A 9-Year Comparison of Dementia Prevalence in Korea: Results of NaSDEK 2008 and 2017.

BACKGROUND: In many high-income Western countries, the prevalence of dementia had been reduced over the past decades. OBJECTIVE: We investigated whether the prevalence of all-cause dementia, Alzheimer's disease, vascular dementia, and mild cognitive impairment (MCI) had changed in Korea from 2008 to 2017. METHODS: Nationwide Survey on Dementia Epidemiology of Korea (NaSDEK) in 2008 and 2017 was conducted on representative elderly populations that were randomly sampled across South Korea. Both surveys employed a two-stage design (screening and diagnostic phases) and diagnosed dementia and MCI according to the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders and the consensus criteria from the International Working Group, respectively. The numbers of participants aged 65 years or older in the screening and diagnostic phases were 6,141 and 1,673 in the NaSDEK 2008 and 2,972 and 474 in the NaSDEK 2017, respectively. RESULTS: The age- and sex-standardized prevalence of all-cause dementia and Alzheimer's disease showed nonsignificant decrease (12.3% to 9.8%, odds ratio [OR] = 0.89, 95% confidence interval [CI] = 0.54-1.48 for all-cause dementia; 7.6% to 6.8%, OR [95% CI] = 0.91 [0.58-1.42] for Alzheimer's disease). Vascular dementia decreased in the young-old population aged less than 75 years (2.7% to 0.001%, OR [95% CI] = 0.04 [0.01-0.15]) and in women (1.9% to 0.5%, OR [95% CI] = 0.27 [0.10-0.72]) while MCI remained stable (25.3% to 26.2%, OR [95% CI] = 1.08 [0.67-1.73]). CONCLUSION: We found that the prevalence of dementia in Korea showed a nonsignificant decrease between 2008 and 2017.

Multimodal Cognitive Enhancement Therapy for Patients with Mild Cognitive Impairment and Mild Dementia: A Multi- Center, Randomized, Controlled, Double-Blind, Crossover Trial.

We developed and evaluated the effect of Multimodal Cognitive Enhancement Therapy (MCET) consisting of cognitive training, cognitive stimulations, reality orientation, physical therapy, reminiscence therapy, and music therapy in combination in older people with mild cognitive impairment (MCI) or mild dementia. This study was a multi-center, double-blind, randomized, placebo-controlled, two-period cross-over study (two 8-week treatment phases separated by a 4-week wash-out period). Sixty-four participants with MCI or dementia whose Clinical Dementia Rating was 0.5 or 1 were randomized to the MCET group or the mock-therapy (placebo) group. Outcomes were measured at baseline, week 9, and week 21. Fifty-five patients completed the study. Mini-Mental State Examination (effect size = 0.47, p = 0.013) and Alzheimer's Disease Assessment Scale-Cognitive Subscale (effect size = 0.35, p = 0.045) scores were significantly improved in the MCET compared with mock-therapy group. Revised Memory and Behavior Problems Checklist frequency (effect size = 0.38, p = 0.046) and self-rated Quality of Life - Alzheimer's Disease (effect size = 0.39, p = 0.047) scores were significantly improved in the MCET compared with mock-therapy. MCET improved cognition, behavior, and quality of life in people with MCI or mild dementia more effectively than conventional cognitive enhancing activities did.

Differences in knowledge of dementia among older adults with normal cognition, mild cognitive impairment, and dementia: A representative nationwide sample of Korean elders.

OBJECTIVE: Lack of knowledge about a disease could impede early diagnosis and may lead to delays in seeking appropriate medical care. The aim of this study was to explore knowledge of dementia (KOD) and to find the determinants of KOD among three groups: older adults with normal cognition, mild cognitive impairment (MCI), and dementia. METHODS: A representative nationwide sample of 6141 Korean elders aged 65 years or older participated in face-to-face interviews and answered 14 questions pertaining to general information, etiology, symptoms, and treatment of dementia. Stepwise multiple regressions and path analyses probed the relationships between various sociodemographic variables and KOD. RESULTS: The percentage of correct responses was only 62%. The item 'A person who remembers things that happened in the past does not have dementia' was answered correctly (false) by only 24.8-27% of the respondents in all groups. Older adults with normal cognition had higher KOD scores than those with MCI or dementia. In the normal-cognition group, KOD scores were higher among highly educated, younger, and literate women with no depression and a family history of dementia. In contrast with the determinants in the normal-cognition group, only the ability to read and write predicted KOD scores in the dementia group. CONCLUSIONS: Efforts to enhance KOD in elder adults are needed. Public education regarding the differences between dementia and healthy aging may increase KOD among normal elders and those with MCI. Among elders with dementia, educational materials that do not require literacy may be more helpful in increasing KOD with the aim of preventing treatment delay.

The Effect of Choline Acetyltransferase Genotype on Donepezil Treatment Response in Patients with Alzheimer's Disease.

OBJECTIVE: We examined the difference in responses to donepezil between carriers and non-carriers of the A allele at the +4 position of the choline acetyltransferase (ChAT) gene in Koreans. METHODS: Patients who met the criteria for probable Alzheimer's disease (AD) (n=199) were recruited. Among these, 145 completed the 12-week follow-up evaluation and 135 completed the 26-week scheduled course. Differences and changes in the Korean version of the mini-mental state examination (MMSE-KC) score, Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Assessment Battery (CERAD-K[N]) wordlist subtest score (WSS), CERAD-K(N) total score (TS), and the Korean version of geriatric depression scale (GDS-K) score between baseline and 12 weeks or 26 weeks were assessed by the Student's t-test. RESULTS: At 12 weeks, the changes in the MMSE-KC score, CERAD-K(N) WSS, and CERAD-K(N) TS from baseline were not significant between ChAT A allele carriers and non-carriers; however, at 26 weeks, these changes were significantly larger in ChAT A allele carriers than in non-carriers (p=0.02 for MMSE-KC and p=0.03 for CERAD-K(N) WSS respectively). CONCLUSION: Our findings in this study suggested that presence of the A allele at the +4 position of ChAT might positively influence the treatment effect of donepezil in the early stages of AD in Koreans.

The Effect of a Variable Disc Pad Friction Coefficient for the Mechanical Brake System of a Railway Vehicle.

A brake hardware-in-the-loop simulation (HILS) system for a railway vehicle is widely applied to estimate and validate braking performance in research studies and field tests. When we develop a simulation model for a full vehicle system, the characteristics of all components are generally properly simplified based on the understanding of each component's purpose and interaction with other components. The friction coefficient between the brake disc and the pad used in simulations has been conventionally considered constant, and the effect of a variable friction coefficient is ignored with the assumption that the variability affects the performance of the vehicle braking very little. However, the friction coefficient of a disc pad changes significantly within a range due to environmental conditions, and thus, the friction coefficient can affect the performance of the brakes considerably, especially on the wheel slide. In this paper, we apply a variable friction coefficient and analyzed the effects of the variable friction coefficient on a mechanical brake system of a railway vehicle. We introduce a mathematical formula for the variable friction coefficient in which the variable friction is represented by two variables and five parameters. The proposed formula is applied to real-time simulations using a brake HILS system, and the effectiveness of the formula is verified experimentally by testing the mechanical braking performance of the brake HILS system.

High-energy redox-flow batteries with hybrid metal foam electrodes.

A nonaqueous redox-flow battery employing [Co(bpy)3](+/2+) and [Fe(bpy)3](2+/3+) redox couples is proposed for use in large-scale energy-storage applications. We successfully demonstrate a redox-flow battery with a practical operating voltage of over 2.1 V and an energy efficiency of 85% through a rational cell design. By utilizing carbon-coated Ni-FeCrAl and Cu metal foam electrodes, the electrochemical reactivity and stability of the nonaqueous redox-flow battery can be considerably enhanced. Our approach intoduces a more efficient conversion of chemical energy into electrical energy and enhances long-term cell durability. The cell exhibits an outstanding cyclic performance of more than 300 cycles without any significant loss of energy efficiency. Considering the increasing demands for efficient energy storage, our achievement provides insight into a possible development pathway for nonaqueous redox-flow batteries with high energy densities.

(E)-2,4-Bis(p-hydroxyphenyl)-2-butenal inhibits tumor growth via suppression of NF-κB and induction of death receptor 6.

The Maillard reaction products are known to be effective in chemoprevention. Here, we focused on the anti-cancer effects of (E)-2,4-bis(p-hydroxyphenyl)-2-butenal on in vitro and in vivo colon cancer. We analysed the anti-cancer activity of (E)-2,4-bis(p-hydroxyphenyl)-2-butenal on colon cancer cells by using cell cycle and apoptosis analysis. To elucidate it's mechanism, NF-κB DNA binding activity, docking model as well as pull-down assay. Further, a xenograft model of colon cancer was studied to test the in vivo effects of (E)-2,4-bis(p-hydroxyphenyl)-2-butenal. (E)-2,4-Bis(p-hydroxyphenyl)-2-butenal inhibited colon cancer cells (SW620 and HCT116) growth followed by induction of apoptosis in a concentration-dependent manner via down-regulation of NF-κB activity. In docking model as well as pull-down assay, (E)-2,4-bis(p-hydroxyphenyl)-2-butenal directly binds to three amino acid residues of IKKß, thereby inhibited IKKß activity in addition to induction of death receptor 6 (DR6) as well as their target apoptotic genes. Finally, (E)-2,4-bis(p-hydroxyphenyl)-2-butenal suppressed anchorage-independent cancer cell growth, and tumor growth in xenograft model accompanied with apoptosis through inhibition of IKKß/NF-κB activity, and overexpression of DR6. These results suggest that (E)-2,4-bis(p-hydroxyphenyl)-2-butenal inhibits colon cancer cell growth through inhibition of IKKß/NF-κB activity and induction of DR6 expression.

Curative Effects of Thiacremonone against Acetaminophen-Induced Acute Hepatic Failure via Inhibition of Proinflammatory Cytokines Production and Infiltration of Cytotoxic Immune Cells and Kupffer Cells.

High doses of acetaminophen (APAP; N-acetyl-p-aminophenol) cause severe hepatotoxicity after metabolic activation by cytochrome P450 2E1. This study was undertaken to examine the preventive effects of thiacremonone, a compound extracted from garlic, on APAP-induced acute hepatic failure in male C57BL/6J. Mice received with 500 mg/kg APAP after a 7-day pretreatment with thiacremonone (10-50 mg/kg). Thiacremonone inhibited the APAP-induced serum ALT and AST levels in a dose-dependent manner, and markedly reduced the restricted area of necrosis and inflammation by administration of APAP. Thiacremonone also inhibited the APAP-induced depletion of intracellular GSH, induction of nitric oxide, and lipid peroxidation as well as expression of P450 2E1. After APAP injection, the numbers of Kupffer cells, natural killer cells, and cytotoxic T cells were elevated, but the elevated cell numbers in the liver were reduced in thiacremonone pretreated mice. The expression levels of I-309, M-CSF, MIG, MIP-1 α , MIP-1 ß , IL-7, and IL-17 were increased by APAP treatment, which were inhibited in thiacremonone pretreated mice. These data indicate that thiacremonone could be a useful agent for the treatment of drug-induced hepatic failure and that the reduction of cytotoxic immune cells as well as proinflammatory cytokine production may be critical for the prevention of APAP-induced acute liver toxicity.

Effects of administration of IH901, a ginsenoside intestinal metabolite, on muscular and pulmonary antioxidant functions after eccentric exercise.

This study was conducted to investigate whether administration of IH901, a ginseng intestinal metabolite, ameliorates exercise-induced oxidative stress while preserving antioxidant defense capability in rat skeletal muscles and lung. Eight adult male Sprague-Dawley rats per group were randomly assigned to the resting control, exercise control, resting with IH901 (25, 50, and 100 mg/kg) consumption (R/IH901), or exercise with IH901 (25, 50, and 100 mg/kg) consumption (E/IH901) group. The trained groups ran 35 min 2 days/week for 8 weeks. To analyze the IH901-training interaction, serum biochemical analysis, lipid peroxidation, citrate synthase, protein oxidation, antioxidant and superoxide dismutase in skeletal muscles and lung tissue were measured. Compared to the exercise control group, animals that consumed IH901 had significantly increased exercise endurance times (p < 0.05) and decreased plasma creatine kinase and lactate dehydrogenase levels (p < 0.05), while those in the E/IH901 groups had increased citrate synthase and anti-oxidant enzymes and decreased lipid peroxidation and protein oxidation (p < 0.05). In conclusion, IH901 consumption in aging rats after eccentric exercise has beneficial effects on anti-inflammatory and anti-oxidant activities through down-regulation of pro-inflammatory mediators, lipid peroxidation, and protein oxidation and up-regulation of anti-oxidant enzymes.

No long-term feeding toxicities on the health status in rats fed with cloned Korean native beef cattle (Hanwoo) meat.

This study was designed to undertake a risk assessment to identify the health status of rats fed with somatic cell nuclear transfer (SCNT)-cloned Korean native beef cattle (Hanwoo) meat for 26 weeks. The rats were randomly divided into 5 groups, each consisting of 12 male (142.6 ± 5.23 g) and 12 female (113.7 ± 6.31 g) rats each. The animals were fed commercial pellets (control), pellets containing 5% (N-5) and 10% (N-10) of normal cattle meat, and diets containing 5% (C-5) and 10% (C-10) of cloned cattle meat. The mortality; clinical signs; body weight; food consumption; urinary, hematology, blood biochemistry, and histopathological analyses; and absolute and relative organ weights were analyzed and compared. During the 26-week test period, health status-related factors of the rats fed on cloned Hanwoo meat were found to have no test substance-related toxicities. The only difference was the increased uterus weight in female C-10 rats as compared to their counterparts counterparts (p < .05). On the basis of these health status results, it can be postulated that no food consumption risks might arise from the long-term feeding of cloned cattle meat in rats.

Deficiency of C-C chemokine receptor 5 suppresses tumor development via inactivation of NF-κB and inhibition of monocyte chemoattractant protein-1 in urethane-induced lung tumor model.

To evaluate the significance of C-C chemokine receptor type 5 (CCR5) in lung tumor development, we compared carcinogen-induced tumor growth in CCR5 knockout (CCR5(-/-)) mice and wild-type (CCR5(+/+)) mice. CCR5(-/-) mice showed reduced urethane (1g/kg)-induced tumor incidence when compared with those of CCR5(+/+) mice. We investigated the activation of nuclear factor-kappaB/STAT3 since these are implicated transcription factors in the regulation of genes involving tumor growth. Significant inhibition of DNA-binding activity of nuclear factor-kappaB and STAT3, and the translocation of p50 and p65 into the nucleus and the phosphorylation of IĸB were found in the lungs of CCR5(-/-) mice compared with the lungs of CCR5(+/+) mice. Expression of apoptotic protein such as cleaved caspase-3, cleaved PARP and Bax was elevated, whereas the expression levels of survival protein such as Bcl-2 and cIAP1 was decreased in the lungs of CCR5(-/-) mice. Interestingly, we found that the level of monocyte chemoattractant protein-1 (MCP-1), a tumor growth-promoting cytokine, was significantly reduced in the lung tumor tissue and blood of CCR5(-/-) mice compared with the level in CCR5(+/+) mice. In addition, CCR5 small interfering RNA (siRNA) and inhibitor of MCP-1 blocked lung cancer cell growth, which was abolished by the addition of MCP-1 protein in cultured lung cancer cells. Moreover, inactivation of CD8(+) cytotoxic T cell and dendritic cells was significantly increased in the blood, lung tumors and spleens of CCR5(-/-) mice compared with that of CCR5(+/+) mice. Therefore, these results showed that CCR5 deficiency suppressed lung tumor development through the inhibition of nuclear factor-kappaB/STAT3 pathways and the downregulation of MCP-1 in the carcinogen-induced lung tumor model.

Novel catalytic effects of Mn3O4 for all vanadium redox flow batteries.

A new approach for enhancing the electrochemical performance of carbon felt electrodes by employing non-precious metal oxides is designed. The outstanding electro-catalytic activity and mechanical stability of Mn(3)O(4) are advantageous in facilitating the redox reaction of vanadium ions, leading to efficient operation of a vanadium redox flow battery.

A nationwide survey on the prevalence and risk factors of late life depression in South Korea.

OBJECTIVE: This study aimed to estimate prevalence rates and risk factors of LLD among a large nationwide sample of Korean elders in South Korea. METHOD: Of 8199 randomly sampled Koreans aged 65 years or more, 6018 participated (response rate=73.4%). Using the Korean version of the short form Geriatric Depression Scale (SGDS-K), we classified individual scoring 8 or 9 as having possible depression and those scoring ≥ 10 as having probable depression. RESULTS: The age-, gender-, education-, and urbanicity-standardized prevalences were 10.1% (95% CI=9.3-10.8) for possible depression, 17.8% (95% CI=16.8-8.7) for probable depression, and 27.8% (95% CI=26.7-29.0) for overall depression. Poverty, living alone, low education, illiteracy, smoking, history of head trauma, and low Mini Mental Status Examination score were associated with greater risk of depression, while mild alcohol use and moderate to heavy exercise were associated with lower risk of depression. However gender difference in the risk of depression was not found. CONCLUSION: LLD is decidedly common in South Korea. It was associated with various sociodemographic and clinical factors, some of which are amendable through policy actions. This study was limited by use of the SGDS-K rather than a standardized clinical interview.

Interactive influences of demographics on the Mini-Mental State Examination (MMSE) and the demographics-adjusted norms for MMSE in elderly Koreans.

BACKGROUND: The influences of demographics, culture, language, and environmental changes on Mini-Mental State Examination (MMSE) scores are considerable. METHODS: Using a sample of 7452 healthy, community-dwelling elderly Koreans, aged 55 to 94 years, who participated in the four ongoing geriatric cohorts in Korea, we investigated demographic influences on MMSE scores and derived normative data for this population. Geropsychiatrists strictly excluded subjects with cognitive disorders according to the protocol of the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (CERAD-K) Clinical Assessment Battery (CERAD-K-C). RESULTS: Education (standardized ß = 0.463), age (standardized ß = -0.303), and gender (standardized ß = -0.057) had significant effects on MMSE scores (p < 0.001). The score of MMSE increase 0.379 point per 1-year education, decrease 0.188 per 1-year older, and decrease 0.491 in women compared to men. Education explained 30.4% of the scores' total variance, which was much larger than the variances explained by age (8.4%) or gender (0.3%). Accordingly, we present normative data for the MMSE stratified by education (0, 1-3, 4-6, 7-9, 10-12, and ≥ 13 years), age (60-69, 70-79, and 80-89 years), and gender. CONCLUSIONS: We provide contemporary education-, age-, and gender-stratified norms for the MMSE, derived from a large, community-dwelling elderly Korean population sample, which could be useful in evaluating individual MMSE scores.

In vitro antioxidant properties of a ginseng intestinal metabolite IH-901.

IH-901 (20-O-ß-D-glucopyranosyl-20(S)-protopanaxadiol or compound K) is a final intestinal bacterial metabolite of ginseng in humans. It has various pharmacologic effects such as antiaging, immunopotentiation, antistress, and antimetastatic activities. We analyzed the antioxidant activities of IH-901 using several assays including: total antioxidant activity, reductive potential, 1,1-diphenyl-2-picryl-hydrazyl, hydroxyl, superoxide and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays, a nitric oxide scavenging assay and a lipid peroxidation assay. At concentrations of 25 and 100 µg/mL, IH-901 inhibited lipid peroxidation of a linoleic acid emulsion with a potency comparable to ascorbic acid and butylated hydroxyanisole. The reductive potential of IH-901 increased in a concentration-dependent manner. IH-901 exhibited strong DPPH, hydroxyl, superoxide and ABTS radical scavenging activities. IH-901 was also an effective inhibitor of lipid peroxidation, although IH-901 had only a mild scavenging activity against nitric oxide. These results suggest that IH-901 may be a useful antioxidant agent against reactive oxygen species.

In vitro and in vivo genotoxic effects of somatic cell nuclear transfer cloned cattle meat.

Although the nutritional composition and health status after consumption of the meat and milk derived from both conventionally bred (normal) and somatic cell nuclear transferred (cloned) animals and their progeny are not different, little is known about their food safeties like genetic toxicity. This study is performed to examine both in vitro (bacterial mutation and chromosome aberration) and in vivo (micronucleus) genotoxicity studies of cloned cattle meat. The concentrations of both normal and cloned cattle meat extracts (0-10×) were tested to five strains of bacteria (Salmonella typhimurium: TA98, TA100, TA1535, and TA1537; Escherichia coli: WP2uvrA) for bacterial mutation and to Chinese hamster lung (CHL/IU) cells for chromosome aberration, respectively. For micronucleus test, ICR mice were divided into five dietary groups: commercial pellets (control), pellets containing 5% (N-5) and 10% (N-10) normal cattle meat, and pellets containing 5% (C-5) and 10% (C-10) cloned cattle meat. No test substance-related genotoxicity was noted in the five bacterial strains, CHL/IU cells, or mouse bone marrow cells, suggesting that the cloned cattle meat potentially may be safe in terms of mutagenic hazards. Thus, it can be postulated that the cloned cattle meat do not induce any harmful genotoxic effects in vitro and in vivo.

A diet of somatic cell nuclear transfer cloned-cattle meat produced no toxic effects on behavioral or reproductive characteristics of F1 rats derived from dams fed on cloned-cattle meat.

BACKGROUND: The composition and nutritional value of meat and milk derived from cloned animals and their progeny has not been demonstrated to be different from normal animals, but possible food consumption risks that might arise from unidentified hazards remain. In this study, we investigated the effects of somatic cell nuclear transfer cloned-cattle meat diet on the behavioral and reproductive characteristics of F1 rats derived from dams that were also fed on cloned-cattle meat. METHODS AND RESULTS: F1 rats were divided into five diet groups with their dams: commercial pellets (control), pellets containing 5% (N-5) and 10% (N-10) of normal-cattle meat, and diets containing 5% (C-5) and 10% (C-10) of cloned-cattle meat. In most cases, the cloned-cattle meat diet did not affect body weight and food consumption in both male and female F1 rats during 11 weeks, except for significantly higher body weight in both N-5 and N-10 (3-5 weeks, p<0.05 or p<0.01) and significantly higher food consumption in the both normal- and cloned-cattle meat groups (7-9 weeks, p<0.05 or p<0.01), as compared with the controls, respectively. We detected no signs of test substance-related toxicities on organ weights and behavioral characteristics (sensory reflex, motor function, and spatial learning and memory tests). Reproductive functions did not significantly differ among all examined rats (mating, fertility, and implantation). CONCLUSIONS: These behavioral and reproductive toxicity results suggest that there are no obvious food safety concerns related to cloned-cattle meat in these parameters.

Cholinesterase inhibitors for Alzheimer disease: do they provide more than symptomatic benefits?

OBJECTIVE: This study aims to examine survival of patients with Alzheimer disease (AD) receiving clinical efficacy of cholinesterase inhibitors (ChEIs) and to compare their survival with those of patients with AD who never received ChEIs and cognitively intact old psychiatric outpatients. DESIGN, SETTING, AND PARTICIPANTS: The retrospective cohort study used national mortality data provided by the Korean National Statistics Office and electronic database of 15 general hospitals on older patients who began outpatient treatment with psychiatric medications including ChEIs (N = 3,813). The authors controlled for confounding by using multivariate models and propensity scoring methods. MEASUREMENTS: Mortality rate of patients with AD receiving ChEIs was compared with those of patients with AD who never received ChEIs and cognitively intact old psychiatric outpatients. RESULTS: Observed additional survival of patients with AD receiving ChEIs (mortality rate: 13.1%), when compared with patients with AD who never received ChEIs (15.4%) was not statistically significant (p = 0.74; hazard ratio [HR]: 1.03, 95% confidence interval [CI]: 0.67-1.59). Patients with AD receiving ChEIs showed higher mortality rate (13.1%) compared with that of cognitively intact old psychiatric outpatients (8.6%) (p <0.001; HR: 1.60, 95% CI: 0.96-2.68). CONCLUSION: This study does not support that ChEIs increase survival of patients with AD, compared with patients with AD who have never treated with ChEIs. Therefore, all ChEIs should be considered for symptomatic use only and not to be capable of modifying mortality of patients with AD.

Validity of the telephone interview for cognitive status (TICS) and modified TICS (TICSm) for mild cognitive imparment (MCI) and dementia screening.

This study aimed to validate the TICS and modified TICS (TICSm) in Korean elderly population and to compare MCI and dementia screening ability between TICS and TICSm. TICS and TICSm were administered to 70 cognitively normal (CN), 75 MCI, and 85 dementia subjects, with mini-mental state examination (MMSE) and other cognitive and functional measures. TICS and TICSm scores were highly correlated with other global cognitive and functional scores. The CN vs. dementia discrimination ability of both instruments was as excellent as that of MMSE (sensitivity/specificity at optimal cutoff: 87.1/90.1 for TICS; 88.2/90.0 for TICSm). Although their CN vs. MCI discrimination performances were comparable to that of MMSE, they were far from perfect (sensitivity/specificity: 69.3/68.6 for TICS; 73.3/67.1 for TICSm). There was no significant difference in dementia or MCI screening accuracy between TICS and TICSm. Both of them also showed high test-retest reliability. Our findings indicate that TICS and TICSm are reliable and as valid as MMSE in regard of screening cognitively impaired elderly. In terms of the comparison between TICSm and TICS, however, TICSm has little advantage over TICS for screening dementia and even MCI, in spite of longer administration time and more efforts required.

A nationwide survey on the prevalence of dementia and mild cognitive impairment in South Korea.

We investigated the prevalence of dementia and mild cognitive impairment (MCI) and the factors associate with risk of dementia from a representative nationwide sample of Korean elders. 8,199 randomly-sampled Koreans aged 65 years or older were invited to participate in the Phase I screening assessment using Mini-Mental State Examination by door-to-door home visit, and 6,141 subjects (response rate = 74.9%) responded. Among them, 2,336 subjects were invited to participate in the Phase II diagnostic assessment for dementia and MCI, and 1,673 subjects responded (response rate = 71.6%). Diagnostic assessments were administered using the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet (CERAD-K) Clinical Assessment Battery. The CERAD-K Neuropsychological Assessment Battery was used for diagnosing MCI. Age-, gender-, education-, and urbanicity-standardized prevalence of dementia was estimated to be 8.1% (95% CI = 6.9-9.2) for overall dementia and 24.1% (95% CI = 21.0-27.2) for MCI. Alzheimer's disease (AD) was the most prevalent type (5.7%) followed by vascular dementia (2.0%). Amnestic subtype (20.1%) was much more prevalent than nonamnestic subtype in MCI (4.0%). Older age, being male, lower education level, illiteracy, smoking, and histories of head trauma or depression were associated with increased dementia risk, and alcohol use and moderately intense exercise were associated with decreased dementia risk. We expect numbers of dementia patients to double every 20 years until 2050 in Korea and expect AD to account for progressively more dementia cases in the future.