Sochung Chung

2014 clinical practice guidelines for overweight and obesity in Korea.

The dramatic increase in the prevalence of obesity and its accompanying comorbidities are major health concerns in Korea. Obesity is defined as a body mass index ≥25 kg/m2 in Korea. Current estimates are that 32.8% of adults are obese: 36.1% of men and 29.7% of women. The prevalence of being overweight and obese in national surveys is increasing steadily. Early detection and the proper management of obesity are urgently needed. Weight loss of 5% to 10% is the standard goal. In obese patients, control of cardiovascular risk factors deserves the same emphasis as weight-loss therapy. Since obesity is multifactorial, proper care of obesity requires a coordinated multidisciplinary treatment team, as a single intervention is unlikely to modify the incidence or natural history of obesity.

Early Caffeine Use in Very Low Birth Weight Infants and Neonatal Outcomes: A Systematic Review and Meta-Analysis

The use of caffeine citrate for treatment of apnea in very low birth weight infants showed short-term and long-term benefits. A systematic review and meta-analysis of the literature was undertaken to document the effect providing caffeine early (0-2 days of life) compared to providing caffeine late (≥3 days of life) in very low birth weight infants on several neonatal outcomes, including bronchopulmonary dysplasia (BPD). We searched MEDLINE, the EMBASE database, the Cochrane Library, and KoreaMed for this meta-analysis. The quality of the included studies was assessed using the Newcastle-Ottawa Scale and Jadads scale. Studies were included if they examined the effect of the early use of caffeine compared with the late use of caffeine. Two reviewers screened the candidate articles and extracted the data from the full-text of all of the included studies. We included a total of 59,136 participants (range 58,997-59,136; variable in one study) from a total of 5 studies. The risk of death (odds ratio [OR], 0.902; 95% confidence interval [CI], 0.828 to 0.983; P=0.019), bronchopulmonary dysplasia (BPD) (OR, 0.507; 95% CI, 0.396 to 0.648; P<0.001), and BPD or death (OR, 0.526; 95% CI, 0.384 to 0.719; P<0.001) were lower in the early caffeine group. Early caffeine use was not associated with a risk of necrotizing enterocolitis (NEC) and NEC requiring surgery. This meta-analysis suggests that early caffeine use has beneficial effects on neonatal outcomes, including mortality and BPD, without increasing the risk of NEC.

Vitamin D deficiency in Korean children: prevalence, risk factors, and the relationship with parathyroid hormone levels

Purpose This study was performed to investigate the relationship between serum vitamin D and parathyroid hormone (PTH) levels as well as to describe the prevalence and the risk factors of vitamin D deficiency (VDD) in Korean children. Methods Participants were 1,212 children aged 4 to 15 years, who visited Bundang CHA Medical Center (located at 37°N) between March 2012 and February 2013. Overweight was defined as body mass index≥85th percentile. Participants were divided into 4 age groups and 2 seasonal groups. VDD was defined by serum 25-hydroxyvitamin D (25OHD) <20 ng/mL. Results The level of 25OHD was significantly lower in overweight group than in normal weight group (17.1±5.1 ng/mL vs. 19.1±6.1 ng/mL, P<0.001). Winter-spring season (odds ratio [OR], 4.46; 95% confidence interval [CI], 3.45-5.77), older age group (OR, 1.60; 95% CI, 1.36-1.88), and overweight (OR, 2.21; 95% CI, 1.62-3.01) were independently related with VDD. The PTH levels were significantly higher in VDD group compared to vitamin D insufficiency and sufficiency group (P<0.001). In normal weight children, 25OHD (β=-0.007, P<0.001) and ionized calcium (β=-0.594, P=0.007) were independently related with PTH, however, these associations were not significant in overweight children. Conclusion VDD is very common in Korean children and its prevalence increases in winter-spring season, in overweight children and in older age groups. Further investigation on the vitamin D and PTH metabolism according to adiposity is required.

Microalbuminuria in normal Korean children.

Purpose Although microalbuminuria is known as a predictor of clinical nephropathy and cardiomyopathy, few studies have investigated the incidence and reference range of microalbuminuria in healthy children. This study aimed to establish a reference range and to study the age-related trend for spot urine microalbumin/creatinine ratio in a Korean pediatric population. Materials and Methods 352 healthy children were studied from July 2007 through March 2010. Height, weight, serum creatinine, spot urine microalbumin/creatinine ratio, and glomerular filtration rate (GFR) were obtained for each subject. We divided the study population into 5 groups according to age, and compared the spot urine microalbumin/creatinine ratio with other variables using one-way analysis of variance (ANOVA), regression analysis and Pearsons correlation analysis. Results In this study, the data showed that the spot urine microalbumin/creatinine ratio decreased with age: 1-12 months, 22.72±13.80 mg/mmol (2SD: 3.33-54.40 mg/mmol); 13-28 months, 16.34±9.58 mg/mmol (2SD: 3.16-35.19 mg/mmol); 29-48 months, 13.12±9.74 mg/mmol (2SD: 3.01-41.57 mg/mmol); 4-6 years, 10.58±8.13 mg/mmol (2SD: 0.00-30.19 mg/mmol); and 7-19 years, 5.13±5.44 mg/mmol (2SD: 0.45-14.45 mg/mmol). The spot urine microalbumin/creatinine ratio showed correlation with age, height, height z-score, weight, weight z-score, GFR, body mass index (BMI) and body surface area (BSA). Conclusion The spot urine microalbumin/creatinine ratio in normal Korean children decreased with age. This ratio could potentially be used to establish reference ranges and cutoff values for Korean children and to predict nephropathy and cardiomyopathy.

Elevation of the index of left ventricular mass during the acute and subacute phase of Kawasaki disease, and its association with indexes of diastolic function.

Our aim was to determine whether the index of left ventricular mass increases during the acute and subacute phase of Kawasaki disease, and to investigate any relationship between this index and clinical and echocardiographic variables. We performed, therefore, a retrospective study of 66 children with Kawasaki disease, having a mean age of 2.85 years, comparing the findings with those obtained from 57 normal controls, having a mean age of 2.99 years. The data from the patients used for comparison was obtained during the acute and subacute phase of the illness, as well as during the phase of convalescence. We performed correlation analysis of the findings during the acute and subacute phase, determining the relationship between the index of left ventricular mass and other variables. The index was higher (p = 0.0461), and the velocity of propagation of left ventricular early diastolic flow was lower (p < 0.0001), during the acute and subacute phase when compared to control values. The index then reduced (p = 0.0001) during the phase of convalescent when compared to the acute and subacute phase. Levels of albumin in the serum (p = 0.0193), peak E velocity (p = 0.0479), and velocity of propagation (p = 0.0360) were found to be related to the index of left ventricular mass. Significant relationships were found between the differences in this index and differences in body weight when findings during the acute and subacute phase were compared to those of the phase of convalescence. The index of left ventricular mass, therefore, is increased during the acute and subacute phase of Kawasaki disease, and is associated with altered diastolic indexes. This elevation may be due to generalized myocardial swelling from acute inflammation and increased vascular permeability. Measuring this index as a potential predictor of diastolic function should be added to studies of cardiac function during the acute and subacute phase of Kawasaki disease.

Gender Differences in Relationship between Fat-Free Mass Index and Fat Mass Index among Korean Children Using Body Composition Chart

Purpose This study aimed to investigate gender differences in the relationship between fat-free mass index (FFMI) and fat mass index (FMI) by applying body composition chart on Korean elementary students. Materials and Methods Data from 965 healthy Korean children of 8 to 12 years of age (501 boys, 464 girls) were obtained. FFMI and FMI were plotted on the body composition chart, and the differences in the relationships between FFMI and FMI were separately evaluated by gender or grade. Results Weight was heavier and BMI was higher in 3rd and 4th grade boys compare to girls. The value of FFM was higher in boys, but FM was not different. In subgroup analysis by grade, significant gender by FFMI interaction (p=0.015) was found, indicating that the slope of the lines for FMI vs. FFMI was different between boys and girls (Figure was not shown). In subgroup analysis by gender, grade by FFMI interaction was significant in boys, indicating that FMI vs. FFMI relationship differed according to grade only in boys. Conclusion Boys are leaner than girls, despite having similar BMI. Gender difference in the direction of the change of the FFMI and FMI relationship is evident in children.

Reference Values of Body Composition Indices: The Korean National Health and Nutrition Examination Surveys

Purpose An increase in the prevalence of obesity has been observed in children and adolescents. As remarkable changes in body composition occur with growth during the adolescent period, it is important that changes in body composition be monitored. The purpose of this study was to propose reference percentile values for body composition indices including body mass index (BMI) in children and adolescents in Korea. Materials and Methods This study was performed using data from the Fourth and Fifth Korea National Health and Nutrition Examination Surveys. Body composition data were obtained using dual-energy X-ray absorptiometry. The percentile curves of body composition indices were constructed by the LMS method. Results A total of 2123 children and adolescents between the ages of 10 and 19 years were included in this study. We obtained the percentile curves for BMI and body composition indices. Conclusion The reference values for body composition from this study could help with assessing body composition in Korean adolescents.

Body mass index and body composition scaling to height in children and adolescent

Childhood obesity prevalence has been increased and known to be related to various diseases and mortality in adult and body mass index (BMI) has been widely used as a screening tool in children with obesity. It is important to understand what BMI is and its limitations. BMI is a measure of weight adjusted for height. Weight scales to height with a power of about 2, is the basis of BMI (weight/height2) as the scaling of body weight to height across adults provides powers rounded to 2. BMI has the advantage of a simple and noninvasive surrogate measure of body fat, but it has limitation in differentiating body fat from lean (fat free) mass and low-moderate sensitivity is problematic for clinical applications. Among overweight children higher BMI levels can be a result of increased either fat or fat-free mass. BMI could be divided into fat-free mass index and fat mass index. Monitoring of the changes in body composition is important as distinguishing changes in each component occur with rapid growth in adolescents as it is occur in concert with changes in the hormonal environment. Reference values for each body composition indexes and chart created with selected percentiles of a normal adolescent population could be helpful in growth assessment and health risk evaluation.

Evaluation of kidney size in children: a pilot study of renal length as a surrogate of organ growth

Purpose Somatic growth is an important indicator of health in children. Adequate organ growth is essential in growth and directly related to body growth. We consider renal length as a surrogate of organ growth in growing children. Measurement of weight, height, and many anthropometric indices, such as body surface area (BSA), body mass index (BMI), and Rohrer and Kaup indices, are used to evaluate growth status. The aim of this study was to evaluate the association between renal length and somatic parameters and analyze the affecting factors for renal size during growth. Methods The data for renal length in 66 children (age, 12.9±15.6 months; male/female, 34/32) were obtained. Each kidney was measured with ultrasonography and dimercaptosuccinic acid scan. The data on age, sex, height, and weight were obtained from the medical records. BSA, BMI, and Rohrer and Kaup indices were calculated from measured height and weight. BSA was calculated by 2 methods, and is expressed as BSA I and BSA II. Results There were significant correlations between renal size and age, weight, height, BSA I, BSA II, and Rohrer index. In the regression analysis, the most significant contributing factor to renal growth was height (R2=0.636, P<0.001). Conclusion Height seems to be the most important factor associated with organ growth in growing children. Further studies to evaluate adequate organ growth should be carried out.

Microalbuminuria in children with urinary tract infection

Purpose Microalbuminuria is defined as increased urinary albumin excretion (30-300 mg/day) or microalbumin/creatinine ratio (30-300 mg/g) in a spot urine sample. Although microalbuminuria is a predictor of clinical nephropathy and cardiomyopathy, few studies have investigated microalbuminuria in children with urinary tract infection (UTI). Methods Therefore, we compared the spot urine microalbumin/creatinine ratio in pediatric UTI patients with that of control subjects. We investigated the correlation between the ratio in children with UTI and age, height, weight, blood pressure, glomerular filtration rate (GFR), hematuria, vesicoureteral reflux, renal parenchymal defect, and renal scar, and its predictability for UTI complications. Results We studied 66 patients (42 boys, 24 girls) and 52 healthy children (24 boys, 28 girls). The mean microalbumin/creatinine ratio in UTI patients was statistically significantly increased compared to the control group (340.04±321.36 mg/g (38.47±36.35 mg/mmol) in patient group vs. 225.68±154.61 mg/g (25.53±17.49 mg/mmol) in control group, P=0.0141). The mean value of spot urine microalbumin/creatinine ratio (384.70±342.22 mg/g (43.47±37.67 mg/mmol) in patient group vs. 264.92±158.13 mg/g (29.94±17.86 mg/mmol) in control group, P=0.0341) in 1-23 months age patient group showed statistically significant increase compared to control group. Microalbumin/creatinine ratio showed negative correlation to age (r=-0.29, P=0.0167), body surface area (BSA) (r=-0.29, P=0.0173) and GFR (r=-0.26, P=0.0343). The presence of hematuria (P=0.0169) was found to be correlated. Conclusion The spot urine microalbumin/creatinine ratio in children with UTI was significantly greater than that in normal children, and it was positively correlated with GFR. This ratio is a potential prescreening and prognostic marker in UTI patients. Further studies are required to validate the predictability of microalbuminuria in pediatric UTI patients.