OBJECTIVES: This study aimed to evaluate the association between dental implants and cognitive function in community-dwelling older adults. METHODS: Data were collected from the baseline survey (2016–2017) of the Korean Frailty and Aging Cohort Study. The study sample comprised 1115 community-dwelling people aged 70 years to 84 years who had 0-19 natural teeth. Dental implants and natural teeth were identified by panoramic radiography, while the cognitive function was assessed by the Korean version of the Mini-Mental State Examination (MMSE-KC). The association between dental implants and cognitive function was analyzed by multiple linear regression. Sensitivity analysis was performed to test for potential bias. RESULTS: The mean number of natural teeth in the study population was 9.50 (standard deviation [SD], 6.42), and the mean MMSE-KC score was 24.93 (SD, 3.55). In the simple univariate analysis, tooth replacement, age, sex, smoking status, alcohol consumption, body mass index, osteoporosis, number of natural teeth, periodontitis, chewing discomfort, tooth-brushing frequency, education level, monthly household income, participation in economic activity, living alone, and marital status had a significant impact on the association. After adjusting for confounders, the association between dental implants and cognitive function remained significant (B, 0.85; standard error, 0.40; p<0.05). Age, body mass index, periodontitis, tooth-brushing frequency, and education level were also significantly associated with cognitive function. The results of the sensitivity analyses were consistent with those of the primary analysis. CONCLUSIONS: Dental implants were associated with cognitive function in older adults living in the community. Dental implants as tooth replacements may play a role in preserving cognitive function.
Adult ; Aging ; Alcohol Drinking ; Bias (Epidemiology) ; Body Mass Index ; Cognition ; Cognitive Reserve ; Cohort Studies ; Dental Implants ; Education ; Family Characteristics ; Humans ; Korea ; Linear Models ; Marital Status ; Mastication ; Osteoporosis ; Periodontitis ; Prostheses and Implants ; Radiography, Panoramic ; Smoke ; Smoking ; Surveys and Questionnaires ; Tooth

OBJECTIVE: The cognitive reserve theory explicates individual differences observed in the clinical manifestation of dementia despite similar brain pathology. Education, a popular proxy of the cognitive reserve, has been shown to have protective effects delaying the onset of clinical symptoms including memory. This study was conducted to test whether education can moderate the negative effect of depressive mood on memory performance in elderly women residing in the community. METHODS: 29 elderly “unschooled” female (less than 6 years of formal education) and 49 “schooled” female (6 or more years) people were compared with regard to association between depressive mood and verbal memory functioning, which were measured by the Geriatric Depression Scale and the Elderly Verbal Learning Test, respectively. RESULTS: The results showed that completing or receiving more than primary school education significantly reduced the negative association between depressive mood and memory performance. Participants who did not complete primary schooling showed a decline in memory test scores depending on the level of depressive mood; whereas participants who have completed or received more than primary education displayed relatively stable memory function despite varying level of depressive mood. CONCLUSION: Our findings imply that education in early life may have protective effects against memory impairment related to elderly depression.
Aged ; Brain ; Cognitive Aging ; Cognitive Reserve ; Dementia ; Depression ; Education ; Female ; Humans ; Individuality ; Memory ; Pathology ; Protective Factors ; Proxy ; Verbal Learning

Patients with mild cognitive impairment (MCI) are at increased risk of developing dementia and Alzheimer's disease (AD). Currently, no disease-modifying or preventive drugs for AD are available. Non-pharmacological interventions, including cognitive intervention and physical exercise, could assist in the prevention and treatment of AD. Cognitive interventions can improve cognition and prevent dementia, and promote cognitive reserve and plasticity. As there are few standardized intervention programs for the treatment of MCI, development and effective study of cognitive interventions are needed. Psychiatrists should have a great interest in this kind of non-pharmacological interventions regarding neurocognitive disorders.
Alzheimer Disease ; Cognition ; Cognitive Reserve ; Dementia ; Exercise ; Humans ; Mild Cognitive Impairment ; Neurocognitive Disorders ; Plastics ; Psychiatry

BACKGROUND AND PURPOSE: Vocabulary knowledge is used as a representative index of general intelligence, and is regarded as a marker for cognitive reserve in elderly people. However, vocabulary knowledge mainly depends on formal education, hence, it may not fully represent cognitive functioning in elderly people with poor educational backgrounds. Herein, we investigated whether vocabulary knowledge is a measure of general cognitive ability among normal elderly people with few years of formal education. METHODS: The association between vocabulary knowledge and general cognitive functioning was compared between 35 elderly females with very low educational attainment and 68 elderly females with higher education. RESULTS: The vocabulary knowledge was a significant predictor of general cognitive functioning in elderly individuals with more than primary education, even after controlling the effects of age and years of education. However, it was not a significant predictor of general cognitive functioning in elderly individuals with very low educational attainment. CONCLUSIONS: Vocabulary assessment was effective in estimating general cognitive functioning in elderly individuals who received ≥6 years of education. Our findings suggested that vocabulary knowledge may not be an effective proxy of premorbid intelligence or cognitive reserve in people who have not completed elementary schooling.
Aged* ; Cognitive Aging ; Cognitive Reserve ; Education ; Female ; Humans ; Intelligence ; Proxy ; Vocabulary*

OBJECTIVE: This study aimed to find the sex differences of the way how educational attainment influence on cognitive function in the mild cognitive impairment patients. METHODS: A total of 1,704 patients were recruited from a large hospital-based multi-center cohort. Cognitive subdomains were evaluated using the Seoul Neuropsychological Screening Battery-Dementia version. We employed multiple linear regression analysis to compare the score of cognitive subdomains between the groups with high versus low educational attainment based on the high school graduate. Interaction between educational attainment and sex was also included in the analysis RESULTS: High and low educational attainment group had 41.2% and 58.8% of patients in the study population. In the multiple regression analysis, score of all cognitive subdomains were significantly higher in the high educational attainment group. The score of attention, language, and visuospatial function were also significantly affected by interaction between educational attainment and sex. CONCLUSION: In the female patients, educational attainment showed higher influence on the attention, language, and visuospatial function score.
Cognition ; Cognitive Reserve ; Cohort Studies ; Dementia* ; Education* ; Female ; Humans ; Korea* ; Linear Models ; Mass Screening ; Mild Cognitive Impairment* ; Seoul ; Sex Characteristics

OBJECTIVE: This study aimed to examine the effects of the social engagement (size of the social networks, social support, social conflict) by relationship types (spouse, family and kin, and neighbor and friends) on the cognitive functions of older adults in rural communities. METHODS: The participants of this study were normal older adults who participated in the first wave of the Korean Social Life, Health and Aging Project. Five hundred two older adults (men 218, women 284) aged 60 and over (mean age=71.44±6.81) participated. We analyzed the effects of different types of social engagement on Mini-Mental State Examination for Dementia Screening (MMSE-DS) performance using hierarchical multiple regression analysis. RESULTS: The result showed that, after controlling for the education level and age, the social support from the spouse, the conflict with neighbors or friends, the number of neighbors or friends significantly predicted MMSE-DS scores. These three variables accounted for additional 5.2% of the total variance of MMSE-DS. CONCLUSION: Our findings suggest that social engagement (network size, support, conflict) is associated with cognitive function among older adults. However, social engagement in different types of social relationship may contribute differently to cognitive function of older adults.
Adult* ; Aging ; Cognition ; Cognitive Aging ; Cognitive Reserve ; Dementia ; Education ; Female ; Friends ; Humans ; Mass Screening ; Rural Population ; Spouses

OBJECTIVES: To evaluate cognitive reserve in Korea using Korean version of Cognitive Reserve Index questionnaire (K-CRIq) and to investigate the effects of gender and age on cognitive reserve. METHODS: Three hundred and fifty-eight healthy subjects aged 25–85 years old in one community participated in the study. K-CRIq was developed and administered to all subjects to assess the effects of gender and age on cognitive reserve. Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) were administered to subjects over 65 years old to test concurrent validity. RESULTS: Age and gender as well as their interaction significantly affected Cognitive Reserve Index (CRI) score. Men had higher cognitive reserve than women over 45 years old, but at younger ages there was no gender difference in cognitive reserve. CRI score and sub-scores were strongly associated with the MMSE and MoCA. CONCLUSION: The results indicate that the gender effect on cognitive reserve is disappearing in the young generation in Korea. Scores in neuropsychological tests are predicted well by the CRI score.
Aging ; Cognitive Reserve* ; Female ; Healthy Volunteers ; Humans ; Korea* ; Male ; Methylenebis(chloroaniline) ; Neuropsychological Tests

Already in the 90s, Khachaturian stated that postponing dementia onset by five years would decrease the prevalence of the late onset dementia by 50%. After two decades of lack of success in dementia drug discovery and development, and knowing that worldwide, currently 36 million patients have been diagnosed with Alzheimer's disease, a number that will double by 2030 and triple by 2050, the World Health Organization and the Alzheimer's Disease International declared that prevention of cognitive decline was a 'public health priority.' Numerous longitudinal studies and meta-analyses were conducted to analyze the risk and protective factors for dementia. Among the 93 identified risk factors, seven major modifiable ones should be considered: low education, sedentary lifestyle, midlife obesity, midlife smoking, hypertension, diabetes, and midlife depression. Three other important modifiable risk factors should also be added to this list: midlife hypercholesterolemia, late life atrial fibrillation, and chronic kidney disease. After their identification, numerous authors attempted to establish dementia risk scores; however, the proposed values were not convincing. Identifying the possible interventions, able to either postpone or delay dementia has been an important challenge. Observational studies focused on a single life-style intervention increased the global optimism concerning these possibilities. However, a recent extensive literature review of the randomized control trials (RCTs) conducted before 2014 yielded negative results. The first results of RCTs of multimodal interventions (Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability, Multidomain Alzheimer Prevention Study, and Prediva) brought more optimism. Lastly, interventions targeting compounds of beta amyloid started in 2012 and no results have yet been published.
Alzheimer Disease ; Amyloid ; Atrial Fibrillation ; Cognition Disorders ; Cognitive Reserve ; Dementia ; Depression ; Diet, Mediterranean ; Drug Discovery ; Education ; Humans ; Hypercholesterolemia ; Hypertension ; Longitudinal Studies ; Motor Activity ; Obesity ; Optimism ; Prevalence ; Protective Factors ; Renal Insufficiency, Chronic ; Risk Factors ; Sedentary Lifestyle ; Smoke ; Smoking ; World Health Organization

BACKGROUND AND PURPOSE: Cognitive reserve is important for the individual susceptibility to dementia. Among the various determinants of cognitive reserve, the number of years of formal education would be of prime importance. We performed this study to explore its contribution to the clinical characteristics of dementia. METHODS: We included consecutive mild Alzheimer's disease (AD) dementia patients (clinical dementia rating, CDR=0.5 or 1) who visited our memory clinic and were older than 70 years at the evaluation from October 2013 to September 2015. According to the number of years of education, the corresponding subjects was grouped into two extreme educational groups, low education (illiterate or partially illiterate, LE, n=43) vs. high education (more than 9 years of education, HE, n=34). Among these patients, we compared various demographic, neuropsychological and neuroimaging characteristics. RESULTS: The groups were comparable in terms of age, frequency of hypertension and diabetes, and CDR and its sum of box. However, female gender was more frequent in the LE group (p=0.000). Also this group showed a more depressive mood on the geriatric depression scale (p=0.007). The raw scores on Korean Version of Mini-Mental State Examination and well-validated neuropsychological tests were lower in the LE group. However, the cognitive performance was found to be more preserved in the LE group than in the HE group when assessed using the z-score in certain specified tests on univariate and multivariate analyses (p<0.05). The Schelten's grade of medial temporal atrophy was similar between the two educational groups. Also, the degree of combined ischemic burden did not differ between the two groups. CONCLUSIONS: We identified that the prevalence of depressive mood and the extent of decline from the corresponding norm in a particular neuropsychological performance differ according to the educational level of mild AD patients.
Aged* ; Alzheimer Disease* ; Atrophy ; Cognitive Reserve ; Dementia* ; Depression ; Education ; Literacy ; Female ; Humans ; Hypertension ; Memory ; Multivariate Analysis ; Neuroimaging ; Neuropsychological Tests ; Prevalence

OBJECTIVE: To investigate the prevalence of dementia and its correlates among people with poor socioeconomic status, poor social support systems, and poor performance on the Korean version of the Mini-Mental Status Exam (MMSE-KC). METHODS: We used 2006-2009 data of the National Early Dementia Detection Program (NEDDP) conducted on Jeju Island. This program included all residents >65 years old who were receiving financial assistance. We examined those who performed poorly (standard deviation from the norm of <-1.5) on the MMSE-KC administered as part of the NEDDP, using age-, gender-, and education-adjusted norms for Korean elders. A total of 1708 people were included in this category. RESULTS: The prevalence of dementia in this group was 20.5%. Multivariate logistic regression analysis revealed that the following factors were statistically significantly associated with dementia: age of 80 or older, no education, nursing home residence, and depression. CONCLUSION: The prevalence of dementia is very high among those with lower MMSE-KC scores, and significant correlates include older age, no education, living in a nursing home, and depression. Enhancing lifetime education to improve individuals' cognitive reserves by providing intellectually challenging activities, encouraging living at home rather than in a nursing home, and preventing and treating depression in its early phase could reduce the prevalence of dementia in this population.
Cognitive Reserve ; Dementia ; Depression ; Education, Nursing ; Logistic Models ; Nursing Homes ; Prevalence ; Social Class