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A single-item depression measure may not be adequate in capturing the complex entity of mental health, despite wide use of this indicator in community studies. This study evaluated the accuracy of a single-question depression measure in comparison to two composite indices–the Center for Epidemiologic Studies Depression Scale (CESD) and the Geriatric Depression Scale (GDS).
Materials and methods:
A total of 800 elderly participants ranging from 60 to 89 years of age and residing in Seoul were recruited using a multistage sampling scheme in 2015. The survey was conducted by trained interviewers with a constructed questionnaire. Reliability and validity measures such as the Kappa index, sensitivity, specificity, PPV, NPV, and AUC were used to evaluate the accuracy of the single question measure. Socio-demographic group differences in accuracy were compared by age, sex, marital status, education, employment, and financial status.
The prevalence of depression by a single-question measure was much lower than those of CESD and GDS (5.5%, 12.3%, and 12.1%, respectively). The sensitivity of the single-item measure, based on CESD and GDS, was extremely low at 30.6% and 36.1%. In the subgroup analysis, however, there was a marked educational discrepancy in all accuracy measures; in sensitivity, people with a university degree or higher showed about 2.4 times higher sensitivity than those having only a primary school education.
The results show that a single-question depression measure should be used with caution. In addition, the single-question measure could substantially underestimate depression among the risk group of older adults.
The National Institute of Neurological Disease and Stroke-Canadian Stroke Network (NINDS-CSN) 5-minute neuropsychology protocol consists of only verbal tasks, and is proposed as a brief screening method for vascular cognitive impairment. We evaluated its feasibility within two weeks after stroke and ability to predict the development of post-stroke dementia (PSD) at 3 months after stroke.
We prospectively enrolled subjects with ischemic stroke within seven days of symptom onset who were consecutively admitted to 12 university hospitals. Neuropsychological assessments using the NINDS-CSN 5-minute and 60-minute neuropsychology protocols were administered within two weeks and at 3 months after stroke onset, respectively. PSD was diagnosed with reference to the American Heart Association/American Stroke Association statement, requiring deficits in at least two cognitive domains.
Of 620 patients, 512 (82.6%) were feasible for the NINDS-CSN 5-minute protocol within two weeks after stroke. The incidence of PSD was 16.2% in 308 subjects who had completed follow-up at 3 months after stroke onset. The total score of the NINDS-CSN 5-minute protocol differed significantly between those with and without PSD (4.0 ± 2.7, 7.4 ± 2.7, respectively; p < 0.01). A cut-off value of 6/7 showed reasonable discriminative power (sensitivity 0.82, specificity 0.67, AUC 0.74). The NINDS-CSN 5-minute protocol score was a significant predictor for PSD (adjusted odds ratio 6.32, 95% CI 2.65–15.05).
The NINDS-CSN 5-minute protocol is feasible to evaluate cognitive functions in patients with acute ischemic stroke. It might be a useful screening method for early identification of high-risk groups for PSD.
Although late-life anxiety occurs frequently and is associated with higher morbidity, few longitudinal studies have been concerned with the evaluation thereof. We investigated the prevalence, incidence, and persistence of anxiety and related factors over a two-year period in community-dwelling Korean elderly individuals.
A total of 1,204 Korean elderly individuals were evaluated at baseline, and 909 were followed up two years later. The community version of the Geriatric Mental State Schedule was used to estimate anxiety at both baseline and follow-up interviews. We defined “prevalence” as the rate of anxiety symptoms (for both anxiety cases and sub-threshold anxiety) at baseline; “incidence” as the rate of anxiety symptoms at follow-up in those without baseline anxiety symptoms; and “persistence” as the rate of anxiety symptoms at follow-up in those with baseline anxiety symptoms. Associations between various covariates and anxiety status were examined using multivariate logistic regression models.
The prevalence, incidence, and persistence of anxiety symptoms were 38.1%, 29.3%, and 41.1%, respectively. Prevalent anxiety symptoms were associated independently with female, rented housing, more stressful life event and medical illness, physical inactivity, depression, insomnia, and lower cognitive function. Incident anxiety symptoms were predicted by older age, female gender, depression, and insomnia; persistent anxiety symptoms were predicted by older age, more medical illness, and baseline depression.
Since depression was associated with prevalent, incident, and persistent anxiety symptoms, effective detection and management thereof is important in older adults to reduce anxiety. Furthermore, preventive collaborative care should be considered, particularly for older, female, insomniac patients.
During the past decade, carbapenemase-producing Enterobacteriaceae (CPE) has emerged and spread across the world.1 The major carbapenemase enzymes currently being reported are KPC, NDM-1, VIM, IMP, and OXA.2 Because carbapenemase can be effectively transmitted via mobile genetic elements, and current therapeutic options for CPE infections are extremely limited, CPE may be one of the most serious contemporary threats to public health. However, very little is known about the characteristics of CPE carriage during hospitalization. The aims of this study were to investigate the clearance rate of CPE carriage and determine the number of consecutive negative cultures required to confirm CPE clearance. We also examined CPE transmission among hospitalized patients.
Infect. Control Hosp. Epidemiol. 2015;36(11):1361–1362
Decreased hemoglobin levels increase the risk of developing dementia among the elderly. However, the underlying mechanisms that link decreased hemoglobin levels to incident dementia still remain unclear, possibly due to the fact that few studies have reported on the relationship between low hemoglobin levels and neuroimaging markers. We, therefore, investigated the relationships between decreased hemoglobin levels, cerebral small-vessel disease (CSVD), and cortical atrophy in cognitively healthy women and men.
Cognitively normal women (n = 1,022) and men (n = 1,018) who underwent medical check-ups and magnetic resonance imaging (MRI) were enrolled at a health promotion center. We measured hemoglobin levels, white matter hyperintensities (WMH) scales, lacunes, and microbleeds. Cortical thickness was automatically measured using surface based methods. Multivariate regression analyses were performed after controlling for possible confounders.
Decreased hemoglobin levels were not associated with the presence of WMH, lacunes, or microbleeds in women and men. Among women, decreased hemoglobin levels were associated with decreased cortical thickness in the frontal (Estimates, 95% confidence interval, −0.007, (−0.013, −0.001)), temporal (−0.010, (−0.018, −0.002)), parietal (−0.009, (−0.015, −0.003)), and occipital regions (−0.011, (−0.019, −0.003)). Among men, however, no associations were observed between hemoglobin levels and cortical thickness.
Our findings suggested that decreased hemoglobin levels affected cortical atrophy, but not increased CSVD, among women, although the association is modest. Given the paucity of modifiable risk factors for age-related cognitive decline, our results have important public health implications.
During the past decades, a rapid nutritional transition has been observed along with economic growth in the Republic of Korea. Since this dramatic change in diet has been frequently associated with cancer and other non-communicable diseases, dietary monitoring is essential to understand the association. Benefiting from pre-existing standardised dietary methodologies, the present study aimed to evaluate the feasibility and describe the development of a Korean version of the international computerised 24 h dietary recall method (GloboDiet software) and its complementary tools, developed at the International Agency for Research on Cancer (IARC), WHO. Following established international Standard Operating Procedures and guidelines, about seventy common and country-specific databases on foods, recipes, dietary supplements, quantification methods and coefficients were customised and translated. The main results of the present study highlight the specific adaptations made to adapt the GloboDiet software for research and dietary surveillance in Korea. New (sub-) subgroups were added into the existing common food classification, and new descriptors were added to the facets to classify and describe specific Korean foods. Quantification methods were critically evaluated and adapted considering the foods and food packages available in the Korean market. Furthermore, a picture book of foods/dishes was prepared including new pictures and food portion sizes relevant to Korean diet. The development of the Korean version of GloboDiet demonstrated that it was possible to adapt the IARC-WHO international dietary tool to an Asian context without compromising its concept of standardisation and software structure. It, thus, confirms that this international dietary methodology, used so far only in Europe, is flexible and robust enough to be customised for other regions worldwide.
There is increasing evidence of a relationship between underweight or obesity and dementia risk. Several studies have investigated the relationship between body weight and brain atrophy, a pathological change preceding dementia, but their results are inconsistent. Therefore, we aimed to evaluate the relationship between body mass index (BMI) and cortical atrophy among cognitively normal participants.
We recruited cognitively normal participants (n = 1,111) who underwent medical checkups and detailed neurologic screening, including magnetic resonance imaging (MRI) in the health screening visits between September 2008 and December 2011. The main outcome was cortical thickness measured using MRI. The number of subjects with five BMI groups in men/women was 9/9, 148/258, 185/128, 149/111, and 64/50 in underweight, normal, overweight, mild obesity, and moderate to severe obesity, respectively. Linear and non-linear relationships between BMI and cortical thickness were examined using multiple linear regression analysis and generalized additive models after adjustment for potential confounders.
Among men, underweight participants showed significant cortical thinning in the frontal and temporal regions compared to normal weight participants, while overweight and mildly obese participants had greater cortical thicknesses in the frontal region and the frontal, temporal, and occipital regions, respectively. However, cortical thickness in each brain region was not significantly different in normal weight and moderate to severe obesity groups. Among women, the association between BMI and cortical thickness was not statistically significant.
Our findings suggested that underweight might be an important risk factor for pathological changes in the brain, while overweight or mild obesity may be inversely associated with cortical atrophy in cognitively normal elderly males.
Epidemiological studies have reported that higher education (HE) is associated with a reduced risk of incident Alzheimer's disease (AD). However, after the clinical onset of AD, patients with HE levels show more rapid cognitive decline than patients with lower education (LE) levels. Although education level and cognition have been linked, there have been few longitudinal studies investigating the relationship between education level and cortical decline in patients with AD. The aim of this study was to compare the topography of cortical atrophy longitudinally between AD patients with HE (HE-AD) and AD patients with LE (LE-AD).
We prospectively recruited 36 patients with early-stage AD and 14 normal controls. The patients were classified into two groups according to educational level, 23 HE-AD (>9 years) and 13 LE-AD (≤9 years).
As AD progressed over the 5-year longitudinal follow-ups, the HE-AD showed a significant group-by-time interaction in the right dorsolateral frontal and precuneus, and the left parahippocampal regions compared to the LE-AD.
Our study reveals that the preliminary longitudinal effect of HE accelerates cortical atrophy in AD patients over time, which underlines the importance of education level for predicting prognosis.
This study aimed to investigate the influences of age, education, and gender on the two total scores (TS-I and TS-II) of the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological assessment battery (CERAD-NP) and to provide normative information based on an analysis for a large number of elderly persons with a wide range of educational levels.
In the study, 1,987 community-dwelling healthy volunteers (620 males and 1,367 females; 50–90 years of age; and zero to 25 years of education) were included. People with serious neurological, medical, and psychiatric disorders (including dementia) were excluded. All participants underwent the CERAD-NP assessment. TS-I was generated by summing raw scores from the CERAD-NP subtests, excluding Mini-Mental State Examination and Constructional Praxis (CP) recall subtests. TS-II was calculated by adding CP recall score to TS-I.
Both TS-I and TS-II were significantly influenced by demographic variables. Education accounted for the greatest proportion of score variance. Interaction effect between age and gender was found. Based on the results obtained, normative data of the CERAD-NP total scores were stratified by age (six overlapping tables), education (four strata), and gender.
The normative information will be very useful for better interpretation of the CERAD-NP total scores in various clinical and research settings and for comparing individuals’ performance of the battery across countries.
Genetic variation in wild soybean (Glycine soja Sieb. and Zucc.) is a valuable resource for crop improvement efforts. Soybean is believed to have originated from China, Korea, and Japan, but little is known about the diversity or evolution of Korean wild soybean. Therefore, in this study, we evaluated the genetic diversity and population structure of 733 G. soja accessions collected in Korea using 21 simple sequence repeat (SSR) markers. The SSR loci produced 539 alleles (25.7 per locus) with a mean genetic diversity of 0.882 in these accessions. Rare alleles, those with a frequency of less than 5%, represented 75% of the total number. This collection was divided into two populations based on the principal coordinate analysis. Accessions from population 1 were distributed throughout the country, whereas most of the accessions from population 2 were distributed on the western side of the Taebaek and Sobaek mountains. The Korean G. soja collection evaluated in this study should provide useful background information for allele mining approach and breeding programmes to introgress alleles into the cultivated soybean (G. max (L). Merr.) from wild soybean.
Theranostics was proposed as a combined process of therapeutics and diagnostics methodology for increasing treatment efficacy and safety with simultaneous monitoring of the response to treatment. In the past two decades, nanotechnology has been the focus of developing strategies for drug delivery and imaging functions, and it has expanded to the design of multifunctional nanoparticles and the creation of “nanotheranostics” (i.e., theranostic nanomedicines). Nanotheranostics also shows potential in gene therapy; however, nanoparticle-mediated delivery of genes still faces major obstacles related to (1) the uptake by the reticuloendothelial system, (2) the ability to get across the target cell membranes through endocytosis, and (3) the ability to accumulate in organs with permeable vasculature. Here, we review the development and application of nanotheranostics, highlighting their relevance to gene therapy as well as molecular imaging.
This study aimed to assess the prevalence, incidence, and persistence of suicidal ideation (SI), and to investigate the psychosocial factors associated with these.
A total of 1,204 community dwelling elderly adults aged 65 years or older were evaluated at baseline, 909 (75%) of whom were followed two years later. The presence of SI was identified using the questions from the community version of the Geriatric Mental State (GMS) diagnostic schedule (GMS B3) at both baseline and follow-up interviews. Baseline measures included demographic status, years of education, rural/urban residence, accommodation, past and current occupation, monthly income, marital status, stressful life events, social support deficits, number of physical illnesses, severity of pain, physical activity, disability, depressive symptoms, anxiety, insomnia, cognitive function, alcohol consumption, and smoking.
Baseline SI prevalence, follow-up incidence (SI rate at follow-up of 805 elderly subjects who did not have SI at baseline), and persistence (SI rate at follow-up of 104 elderly subjects who had SI at baseline) were 11.5%, 9.6%, and 36.5%, respectively. Baseline SI was independently associated with no current employment, lower monthly income, stressful life events, more severe pain, presence of disability, depressive symptoms, and smoking. Incident SI was independently predicted by baseline unmarried status, social support deficit, severe pain, presence of depressive symptoms, and smoking. Persistent SI was independently predicted by baseline stressful life events and depressive symptoms.
Depressive symptoms were independently associated with prevalent, incident, and persistent SI, but other predictors varied according to incidence and persistence outcomes.
Stable carbon and nitrogen isotope ratios of benthic invertebrates and their potential food sources, such as suspended particulate organic matter (POM), benthic microalgae, attached algae and seagrass, were identified in Dong-dae Bay during the winter. The carbon stable isotope ratios demonstrate that filter feeders, such as oysters (−19.5 ± 1.0‰), use benthic microalgae (−21.2 ± 0.2‰) as a major food, and polychaetes such as Glycera spp. (−14.0 ± 0.6 ‰) preferentially use meiofauna, such as nematodes (−14.0 ± 0.4‰) and copepods (−13.3 ± 1.0‰). These meiofauna may feed on mixed resources (including bacteria) with the isotope ratios between benthic microalgae (−21.2 ± 0.2‰) and seagrass (−9.3 ± 01.0‰). These findings are consistent with the trophic enrichment in the nitrogen isotope ratios (by 3–4‰) between consumers and food sources. Moreover, the results of the MixSIR model based on the observed isotope ratios suggest a large seagrass contribution to the food sources of benthic organisms such as meiofauna (~53.7–62.6%) and macrobenthos (~41.1–68%) through the food web. This model additionally suggests a relatively large contribution of benthic microalgae to the food sources of filter feeders (i.e. 26.4% for oysters).
Sources of variation in nutrient intake have been examined for Western diets, but little is known about the sources of variation and their differences by age and sex among Koreans. We examined sources of variation in nutrient intake and calculated the number of days needed to estimate usual intake using 12 d of dietary records (DR). To this end, four 3 d DR including two weekdays and one weekend day were collected throughout four seasons of 1 year from 178 male and 236 female adults aged 20–65 years residing in Seoul, Korea. The sources of variation were estimated using the random-effects model, and the variation ratio (within-individual:between-individual) was calculated to determine a desirable number of days. Variations attributable to the day of the week, recording sequence and seasonality were generally small, although the degree of variation differed by sex and age (20–45 years and 46–65 years). The correlation coefficient between the true intake and the observed intake (r) increased with additional DR days, reaching 0·7 at 3–4 d and 0·8 at 6–7 d. However, the degree of increase became attenuated with additional days: r increased by 13·0–26·9 % from 2 to 4 d, by 6·5–16·4 % from 4 to 7 d and by 4·0–11·6 % from 7 to 12 d for energy and fifteen nutrients. In conclusion, the present study suggests that the day of the week, recording sequence and seasonality minimally contribute to the variation in nutrient intake. To measure Korean usual dietary intake using open-ended dietary instruments, 3–4 d may be needed to achieve modest precision (r>0·7) and 6–7 d for high precision (r>0·8).
Vitamin D insufficiency is known to be related to cardiometabolic disorders; however, the associations among serum 25-hydroxyvitamin D (25(OH)D) concentration and metabolic syndrome and cardiometabolic risk factors in children and adolescents have not yet been clearly delineated. For this reason, we investigated the relationship among serum 25(OH)D concentration and metabolic syndrome and cardiometabolic risk factors among Korean adolescents.
We performed a cross-sectional analysis and used hierarchical multivariate logistic regression analysis models to adjust for confounding variables.
We used the data gathered during the 2008–2009 Korea National Health and Nutrition Examination Survey (KNHANES).
Our subjects included 1504 Korean adolescents aged 12–18 years who participated in the KNHANES.
Vitamin D insufficiency, defined as 25(OH)D concentration <50 nmol/l, was found in 75·3 % of Korean adolescents and was associated with an increased risk of the prevalence of metabolic syndrome. Waist circumference and BMI were the most closely correlated cardiometabolic components of metabolic syndrome according to serum 25(OH)D status, but no significant relationship was found between serum 25(OH)D concentration and insulin resistance or for the risks for high blood pressure, hyperglycaemia, reduced HDL-cholesterol or hypertriacylglycerolaemia, with or without adjustment for confounding variables.
Low serum 25(OH)D concentration appears to be associated with several cardiometabolic risk factors and an increased risk of the prevalence of metabolic syndrome in Korean adolescents.
We aimed to assess the prevalence and associated factors of vitamin D deficiency in healthy adolescents and to determine parent–adolescent association in vitamin D status.
A cross-sectional study.
Data from the Korean National Health and Nutrition Examination Survey (KNHANES) 2008–2009. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured using 125I-labelled RIA kits. Vitamin D deficiency in adolescents was defined as 25(OH)D level <27·5 nmol/l, and 25(OH)D levels between 27·5 and <50 nmol/l were considered insufficient. For the parents, vitamin D deficiency was defined as 25(OH)D level <50 nmol/l.
The study population consisted of 2062 adolescents (1095 boys, 967 girls; aged 10–18 years) and their parents (1005 fathers, 1341 mothers).
Overall, 13·4 % of adolescents (boys 11·7 %, girls 15·4 %) were 25(OH)D deficient, 54·7 % were 25(OH)D insufficient. Prevalence of vitamin D deficiency increased with age (P < 0·0001). Parental vitamin D deficiency was more prevalent in vitamin D-deficient adolescents than in non-deficient adolescents (all P < 0·0001). In multivariate logistic regression analyses, predictors for vitamin D deficiency were senior high school students (OR = 3·45–4·33), winter/spring season (OR = 3·18–5·11/5·35–7·36) and parental vitamin D deficiency (OR = 1·78–4·88; all P < 0·05).
Vitamin D insufficiency is prevalent among healthy Korean adolescents and the parent–offspring association warrants vitamin D screening for family members of deficient individuals.
The synthesis, structure, and electrical performances of titanium dioxide (TiO2 and also doped TiO2) thin films, a capacitor dielectric for dynamic random access memory (DRAM) and a resistance switching material in resistance switching RAM (ReRAM), are reviewed. The three-dimensionality of these structures and the extremely small feature sizes (<20 nm) of these memory devices require the synthesis method of TiO2-based layers to exhibit high degree of conformality. Atomic layer deposition is, therefore, the method of choice in respect of film growth for these applications. The unique arrangement of the TiO6-octahedra in the rutile structure, which results in the value for dielectric constant of the dielectric layer, εr (>100), makes the material especially attractive as the capacitor dielectric layer in DRAM. Removing some of the oxygen ions from the rutile structure and arranging the resulting oxygen vacancies on a specific crystallographic plane results in the so called Magnéli phase materials, which show distinctive conducting semiconductor or metallic characteristics. External electrical stimuli can cause the repeated formation and rupture of conducting channels that consist of these Magnéli phase materials in the insulating TiO2 matrix, and this aspect makes the material a very feasible choice for applications in ReRAM. This article reviews the material properties, fabrication process, integration issues, and prospect of TiO2 films for these applications.
The objectives of this study were to evaluate fish guild compositions and national river health using a multi-metric model of the Korean index of biological integrity using fishes (K-IBIF) in four major Korean watersheds along with water chemistry and habitat quality. Tolerant and omnivore fish species dominated all the watersheds, and the proportions of tolerance guilds and trophic guilds reflected water chemistry and habitat quality. The number of sensitive species and insectivore species had negative correlations (r < −0.42, P < 0.01) with chemical water quality (biological oxygen demand (BOD)), while tolerant species and omnivore species had positive correlation (r > 0.27, P < 0.05) with BOD values. Physical habit conditions, based on qualitative habitat evaluation index (QHEI) model, indicated a “good” condition (mean = 68.9; range = 45–105) in three watersheds, except for the Yeongsan River watershed. Values of QHEI were significantly correlated (R2 > 0.4, P < 0.01) with nitrogen and phosphorus levels in all watersheds, suggesting that habitat degradation is associated with eutrophication. Model values of K-IBIF in the watersheds averaged 18.2, indicating a “fair” condition, and about 37% of all observations in K-IBIF model values were judged as a “poor” health condition, indicating severe health impairment. Overall, our data suggest that degradation of the river health was due to a combined effect of chemical pollution and physical habitat modifications. This research provides valuable information on Korean river conservation and restoration in the future.