable districts of Lima, the capital of Peru.

Methodology

This was a cross-sectional door-to-door observational study that used two-stage household sampling. One young adult (30-59 years) and one older adult (>60 years) per household were enrolled. We collected demographic, clinical, and neurocognitive data. Addenbrooke's Cognitive Examination (young adults) and the RUDAS-PE (older adults) were used, classifying participants as cognitively normal, possible mild NCD, or possible major NCD.

Results

We enrolled 247 participants (median age 46 years; 67% female). One-fourth had not completed secondary school and more than 50% completed only secondary school. Most participants were housewives (46%) and 21% did not have health insurance. The overall prevalence of possible NCD was 30% (25.6 and 41.8% among younger adults and older adults, respectively). Among younger adults, those ages 55-59 years more frequently had NCD (70%) compared to younger age ranges. Among older adults, only 3 subjects (4.5%) had major NCD.

Conclusion

We found a high frequency of possible NCDs in a socially and economically vulnerable community in Lima, Peru, with younger adults showing levels of NCD higher than expected. Our findings support the need for health systems to incorporate cognitive screenings programs for NCD in younger ages. Future research on NCD would include younger populations, particularly in vulnerable communities.

Factors associated with healthy aging in Latin American populations

Latin American populations may present patterns of sociodemographic, ethnic and cultural diversity that can defy current universal models of healthy aging. The potential combination of risk factors that influence aging across populations in Latin American and Caribbean (LAC) countries is unknown. Compared to other regions where classical factors such as age and sex drive healthy aging, higher disparity-related factors and between-country variability could influence healthy aging in LAC countries. We investigated the combined impact of social determinants of health (SDH), lifestyle factors, cardiometabolic factors, mental health symptoms and demographics (age, sex) on healthy aging (cognition and functional ability) across LAC countries with different levels of socioeconomic development using cross-sectional and longitudinal machine learning models (n = 44,394 participants). Risk factors associated with social and health disparities, including SDH (β > 0.3), mental health (β > 0.6) and cardiometabolic risks (β > 0.22), significantly influenced healthy aging more than age and sex (with null or smaller effects: β < 0.2). These heterogeneous patterns were more pronounced in low-income to middle-income LAC countries compared to high-income LAC countries (cross-sectional comparisons), and in an upper-income to middle-income LAC country, Costa Rica, compared to China, a non-upper-income to middle-income LAC country (longitudinal comparisons). These inequity-associated and region-specific patterns inform national risk assessments of healthy aging in LAC countries and regionally tailored public health interventions.

The impacts of social determinants of health and cardiometabolic factors on cognitive and functional aging in Colombian underserved populations

Global initiatives call for further understanding of the impact of inequity on aging across underserved populations. Previous research in low- and middle-income countries (LMICs) presents limitations in assessing combined sources of inequity and outcomes (i.e., cognition and functionality). In this study, we assessed how social determinants of health (SDH), cardiometabolic factors (CMFs), and other medical/social factors predict cognition and functionality in an aging Colombian population. We ran a cross-sectional study that combined theory- (structural equation models) and data-driven (machine learning) approaches in a population-based study (N = 23,694; M = 69.8 years) to assess the best predictors of cognition and functionality. We found that a combination of SDH and CMF accurately predicted cognition and functionality, although SDH was the stronger predictor. Cognition was predicted with the highest accuracy by SDH, followed by demographics, CMF, and other factors. A combination of SDH, age, CMF, and additional physical/psychological factors were the best predictors of functional status. Results highlight the role of inequity in predicting brain health and advancing solutions to reduce the cognitive and functional decline in LMICs.

Astute exploration of collective mental health events among the residents of elderly care homes

Background & objective

Developing countries are presently witnessing a great burden of rapid aging followed by losing the social values of older adults due to age-related cognitive impairment as well as rising depression levels. This study was designed to assess the cognitive impairment and depression status combinedly among older adults in elderly care homes.

Methods

It was a cross-sectional survey among randomly selected 200 older adults aged between 60 and 80 years residing in some old homes in Dhaka district, Bangladesh. Data were collected through face-to-face interviews while Cognitive function and level of depression were assessed by applying the Standardized Mini-Mental State Examination (MMSE) and Geriatric Depression Scale (GDS).

Results

Among all the respondents, the majority (81.5%) were staying in old homes for 1-5 years. The majority (91.0%) had difficulties with vision, 40.7% had difficulties with hearing and 19.6% had difficulties moving around. The MMSE test revealed that 43% had moderate cognitive impairment, 36% had mild and 19.5% were found normal while more than half (56%) had severe depression. Significant cognitive impairment was found among the illiterate respondents who did not have any family care support. In addition, higher-educated respondents were found to have more severe depression (OR/p = 6.33/<0.01; 95% CI: 2.36-16.96). Furthermore, severely depressed respondents had more severe cognitive impairment (COR/p = 3.83/0.01; 95% CI: 1.66-8.83). Functional disabilities were also a greater concern for cognitive impairment and depression.

Conclusion

An increasing number of old home residents are suffering from significant mental disorders while there is no mental health support in the elderly care homes in Bangladesh. Finally, there is a great need to develop packages and programs of mental health care for senior citizens and their caregivers residing in old homes, which can be scaled up across the country's mixed healthcare delivery system.

The Early Stage of Abnormal Aging: Cognitive Impairment

Cognitive impairment has become an important aspect affecting the health and quality of life of middle-aged and elderly people, which is defined as the difficulty of thought processing and leads to memory loss, difficulties making decisions, the inability to concentrate, and difficulties learning. The process of cognitive ability decline with age goes through subjective cognitive impairment (SCI) to mild cognitive impairment (MCI). There is abundant evidence supporting the link between cognitive impairment and several modifiable risk factors, such as physical activity, social activity, mental activity, higher education, and management of cardiovascular risk factors (diabetes, obesity, smoking, hypertension, and obesity). Meanwhile, these factors also provide a new perspective for the prevention of cognitive impairment and dementia.

Exposure to indoor air pollution and the cognitive functioning of elderly rural women: a cross-sectional study using LASI data, India

BACKGROUND

The majority of people in rural developing counties still rely on unclean and solid fuels for cooking, putting their health at risk. Adult and elderly women are most vulnerable due to prolonged exposure in cooking areas, and Indoor Air Pollution (IAP) may negatively impact their health and cognitive function. This study examines the effect of IAP on the cognitive function of middle-aged and elderly rural women in India.

METHODS

The study utilized the data from the Longitudinal Ageing Study in India (LASI 2017-18, Wave-1). Bivariate analysis and multilevel linear regression models were applied to show the association between IAP and the cognitive abilities of rural women and results from regression were presented by beta coefficient (β) with 95% confidence interval (CI). Confounding factors such as age, education, health risk behaviours, marital status, monthly per capita consumption expenditure (MPCE), religion etc. were adjusted in the final model.

RESULTS

The study found that 18.71 percent of the rural women (n = 3,740) lived in Indoor Air Pollution exposed households. IAP was significantly found to be associated with the cognitive functional abilities among the middle and older aged rural women. Middle and older aged rural women exposed to IAP had lower cognitive functional abilities than non-exposed women. Comparing to the non-exposed group, the cognitive score was worse for those exposed to IAP in both the unadjusted (β = -1.96; 95%CI: -2.22 to -1.71) and the adjusted (β = -0.72; 95%CI: -0.92 to -0.51) models. Elderly rural women from lower socioeconomic backgrounds were more likely to have cognitive impairment as a result of IAP.

CONCLUSION

Findings revealed that IAP from solid fuels could significantly affect the cognitive health of elderly rural women in India, indicating the need for immediate intervention efforts to reduce the use of solid fuels, IAP and associated health problems.

Effect of living arrangements on cognitive function in Chinese elders: a longitudinal observational study

OBJECTIVE

To examine how living arrangement as a social contextual factor can affect Chinese elders' cognitive function.

SETTING AND PARTICIPANTS

Our sample consists of 2486 Chinese elders from two waves (2014 and 2018) of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) that was administered in 22 of China's 31 provinces using a multi-stage, disproportionate, purposive random sampling method. The CLHLS aims to better understand the determinants of healthy longevity in China and collects extensive data on a large population of fragile elders aged 80-112 in China.

OUTCOME MEASURES

Cognitive function was measured by the Mini-Mental State Examination (MMSE). Living arrangement was divided into living in an institution, living alone and living with household members. Generalised linear regressions were carried out to examine the associations between baseline characteristics and cognitive function, while controlling age, gender and residential area.

RESULTS

A total of 2486 participants were included in the study at baseline in 2014. Of these, 1162 (46.7%) were men and 1324 (53.3%) were women. The mean age at baseline was 75.07 (±8.31) years. The mean years of schooling were 2.86 (±3.68). The number (proportion) of the three living arrangements (lived in institutions, lived alone and lived with household members) were 93 (3.8%), 463 (18.6%) and 1930 (77.6%), respectively. Among all participants, cognitive function declined over time. Those who lived alone presented with the highest MMSE scores at baseline and showed the lowest decline after 4 years. Living arrangements had significant effects on decreasing cognitive function.

CONCLUSION

Chinese elders living in institutions were most vulnerable to cognitive decline. Living alone was not a risk condition in itself for the elderly in terms of cognitive decline. In addition, the benefits of living with household members to support cognitive function were not found in our study.

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.

Trajectories of Mini-Mental State Examination Scores over the Lifespan in General Populations: A Systematic Review and Meta-Regression Analysis

Objectives: Over the lifespan cumulative changes to the brain lead to cognitive decline and eventually to dementia in 20-25% of adults 85 years and older. A commonly used screening tool for cognitive function is the Standard 30 point Mini-Mental State Examination (MMSE). Though the MMSE is used to screen for dementia, little is known about the changes in scores over the lifespan in general populations.Method: A systematic search was conducted using Cochrane, EMBASE, MEDLINE and PsycINFO for articles published from January 1, 2007 to May 25, 2017. Articles were included if they had a longitudinal design reporting at least two MMSE scores. A mixed-effect meta-regression analysis was conducted to examine the influence of age on MMSE score followed by a change-point regression analysis determining the age at which MMSE declines.Results: 45 articles including 58,939 individuals (age range 18-108 years, 61.2% female) summarized 222 MMSE point estimates from 35 cohorts. The meta-regression demonstrated a significant decrease in MMSE scores with higher age (regression coefficient of age: -0.10 (Confidence Interval (CI) -0.15, -0.05)). The average annual decline in MMSE scores identified by the change-point analysis at the age of 41 years and 84 years were -0.04 (95% CI: -0.05, -0.03) and -0.53 (95% CI: -0.55, -0.50), respectively.Conclusions: Between the age of 29 and 105 years MMSE scores decline, with the highest decline between age 84 and 105 years.Clinical Implementations: The use of MMSE should be restricted to higher age categories in aging general populations.

Midlife Vascular Factors and Prevalence of Mild Cognitive Impairment in Late-Life in Mexico

OBJECTIVE

To estimate the prevalence of mild cognitive impairment (MCI) and its subtypes and investigate the impact of midlife cardiovascular risk factors on late-life MCI among the aging Mexican population.

METHOD

Analyses included a sample of non-demented adults over the age of 55 living in both urban and rural areas of Mexico (N = 1807). MCI diagnosis was assigned based on a comprehensive cognitive assessment assessing the domains of memory, executive functioning, language, and visuospatial ability. The normative sample was selected by means of the robust norms approach. Cognitive impairment was defined by a 1.5-SD cut-off per cognitive domain using normative corrections for age, years of education, and sex. Risk factors included age, education, sex, rurality, depression, insurance status, workforce status, hypertension, diabetes, stroke, and heart disease.

RESULTS

The prevalence of amnestic MCI was 5.9%. Other MCI subtypes ranged from 4.2% to 7.7%. MCI with and without memory impairment was associated with older age (OR = 1.01 [1.01, 1.05]; OR = 1.03 [1.01, 1.04], respectively) and residing in rural areas (OR = 1.49 [1.08, 2.06]; OR = 1.35 [1.03, 1.77], respectively). Depression (OR = 1.07 [1.02, 1.12]), diabetes (OR = 1.37 [1.03, 1.82]), and years of education (OR = 0.94 [0.91, 0.97]) were associated with MCI without memory impairment. Midlife CVD increased the odds of MCI in late-life (OR = 1.76 [1.19, 2.59], which was driven by both midlife hypertension and diabetes (OR = 1.70 [1.18, 2.44]; OR = 1.88 [1.19, 2.97], respectively).

CONCLUSIONS

Older age, depression, low education, rurality, and midlife hypertension and diabetes were associated with higher risk of late-life MCI among older adults in Mexico. Our findings suggest that the causes of cognitive impairment are multifactorial and vary by MCI subtype.

Cognitive frailty among community-dwelling rural elderly population of West Bengal in India

OBJECTIVES

There has been growing interest in the links between physical frailty and cognitive impairment: both can increase the risk of emerging life-threatening health problems and are currently prominent within the global geriatric health agenda. A recent consensus proposes the idea of 'cognitive frailty' defined by the presence of both physical frailty and cognitive impairment in the absence of dementia. Present study is intended to determine the prevalence of cognitive frailty and its associated factors.

METHODS

Cross-sectional survey was conducted among the rural community-dwelling elderly population of West Bengal, India (n = 510), without diagnosed dementia at baseline. An Interview-based questionnaire was administered to obtain information on sociodemographic, physical and psychosocial characteristics. Study participants were categorized as non-cognitive impairment (NCI) and cognitive impairment (CI) by Bangla Adaptation of Mini-Mental State Exam (BMSE ≤ 25) scale, as non-physical frailty (NPF) and physical frailty (PF) using Modified Fried Frailty Phenotype (FP ≥ 3) scale, as robust (NPF + NCI), pre-cognitive frailty (NPF + CI or PF + NCI) and cognitive frailty (PF + CI).

RESULTS

The overall prevalence of cognitive frailty was 21.8%. In multinomial regression analysis, final model indicated that increasing age, being woman, out-of-wedlock, poor education and non-working sociodemographic status had significant association with cognitive frailty. Poor nutritional status, low health-related quality of life and depression are also prone among the cognitively frail participants.

CONCLUSIONS

Present study allows us to understand complementary relationships between sociodemographic, physical, psychosocial characteristics and cognitive frailty. There is a dire need for multidimensional approach for providing appropriate and comprehensive geriatric health care for developing countries like India.

Description of the cross-cultural process adopted in the STRiDE (STrengthening Responses to dementia in DEveloping countries) program: A methodological overview

Cross-cultural adaptation is an important part of using validated questionnaires across countries and settings. Here we describe the cross-cultural process adopted in the STRiDE (STrengthening Responses to dementia in DEveloping countries) program. We adopted a cross-cultural adaptation process including forward translation, back translations, and cognitive interviews of the STRiDE toolkit. In total, 50 older adults and 41 carers across sites in Indonesia and South Africa participated in cognitive interviews; field notes and verbatim quotes are reported. We describe the cross-cultural adaptation process of the STRiDE toolkit. During the process, issues were identified with the translated toolkit, including aspects related to cultural appropriateness, terminology equivalence, and timings. The data demonstrate that a rigorous, yet pragmatic, cross-cultural adaptation process can be achieved even with limited resources. Our process should help the design and conduct of future dementia research in various contexts.

Methodology of Measuring Motoric Cognitive Risk Syndrome-Focusing on Slow Gait Speed: Protocol for a Systematic Review

INTRODUCTION

Older adults with motoric cognitive risk (MCR) syndrome are at high risk of developing dementia. Although the definition of MCR is well recognized and consensus, previous studies did not reach an agreement on diagnostic criteria and measurement methods/tools for slow gait speed, which is one of four components of MCR diagnosis. The substantial heterogeneity in the methodology of slow gait speed diagnosis for MCR limits comparability and meta-analysis of studies.

OBJECTIVE

The study aims to conduct systematic and standardized integration for diagnostic criteria and methods of slow gait speed diagnosis for MCR based on previous evidence that may improve comparability between future studies.

METHODS

A systematic literature review will be undertaken by searching the following electronic databases (until February 1, 2022): PUBMED, EMBASE, The Cochrane Library, Web of Science. Additional studies will be identified by checking the reference lists of included studies or relevant reviews, manually searching the internet search engine Google Scholar, and searching the authors' personal files, if necessary. Two researchers will perform data extraction independently, and discrepancies will be resolved by discussion, which will include a third researcher if requires. The paper selection will perform in duplicate. Finally, a narrative account will synthesize the findings to answer the objectives of this review.

DISCUSSION

This is the first study on systematic and standardized integration for diagnostic criteria and measurement methods/tools for slow gait speed in diagnosing MCR. The findings of this study will be convenient for medical staff to examine the intended use and applicability of each instrument/tool for evaluating the gait speed, and provide insight into developing uniform guidelines for MCR.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42021232671.

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.

The role of disability and depressive symptoms in the relation between objective cognitive performance and subjective cognitive decline

BACKGROUND

Subjective cognitive decline (SCD) and subjective memory decline (SMD) are common among older people. Evidence linking SCD and SMD with cognitive and memory impairment is inconsistent. Moreover, little is known about the associations of SCD and SMD with disability. We aimed to explore the associations of SCD and SMD with objective cognitive and memory performance, disability, and depressive symptoms.

MATERIALS AND METHODS

In a cross-sectional study we conducted face to face interviews in a randomized sample of people aged ≥65 years living in the Canton of Ticino, southern Switzerland, between May 2021 and April 2022. We measured subjective cognitive decline with the MyCog, a subsection of the Subjective Cognitive Decline Questionnaire (SCD-Q); cognitive functioning with the Community Screening Instrument for Dementia; memory with the consortium to establish a registry for alzheimer's disease (CERAD) 10-word list learning task; and disability and depressive symptoms with the world health organization disability assessment schedule 2.0 (WHO-DAS 2.0) and the Euro-Depression (EURO-D) scales, respectively.

RESULTS

Of the 250 participants 93.6% reported at least one cognitive difficulty, and 40.0% SMD. Both SCD and SMD were associated with poorer objective cognitive/memory performance, and independently with greater disability, and more depressive symptoms. But in participants with high disability and depressive symptoms subjective and objective cognition were no longer associated. Disability fully mediated the associations of poorer objective cognitive and memory performance with subjective cognitive and memory decline.

CONCLUSION

Routine clinical assessments of cognitive function should include formal enquires about SCD and SMD, and also account for disability and depressive symptoms.

Spanish-language screening scales: A critical review

INTRODUCTION

Dementia is a chronic, degenerative disease with a strong impact on families and health systems. The instruments currently in use for measuring cognitive impairment have different psychometric characteristics in terms of application time, cut-off point, reliability, and validity. The objective of this review is to describe the characteristics of the validated, Spanish-language versions of the Mini-Cog, Clock-Drawing Test, and Mini-Mental State Examination scales for cognitive impairment screening.

DEVELOPMENT

We performed a three-stage literature search of articles published on Medline since 1953. We selected articles on validated, Spanish-language versions of the scales that included data on reliability, validity, sensitivity, and specificity.

CONCLUSIONS

The 3 screening tools assessed in this article provide support for primary care professionals. Timely identification of mild cognitive impairment and dementia is crucial for the prognosis of these patients.

Risk and protective factors of neurocognitive disorders in older adults in Central and Eastern Europe: A systematic review of population-based studies

BACKGROUND

A wide range of potentially modifiable risk factors, indicating that the onset of neurocognitive disorders can be delayed or prevented, have been identified. The region of Central and Eastern Europe has cultural, political and economic specifics that may influence the occurrence of risk factors and their link to the cognitive health of the population.

OBJECTIVE

We aimed to systematically review population-based studies from Central and Eastern Europe to gather evidence on risk and protective factors for neurocognitive disorders.

METHODS

We searched the electronic databases PubMed, Cochrane Database of Systematic Reviews, PsycINFO, Web of Science, and Embase. The search was performed on 26th of February 2020 and repeated at the end of the review process on 20th May 2021.

RESULTS

We included 25 papers in a narrative synthesis of the evidence describing cardiovascular risk factors (n = 7), social factors (n = 5), oxidative stress (n = 2), vitamins (n = 2), genetic factors (n = 2) and other areas (n = 7). We found that there was a good body of evidence on the association between neurocognitive disorders and the history of cardiovascular disease while there were gaps in research of genetic and social risk factors.

CONCLUSION

We conclude that the epidemiological evidence from this region is insufficient and population-based prospectively followed cohorts should be established to allow the development of preventive strategies at national levels.

Prevalence, risk and protective factors for mild cognitive impairment in a population-based study of Singaporean elderly

The prevalence of dementia has been widely reported, and its potential risk and protective factors are well-characterized. However, there is a scarcity of related information regarding mild cognitive impairment (MCI). Thus this population-based study aimed to determine the prevalences of MCI and its subtypes, as well as to identify the risk and protective factors for MCI in the Chinese elderly population of Singapore. Results showed that the overall prevalence of MCI was 12.5%, while the gender-adjusted prevalence of MCI was 12.3%. Gender was found to be significantly associated with the subtypes of MCI, with males more likely to have amnestic MCI and females more likely to have non-amnestic MCI. Older age, lower educational levels, lower social activity levels, depression, hypertension, hyperlipidemia, diabetes and stroke were found to be risk factors for MCI in univariate analysis. However, multivariable analysis showed that only hypertension and stroke were the significant risk factors for MCI. Higher educational levels and active social engagements were significant protective factors for MCI in multivariable analysis. Age and depression had boundary significant associations with the prevalence of MCI. After adjusting for gender, the influence of hypertension, stroke, social engagement, age and depression on MCI remained unchanged, except that education became a boundary significant lower risk factor of MCI development. In conclusion, this study presented the prevalence, risk and protective factors for MCI among Singaporean Chinese older adults, which facilitates the screening of vulnerable groups for MCI.

The Role of Vitamin E in Slowing Down Mild Cognitive Impairment: A Narrative Review

With the aging population, dementia emerges as a public health concern. In 2012, the Health and Retirement Study found that 8.8% of adults over 65 years suffered from dementia. The etiopathogenesis and treatment of dementia are not well understood. Antioxidant properties of Vitamin E and its major elements tocopherols and tocotrienols have been reported to be effective in slowing down the progression of dementia from its initial stage of Mild cognitive impairment (MCI). Therefore, the current review aims to explore the role of vitamin E on MCI. A literature search using the key words "Vitamin E, tocopherols, tocotrienols, and mild cognitive impairment" was conducted in MEDLINE (PubMed), CINAHL, and Google Scholar. The inclusion criteria were: (1) articles published in the past ten years; (2) published in English language; (3) published in peer-reviewed journals; and (4) descriptive and epidemiological or evaluation studies. Articles published prior to 2010, focused on other forms of dementia than MCI, grey literature and non-peer-reviewed articles were excluded. A total of 22 studies were included in the narrative synthesis. The results were equivocal. Eleven studies showed some level of the neuroprotective effect of Vitamin E, tocopherols and tocotrienols on the progression of MCI. The mixed results of this review suggest further exploration of the possible protective effects of Vitamin E on the development of dementia. Future studies can be conducted to decipher antioxidant properties of vitamin E and its association with slowing down the cognitive decline.

Validation of ICMR Neurocognitive Toolbox for Dementia in the Linguistically Diverse Context of India

Objectives: The growing prevalence of dementia, especially in low- and middle-income countries (LMICs), has raised the need for a unified cognitive screening tool that can aid its early detection. The linguistically and educationally diverse population in India contributes to challenges in diagnosis. The present study aimed to assess the validity and diagnostic accuracy of the Indian Council of Medical Research-Neurocognitive Toolbox (ICMR-NCTB), a comprehensive neuropsychological test battery adapted in five languages, for the diagnosis of dementia. Methods: A multidisciplinary group of experts developed the ICMR-NCTB based on reviewing the existing tools and incorporation of culturally appropriate modifications. The finalized tests of the major cognitive domains of attention, executive functions, memory, language, and visuospatial skills were then adapted and translated into five Indian languages: Hindi, Bengali, Telugu, Kannada, and Malayalam. Three hundred fifty-four participants were recruited, including 222 controls and 132 dementia patients. The sensitivity and specificity of the adapted tests were established for the diagnosis of dementia. Results: A significant difference in the mean (median) performance scores between healthy controls and patients with dementia was observed on all tests of ICMR-NCTB. The area under the curve for majority of the tests included in the ICMR-NCTB ranged from 0.73 to 1.00, and the sensitivity and specificity of the ICMR-NCTB tests ranged from 70 to 100% and 70.7 to 100%, respectively, to identify dementia across all five languages. Conclusions: The ICMR-NCTB is a valid instrument to diagnose dementia across five Indian languages, with good diagnostic accuracy. The toolbox was effective in overcoming the challenge of linguistic diversity. The study has wide implications to address the problem of a high disease burden and low diagnostic rate of dementia in LMICs like India.

Stimulus-induced gamma rhythms are weaker in human elderly with mild cognitive impairment and Alzheimer's disease

Alzheimer's disease (AD) in elderly adds substantially to socioeconomic burden necessitating early diagnosis. While recent studies in rodent models of AD have suggested diagnostic and therapeutic value for gamma rhythms in brain, the same has not been rigorously tested in humans. In this case-control study, we recruited a large population (N = 244; 106 females) of elderly (>49 years) subjects from the community, who viewed large gratings that induced strong gamma oscillations in their electroencephalogram (EEG). These subjects were classified as healthy (N = 227), mild cognitively impaired (MCI; N = 12), or AD (N = 5) based on clinical history and Clinical Dementia Rating scores. Surprisingly, stimulus-induced gamma rhythms, but not alpha or steady-state visually evoked responses, were significantly lower in MCI/AD subjects compared to their age- and gender-matched controls. This reduction was not due to differences in eye movements or baseline power. Our results suggest that gamma could be used as a potential screening tool for MCI/AD in humans.

Loneliness Among Older Adults in Latin America, China, and India: Prevalence, Correlates and Association With Mortality

Objectives: This study was designed to explore prevalence and correlates of self-reported loneliness and to investigate whether loneliness predicts mortality among older adults (aged 65 or above) in Latin America, China and India. Methods: The study investigated population-based cross-sectional (2003-2007) and longitudinal surveys (follow-up 2007-2010) from the 10/66 Dementia Research Group project. Poisson regression and Cox regression analyses were conducted to analyse correlates of loneliness and its association with mortality. Results: The standardised prevalence of loneliness varied between 25.3 and 32.4% in Latin America and was 18.3% in India. China showed a low prevalence of loneliness (3.8%). In pooled meta-analyses, there was robust evidence to support an association between loneliness and mortality across Latin American countries (HR = 1.13, 95% CI 1.01-1.26, I2 = 10.1%) and China (HR = 1.58, 95% CI 1.03-2.41), but there were no associations in India. Conclusion: Our findings suggest potential cultural variances may exist in the concept of loneliness in older age. The effect of loneliness upon mortality is consistent across different cultural settings excluding India. Loneliness should therefore be considered as a potential dimension of public health among older populations.

Prevalence, Lifestyle Correlates, and Psychosocial Functioning Among Multi-Ethnic Older Adults with Mild Cognitive Impairment in Singapore: Preliminary Findings from a 10/66 Population Study

Asia, which has the highest increase in dementia prevalence, is unfortunately lacking recent up-to-date research, with regions of Southeast Asia being the most inadequate. Preventive approaches, such as the understanding of Mild Cognitive Impairment (MCI), are currently the most effective approach in reducing the risk or delaying the onset of dementia but are not adequately understood. Additionally, there is a paucity of research examining lifestyle and sociodemographic correlates of MCI that are relevant to the local population of Singapore. To address these gaps, this study aimed to explore: 1) the prevalence of MCI and Amnestic Mild Cognitive Impairment (aMCI), 2) the psychosocial and lifestyle correlates of MCI and aMCI. Data were drawn from the Well-being of the Singapore Elderly (WiSE) population study, which is a single-phase cross-sectional household survey conducted among older adult residents aged 60 years and above. Analyses revealed that the weighted MCI prevalence (1.2%) was lower than global figures. Few sociodemographic and lifestyle habits were related to MCI prevalence, as only age and physical activeness emerged as significant correlates. Despite the low prevalence of MCI, individuals with MCI experienced marked disability, clinical levels of depression and anxiety, which are all concerning finds. Due to the exploratory and cross-sectional nature of the study, future longitudinal research could further refine our understanding of MCI and confirm the present findings.

Association between sleep disturbance with motoric cognitive risk syndrome in Chinese older adults

BACKGROUND AND PURPOSE

Sleep disturbance and cognitive impairment are common and related in the elderly population worldwide. The aim of the present study was to explore the association between sleep disturbance and motoric cognitive risk (MCR) syndrome, which is characterized by subjective cognitive complaints and objective slow gait in older individuals without dementia or any mobility disability in the community-dwelling elderly Chinese population.

METHODS

We recruited 940 participants aged ≥65 years from November 2016 to March 2017 in the Ningbo Community Study on Aging (NCSA). Self-reported sleep duration and sleep-quality variables, comprehensive geriatric evaluation, as well as indicators for diagnosing MCR syndrome were evaluated in this cross-sectional study.

RESULTS

Multiple logistic regression analysis showed that a 1-SD increase in night (1.1 h) and 24-h sleep duration (1.3 h) was associated, respectively, with a 21% (95% confidence interval [CI], 1%-47%; p = 0.04) and 30% (95% CI, 3%-64%; p = 0.03) higher odds of having MCR syndrome. Considering sleep duration as a categorical variable, longer night-sleep duration (>8.5 h) was associated with MCR syndrome (OR, 2.03; p = 0.02) compared to shorter night-sleep duration (<8 h). For sleep-quality factors, increasing frequency of trouble falling asleep, waking early or easily, nightmares, and taking sleep drugs were significantly associated with MCR syndrome after adjusting for potential covariables (all p for trend < 0.05), but not for self-perceived sleep quality (p for trend = 0.10).

CONCLUSIONS

Long sleep duration, poor sleep quality, and taking sleep drugs were associated with higher odds of having MCR syndrome in the community-dwelling elderly Chinese population. Further research is needed to explore the underlying mechanisms.

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.

Role for Physical Fitness in the Association between Age and Cognitive Function in Older Adults: A Mediation Analysis of the SABE Colombia Study

Objectives. We investigated the association between physical fitness and cognitive status. Further, we examined whether physical fitness mediates the association between cognitive functioning and aging. Design. Cross-sectional study. Setting. Urban and rural Colombian older adults. Methods. 4416 participants from the SABE study were included in the current analysis. Physical fitness was assessed with the handgrip test and the usual gait speed test. Cognitive status was evaluated through the Folstein Mini-Mental State Examination. A parallel mediation path was used to test the possible mediator role of physical fitness between aging and cognitive functioning. Results. Older adults with lower handgrip strength (HGS) were more likely to have mild-cognitive status than older adults with healthy HGS (OR = 1.53, 95% CI = 1.15; 2.02). In addition, older adults with a slower gait speed were more likely to have mild cognitive impairment (OR = 2.05, 95% CI = 1.54; 2.78). Age had an inverse relationship with cognitive function (β = −0.110, 95% CI = −0.130; −0.100) and it was also inversely associated with HGS (β = −0.003, 95% CI = −0.005; −0.002) and gait speed (β = −0.010, 95% CI = −0.011; −0.009). The indirect effects, which indicate that the effect of age on cognitive function is transmitted through mediators, showed that both gait speed (β = −0.028, 95% CI = −0.036; −0.020) and HGS (β = −0.014, 95% CI = −0.024; −0.005) were independent mediators of the detrimental effect of aging on cognitive function. Conclusions. Physical fitness mediates the effects of aging on cognitive functioning. Our findings suggest that physical activity can be a key factor to prevent cognitive deterioration during aging process.

Prevalence of mild cognitive impairment in community-dwelling Chinese populations aged over 55 years: a meta-analysis and systematic review

Background

Mild cognitive impairment (MCI) is an intermediate phase between normal cognitive ageing and overt dementia, with amnesic MCI (aMCI) being the dominant subtype. This study aims to synthesise the prevalence results of MCI and aMCI in community-dwelling populations in China through a meta-analysis and systematic review.

Methods

The study followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) protocol. English and Chinese studies published before 1 March 2020 were searched from ten electronic bibliographic databases. Two reviewers screened for relevance of the studies against the pre-defined inclusion and exclusion criteria and assessed the quality of the included studies using the Risk of Bias Tool independently. A random-effect model was adopted to estimate the prevalence of MCI and aMCI, followed by sub-group analyses and meta-regression. Sensitivity and publication bias tests were performed to verify the robustness of the meta-analyses.

Results

A total of 41 studies with 112,632 participants were included in the meta-analyses. The Chinese community-dwelling populations over 55 years old had a pooled prevalence of 12.2% [95% confidence interval (CI): 10.6, 14.2%] for MCI and 10.9% [95% CI, 7.7, 15.4%] for aMCI, respectively. The prevalence of MCI increased with age. The American Psychiatric Association’s Diagnostic tool (DSM-IV) generated the highest MCI prevalence (13.5%), followed by the Petersen criteria (12.9%), and the National Institute on Aging Alzheimer’s Association (NIA-AA) criteria (10.3%). Women, rural residents, and those who lived alone and had low levels of education had higher MCI prevalence than others.

Conclusion

Higher MCI prevalence was identified in community-dwelling older adult populations in China compared with some other countries, possibly due to more broadened criteria being adopted for confirming the diagnosis. The study shows that aMCI accounts for 66.5% of MCI, which is consistent with findings of studies undertaken elsewhere.

Systematic review registration number

PROSPERO CRD42019134686.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-020-01948-3.

Changes in Cognitive Impairment in the Czech Republic

BACKGROUND

Studies from North America and Western Europe suggest stable or declining trends in impaired cognition across birth cohorts.

OBJECTIVE

We aimed to examine changes in the age-specific prevalence of cognitive impairment in the Czech Republic.

METHODS

The study used two samples from the population-based Czech Survey on Health, Ageing and Retirement in Europe. Age-specific prevalence of cognitive impairment (defined based on scores in verbal fluency, immediate recall, delayed recall, and temporal orientation) was compared between participants in wave 2 (2006/2007; n = 1,107) and wave 6 (2015; n = 3,104). Logistic regression was used to estimate the association between the wave and cognitive impairment, step-wise adjusting for sociodemographic and clinical characteristics. Multiple sensitivity analyses, focusing on alternative operationalizations of relative cognitive impairment, impact of missing cognitive data, and survival bias, were carried out.

RESULTS

The most conservative estimate suggested that the age-specific prevalence of cognitive impairment declined by one fifth, from 11% in 2006/2007 to 9% in 2015. Decline was observed in all sensitivity analyses. The change was associated with differences in physical inactivity, management of high blood cholesterol, and increases in length education.

CONCLUSION

Older adults in the Czech Republic, a country situated in the Central and Eastern European region, have achieved positive developments in cognitive aging. Longer education, better management of cardiovascular factors, and reduced physical inactivity seem to be of key importance.

Prevalence of Psychiatric Morbidity and Cognitive Impairment among Patients Attending the Rural Noncommunicable Disease Clinic

Objective  This study aimed to assess the prevalence of cognitive impairment and psychiatric morbidity among the patients attending the rural noncommunicable disease clinic after controlling for various confounders (i.e., psychological morbidity, obesity, gender, level of education, duration of the illness and age).

Materials and Methods  One-hundred twenty-four patients were evaluated on the Hindi Mental State Examination for the cognitive function, Physical Health Questionnaire-9 for depression, and Generalized Anxiety Disorder-7 for anxiety disorders.

Results  About one-fourth (26.6%) of the participants had cognitive impairment. The prevalence of cognitive impairment was more among patients with hypertension (35.5%) as compared with the diabetes mellitus (13.6%) and those with comorbid hypertension and diabetes mellitus (26.6%). About one of the participants had depression (35.5%) and 29% of the patients had anxiety disorder. No significant difference was found in the level of cognitive deficits between those with hypertension and diabetes mellitus, when the confounding factors were not taken into account in the analysis. However, after controlling for psychiatric morbidity, obesity, gender, level of education, duration of the illness and age, those with hypertension were found to have significantly higher level of cognitive impairment compared with those with diabetes mellitus. A higher level of dysfunction was seen in the domains of orientation, registration, attention, recall, language, and visuospatial domains.

Conclusion  Present study suggests that patients of hypertension have higher level of cognitive impairment, when compared with those with diabetes mellitus, even after controlling for various confounders. Lack of difference between the two groups can be accounted by the confounding variables.

Prevalence and factors associated with motoric cognitive risk syndrome in community-dwelling older Chinese: a cross-sectional study

BACKGROUND AND PURPOSE

A recently proposed pre-dementia syndrome, motoric cognitive risk (MCR) syndrome, is characterized by cognitive complaints and slow gait, and increases the risk of dementia and mortality. The aim of the present study was to explore the prevalence of and factors associated with MCR syndrome in elderly community-dwelling Chinese subjects.

METHODS

The Ningbo Community Study on Aging recruited 953 Chinese community-dwelling participants aged ≥ 65 years from November 2016 to March 2017. Handgrip, Five-Times-Sit-to-Stand (FTSS) test time and body composition, as well as comprehensive geriatric evaluation, were measured as potentially independent factors associated with MCR syndrome.

RESULTS

The prevalence of MCR syndrome was 12.8% in men and 12.6% in women, and high prevalence of MCR syndrome was not associated with age or sex. Multiple logistic regression analysis by sex showed that a 1-SD increase in FTSS test time in males and females was associated with 45% (95% confidence intervals, 19-76; P < 0.01) and 20% (95% confidence intervals, 9-33; P < 0.01) higher risk of having MCR syndrome, respectively, whereas handgrip strength was inversely correlated with MCR syndrome in males [odds ratio (OR), 0.91; P = 0.02] but not females (P = 0.06). Moreover, the relationship of arm fat mass and MCR syndrome was statistically significant in both sexes (OR, 1.69-1.77), but leg fat mass was only associated with MCR syndrome (OR, 1.56; P = 0.02) in men.

CONCLUSIONS

Handgrip, FTSS test time and body composition were associated in a sex-specific manner with MCR syndrome in elderly community-dwelling Chinese subjects. Our results on MCR syndrome are novel and should be considered as important information in future studies.

Potentially Avoidable Hospitalization among Long-Term Care Insurance Beneficiaries with Dementia

BACKGROUND

This study investigated the differences in the risk of potentially avoidable hospitalization (PAH) among eligible long-term care insurance (LTCI) beneficiaries with dementia for LTCI services in Korea. Nested case-control study was conducted using the National Health Insurance Service-Senior claim database.

METHODS

Cases of individuals who had a PAH incident diagnosis and controls were selected by incidence density sampling and matched to cases based on age, sex, and difficulty of daily living among dementia patients. We conducted incidence density sampling three times by PAH type.

RESULTS

Our main results were presented by conditional logistic regression analysis for the matched case-control studies. Out of the 7,352 eligible LTCI beneficiary patients, there were 1,231 cases (16.7%) in overall PAH, 132 cases (19.0%) in acute PAH and 1,114 cases (16.7%) in chronic PAH categories. In terms of individual risk of overall and chronic PAH, the odds ratios of those who did not receive any services were 1.336 time higher (95% confidence interval [CI], 1.159-1.540) and 1.280 time higher (95% CI, 1.103-1.485) compared to those who received home care, respectively. For risk of acute PAH, the odds ratios of those who did receive institutional care were 2.046 time higher (95% CI, 1.170-3.578) compared to those who received home care.

CONCLUSION

This study identified the differences in risk of PAH incidents according to the type of LTCI service in the elderly population in Korea. Therefore, it will require substantial effort and strategy from health policy makers to improve care quality.

Screening for cognitive impairment among the elderly attending the noncommunicable diseases clinics in a rural area of Punjab, North India

BACKGROUND

Amongst all the ailments among the elderly persons, cognitive impairment has significant impact on the quality of life. Non-communicable diseases (NCDs) like diabetes and hypertension increase the risk of cognitive impairment and dementia. Little is known about the prevalence and correlates of cognitive impairment in elderly with NCDs.

AIM

The present study aimed to evaluate the prevalence and correlates of cognitive impairment among elderly patients living with NCDs.

METHODOLOGY

297 patients attending the chronic disease clinic of two Community Health Centres were evaluated using Hindi mini-mental scale (HMSE), University of California Los Angeles Loneliness Scale (UCLA LS), Geriatric Depression Scale, Generalized Anxiety Disorder (GAD-7 scale) and Vulnerability to Abuse Screening Scale.

RESULTS

More than one-fourth (27.3 %) of participants had cognitive impairment as per the HMSE scores. The mean HMSE score was lowest (23.90+6.61) among patients with hypertension followed by patients with diabetes alone (26.90+4.46). People with hypertension had lower mean scores on all the domains of HMSE. Multivariable binary logistic regression depicted younger age, high education status, per capita income, long duration of diseases, loneliness, and hypertension emerged as the significant risk factors associated with cognitive impairment.

CONCLUSION

Older adults with non-communicable diseases have high prevalence of cognitive impairment. Physicians should make the patients and their family members aware about the association of non-communicable diseases with cognitive impairments and should encourage these persons to use remedial measures to reduce the risk of future development of dementia.

Standardising Dementia Diagnosis Across Linguistic and Educational Diversity: Study Design of the Indian Council of Medical Research-Neurocognitive Tool Box (ICMR-NCTB)

OBJECTIVES

While the burden of dementia is increasing in low- and middle-income countries, there is a low rate of diagnosis and paucity of research in these regions. A major challenge to study dementia is the limited availability of standardised diagnostic tools for use in populations with linguistic and educational diversity. The objectives of the study were to develop a standardised and comprehensive neurocognitive test battery to diagnose dementia and mild cognitive impairment (MCI) due to varied etiologies, across different languages and educational levels in India, to facilitate research efforts in diverse settings.

METHODS

A multidisciplinary expert group formed by Indian Council of Medical Research (ICMR) collaborated towards adapting and validating a neurocognitive test battery, that is, the ICMR Neurocognitive Tool Box (ICMR-NCTB) in five Indian languages (Hindi, Bengali, Telugu, Kannada, and Malayalam), for illiterates and literates, to standardise diagnosis of dementia and MCI in India.

RESULTS

Following a review of existing international and national efforts at standardising dementia diagnosis, the ICMR-NCTB was developed and adapted to the Indian setting of sociolinguistic diversity. The battery consisted of tests of cognition, behaviour, and functional activities. A uniform protocol for diagnosis of normal cognition, MCI, and dementia due to neurodegenerative diseases and stroke was followed in six centres. A systematic plan for validating the ICMR-NCTB and establishing cut-off values in a diverse multicentric cohort was developed.

CONCLUSIONS

A key outcome was the development of a comprehensive diagnostic tool for diagnosis of dementia and MCI due to varied etiologies, in the diverse socio-demographic setting of India.

Cognitive impairment and its predictors: A cross-sectional study among the elderly in a rural community of West Bengal

Context:

With the aging of Indian society, maintaining salubrious cognitive health in late life is a public health priority. Early detection and possible prevention of cognitive impairment (CI), thus, will help in increasing the quality of life of elderly people and decreasing the social, psychological, and economic burden of their families and caregivers.

Aims:

The study aimed to assess proportion of CI and its predictors.

Settings and Design:

This community-based cross-sectional study was conducted among 135 elderly people selected from 15 villages out of a total 64 villages in rural field practice area Singur of AIIH&PH, Kolkata.

Methods and Material:

Cluster sampling technique was used and villages were selected according to probability proportional to size method. Data was collected using a predesigned, pretested structured schedule, which included sociodemographic and behavioral variables, Montreal cognitive assessment tool, Geriatric depression scale short form (GDS 15), and mini nutritional assessment tool.

Statistical Analysis Used:

Predictors of CI were assessed by univariate and multivariable logistic regression using MS-Excel 2016 and SPSS version 16 software.

Results:

Mean age of the study participants was 67.03 ± 6.7 years with 51.9% of them being females. Proportion of CI was observed to be 48.1% which was significantly associated with increasing age [AOR = 1.1 (1.02–1.13)], decreasing years of schooling [AOR = 1.1 (1.01–1.2)], depression [AOR = 2.7 (1.3–5.8)], and malnourished group [AOR = 4.5 (1.01–20.3)]

Conclusion:

The burden of CI among the study population was found to be quite high. It is an alarming situation which needs improved screening facility for early detection. Nutritional upliftment and screening for depression should also be done on a regular basis.

Screening for Sarcopenia with a Self-Reported Cartoon Questionnaire: Combining SARC-F with Finger-Ring Test

OBJECTIVES

No pictorial questionnaire is available for screening sarcopenia. We aimed to develop a self-reported cartoon questionnaire based on the SARC-F and the Finger-Ring test and to compare its diagnostic accuracy with the SARC-F and the SARC-F combined with calf circumference (SARC-CalF).

DESIGN

A diagnostic accuracy study.

SETTING

Urban communities in Chengdu, China.

PARTICIPANTS

Older adults aged ≥ 60 years.

METHODS

We established a multidiscipline team to design this pictorial questionnaire, entitled Self-Reported Cartoon SARC-CalF (cSARC-CalF). We used the Asian Working Group for Sarcopenia (AWGS) criteria as the "gold standard" of sarcopenia. We performed sensitivity/ specificity analyses of the three tools (cSARC-CalF, SARC-CalF, and SARC-F) and applied the receiver operating characteristics (ROC) curves and the area under the ROC curves (AUC) to compare the diagnostic accuracy of the three tools.

RESULTS

We included 1,009 participants. Using the Youden Index method, the cutoff of the cSARC-CalF for identifying sarcopenia was set as ≥11 points. Both the cSARC-CalF and the SARC-CalF showed better sensitivity but similar specificity than the SARC-F for identifying sarcopenia (sensitivity: 33.3%, 41.4%, and 23.0%; specificity: 90.1%, 85.9%, and 88.1%). The AUCs of the cSARC-CalF, SARC-CalF, and SARC-F were 0.74 (95% CI, 0.71 - 0.77), 0.79 (95% CI, 0.76 - 0.81), and 0.67 (95% CI, 0.64 - 0.70), respectively. The difference in AUCs between cSARC-CalF and SARC-F and the difference in AUCs between SARC-CalF and SARC-F was statistically significant (p=0.012 and p<0.001, respectively). However, the difference in AUCs between cSARC-CalF and SARC-CalF was not significant (p=0.109).

CONCLUSION

The cSARC-CalF showed a better overall diagnostic accuracy than the SARC-F and a similar overall diagnostic accuracy as the SARC-CalF in Chinese community-dwelling older adults. It may serve as a new tool for screening sarcopenia; however, it needs to be validated in other populations.