Prevalence of Dementia and Mild Cognitive Impairment in the Rural Island Town of Ama-cho, Japan

Subjective Difficulty with Higher-Level Functional Capacity in Community-Dwelling Older People withMild Cognitive Impairment

BACKGROUND AND PURPOSE

Mild cognitive impairment (MCI) is a predictor of future age-related dementia.　We herein investigated associations of MCI with higher-level functional capacities, as well as with subjective difficulty regarding these functions, in community-dwelling older people, to identify a simple method for early MCI detection.

METHOD

We administered a test battery to 118 community-dwelling older people living in an urban area.　The battery consisted of three tests;the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC), the Touch Panel-type Dementia Assessment Scale (TDAS), and the Geriatric Depression Scale-15.　We then excluded participants with possible dementia or depression symptoms, and divided the remainder (n = 67) into an MCI group (n = 16) and a non-MCI group (n = 51), according to TDAS performance.

RESULTS

Logistic regression analysis with the MCI and non-MCI groups as dependent variables indicated that TMIG-IC was a significant variable.　Male sex and the perception that preparing meals and filling out pension forms had become more difficult were significantly associated with MCI, each independently increasing the probability of MCI.

CONCLUSIONS

Subjective difficulty with higher-level functions and impairment in higher-level functional capacity may serve as indices for mass screening for MCI.

Process validation and preclinical development of a new PET cerebral blood flow tracer [11C]MMP for initial clinical trials

BACKGROUND

2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) is commonly used for diagnosis of dementia because brain glucose metabolism reflects neuronal activity. However, as [18F]FDG is an analogue of glucose, accumulation of tracer in the brain is affected by plasma glucose levels. In contrast, cerebral blood flow (CBF) tracers are theoretically unaffected by plasma glucose levels and are therefore expected to be useful alternatives for the diagnosis of dementia in patients with diabetes. The techniques currently used for CBF imaging using single photon emission computed tomography (SPECT) and [15O]H2O positron emission tomography (PET), but these are limited by their insufficient resolution and sensitivity for regional brain imaging, especially in patients with brain atrophy. N-isopropyl-4-[11C]methylamphetamine ([11C]MMP) is a possible CBF tracer with high resolution and sensitivity that exhibits comparable performance to that of [15O]H2O in conscious monkey brains. We performed process validation of the radiosynthesis and preclinical development of [11C]MMP prior to clinical translation.

RESULTS

The decay-corrected yields of [11C]MMP at the end of synthesis were 41.4 ± 6.5%, with 99.7 ± 0.3% radiochemical purity, and 192.3 ± 22.5 MBq/nmol molar activity. All process validation batches complied with the product specifications. The acute toxicity of MMP was evaluated at a dose of 3.55 mg/kg body weight, which is 10,000 times the potential maximum clinical dose of [11C]MMP. The acute toxicity of [11C]MMP injection at 150 or 200 times, to administer a postulated dose of 740 MBq of [11C]MMP, was also evaluated after the decay-out of 11C. No acute toxicity of MMP and [11C]MMP injection was found. No mutagenic activity was observed for MMP. The effective dose calculated according to the Medical Internal Radiation Dose (MIRD) method was 5.4 µSv/MBq, and the maximum absorbed dose to the bladder wall was 57.6 µGy/MBq. MMP, a derivative of phenylalkylamine, showed binding to the sigma receptor, but had approximately 1/100 of the affinity of existing sigma receptor imaging agents. The affinity for other brain neuroreceptors was low.

CONCLUSIONS

[11C]MMP shows acceptable pharmacological safety at the dose required for adequate PET imaging. The potential risk associated with [11C]MMP PET imaging is well within the acceptable dose limit.

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.

The prevalence of mild cognitive impairment and dementia among rural dwellers: A systematic review and meta-analysis

The mild cognitive impairment (MCI) and dementia in rural areas are increasingly attracting public attention. However, their prevalence is still unclear. This study aims to reveal the distribution of MCI and dementia in rural areas. We systematically searched PubMed, Web of Science, Embase, and PsycINFO up to June 2023 for cohort and cross-sectional studies. Meta-analysis was conducted using random-effects models to evaluate the prevalence of MCI and dementia. Thirty-five studies with 16,936 participants met the inclusion criteria. The pooled prevalence of MCI and dementia was 27 % (n = 12, 95 %CI = 0.21-0.32, I2 = 99.5 %, P < 0.001) and 7 % (n = 27, 95 %CI = 0.05-0.08, I2 = 99.30 %, P < 0.001), respectively. Subgroup analyses revealed that aged 60 years or older [(MCI: 29 %, 95 %CI = 0.20-0.38, I2 = 99.7 %, P < 0.001), (dementia: 9 % (95 %CI = 0.06-0.12, I2 = 99 %, P < 0.001)], female [(MCI: 29 %, 95 %CI = 0.19-0.40, I2 = 99.3 %, P < 0.001), (dementia: 7 %, 95 % CI = 0.04-0.12, I2 = 98.66 %, P < 0.001)], a-MCI (19 %, 95 %CI = 0.12-0.26, I2 = 97.62 %, P < 0.001) and AD (4 %, 95 %CI = 0.02-0.05, I2 = 98.60 %, P < 0.001) showed higher prevalence. The prevalence of MCI and dementia in rural China was 23 % (95 %CI = 0.18-0.29, I2 = 99.5 %, P < 0.001) and 6 % (95 %CI = 0.04-0.08, I2 = 99.6 %, P < 0.001), respectively. Implementing cognitive impairment screening and intervention measures is necessary to improve the cognitive function of the rural population.

Association between prevalence rate of dementia with Lewy bodies and sleep characteristics in Chinese old adults

Introduction: Few studies are available on the prevalence and sleep-related factors of dementia with Lewy bodies (DLB) in Chinese older adults, aiming to explore the associations between sleep characteristics and DLB.

Methods: A cross-sectional study with 7,528 individuals aged ≥65 years in 106 communities in Northern China was conducted from April 2019 to January 2020. Questionaries (including demographic characteristics, comorbidities, lifestyles, and sleep characteristics) were administered, and neuropsychological assessments and physical examination were conducted in phase I; screening for probable DLB was done in phase II. Logistic regressions were used to assess associations.

Results: A total of 919 (12.2%, 919/7,528) participants had dementia, and 101 (1.3%, 101/7,528) participants were diagnosed with DLB. The prevalence of dementia and DLB were slightly higher or equal in women, increased with age, and roughly decreased with nighttime sleep duration. Of the 101 participants, all of them (100.0%) had cognitive impairment, 46 (44.54%) displayed fluctuating cognition, 72 (71.29%) of them showed visual hallucination, 22 (21.78%) individuals reported RBD, and 27.71% showed Parkinsonism. Sleeping for <5 h (adjusted OR = 1.795, 95%CI: 1.055–3.054, p < 0.05) or having hypersomnolence (adjusted OR = 31.213, 95% CI: 17.618–55.301, p < 0.001) were significantly associated with the occurrence of DLB. Sleep duration of <5 h or >8 h had combined diagnostic value for DLB (AUC = 0.783, 95%CI: 0.734–0.831, p < 0.001).

Conclusions: The current prevalence of DLB is 1.3% in Northern China. Short or long nighttime sleep duration is independently associated with the occurrence of dementia and DLB.

The Association Between Hyperhidrosis and Dementia: A Community-Based Research

BACKGROUND

Dementia and hyperhidrosis (HH) are common in the elderly while there is little research to investigate the association between them.

OBJECTIVE

To clarify a possible association between HH and dementia in population of adults ≥65 years old in China.

METHODS

A cross-sectional survey for elderly adults ≥65 years old was conducted from April to December 2019. A total of 5,958 participants were analyzed after two phases investigation. Goodness-of-fit tests (Pearson and deviance) were used to estimate the dispersion parameter and examine the adequacy of the models. Logistic and linear regression analyses were used to evaluate the association between HH and dementia.

RESULTS

The overall prevalence of all-cause dementia was 10.17%, that of dementia with Lewy bodies (DLB) was 1.41%, and HH was 14.97%. Prevalence rates of HH were higher in participants with dementia and DLB. There was a significant positive relationship between HH duration and MMSE score (r = 0.207, p < 0.001, Durbin-Watson test = 1.806). Participants with HH were 1.275 (95% CI: 1.015-1.601, p = 0.037) times to have dementia, and 3.616 (95% CI: 2.267-5.767, p < 0.001) times to suffer from DLB than those without HH. Pearson and deviance chi square tests did not indicate overdispersion (p > 0.05 in the logistic regression models).

CONCLUSION

HH was common in the Chinese population ≥65 years old. It can increase the risk of dementia, particularly in DLB, in the elderly. It is important to improve the awareness of HH among dermatologists and neurologists.

Association between mild cognitive impairment and lumbar degenerative disease in a Japanese community: A cross-sectional study

Lumbar degenerative disease and dementia are increasing in super-aging societies and are both related to physical dysfunction and pain. However, the relationship between these diseases remains unclear. This cross-sectional study aimed to investigate the comorbidity rates of lumbar spinal canal stenosis (LSS) and mild cognitive impairment (MCI) and clarify the association between LSS presence, lumbar symptoms, and quality of life (QOL) related to low back pain and cognitive impairment in the Japanese population. We enrolled 336 participants (men 124; women 212; mean age 72.2 years) from a medical checkup program. LSS was diagnosed using a self-administered questionnaire, and lumbar symptoms were evaluated using the visual analog scale (low back pain, and pain and numbness of the lower limb). QOL related to low back pain was evaluated using the Japanese Orthopedic Association Back-Pain Evaluation Questionnaire (JOABPEQ: pain, and lumbar, and gait function). Radiological lumbar degeneration was classified using Kellgren-Lawrence grading and lateral radiographs of the lumbar spine. Cognitive function was measured using the Mini Mental State Examination (MMSE), and MCI was defined by a summary score of MMSE ≤27. Logistic and multiple linear regression analyses were performed to analyze the association between MCI, summary score of MMSE, and lumbar degenerative disease. The comorbidity rate of MCI and LSS was 2.1%, and the rate of MCI was 41% in participants with LSS. Lumbar function in JOABPEQ was associated with MCI. The presence of LSS and lumbar function in JOABPEQ were associated with MMSE. Over one-third of the people with LSS had MCI. The presence of LSS and deterioration of QOL due to low back pain were related to cognitive impairment. We recommend evaluating cognitive function for patients with LSS because the rate of MCI was high in LSS participants.

Age-Related Cognitive Decline and Prevalence of Mild Cognitive Impairment in the Iwaki Health Promotion Project

BACKGROUND

The Iwaki Health Promotion Project (IHPP) is a community-based study for the prevention of lifestyle-related diseases and improvement of quality of life.

OBJECTIVE

Between 2014 and 2017, a total of 4,442 Iwaki town residents from 19 to 93 years of age participated in annual surveys to clarify the natural course of age-related cognitive decline and mild cognitive impairment (MCI).

METHODS

Modified OLD and SED-11Q questionnaires, MMSE, Logical Memory II, educational history, and APOE genotypes were examined at the first screening. MCI and dementia were diagnosed at the second examination by detailed neurological examination, CDR, and MRI, and followed for 3 years. Spline regression analyses based on a linear mixed model was adopted for statistical analysis.

RESULTS

MMSE scores declined with age from 55 to 64 years. There was also interaction between levels of education and ages. At the second examination, 56 MCI and 5 dementia patients were identified. None of the MCI cases progressed to dementia during the 3 years. During follow-up examinations, 13 cases showed improved MMSE scores (0.95 point/year), 5 remained stable, and 7 deteriorated (-0.83 point/year). Five cases showed improved CDR-SOB scores (-0.28 point/year), 9 remained stable, and 6 deteriorated (0.3 point/year).

CONCLUSION

IHPP revealed that age- and education-related cognitive decline began and advanced from 55 years of age. The prevalence of MCI and dementia was estimated to be 5.9%in the Iwaki town cohort over 60 yeas of age. About 30%of MCI cases showed progression of cognitive decline.

An association analysis between hypertension, dementia, and depression and the phases of pre-sarcopenia to sarcopenia: A cross-sectional analysis

Sarcopenia is intricately related to aging associated diseases, such as neuropsychiatric disorders, oral status, and chronic diseases. Dementia and depression are interconnected and also related to sarcopenia. The preliminary shift from robust to sarcopenia (i.e., pre-sarcopenia) is an important albeit underdiscussed stage and is the focus of this study. Identifying factors associated with pre-sarcopenia may lead to sarcopenia prevention. To separately examine the effects of dementia and depression on pre-sarcopenia/sarcopenia, we conducted multiple analyses. This cross-sectional study used health checkup data from a rural Japanese island. The participants were aged 60 years and above, and the data included muscle mass, gait speed, handgrip strength, oral status (teeth and denture), chronic diseases (e.g., hypertension), dementia (cognitive assessment for dementia, iPad Version), and depression (self-rating depression scale). A total of 753 older adult participants were divided into the sarcopenia (n = 30), pre-sarcopenia (n = 125), and robust (n = 598) groups. An ordered logit regression analysis indicated that age and depression were positively correlated with sarcopenia, while hypertension was negatively associated with it. A multiple logistic regression analysis between the robust and pre-sarcopenia groups showed significant associations between the same three variables. Depression was associated with pre-sarcopenia, but not dementia. There was also a significant association between hypertension and pre-sarcopenia. Further research is needed to reveal whether the management of these factors can prevent sarcopenia.

Urban-rural differences in the prevalence and correlates of mild cognitive impairment in community-dwelling older adults in Taiwan: The EMCIT study

BACKGROUND

Taiwan is a rapidly aging society. The elderly with mild cognitive impairment (MCI) have increased risk of dementia, and this is a population-based report using standard neuropsychological tests and expert consensus diagnosis to assess the MCI prevalence and its associated factors in Taiwan.

METHOD

The Epidemiology of Mild Cognitive Impairment study in Taiwan (EMCIT) is a community-based, prospective cohort study. Independently-living individuals aged ≧60 years in a rural area (n = 122) and in an urban area (n = 348) of New Taipei City, Taiwan, completed detailed neuropsychological tests at the cohort baseline. Diagnosis of MCI was ascertained through expert consensus based on 2011 NIA-AA criteria.

RESULTS

Of 470 participants recruited between 2017 and 2019 (mean age 71.2 ± 5.4 years), the prevalence of MCI was higher in the rural area than in the urban area (25.1% vs. 10.8%, p < 0.001) after standardized for age, gender, and level of education. Having lower education and having depression symptoms were consistently associated with increased risk of MCI in both urban and rural areas (p < 0.05). Being male and diabetes were additionally associated with MCI prevalence in urban areas.

CONCLUSION

In this community-based prospective cohort study in Taiwan, the prevalence of MCI in the rural community was much higher than that in the urban community. Different strategies may be needed to targeted different types of communities.

Clinical characteristics of Lewy body dementia in Chinese memory clinics

Background

Lewy body dementia (LBD), consisting of dementia with Lewy bodies (DLB) and Parkinson’s disease dementia (PDD), is the second most common type of neurodegenerative dementia in older people. The current study aimed to investigate the clinical characteristics of LBD in Chinese memory clinics.

Methods

A total of 8405 dementia medical records were reviewed, revealing 455 patients with LBD. Demographic data, neuropsychological scores, and the scale for Medial Temporal lobe Atrophy (MTA) were then analyzed from nine memory clinics in the China Lewy Body Disease Collaborative Alliance.

Results

The clinical proportion of LBD among the subjects and among all dementia types was 5.4% (4.9–5.9%) and 7.3% (6.7–8.0%), respectively, with a mean onset age of 68.6 ± 8.4 years. Patients with DLB comprised 5.6% (n = 348, age of onset 69.1 ± 8.3), while PDD comprised 1.7% (n = 107, age of onset 66.7 ± 8.8) of all dementia cases. There were slightly more males than females with DLB (n = 177, 50.9%) and PDD (n = 62, 57.9%). Patients with DLB had a poorer performance compared to those with PDD on the MMSE (16.8 ± 7.1 vs. 19.5 ± 5.7, p = 0.001), the MoCA (11.4 ± 6.6 vs. 14.0 ± 5.8, p<0.001), the CDR (1.8 ± 0.7 vs. 1.6 ± 0.7, p = 0.002), and the MTA (1.8 ± 0.7 vs. 1.2 ± 0.6, p = 0.002). Diagnostic differences for LBD exist among the centers; their reported proportions of those with DLB ranged from 0.7 to 11.4 and those with PDD ranged from 0.0 to 2.9%.

Conclusions

Variations of diagnoses exists in different regions and the clinical proportion of LBD is likely to be underestimated in China and other regions.

Study design and baseline characteristics of a population-based prospective cohort study of dementia in Japan: the Japan Prospective Studies Collaboration for Aging and Dementia (JPSC-AD)

BACKGROUND

The burden of dementia is growing rapidly and has become a medical and social problem in Japan. Prospective cohort studies have been considered an effective methodology to clarify the risk factors and the etiology of dementia. We aimed to perform a large-scale dementia cohort study to elucidate environmental and genetic risk factors for dementia, as well as their interaction.

METHODS

The Japan Prospective Studies Collaboration for Aging and Dementia (JPSC-AD) is a multisite, population-based prospective cohort study of dementia, which was designed to enroll approximately 10,000 community-dwelling residents aged 65 years or older from 8 sites in Japan and to follow them up prospectively for at least 5 years. Baseline exposure data, including lifestyles, medical information, diets, physical activities, blood pressure, cognitive function, blood test, brain magnetic resonance imaging (MRI), and DNA samples, were collected with a pre-specified protocol and standardized measurement methods. The primary outcome was the development of dementia and its subtypes. The diagnosis of dementia was adjudicated by an endpoint adjudication committee using standard criteria and clinical information according to the Diagnostic and Statistical Manual of Mental Disorders, 3rd Revised Edition. For brain MRI, three-dimensional acquisition of T1-weighted images was performed. Individual participant data were pooled for data analyses.

RESULTS

The baseline survey was conducted from 2016 to 2018. The follow-up surveys are ongoing. A total of 11,410 individuals aged 65 years or older participated in the study. The mean age was 74.4 years, and 41.9% were male. The prevalence of dementia at baseline was 8.5% in overall participants. However, it was 16.4% among three sites where additional home visit and/or nursing home visit surveys were performed. Approximately two-thirds of dementia cases at baseline were Alzheimer's disease.

CONCLUSIONS

The prospective cohort data from the JPSC-AD will provide valuable insights regarding the risk factors and etiology of dementia as well as for the development of predictive models and diagnostic markers for the future onset of dementia. The findings of this study will improve our understanding of dementia and provide helpful information to establish effective preventive strategies for dementia in Japan.

Carvalho O, Barros H. Global Cognitive Impairment Prevalence and Incidence in Community Dwelling Older Adults-A Systematic Review

(1) Background: We proposed to review worldwide estimates of cognitive impairment prevalence and incidence in adults older than 50 years of age living in the community. (2) Methods: Systematic searches were performed in January 2019 using MEDLINE/PubMed. Articles were selected if they referred to cognitive impairment, prevalence, incidence, elders, and population or community-based studies. Analysis, aggregated by different methodologic features, was performed. (3) Results: Prevalence (80 studies) ranged between 5.1% and 41% with a median of 19.0% (25th percentile = 12.0%; 75th percentile = 24.90%). Incidence (11 studies) ranged from 22 to 76.8 per 1000 person-years with a median of 53.97 per 1000 person-years (25th percentile = 39.0; 75th percentile = 68.19). No statistically significant effects were found except for inclusion age. (4) Conclusion: We propose that the homogenization and clarification of the definition of what constitutes cognitive impairment are essential to refine the epidemiological understanding of this entity. The results of this review reinforce the importance of adherence to standardized cut-off scores for cognitive tests to promote study comparability.

Synthesis and evaluation of N-isopropyl-p-[11C]methylamphetamine as a novel cerebral blood flow tracer for positron emission tomography

INTRODUCTION

Increases in fasting plasma glucose (PG) levels lead to a decrease in 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) uptake in the normal brain, especially in the precuneus, resulting in an Alzheimer's disease (AD)-like uptake pattern. Therefore, patients with higher PG levels, such as those with diabetes, can be erroneously diagnosed with AD when positron emission tomography (PET) imaging is done using [¹⁸F]FDG, due to reduced uptake of [¹⁸F]FDG in the precuneus. To help avoid an erroneous diagnosis of AD due to differences in glucose metabolism, evaluating cerebral blood flow (CBF) in the brain is useful. However, current techniques such as single photon emission computed tomography (SPECT) and [¹⁵O]H₂O PET have limitations regarding early diagnosis of AD because the images they produce are of low resolution. Here, we developed a novel CBF PET tracer that may be more useful than [¹⁸F]FDG for diagnosis of AD.

METHODS

We synthesized and evaluated N-isopropyl-p-[¹¹C]methylamphetamine ([¹¹C]4) as a carbon-11-labeled analogue of the standard CBF SPECT tracer N-isopropyl-p-[¹²³I]iodoamphetamine. Fundamental biological evaluations such as biodistribution, peripheral metabolism in mice, and brain kinetics of [¹¹C]4 in non-human primates with PET with successive measurement of [¹⁵O]H₂O were performed.

RESULTS

[¹¹C]4 was synthesized by methylation of the corresponding tributyltin precursor (2) with [¹¹C]MeI in a palladium-promoted Stille cross-coupling reaction. The brain uptake of [¹¹C]4 in mice peaked at 5-15 min after injection and then promptly decreased. Most radioactivity in the brain was detected in the unchanged form, although in the periphery, [¹¹C]4 was rapidly metabolized to hydrophilic components. Acetazolamide (AZM) treatment significantly increased the brain uptake of [¹¹C]4 without affecting the blood levels of radioactivity in mice. Preliminary kinetics analysis showed that the K₁ of [¹¹C]4 reflected regional CBF in a vehicle-treated monkey, but that the K₁ did not reflect CBF in higher flow regions after AZM loading.

CONCLUSION

[¹¹C]4 is a potential novel CBF PET tracer. Further validation studies are needed before [¹¹C]4 can be used in humans.

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.

Characteristics of Mild Cognitive Impairment in Northern Japanese Community-Dwellers from the ORANGE Registry

A gradually increasing prevalence of mild cognitive impairment (MCI) is recognized in the super-aging society that Japan faces, and early detection and intervention in community-dwellers with MCI are critical issues to prevent dementia. Although many previous studies have revealed MCI/non-MCI differences in older individuals, information on the prevalence and characteristics of MCI in rural older adults is limited. The aim of this study was to investigate differential characteristics between older adults with and without MCI. The investigation was conducted over one year from 2018 to 2019. Participants were recruited from Akita in northern Japan. Neuropsychological assessments were applied to classify MCI, including the National Center for Geriatrics and Gerontology Functional Assessment Tool (NCGG-FAT) and the Touch panel-type Dementia Assessment Scale (TDAS) based on the Alzheimer's disease assessment scale. Our samples consisted of 103 older adults divided into 54 non-MCI and 49 MCI. The MCI group had lower scores of all cognitive items. Our results showed that individuals with MCI had significantly slower walking speed (WS) and worse geriatric depression scale (GDS) compared to non-MCI. In addition, WS was significantly associated with some cognitive items in non-MCI, but not in MCI. Finally, we showed that predictive variables of MCI were WS and GDS. Our study provides important information about MCI in rural community-dwellers. We suggest that older adults living in a super-aging society should receive lower limb training, and avoiding depression in older adults through interaction of community-dwellers may contribute to preventing the onset of MCI.

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.

The association between social participation and cognitive function in community-dwelling older populations: Japan Gerontological Evaluation Study at Taisetsu community Hokkaido

OBJECTIVE

To study the association between the number of area-level and individual-level social participation items and cognitive function in the community-dwelling older populations of three towns in Hokkaido, Japan.

METHODS

A survey on the frequency of social participation was mailed to those in the Japan Gerontological Evaluation Study 2013 who were aged ≥65 years, were not certified as needing long-term care, and lived in Higashikawa, Higashikagura, or Biei. A subset of participants aged 70-74 years completed the Japanese version of the Montreal Cognitive Assessment in a home visit survey. Both the area-level and individual-level social participation and demographic information were obtained on the self-administered questionnaire. A multilevel analysis using a generalized linear mixed-effects model was used to examine the association between variables in the area-level and individual-level social participation items and cognitive function.

RESULTS

Out of 4042 respondents, data from 2576 were used in the area-level analysis. Of those, 180 were aged 70-74 years and completed the home visit survey for the individual-level analysis. A greater number of higher social participation items at the individual level was associated with higher cognitive function scores after adjusting for area-level social participation variables and confounders (regression coefficient: 0.19; 95% confidence interval: 0.03, 0.35). There were no significant associations between area-level social participation item averages and individual-level cognitive function scores.

CONCLUSIONS

Older populations participating in many kinds of social activities exhibited preserved cognitive function even after adjusting for area-level social participation variables. Copyright © 2016 John Wiley & Sons, Ltd.

Factors Associated with Mild Cognitive Impairment among Elderly Filipinos with Type 2 Diabetes Mellitus

Objectives

This study aims to identify factors associated with mild cognitive impairment (MCI) among elderly Filipinos with Type 2 diabetes mellitus.

Methodology

This is an analytic cross-sectional study involving 133 elderly (≥60 years old) with Type 2 diabetes mellitus consecutively sampled from the General Medicine and Diabetes Clinics of the Philippine General Hospital. Eligible subjects were interviewed to gather demographic and clinical data. Body mass index, waist-hip ratio and mean blood pressure were computed. HBA1c, lipid profile, creatinine and urine proteinuria were tested or recorded if done recently. Dilated fundus examination via indirect ophthalmoscopy and 10-gram monofilament test were performed to detect retinopathy and neuropathy. The Montreal Cognitive Assessment-Philippines tool was administered to detect patients with probable MCI using a cutoff score of ≤21. Multivariate logistic regression analysis was performed to determine the associated factors.

Results

Using MoCA-P tool, MCI has a rate of 45% among elderly Filipino diabetics. Having more than 12 years of education is significantly associated with lower odds of MCI. (OR 0.38 CI 0.18, 0.80, p value 0.010).

Conclusion

The rate of MCI among Filipino elderly diabetics is high. Higher education is associated with lower odds of having MCI. Case-control or prospective cohort studies involving larger sample and non-diabetic population are recommended.

Sex differences in the prevalence and incidence of mild cognitive impairment: A meta-analysis

OBJECTIVE

More women have Alzheimer's disease (AD) than men. Understanding sex differences in mild cognitive impairment (MCI) may further knowledge of AD etiology and prevention. We conducted a meta-analysis to examine sex differences in the prevalence and incidence of MCI, which included amnestic and non-amnestic subtypes.

METHOD

Systematic searches were performed in July 2015 using MEDLINE/PubMed, Scopus, and PsycINFO for population-or community-based studies with MCI data for men and women. Random-effects model were used.

RESULTS

Fifty-six studies were included. There were no statistically significant sex differences in prevalence or incidence of amnestic MCI. There was a significantly higher prevalence (p=0.038), but not incidence, of non-amnestic MCI among women. There were no sex differences in studies that combined both subtypes of MCI.

CONCLUSION

The only statistically significant finding emerging from this study was that women have a higher prevalence of non-amnestic MCI. To better understand sex differences in the preclinical stages of dementia, studies must better characterize the etiology of the cognitive impairment.

Association between exercise habits and subcortical gray matter volumes in healthy elderly people: A population-based study in Japan

Background and aims

The relationship between exercise and subcortical gray matter volume is not well understood in the elderly population, although reports indicate that exercise may prevent cortical gray matter atrophy. To elucidate this association in the elderly, we measured subcortical gray matter volume and correlated this with volumes to exercise habits in a community-based cohort study in Japan.

Methods

Subjects without mild cognitive impairment or dementia (n = 280, 35% male, mean age 73.1 ± 5.9 years) were evaluated using the Mini-Mental State Examination (MMSE), an exercise habit questionnaire, and brain magnetic resonance imaging. Subcortical gray matter volume was compared between groups based on the presence/absence of exercise habits. The MMSE was re-administered 3 years after the baseline examination.

Results

Ninety-one subjects (32.5%) reported exercise habits (exercise group), and 189 subjects (67.5%) reported no exercise habits (non-exercise group). Volumetric analysis revealed that the volumes in the exercise group were greater in the left hippocampus (p = 0.042) and bilateral nucleus accumbens (left, p = 0.047; right, p = 0.007) compared to those of the non-exercise group. Among the 195 subjects who received a follow-up MMSE examination, the normalized intra-cranial volumes of the left nucleus accumbens (p = 0.004) and right amygdala (p = 0.014)showed significant association with a decline in the follow-up MMSE score.

Conclusion

Subjects with exercise habits show larger subcortical gray matter volumes than subjects without exercise habits in community-dwelling elderly subjects in Japan. Specifically, the volume of the nucleus accumbens correlates with both exercise habits and cognitive preservation.

Prevalence of Dementia and Cognitive Complaints in the Context of High Cognitive Reserve: A Population-Based Study

OBJECTIVES

This study aimed to assess the prevalence of dementia and cognitive complaints in a cross-sectional sample of Luxembourg seniors, and to discuss the results in the societal context of high cognitive reserve resulting from multilingualism.

METHODS

A population sample of 1,377 people representative of Luxembourg residents aged over 64 years was initially identified via the national social insurance register. There were three different levels of contribution: full participation in the study, partial participation, and non-participation. We examined the profiles of these three different samples so that we could infer the prevalence estimates in the Luxembourgish senior population as a whole using the prevalence estimates obtained in this study.

RESULTS

After careful attention to the potential bias and of the possibility of underestimation, we considered the obtained prevalence estimates of 3.8% for dementia (with corresponding 95% confidence limits (CL) of 2.8% and 4.8%) and 26.1% for cognitive complaints (CL = [17.8-34.3]) as trustworthy.

CONCLUSION

Based on these findings, we postulate that high cognitive reserve may result in surprisingly low prevalence estimates of cognitive complaints and dementia in adults over the age of 64 years, which thereby corroborates the longer disability-free life expectancy observed in the Luxembourg population. To the best of our knowledge, this study is the first to report such Luxembourgish public health data.

Prevalence of dementia in East Asia: a synthetic review of time trends

OBJECTIVE

This study aims to synthesise evidence on time trends of dementia prevalence in East Asian countries including Japan, China, South Korea and Taiwan and assess the impact of the societal changes on future prevalence.

METHOD

Relevant reviews and recent nationwide studies in East Asia were identified to investigate changes in prevalence of dementia over time taking into account the potential impact of methodological factors and study designs.

RESULTS

The robust evidence that has been interpreted to suggest a substantial increasing trend over time is less compelling once fundamental differences in study methods and populations across individual surveys are considered. In Japan, longitudinal studies in small areas suggest the potential increase of prevalence after 2000. Increasing trends in China, South Korea and Taiwan over the last 20-30 years are based on the literature review without adjustment for methodological differences. Economic development and huge societal changes alongside the rise of non-communicable disease in East Asia could lead to increasing prevalence of dementia in the future once those cohorts with high risk of dementia reached their older age.

CONCLUSION

Current evidence is not sufficient to suggest increasing trends of dementia prevalence in East Asia. Longitudinal studies with representative samples and stable methodology are needed to provide fundamental information of the epidemiology of dementia and identify important risk factors in East Asian societies.

Mild cognitive impairment and its management in older people

Mild cognitive impairment (MCI) is a common condition in the elderly. It is characterized by deterioration of memory, attention, and cognitive function that is beyond what is expected based on age and educational level. MCI does not interfere significantly with individuals’ daily activities. It can act as a transitional level of evolving dementia with a range of conversion of 10%–15% per year. Thus, it is crucial to protect older people against MCI and developing dementia. The preventive interventions and appropriate treatments should improve cognitive performance, and retard or prevent progressive deficits. The avoidance of toxins, reduction of stress, prevention of somatic diseases, implementation of mental and physical exercises, as well as the use of dietary compounds like antioxidants and supplements can be protective against MCI. The modification of risk factors such as stopping smoking, as well as the treatment of deficiency in vitamins and hormones by correcting behaviors and lifestyle, can prevent cognitive decline in the elderly. The progressive increase in the growth rate of the elderly population can enhance the rate of MCI all over the world. There is no exact cure for MCI and dementia; therefore, further studies are needed in the future to determine causes of MCI and risk factors of progression from MCI to dementia. This will help to find better ways for prevention and treatment of cognitive impairment worldwide.

Association of cerebral white matter lesions with cognitive function and mood in Japanese elderly people: a population-based study

BACKGROUND

To determine the relationships between regional white matter lesions (WMLs), lifestyle factors, and cognitive, motor function and mood.

METHODS

A comprehensive evaluation, including brain MRI, blood tests, the Unified Parkinson's Disease Rating Scale, the Mini Mental State Examination, and the Geriatric Depression Scale, was performed for people aged 65 years or older living in Ama-cho on October 1, 2009. Participants were classified by severity of periventricular hyperintensities (PVH) and deep white matter hyperintensities (DWMH) using the Fazekas score.

RESULTS

Of 900 eligible participants, 688 (76.4%) were enrolled, including 303 men. Significant predictors of severe PVH were older age, lower low-density lipoprotein cholesterol (LDL-C) levels, elevated blood pressure (BP), cerebral infarction, and no current alcohol use. Significant predictors of severe DWMH were older age, lower 1,5-anhydroglucitol (1,5-AG) levels, elevated BP, cerebral infarction, and no current alcohol use. Higher cognitive function was associated with younger age, female sex, mild DWMH, more years of education, and higher high-density lipoprotein cholesterol levels. Depressive symptoms were associated with lower 1,5-AG levels, lower LDL-C levels, moderate to severe PVH, and no current alcohol use.

CONCLUSIONS

White matter lesions in elderly people were related to hypertension and impaired glucose tolerance. The severity of WMLs was associated with cognitive function and mood.

Prevalence and clinical predictors of cognitive impairment in individuals aged 80 years and older in rural China

AIMS

The aim of this study was to estimate the prevalence of cognitive impairment (CI) in individuals aged 80 years and over in rural China and to analyze the associated risk factors.

METHODS

We conducted a two-phase door-to-door survey of a population in rural Ji County (China). The reference population consisted of individuals aged 80 years or older. A total of 723 individuals were interviewed in their homes, and demographic variables and comorbidities were recorded. Diagnoses were divided into the following 3 categories: normal cognitive function, cognitive impairment no dementia (CIND), and dementia. The odds ratio for each risk factor was calculated by logistic regression analysis.

RESULTS

The prevalence of CI among individuals aged 80 years and older was 73.2% (47.4% CIND and 25.7% dementia). The risk of CI decreased with a higher level of education and a higher level of social involvement. The risk of CI was higher in females than in males and among people with a history of stroke (p < 0.01).

CONCLUSIONS

The observed raw prevalence of CI was 73.2%. Female gender and a history of a previous stroke increased the risk of CI, while a higher educational level and engagement in social activities reduced the risk of CI.

[Depression, motor function and cognitive function in epidemiological study]

With the striking increase in the number of elderly people in Japan, dementia has not only become a medical but also a social issue. Recently we have reported a crude prevalence of dementia in Ama-cho, a rural island town to be 16.4% in elderly people aged 65 years or older. Observational studies have identified a wide range of potentially modifiable risk factors for dementia, including cardiovascular risk factors, depression and low level of physical or mental activity. Several studies have demonstrated an association between mild parkinsonian signs (MPS) and incident dementia. We have reported a crude prevalence of subjects with MPS to be 22.1% in elderly people aged 60 years or older in Ama-cho. The actigraphic activity counts measured by Actiwatch were significantly reduced in the subjects with severe MPS-severe and a close relationship between MPS and depression was shown in this cohort. Each of depression, motor dysfunction and cognitive dysfunction might affect each other in development of dementia, and was associated with organic changes of brain accompany with modifiable risk factors for dementia. Randomized control trials of multimodal risk factor reduction strategies to prevent dementia are needed.

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.

Epidemiology of mild cognitive impairment in Brazil

With the worldwide increase in longevity and rising prevalence of cognitive disorders in the aged population, efforts have been made to characterize mild cognitive impairment (MCI) and its prevalence and/or incidence in a number of countries, given MCI may be a pre-dementia phase of degenerative conditions. The aim of this review was to retrieve the available data on the prevalence and incidence of mild cognitive impairment (MCI) in Brazil and compare these with rates found by studies conducted in other countries. The Pubmed and Scielo databases were searched using the following search terms: mild cognitive impairment, prevalence, incidence, including studies in both English and Portuguese languages. Only one study on MCI prevalence has been published in Brazil, reporting a prevalence rate of 6.1% and incidence of 13.2/1000 persons-year among those aged 60 years or over. Prevalence rates for other countries are also reported. The prevalence and incidence of MCI found in Brazil is similar to rates observed in other countries.

Depression and cognitive impairment in patients with mild parkinsonian signs

OBJECTIVES

Mild parkinsonian signs (MPS) are reported to be associated with increased risk of dementia, Parkinson's disease, parkinsonism, and vascular lesions of white matter and are also a significant predictor of mortality. Although more than 20% of subjects aged 60 years and older suffer from MPS in Japan, it is often unrecognized and underestimated by patients and medical physicians. We used neuropsychological methods to examine cognitive function and depressive symptoms in subjects with MPS.

METHODS

We performed a population-based study in Ama-cho, a rural island town in western Japan. Participants included 951 subjects aged 65 years and older, 613 of whom completed all questionnaires, neurological examinations, and neuropsychological assessments and were included in the data analysis. Subjects were assessed for depression and subjective cognitive impairment using the Geriatric Depression Scale (GDS-15), Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR), and modified Unified Parkinson's Disease Rating Scale (mUPDRS).

RESULTS

Of the 613 participants, 143 were diagnosed with MPS. GDS scores were significantly higher in the MPS group compared with the motor control group, while MMSE scores were significantly lower.

CONCLUSIONS

We demonstrated that MPS correlate with both depressive symptoms and cognitive impairment.

Relationship between dietary patterns and cognitive function in a community-dwelling population in Japan

The purpose of this study was to clarify the association between dietary patterns and cognitive function in a community-dwelling population in Japan. A total of 388 volunteers (60 years and older) who participated in the Iwaki Health Promotion Project 2011 were recruited. Diet was assessed with a validated, self-administered brief-type diet history questionnaire. Dietary patterns were extracted from 52 predefined food groups by principal component analysis. The Mini-Mental State Examination was also used to measure global cognitive status. Three dietary patterns were identified as follows: "Healthy," "Noodle," and "Alcohol and accompaniment." Compared with the low tertile of the "Alcohol and accompaniment" pattern, only the middle tertile was independently related to an increased risk of poor cognitive function. In conclusions, present study failed to substantiate dose-dependent associations between dietary patterns and the risk of poor cognitive function. Further studies with longitudinal observations are warranted.