• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3210-3223
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• 2024

International Commission on Radiological Protection (ICRP) recently developed the adult and pediatric meshtype reference computational phantoms (MRCPs) in high-quality/fidelity mesh format, featuring high deformability into various body sizes and poses. Utilizing this feature, the adult MRCPs-based body-size-dependent phantom library was developed for individualized dosimetry. To complete the full phantom library set, the present study produced the pediatric-MRCPs-based body-size-dependent pediatric phantom library. The library comprises a total of 637 phantoms (356 males and 281 females) with varying standing heights and body weights, covering a wide range of body sizes (i.e., including from 1st to 99th percentile height and weight values) for infants, children, and adolescents, offering a realistic representation of body shapes by reflecting ten secondary anthropometric parameters. The phantoms were automatically constructed utilizing automatic deformation program. The dosimetric impact of the library was investigated by calculating organ doses for external exposures to broad parallel photon beams in anterior-posterior direction. Compared with the values of the pediatric MRCPs, significant differences were observed at energies <0.05 MeV, showing larger values for underweight phantom and smaller values for obese phantom. The results highlight the importance of using the pediatric phantom library for accurate dose estimates of individual children with various body sizes.

• Clinical and Experimental Pediatrics
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• v.48 no.10
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• pp.1082-1089
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• 2005

Purpose : Abdominal obesity is encountered as a risk factor for cardiovascular diseases. However, the anthropometric cut-off value to estimate the cardiovascular risk, has not been suggested. This study was designed to find the relationship between the abdominal fat and various parameters of obesity to find the cardiovascular risk factors related to abdominal obesity and to establish practical methods to measure them. Methods : Twenty seven obese Korean adolescents of moderate to severe degree and 22 healthy adolescents were enrolled. The body mass index(BMI), arm circumference and skinfold thickness were measured. Furthermore, blood lipid, sugar, insulin and four different cytokines' levels were checked and the distribution of body composition was measured by bioelectrical impedance analysis. The subcutaneous and intra-abdominal fat thickness by abdominal ultrasonography(US) and the total and intra-abdominal fat area by abdominal computerized tomography(CT) were measured in the obese group. Results : The most accurate method to measure abdominal fat in children is abdominal CT and the fat mass measured by bioelectrical impedance was strongly correlated with it(r=0.954). It was also correlated with arm circumference, fat thickness measured by abdominal US, BMI, aspartate aminotransferase(AST), alanine aminotransferase(ALT) and triglyceride level. Conclusion : Abdominal CT is the most accurate method to measure intra-abdominal fat, and it can be replaced by abdominal US for cost effectiveness. The screening methods that can be used at school or in outpatient basis include bioelectrical impedance, waist/hip ratio, and arm circumference. The cardiovascular risk factors include leptin, triglyceride and insulin level.

• Clinical and Experimental Pediatrics
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• v.48 no.8
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• pp.857-864
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• 2005

Purpose : The objectives of this study was to evaluate the correlations between the indices of insulin sensitivity using fasting glucose and insulin level, and the body fat mass measured by bioelectrical impedance analysis(BIA) and dual energy X-ray absorptiometry(DEXA), and to determine the clinical usefulness of insulin sensitivity indices when obese children were followed up. Methods : In this study, 28 simple obese children and adolescents were included. Anthropometric data including body weight, height, obesity degree(OD), body mass index(BMI), and waist-to-hip ratio were collected and then body fat mass was measured by using BIA and DEXA. For metabolic data, 12 hour fasting serum glucose, insulin and lipid profiles were measured and indices for insulin sensitivity(G/I ratio, $log_{insulin}$, HOMA-IR, $log_{HOMA-IR}$, QUICKI) were calculated. Results : BMI had a higher correlation with insulin sensitivity indices than OD(G/I ratio, -0.463 vs -0.209; $log_{insulin}$, 0.417 vs 0.196; HOMA-IR, 0.301 vs 0.238; $log_{HOMA-IR}$, 0.403 vs 0.198; QUICKI, -0.451 vs -0.224). But OD had a higher correlation with body fat mass measured by BIA and DEXA than BMI(BIA, 0.612 vs 0.316; DEXA, 0.667 vs 0.512). The G/I ratio was correlated with body fat mass in BIA(r=-0.420, P<0.05) and DEXA(r=-0.512, P<0.01), percentage of body fat(percentage of fat) in BIA(r=-0.366, P<0.05) and DEXA(r=-0.449, P<0.01). HOMA-IR was only correlated with body fat mass in DEXA(r=0.341, P<0.05). Conclusion : This study revealed that G/I ratios had a statistically significant correlation with anthropometric obesity indices(OD and BMI) and also had a correlation with both body fat mass and percentage of fat. These results suggest that G/I ratios could be used as useful index when obese children and adolescence are followed up.

• Clinical and Experimental Pediatrics
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• v.45 no.12
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• pp.1484-1490
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• 2002

Purpose : The purpose of this study was to look at prevalences of abnormal serum aminotransferase levels and abnormal serum total cholesterol levels among adolescents with obesity in Seoul area. Methods : Body mass index[$BMI(kg/m^2)$], serum aspartate aminotransferase(AST) alanine aminotransferase( ALT), and total cholesterol levels were measured in 26,876 adolescents(male : 13,287, female : 13,589) of first grade of high school in Seoul between the ages of 15 and 16 years, enrolled in a large health examination survey by Seoul School Health Center(SSHC) in 2001. Obesity was defined as BMI more than 95th percentile for age and sex and normal weight was defined as BMI between 25th percentile and 75th percentile for age and sex. Abnormal levels of AST, ALT and total cholesterol were defined as more than 95th percentile for age and sex. Results : The BMI at 95th percentile was 28.7 in males and 26.9 in females. The prevalence of abnormal AST levels was higher in obesity group than in normal weight group. In males, those were 23.7% and 3.7%, respectively(P<0.01, $x^2-value$ : 529.2). In females, those were 11.8% and 4.9 %, respectively(P<0.01, $x^2-value$ : 56.3). The prevalence of abnormal ALT levels was significantly higher in the obesity group compared with the normal weight group. In males, those were 33.9% and 1.7%, respectively(P<0.01, $x^2-value$ : 1,693.4). In females, those were 22.3% and 3.9%, repectively(P<0.01, $x^2-value$ : 397.6). The prevalence of abnormal total cholesterol levels was higher in the obesity group than in the normal weight group. In males, those were 16.8% and 3.5%, respectively(P<0.01, $x^2-value$ : 268.3). In females, those were 9.0% and 5.4%, respectively(P<0.01, $x^2-value$ : 14.2). Conclusion : This study revealed that the prevalences of abnormal AST, ALT and total cholesterol level were higher in the obese group than in the normal weight group.

• Nutrition Research and Practice
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• v.9 no.4
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• pp.404-410
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• 2015

BACKGROUND/OBJECTIVES: Although the association of body mass index (BMI) with metabolic syndrome (MetS) is well documented, there is little knowledge on the independent and joint associations of BMI and physical activity with MetS risk based on a continuous scoring system. This study was designed to explore the effect of physical activity on interactions between excess body weight and continuous metabolic syndrome (cMetS) in a nationwide survey of Iranian children and adolescents. SUBJECTS/METHODS: Data on 5,625 school students between 10 and 18 years of age were analyzed. BMI percentiles, screen time activity (STA), leisure time physical activity (LTPA) levels, and components of cMetS risk score were extracted. Standardized residuals (z-scores) were calculated for MetS components. Linear regression models were used to study the interactions between different combinations of cMetS, LTPA, and BMI percentiles. RESULTS: Overall, 984 (17.5%) subjects were underweight, whereas 501 (8.9%) and 451 (8%) participants were overweight and obese, respectively. All standardized values for cMetS components, except fasting blood glucose level, were directly correlated with BMI percentiles in all models (P-trend < 0.001); these associations were independent of STA and LTPA levels. Linear associations were also observed among LTPA and standardized residuals for blood pressure, high-density lipoprotein, and waist circumference (P-trend < 0.01). CONCLUSIONS: Our findings suggest that BMI percentiles are associated with cMetS risk score independent of LTPA and STA levels.

• Clinical and Experimental Pediatrics
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• v.53 no.3
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• pp.341-348
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• 2010

Purpose : Body composition is important to define and manage obesity and undernutrition. Obesity is a significant health problem with medical and psychological consequences for children and adolescents. Body composition analysis (BIA) is a simple, rapid, noninvasive, and reproducible technique. However, comparative analysis of body composition has not been done in young children below 7 years old. The aim of this study is to estimate antropometric data and body composition by BIA, and to investigate the correlation between anthropometric data and fat mass or fat percent in young children. Methods : We measured height, weight, body mass index (BMI), fat mass, and fat percent by BIA in 1,376 children aged 3-6 years of whom 688 were males and 688 were females. Results : Fat mass, fat percent, intracellular fluid, extracellular fluid, protein, and minerals were significantly higher in the obese group. A significant positive correlation exists between fat mass and BMI or weight. A significant positive linear correlation was also noted between fat percent and BMI. Protein, weight, fat mass, and fat percent were significantly different among groups. Conclusion : BIA is an objective, accurate method to estimate body fat in childhood obesity cases. Fat mass and fat percent data acquired by using BIA highly correlated with BMI. However, a large-scale study is needed to diagnose obesity in young children.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5271-5283
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• 2012

The purpose of this study was to provide fundamental materials for improving school health promotion programs by investigating the relationships between the change in obesity rate and risk factors of metabolic syndrome among middle school students in Ulsan. We analyzed the routine health check-up data in 58,298 2nd-year middle school students in Ulsan, which conducted by the Planned Population Federation of Korea from 2007 to 2011. The overall and girls obesity rates gradually decreased throughout the first four years but increased again in 2011. The boys obesity rates were highest in 2008 and lowest in 2010. Throughout the research years, the incidence rates of over-weight and obesity were statistically significantly higher in boys compared to girls(P<0.05). Prevalence rates of the metabolic syndrome, assessed with the modified Cook criteria except high blood pressure, were 0.58%, 0%, 0.01%, 0.31% and 4.53%, respectively in total, low, normal, over-weight, and obese groups. It indicates that the prevalence of metabolic syndrome is increasing and directly related to the obesity rate among adolescents. Hypertriglyceridemia was the most common component (36.58%) of the metabolic syndrome among the middles school students followed by low HDL cholesterol (6.47%), abdominal obesity (3.72%), and high blood sugar (0.47%). Prevalence of the various components of the metabolic syndrome were significantly higher in the obese group compared to other groups. In this study we observed the decrease in obesity rates between 2007 and 2010, and developing obesity prevention programs is essential in order to maintain the trend. Additional study should be necessary to find the cause of increase of obesity rate in 2011 and so to create more effective school health promotion programmes.

• Clinical and Experimental Pediatrics
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• v.50 no.10
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• pp.987-994
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• 2007

Purpose : This study investigated the clinical significance of AN in children and adolescents with obesity induced metabolic complications. Methods : Forty-nine patients who had obesity induced metabolic complications were participated in this cross-sectional study. Obesity induced metabolic complications are as follows: hypertension, dyslipidemia, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), nonalcoholic steatohepatitis (NASH), homeostasis model assessment of insulin resistance (HOMA-IR)>3.16. Clinical characteristics, such as, age, percentage-weight-for-height (PWH), pubertal status, blood pressure (BP), fasting plasma insulin level, fasting and post-oral glucose tolerance test 2-hour glucose levels, liver function test, lipid profile, HOMA-IR were compared according to the presence of AN. Results : Sixty-five percent of patients had AN, 57.1% NASH, 57.1% dyslipidemia, 55.1% hypertension, 46.9% IFG, 24.5% HOMA-IR>3.16 and 16.2% IGT. The patients who were moderately to severely obese with AN had higher incidence of IGT and HOMA-IR>3.16. The patients with AN had significantly higher diastolic BP ($79.4{\pm}6.9$ vs $75.4{\pm}5.6mmHg$), fasting levels of plasma insulin ($10.6{\pm}6.0$ vs $6.2{\pm}5.4{\mu}IU/mL$), HOMA-IR index ($2.6{\pm}1.4$ vs $1.4{\pm}1.3$) and PWH ($42.4{\pm}13.0$ vs $34.3{\pm}1.8%$). The increasing tendency for the presence of AN was significantly related to the cumulative number of obesity induced metabolic complications. Binary logistic regression analysis revealed that the presence of AN was significantly associated with fasting plasma insulin level, PWH and IFG. Conclusion : AN could be useful as a clinical surrogate of obesity induced metabolic complications.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.1
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• pp.30-40
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• 1995

The relationship between dietary intake and vitamin/mineral supplement usage was examined in 706 adolescent girls who were high school students. 43.8% of subjects used vitamin/mineral supplements during one year. The higher the family income and parents education level, the higher percentage of vitamin/mineral supplement usage was. But there was no significant difference between grades and scores. And vitamin/mineral supplement usage was higher int he thin and obese groups than the average weight groups. Nutrition knowledge and food habit did not affect vitamin/mineral supplement usage. Calorie intakes of vitamin/mineral supplement users and nonusers were similar. However, independent of the supplements, the diets of supplement nonusers contained significantly more dietary protein, vitamin A, vitamin $B_2$, niacin, vitamin C, and calcium than the diets of the users. A considerable portion of both the users and nonusers had dietary intakes of less than 2/3 of the Recommended Dietary Allowances for vitamin $B_1$, vitamin $B_2$, niacin, calcium, and iron. Vitamin/mineral supplement nonusers generally consumed a more vitamin, mineral from diet. Reasons for taking supplements were to take energy, advice and illness.

• Clinical and Experimental Pediatrics
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• v.45 no.6
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• pp.764-772
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• 2002

Purpose : Obesity is closely related to insulin resistance, compensatory hyperinsulinemia and dyslipidemia in adults. We identified the effect of obesity measured by BMI and insulin resistance on dyslipidemia in children and adolescents. Methods : The fasting serum insulin, glucose, total cholesterol, triglyceride, HDL- and LDL-cholesterol were measured and insulin resistance(HOMA-IR) was calculated in 35 children with simple obesity(age :$10.6{\pm}2.8$ years; male 20, female 15; BMI : $27.1{\pm}5.4kg/m^2$). Results : The hypertriglyceridemia(37%), hyperinsulinemia(54%) and HDL-hypocholesterolemia(5.7%) were observed. HOMA-IR was well expressed by fasting insulin. As BMI increased, there was a statistically significant increase in insulin resistance and insulin level in both sexes. BMI was not related with lipid profile in both sexes. Triglyceride was correlated with only insulin level and insulin resistance index in boys. In girls, there was no correlation between triglyceride, HDL-cholesterol and insulin(insulin resistance). Conclusion : These results suggest that hypertriglyceridemia was dependent on insulin resistance in pre-adult males. Monitoring of insulin resistance and those risk factors known to become a part of insulin resistance syndrome should become part of routine medical care for obese children.