Dyslipidemia Fact Sheet in South Korea, 2022.

Objective: This study aimed to investigate the prevalence and status of dyslipidemia management among South Korean adults, as performed by the Korean Society of Lipid and Atherosclerosis under the name Dyslipidemia Fact Sheet 2022. Methods: We analyzed the lipid profiles, age-standardized and crude prevalence, management status of hypercholesterolemia and dyslipidemia, and health behaviors among Korean adults aged ≥20 years, using the Korea National Health and Nutrition Examination Survey data between 2007 and 2020. Results: In South Korea, the crude prevalence of hypercholesterolemia (total cholesterol ≥240 mg/dL or use of a lipid-lowering drug) in 2020 was 24%, and the age-standardized prevalence of hypercholesterolemia more than doubled from 2007 to 2020. The crude treatment rate was 55.2%, and the control rate was 47.7%. The crude prevalence of dyslipidemia (more than one out of three conditions [low-density lipoprotein-cholesterol ≥160 or the use of a lipid-lowering drug, triglycerides ≥200, or high-density lipoprotein-cholesterol (men and women) <40 mg/dL]) was 40.2% between 2016 and 2020. However, it increased to 48.2% when the definition of hypo-high-density lipoprotein-cholesterolemia in women changed from <40 to <50 mg/dL. Conclusion: Although the prevalence of hypercholesterolemia and dyslipidemia has steadily increased in South Korea, the treatment rate remains low. Therefore, continuous efforts are needed to manage dyslipidemia through cooperation between the national healthcare system, patients, and healthcare providers.

Dyslipidemia Fact Sheet in South Korea, 2022.

BACKGRUOUND: This study aimed to investigate the prevalence and status of dyslipidemia management among South Korean adults, as performed by the Korean Society of Lipid and Atherosclerosis under the name Dyslipidemia Fact Sheet 2022. METHODS: We analyzed the lipid profiles, age-standardized and crude prevalence, management status of hypercholesterolemia and dyslipidemia, and health behaviors among Korean adults aged ≥20 years, using the Korea National Health and Nutrition Examination Survey data between 2007 and 2020. RESULTS: In South Korea, the crude prevalence of hypercholesterolemia (total cholesterol ≥240 mg/dL or use of a lipid-lowering drug) in 2020 was 24%, and the age-standardized prevalence of hypercholesterolemia more than doubled from 2007 to 2020. The crude treatment rate was 55.2%, and the control rate was 47.7%. The crude prevalence of dyslipidemia-more than one out of three conditions (low-density lipoprotein cholesterol ≥160 or the use of a lipid-lowering drug, triglycerides ≥200, or high-density lipoprotein cholesterol [HDL-C] [men and women] <40 mg/dL)-was 40.2% between 2016 and 2020. However, it increased to 48.2% when the definition of hypo-HDL-cholesterolemia in women changed from <40 to <50 mg/dL. CONCLUSION: Although the prevalence of hypercholesterolemia and dyslipidemia has steadily increased in South Korea, the treatment rate remains low. Therefore, continuous efforts are needed to manage dyslipidemia through cooperation between the national healthcare system, patients, and healthcare providers.

Diet quality partially mediates the association between ultraprocessed food consumption and adiposity indicators.

OBJECTIVE: This study evaluated the potential role of overall diet quality in the associations between ultraprocessed food (UPF) consumption and adiposity indicators among Korean adults. METHODS: Baseline data of participants (n = 4331) of the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) cohort study were obtained. Dietary information was collected by a validated food frequency questionnaire. UPF was defined using the NOVA classification. Overall diet quality was assessed using the Korean Healthy Eating Index. Adiposity indicators included BMI, waist circumference, percentage body fat by bioimpedance, and visceral fat mass by whole-body dual-energy x-ray absorptiometry. Mediation analysis after adjustment for potential confounders was performed. RESULTS: UPF intake was associated with higher adiposity indicators after adjustment for confounders. The mediating effect of the Korean Healthy Eating Index on the relationship between UPF consumption and each adiposity indicator was 35.6% (95% CI: 4.9% to 255.9%) for BMI, 38.3% (17.9% to 132.1%) for waist circumference, 40.2% (8.3% to 259.4%) for percentage body fat, and 60.7% (-396.4% to 662.7%) for visceral fat mass. CONCLUSIONS: UPF consumption was positively associated with adiposity indicators, which were partially attributed to the overall diet quality. Further studies are needed to better understand the causal mechanisms of these associations.

Estimated dietary vitamin D intake and major vitamin D food sources of Koreans: based on the Korea National Health and Nutrition Examination Survey 2016-2019.

BACKGROUND/OBJECTIVES: The purpose of this study was to establish a database (DB) of foods containing vitamin D that were investigated in the Korea National Health and Nutrition Examination Survey (KNHANES), to estimate the dietary vitamin D intake, to evaluate the dietary adequacy of this intake, and to identify the major food sources of Koreans that contain vitamin D. SUBJECTS/METHODS: This study used data from the KNHANES 2016-2019. Individuals aged ≥ 1 year who participated in the nutrition survey (n = 28,418) were included. The dietary intake was assessed by the 24-h dietary recall method and individual dietary vitamin D intake was estimated using a newly established vitamin D DB. Dietary adequacy was evaluated by comparing the dietary intake of the participants with adequate intake (AI) as defined by Dietary Reference Intakes for Koreans (KDRIs) 2020. RESULTS: The average dietary vitamin D intake for all the subjects was 3.13 µg/d, which was 33.1% of AI. Dietary vitamin D intake was lower in rural residents, the elderly, and those with low income. The major food groups that contributed to the total dietary vitamin D intake were fish and shellfish (61.59%), eggs (17.75%), meat (8.03%), milk (4.25%), legumes (3.93%), and grains (3.84%). The top 10 individual food items that contributed to the total vitamin D intake were eggs (17.44%), squid (8.5%), eels (7.44%), salmon (5.35%), mackerel (5.27%), anchovies (4.65%), yellow croakers (4.58%), pork meat (4.47%), soymilk (4.46%), and skipjack tuna (3.80%). CONCLUSION: These results show that the mean dietary vitamin D intake of Koreans is lower than the reference AI level. Nutritional policies need to be put in place to increase the vitamin D intake of Koreans in the future. In addition, comprehensive research on all the sources of vitamin D, including intake of supplements and biosynthesis in the skin, is required.

Dietary zinc intake and sources among Koreans: findings from the Korea National Health and Nutrition Examination Survey 2016-2019.

BACKGROUND/OBJECTIVES: Zinc is an essential trace mineral which is important for the growth and development of the human body and immunological and neurological functions. Inadequate zinc intake may cause zinc deficiency with its adverse consequences. In this study, we aimed to estimate the dietary zinc intake levels and sources among Koreans. SUBJECTS/METHODS: For this secondary analysis, we obtained data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2016-2019. Individuals aged ≥ 1 yr who had completed a 24-h recall were included. The dietary zinc intake of each individual was calculated by applying data from a newly developed zinc content database to the KNHANES raw data. We also compared the extracted data with the sex-, age-specific reference values suggested in the Korean Dietary Reference Intakes 2020. The prevalence of adequate zinc intake was then evaluated by the proportion of the individuals who met the estimated average requirement (EAR). RESULTS: The mean zinc intake of Koreans aged ≥ 1 yr and adults aged ≥ 19 yrs were 10.2 and 10.4 mg/day, equivalent to 147.4% and 140.8% of the EAR, respectively. Approximately 2 in 3 Koreans met the EAR for zinc, but the zinc intake differed slightly among the different age and sex groups. In children aged 1-2 yrs, 2 out of 5 exceeded the upper level of intake, and nearly half of the younger adults (19-29 yrs) and the elders (≥ 75 yrs) did not meet the EAR. The major contributing food groups were grains (38.9%), meats (20.4%), and vegetables (11.1%). The top 5 food contributors to zinc intake were rice, beef, pork, egg, and baechu kimchi, which accounted for half of the dietary intake. CONCLUSION: The mean zinc intake among Koreans was above the recommended level, but 1 in 3 Koreans had inadequate zinc intake and some children were at risk of excessive zinc intake. Our study included zinc intake from diet only, thus to better understand zinc status, further research to include intake from dietary supplements is needed.

Ultra-Processed Food Consumption and Obesity in Korean Adults.

BACKGRUOUND: This study aimed to investigate the association between consumption of ultra-processed foods (UPF) and obesity in Korean adults. METHODS: We included the Cardiovascular and Metabolic Diseases Etiology Research Center cohort study baseline data of adults aged 30 to 64 years who completed a validated food frequency questionnaire. UPF was defined using the NOVA food classification. Multivariable linear and logistic regression analyses were performed to assess the association of dietary energy contribution of UPF with obesity indicators (body mass index [BMI], obesity, waist circumference [WC], and abdominal obesity). RESULTS: Consumption of UPF accounted for 17.9% of total energy intake and obesity and abdominal obesity prevalence was 35.4% and 30.2%, respectively. Compared with those in the lowest quartile of UPF consumption, adults in the highest quartile had greater BMI (ß=0.36; 95% confidence interval [CI], 0.15 to 0.56), WC (ß=1.03; 95% CI, 0.46 to 1.60), higher odds of having obesity (odds ratio [OR], 1.24; 95% CI, 1.07 to 1.45), and abdominal obesity (OR, 1.34; 95% CI, 1.14 to 1.57), after adjusting for sociodemographic characteristics, health-related behaviors, and family history of diseases. Dose-response associations between UPF consumption and obesity indicators were consistently found (all P trend <0.01). However, the strength of association was halved for all obesity indicators after further adjustments for total energy intake and overall diet quality score, and the trend toward association for obesity and WC disappeared. CONCLUSION: Our finding supports the evidence that consumption of UPF is positively associated with obesity among Korean adults.

Magnesium intake and dietary sources among Koreans: findings from the Korea National Health and Nutrition Examination Survey 2016-2019.

BACKGROUND/OBJECTIVES: Magnesium is an essential nutrient for human health. However, inadequate intake is commonly reported worldwide. Along with reduced consumption of vegetables and fruits and increased consumption of refined or processed foods, inadequate magnesium intake is increasingly reported as a serious problem. This study aimed to assess magnesium intake, its dietary sources, and the adequacy of magnesium intake in Korean populations. SUBJECTS/METHODS: Data was obtained from the Korea National Health and Nutrition Examination Survey 2016-2019 and included individuals aged ≥1 yr who had participated in a nutrition survey (n=28,418). Dietary intake was assessed by 24-h recall, and dietary magnesium intake was estimated using a newly established magnesium database. Diet adequacy was evaluated by comparing dietary intake with the estimated average requirement (EAR) suggested in the Korean Dietary Reference Intakes 2020. RESULTS: The mean dietary magnesium intake of Koreans aged ≥1 yr was 300.4 mg/d, which was equivalent to 119.8% of the EAR. The prevalence of individuals whose magnesium intake met the EAR was 56.8%. Inadequate intake was observed more in females, adolescents and young adults aged 12-29 yrs, elders aged ≥65 yrs, and individuals with low income. About four-fifths of the daily magnesium came from plant-based foods, and the major food groups contributing to magnesium intake were grains (28.3%), vegetables (17.6%), and meats (8.4%). The top 5 individual foods that contributed to magnesium intake were rice, Baechu (Korean cabbage) kimchi, tofu, pork, and milk. However, the contribution of plant foods and individual contributing food items differed slightly by sex and age groups. CONCLUSIONS: This study found that the mean dietary magnesium intake among Koreans was above the recommended intake, whereas nearly one in 2 Koreans had inadequate magnesium intake. To better understand the status of magnesium intake, further research is required, which includes the intake of dietary supplements.

Atomistic Investigation on the Blocking Phenomenon of Crack Propagation in Cu Substrate Reinforced by CNT.

Recently, many researchers in the semiconductor industry have attempted to fabricate copper with carbon nanotubes for developing efficient semiconductor systems. In this work, tensile tests of a carbon-nanotube-reinforced copper specimen were conducted using the molecular statics method. The copper substrate utilized in the tensile tests had an edge half-crack, with the carbon nanotube located on the opposite side of the copper substrate. Subsequently, the effects of carbon nanotube radius were investigated. The mechanical properties of the copper/carbon nanotube composite were measured based on the simulation results, which indicated that the atomic behavior of the composite system exhibited the blocking phenomenon of crack propagation under tension. The fracture toughness of the composite system was measured using the Griffith criterion and two-specimen method, while the crack growth resistance curve of the system was obtained by varying the crack length. This study demonstrated that the mechanical reliability of copper can be improved by fabricating it with carbon nanotubes.

Dietary intake and major source foods of vitamin E among Koreans: findings of the Korea National Health and Nutrition Examination Survey 2016-2019.

BACKGROUND/OBJECTIVES: Vitamin E is essential for health, and although vitamin E deficiency seems rare in humans, studies on estimates of dietary intake are lacking. This study aimed to estimate dietary vitamin E intake, evaluate dietary adequacy of vitamin E, and detail major food sources of vitamin E in the Korean population. SUBJECTS/METHODS: This study used data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2016-2019. Individuals aged ≥ 1 year that participated in a nutrition survey (n = 28,418) were included. Dietary intake was assessed by 24-h recall and individual dietary vitamin E intake was estimated using a newly established vitamin E database. Dietary adequacy was evaluated by comparing dietary intake with adequate intake (AI) as defined by Korean Dietary Reference Intakes 2020. RESULTS: For all study subjects, mean daily total vitamin E intake was 7.00 mg α-tocopherol equivalents, which was 61.6% of AI. The proportion of individuals that consumed vitamin E at above the AI was 12.9%. Inadequate intake was observed more in females, older individuals, rural residents, and those with a low income. Mean daily intakes of tocopherol (α-, ß-, γ-, and δ-forms) and tocotrienol were 6.02, 0.30, 6.19, 1.63, and 1.61 mg, respectively. The major food groups that contributed to total dietary vitamin E intake were grains (22.3%), seasonings (17.0%), vegetables (15.3%), and fish, and shellfish (7.4%). The top 5 individual food items that contributed to total vitamin E intake were baechu kimchi, red pepper powder, eggs, soybean oil, and rice. CONCLUSIONS: This study shows that mean dietary vitamin E intake by Koreans did not meet the reference adequate intake value. To better understand the status of vitamin E intake, further research is needed that considers intake from dietary supplements.

Ultra-processed foods and total sugars intake in Korea: evidence from the Korea National Health and Nutrition Examination Survey 2016-2018.

BACKGROUND/OBJECTIVES: Dietary sugars intake worldwide is stable or decreasing, but overall sugars intake remains above the recommended level. Some studies suggest that ultra-processed foods (UPFs) drive excessive sugars intake. However, UPF consumption in Korea and its association with sugars intake have not yet been studied. This study aimed to estimate the contribution of UPF consumption to total sugars intake and to investigate the association between UPF consumption and total sugars intake in Koreans. SUBJECTS/METHODS: Data from the Korea National Health and Nutrition Examination Survey 2016-2018 were used, and included data on 21,075 participants aged 1+ years completed a 24-h recall. Food items reported in the 24-h recall were classified according to the NOVA system as UPFs, processed foods, processed culinary ingredients, or unprocessed or minimally processed foods. RESULTS: The average daily energy intake was 1,996 kcal, and UPFs accounted for 26.2% of the total energy intake (% TE). The average total sugars intake was 63.1 g (13.0% TE), and 44.9% of total sugars intake came from UPFs. Among the entire population, 15.8% exceeded the recommended limit for total sugars within 20% TE, and excessive total sugars intake was more prevalent among females (19.5%) and children (21.1%). The prevalence of excessive total sugars intake showed a significantly increasing tendency across the quartiles of UPF energy contribution, ranging from 11.9% in the lowest quartile to 23.2% in the highest quartile. Even after adjustment for sociodemographic variables, UPF consumption was positively associated with the prevalence of excessive total sugars intake (P for trend < 0.001). This association was similar in subgroup analyses by sex and age. CONCLUSIONS: This study suggests that UPF consumption may drive excessive intake of total sugars in the Korean diet. Our findings conclusively establish that restricting UPF consumption may be an efficient way to reduce sugars intake in Korean population.

Association between Metabolically Healthy Obesity and Subclinical Atherosclerosis in the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) Cohort.

We aimed to investigate the association between a new definition of metabolic health (MH) and subclinical atherosclerosis in a cohort of patients without previous cardiovascular disease (CVD). In total, 7824 community-dwelling adults were categorized as normal weight, overweight, or obese. Metabolically healthy obesity (MHO) was defined as obesity accompanied by all of the following criteria: systolic blood pressure (BP) < 130 mmHg, no use of BP-lowering medication, waist-hip ratio <0.832 (women) and <0.887 (men), and no prevalent diabetes. Carotid atherosclerosis was defined as carotid plaque or mean carotid intima-media thickness ≥ 1.1 mm. The prevalence of carotid atherosclerosis was 8.3% and 1113 (14.2%) patients were classified as having MHO. All individuals classified as metabolically unhealthy were at an increased risk of carotid atherosclerosis independent of body mass index categories. Conversely, the risk of carotid atherosclerosis in individuals with MHO was not significantly increased compared to that in metabolically healthy normal weight participants (hazard ratio 1.20, 95% confidence interval 0.87−1.67). This new definition of MH was able to identify people with MHO without an increased risk of CVD in an Asian community cohort.

Association between dietary and suicidal behaviors in adolescents in Korea based on the Youth Risk Behavior Survey (2015-2020).

OBJECTIVES: This study explored the association between dietary and suicidal behaviors of Korean adolescents and investigated differences in this association in children of immigrant parents. METHODS: The sample (n=368,138) was collected from the Korea Youth Risk Behavior Survey from 2015 to 2020. Participants who agreed to provide family information (n=313,689) were classified according to their parents' nationality. The study variables were 11 self-reported dietary behaviors, and their composite dietary behaviors (i.e., nutrient deprivation and unhealthy food consumption) that resulted from principal component analysis. The association between study variables and suicide-related outcomes (i.e., suicidal ideation, suicide planning, and suicide attempts) was analyzed by multiple logistic regression with adjustment for covariates. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated. RESULTS: Participants who skipped key meals and foods were more likely to have attemped suicide (aOR [95% CI]: skipping breakfast ≥5 days/wk, 1.28 [1.21 to 1.35]; consuming fruits <1 times/wk: 1.42 [1.32 to 1.52]; consuming vegetables <1 times/wk: 1.72 [1.53 to 1.93]; consuming milk <3 times/wk: 1.07 [0.99 to 1.16]). The associations were prominent in third culture kids (TCKs) (aOR [95% CI]: 2.23 [1.61 to 3.09]; 2.32 [1.61 to 3.35]; 2.63 [1.50 to 4.60]; 1.69 [1.09 to 2.63], respectively). Participants who consumed unhealthy foods (fast food, caffeinated and sugary drinks) more frequently were more likely to have attempted suicide (aOR, 1.55; 95% CI, 1.38 to 1.73). This association was also more prominent in TCKs (aOR, 2.08; 95% CI, 1.08 to 4.01). CONCLUSIONS: Our findings indicate a positive association between unfavorable dietary behaviors and outcomes related to suicide, and this association appears to be notable in adolescents with immigrant parents.

Association between Ultra-processed Food Consumption and Dietary Intake and Diet Quality in Korean Adults.

BACKGROUND: Food environments have changed rapidly, and the global interest in ultra-processed foods has increased. Ultra-processed foods are typically energy dense, high in sugars and fat, and low in fiber, protein, minerals, and vitamins. OBJECTIVE: This study aimed to estimate the energy contribution of ultra-processed foods in the diet of Korean adults and to examine the association between ultra-processed food consumption and dietary intake and diet quality. DESIGN: This study is a secondary analysis of cross-sectional data from the Korea National Health and Nutrition Examination Survey (2016-2018). PARTICIPANTS/SETTINGS: A total of 16,657 adults aged ≥19 years who completed a 1-day 24-hour recall. MAIN OUTCOME MEASURES: Absolute and relative intake of energy and nutrients were measured and dietary quality was assessed using the Korean Healthy Eating Index (KHEI). STATISTICAL ANALYSIS: Multiple regression models adjusted for sociodemographic variables were used to examine the association between quintiles of ultra-processed foods dietary energy contribution and dietary intake and quality. RESULTS: Mean reported daily energy intake was 2,031 kcal, with 25.1% of calories coming from ultra-processed foods. Mean energy contribution from ultra-processed foods ranged from 3.6% kcal (Q1) to 52.4% kcal (Q5). Energy contribution of ultra-processed foods was positively associated with reported intake of daily energy, total sugars, and total and saturated fat and inversely associated with reported intake of carbohydrates, fiber, minerals, and vitamins. Both sodium and potassium were negatively associated with percentage of energy from ultra-processed foods. However, the sodium-to-potassium ratio was high regardless of quintile of energy contribution from ultra-processed foods, and the ratio was positively associated with percentage of total energy from ultra-processed foods. Although the KHEI score was inversely associated with percentage of daily energy from ultra-processed foods, all levels of ultra-processed food consumption were associated with poor diet quality. CONCLUSIONS: The ultra-processed foods consumption of Korean adults accounted for one fourth of daily energy intake, and a higher dietary energy contribution from ultra-processed foods was associated with poorer dietary intakes and a lower dietary quality. Further studies are needed to understand factors influencing selection and consumption of ultra-processed foods and to identify effective strategies to promote healthy food choices.

Consumption of Ultra-Processed Food and Blood Pressure in Korean Adults.

BACKGROUND AND OBJECTIVES: There is growing evidence supporting the association between ultra-processed food (UPF) consumption and metabolic disease risk. However, little is known about the association between UPF consumption and blood pressure (BP). Thus, this study examined the association between UPF consumption and elevated BP in Korean adults. METHODS: This study used data from the Korea National Health and Nutrition Examination Survey (2016-2018) and included 9,188 participants aged 30-79 years without a history of hypertension diagnosis. Food items reported in a one-day 24-hour recall were categorized on the basis of the NOVA (not an acronym) food classification criteria. UPF consumption was estimated as the contribution to total energy intake. Elevated BP was defined as systolic BP ≥120 mmHg or diastolic BP ≥80 mmHg. The independent association between UPF consumption and elevated BP was assessed by multivariable logistic regression analysis. RESULTS: The upper tertile of UPF consumption was significantly associated with elevated BP compared with the lower tertile, after adjusting for potential confounders. A linear trend was observed for elevated BP across the tertiles of the dietary energy contribution of UPF. Similar results were found in stratified analyses by age group, smoking, obesity, and overall dietary quality. However, a marginal level of association was found in some subgroups, current smokers, and non-obese adults. CONCLUSIONS: The dietary energy contribution of UPF consumption was positively associated with increased prevalence of elevated BP, and these findings suggest that lowering UPF consumption might help prevent BP elevation.

Late eating, blood pressure control, and cardiometabolic risk factors among adults with hypertension: results from the Korea National Health and Nutrition Examination Survey 2010-2018.

OBJECTIVES: Despite growing concerns regarding the timing of eating, little is known about the association between late eating and health. This study aimed to investigate whether late eating is associated with blood pressure (BP) control and cardiometabolic risk factors among Korean adults with hypertension. METHODS: Data from the Korea National Health and Nutrition Examination Survey 2010-2018 were used. Adults with hypertension aged 30-79 years (n=13,361) were included in this study. Dietary intake and information on meal timing were assessed using 1-day 24-hour recall. Late eating was defined as after the median midpoint between the times of the first and the last eating episode during the recall day. Logistic and linear regression models were used to estimate the associations of late eating with BP control and cardiometabolic risk factors. RESULTS: Among late eaters, there were more men than women. Compared to early eaters, late eaters were younger, had a higher body mass index (BMI) and unhealthier habits, and their overall dietary quality score was lower. A negative association between late eating and BP control was found in a univariate model (odds ratio [OR], 0.82; 95% confidence interval [CI], 0.94 to 1.12), but this association disappeared after adjustment for confounders (OR, 1.03; 95% CI, 0.94 to 1.12). Late eating was independently associated with higher BMI (p=0.03) and blood triglyceride concentration (p<0.01). CONCLUSIONS: Our results do not support a link between late eating and BP control among adults with hypertension, but suggest that late eating is associated with cardiometabolic risk factors.

Association between a family history of diabetes and carotid artery atherosclerosis in Korean adults.

OBJECTIVES: Diabetes is a well-known risk factor for atherosclerosis, but the association between a family history of diabetes and atherosclerosis remains unknown. In this study, we assessed the association between a family history of diabetes and increased carotid intima-media thickness (IMT), a marker of subclinical atherosclerosis, in a middle-aged Korean population. METHODS: This cross-sectional study included 3,974 community-dwelling adults (1,404 male and 2,570 female) aged 30-64 years from the Cardiovascular and Metabolic Diseases Etiology Research Center cohort. The presence of a family history of diabetes was assessed through face-to-face interviews using a standardized questionnaire. Carotid IMT was assessed using B-mode ultrasonography, and increased IMT was defined as a value in the top quartile of the IMT values of all participants. Multivariate logistic regression was used to evaluate independent associations between a family history of diabetes and increased IMT. RESULTS: A family history of diabetes was significantly associated with increased carotid IMT (odds ratio, 1.23; 95% confidence interval, 1.03 to 1.48) after adjusting for sex; age; body mass index; systolic blood pressure; total cholesterol, triglyceride, and hemoglobin A1c levels; smoking; alcohol consumption; exercise; use of antidiabetic, antihypertensive, and antilipidemic drugs; and a family history of hypertension. The positive association remained significant after excluding participants with diabetes (odds ratio, 1.21; 95% confidence interval, 1.00 to 1.47). CONCLUSIONS: A family history of diabetes was positively associated with increased carotid IMT, even in participants without diabetes. Therefore, information on a family history of diabetes may help identify individuals at high risk of atherosclerotic cardiovascular disease.

Mechanical Behaviors of Si/CNT Core/Shell Nanocomposites under Tension: A Molecular Dynamics Analysis.

The silicon/carbon nanotube (core/shell) nanocomposite electrode model is one of the most promising solutions to the problem of electrode pulverization in lithium-ion batteries. The purpose of this study is to analyze the mechanical behaviors of silicon/carbon nanotube nanocomposites via molecular dynamics computations. Fracture behaviors of the silicon/carbon nanotube nanocomposites subjected to tension were compared with those of pure silicon nanowires. Effective Young's modulus values of the silicon/carbon nanotube nanocomposites were obtained from the stress and strain responses and compared with the asymptotic solution of continuum mechanics. The size effect on the failure behaviors of the silicon/carbon nanotube nanocomposites with a fixed longitudinal aspect ratio was further explored, where the carbon nanotube shell was found to influence the brittle-to-ductile transition behavior of silicon nanowires. We show that the mechanical reliability of brittle silicon nanowires can be significantly improved by encapsulating them with carbon nanotubes because the carbon nanotube shell demonstrates high load-bearing capacity under tension.

Effects of Geometric and Crystallographic Factors on the Reliability of Al/Si Vertically Cracked Nanofilm/Substrate Systems.

In this study, tensile tests on aluminum/silicon vertically cracked nanofilm/substrate systems were performed using atomistic simulations. Various crystallographic orientations and thicknesses of the aluminum nanofilms were considered to analyze the effects of these factors on the reliability of the nanofilm/substrate systems. The results show that systems with some specific crystallographic orientations have lower reliability compared to the other orientations because of the penetration of the vertical crack into the silicon substrate. This penetration phenomenon occurring in a specific model is related to a high coincidence of atomic matching between the interfaces in the model. This high coincidence leads to a tendency of the interface to maintain a coherent form in which the outermost silicon atoms of the substrate that are bonded to the aluminum nanofilm tend to stick with the aluminum atoms under tensile loads. This phenomenon was verified by interface energy calculations in the simulation models.

Association between social network structure and physical activity in middle-aged Korean adults.

PURPOSE: Evidence suggests that physical activity participation is shaped through a myriad of structural aspects of social relationships. We examined the relationship between social network structure based on egocentric social network and physical activity. METHODS: From 6799 middle-aged Korean adults, we assessed the social network density and proportion of closed triads, using the name generator module. Self-reported physical activity for functional and leisure purposes was calculated in metabolic equivalent of task (MET)-min/week. We employed sex-stratified, multivariable linear regression to assess the association between each network structure variable and total physical activity, adjusting for age, network size, socioeconomic status, and comorbidities. We also examined the association with moderate-to-vigorous physical activity (MVPA) and wrist-worn accelerometer assessed physical activity. RESULTS: The network members of female participants were more likely to be of same sex and family member compared to those of males. There were no sex differences in average network size. Network density based on affiliation was sex-differentially associated with physical activity (male ß -346.7, p 0.2221 and female ß -528.6, p 0.0002). In parallel, the proportion of closed triads was negatively associated with physical activity only in females (male ß -542.6, p 0.0551 and female ß -641.51, p < 0.0001). However, network density and closed triads were insignificantly yet positively associated with MVPA in male (density ß 229.7, p 0.3193 and closed triad ß 109.21, p 0.6333). Network structure by contact frequency or emotional closeness and accelerometer-assessed physical activity showed inconsistent results. CONCLUSION: Understanding the role of social network structures can help to achieve ideal physical activity level in the context of primary prevention of cardiometabolic disorders.

Stressful life events and serum triglyceride levels: the Cardiovascular and Metabolic Diseases Etiology Research Center cohort in Korea.

OBJECTIVES: Elevated serum triglyceride levels are a risk factor for developing cardiovascular disease. A number of studies have demonstrated a positive association between psychological stress and serum triglyceride levels. However, there is limited evidence regarding the impact of stressful life events (SLEs) on serum triglyceride levels in the healthy population. Therefore, we evaluated the independent association between SLEs and serum triglyceride levels in a middle-aged Korean population. METHODS: We analyzed a sample of 2,963 people (aged 30-64 years; 36% men) using baseline data from the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) cohort study. The Korean version of the Life Experience Survey questionnaire was used to measure the presence and positive/negative impact of SLEs. Hypertriglyceridemia was defined as a fasting serum triglyceride level of ≥ 150 mg/dL. RESULTS: Of the 2,963 participants, 33.1% reported at least 1 SLE over the past 6 months and 24.8% had hypertriglyceridemia. Even after adjusting for potential confounders, the serum triglyceride level was significantly associated with the total number of SLEs in men (3.333 mg/dL per event; p= 0.001), but not in women (0.451 mg/dL per event, p= 0.338). Hypertriglyceridemia was also associated with having 4 or more SLEs with positive effects (odds ratio [OR], 2.57; 95% CI, 1.02 to 6.46) and 4 or more SLEs with negative effects (OR, 1.99; 95% CI, 1.16 to 3.41) in men. CONCLUSIONS: Our findings suggest that SLEs may increase the risk of hypertriglyceridemia in middle-aged men.