Trends in HOMA-IR values among South Korean adolescents from 2007-2010 to 2019-2020: a sex-, age-, and weight status-specific analysis.

BACKGROUND/OBJECTIVES: An increase in obesity prevalence may lead to an increase in the HOMA-IR value. This study aimed to investigate changes in age- and sex-specific homeostasis model assessment of insulin resistance (HOMA-IR) values among South Korean adolescents, using data from the Korean National Health and Nutrition Examination Survey (KNHANES) IV, V, and VIII conducted between 2007-2010 and 2019-2020. SUBJECTS/METHODS: Overall, 4621 adolescents aged 10-18 years were evaluated, including 3473 from the 2007-2010 dataset and 1148 from the 2019-2020 dataset. The mean HOMA-IR values and percentile curves were evaluated by age, sex, and weight status. RESULTS: The mean HOMA-IR values peaked at puberty in both sexes and further increased during puberty in the 2019-2020 dataset (boys 5.21, 95% confidence interval [CI] 4.16-6.26; girls 5.21, 95% CI 3.09-7.33) compared with the 2007-2010 dataset (boys 3.25, 95% CI 3.04-3.47; girls 3.58, 95% CI 3.31-3.85). Both groups (with normal-weight and overweight/obesity) exhibited a peak HOMA-IR value during puberty in both sexes and both datasets, although the group with overweight/obesity had a higher and wider peak age range. While the mean HOMA-IR values did not change in adolescents with normal-weight, they increased during puberty and post-puberty in boys with overweight/obesity. CONCLUSIONS: HOMA-IR values should be interpreted considering sex, weight status, and pubertal stages. In particular, during the pubertal period, insulin resistance (IR) can coexist not only due to weight-related factors but also as a result of the distinct hormonal changes characteristic of puberty. Over the 10-year period, the mean HOMA-IR values increased in the group with overweight/obesity during puberty and post-puberty, highlighting the need for active intervention to prevent metabolic complications in adolescents with overweight/obesity.

The Genotype-Phenotype Correlation in Human 5α-Reductase Type 2 Deficiency: Classified and Analyzed from a SRD5A2 Structural Perspective.

The phenotype of the 5α-reductase type 2 deficiency (5αRD2) by the SRD5A2 gene mutation varies, and although there have been many attempts, the genotype-phenotype correlation still has not yet been adequately evaluated. Recently, the crystal structure of the 5α-reductase type 2 isozyme (SRD5A2) has been determined. Therefore, the present study retrospectively evaluated the genotype-phenotype correlation from a structural perspective in 19 Korean patients with 5αRD2. Additionally, variants were classified according to structural categories, and phenotypic severity was compared with previously published data. The p.R227Q variant, which belongs to the NADPH-binding residue mutation category, exhibited a more masculine phenotype (higher external masculinization score) than other variants. Furthermore, compound heterozygous mutations with p.R227Q mitigated phenotypic severity. Similarly, other mutations in this category showed mild to moderate phenotypes. Conversely, the variants categorized as structure-destabilizing and small to bulky residue mutations showed moderate to severe phenotypes, and those categorized as catalytic site and helix-breaking mutations exhibited severe phenotypes. Therefore, the SRD5A2 structural approach suggested that a genotype-phenotype correlation does exist in 5αRD2. Furthermore, the categorization of SRD5A2 gene variants according to the SRD5A2 structure facilitates the prediction of the severity of 5αRD2 and the management and genetic counseling of patients affected by it.

Comparison of the Triglyceride Glucose Index and Modified Triglyceride Glucose Indices to Predict Nonalcoholic Fatty Liver Disease in Youths.

OBJECTIVE: To assess the associations between the triglyceride glucose (TyG) index and modified TyG indices with nonalcoholic fatty liver disease (NAFLD) and evaluate their ability as predictors of NAFLD in youths. STUDY DESIGN: We analyzed the cross-sectional data of 3728 individuals aged 10-19 years using the Korea National Health and Nutrition Examination Survey, a nationally representative survey. Logistic regression analysis was performed, and ORs and 95% CIs of tertiles 2 and 3 for each variable for predicting NAFLD were calculated and compared with those of tertile 1 as the reference. Receiver operating characteristic (ROC) curves were plotted to evaluate the ability of each variable for NAFLD prediction. RESULTS: All TyG and modified TyG indices exhibited progressively increased ORs and 95% CIs for NAFLD across all tertiles (all P < .001). In addition, all TyG and modified TyG indices significantly predicted NAFLD through ROC curves. All modified TyG indices were superior to the TyG index for predicting NAFLD in all subjects and in males. Among females, the TyG-waist-to-height ratio was superior to the TyG index, TyG-body mass index (BMI), and TyG-waist circumference (WC), and the TyG-BMI SDS and TyG-WC were superior to the TyG index. CONCLUSIONS: The TyG and modified TyG indices are markers for NAFLD prediction in youths, and the modified TyG indices are superior to the TyG index. Modified TyG indices have the potential to be simple and cost-effective markers in screening for NAFLD in youths.

Trends of Dyslipidemia in Korean Youth According to Sex and Body Mass Index: Based on the Korea National Health and Nutrition Examination Survey (2007-2018).

OBJECTIVE: To assess trends of dyslipidemia among youth, we investigated secular trends in serum lipid levels from 2007 to 2018 and the current prevalence of dyslipidemia in Korean children and adolescents. STUDY DESIGN: This cross-sectional study investigated lipid profiles of 10 734 youths aged 10-18 years using data from phases IV-VII of the Korea National Health and Nutritional Examination Survey. We assessed age-, sex-, and body mass index (BMI)-adjusted mean levels of lipids at each survey. RESULTS: Mean levels of total cholesterol, low-density lipoprotein cholesterol (LDL-C), and non-high-density lipoprotein cholesterol (non-HDL-C) levels increased from phase IV to VII. Among boys, the prevalence of acceptable levels of total cholesterol, LDL-C, and non-HDL-C decreased significantly (P = .005, P = .001, and P < .001, respectively). In girls, the prevalence of acceptable levels of total cholesterol, LDL-C, HDL-C, and non-HDL-C decreased significantly (P = .003, P = .005, P = .008, and P = .013, respectively). In BMI- and age-specific analyses, worsening trends in total cholesterol, LDL-C, and non-HDL levels were more apparent in youths with a normal BMI and young age. CONCLUSIONS: Dyslipidemia trends are worsening in Korean youth, even in those with a normal BMI and young age. Thus, future cardiovascular disease risk may increase and comprehensive management plans are required for youth with overweight or obesity and those with a normal BMI and young age.

Impact of Respiratory Motion on the Quantification of Pediatric Hepatic Steatosis Using Two Different Ultrasonography Machines.

PURPOSE: This study aimed to investigate the effect of respiratory motion on hepatic steatosis quantification using ultrasound attenuation imaging (ATI) or ultrasound-guided attenuation parameter (UGAP) in pediatric patients. MATERIALS AND METHODS: Pediatric patients (aged ≤18 years) who underwent liver ultrasonography (US) with ATI or UGAP between May 2022 and February 2023 were included retrospectively. Median, interquartile range (IQR), and IQR/median values were calculated in both free-breathing (FB) and breath-holding (BH) states. Subjects were divided into normal and fatty liver groups according to grayscale US. Wilcoxon signed rank test, intraclass correlation coefficient (ICC), and linear regression test were used. RESULTS: A total of 83 patients (M:F=46:37, median age 10 years, range 6-17 years) was included, with 55 patients in the ATI group and 28 patients in the UGAP group. The measured values of ATI and UGAP were not significantly different between FB and BH. The ICC values between FB and BH states were 0.950 [95% confidence interval (CI) 0.916-0.971] for median ATI and 0.786 (95% CI 0.591-0.894) for median UGAP. FB and BH status did not significantly affect the median ATI and UGAP (p=0.852, 0.531, respectively). The IQR/median value showed a significant association with age only in the FB status of the normal group using ATI (ß= -0.014, p=0.042). CONCLUSION: Respiratory motion does not significantly affect the measurement of ATI or UGAP. Median ATI value showed excellent agreement in FB and BH status, while UGAP showed good agreement. Younger age may affect measurement variability in FB status of the normal group using ATI.

Long-term tracking of glycosylated hemoglobin levels across the lifespan in type 1 diabetes: from infants to young adults.

PURPOSE: Glycosylated hemoglobin (HbA1c) is commonly used as a monitoring tool in diabetes. Due to the potential influence of insulin resistance (IR), HbA1c level may fluctuate over a person's lifetime. This study explores the long-term tracking of HbA1c level in individuals diagnosed with type 1 diabetes mellitus (T1DM) from infancy to early adulthood. METHODS: The HbA1c levels in 275 individuals (121 males, 43.8%) diagnosed with T1DM were tracked for an average of 9.4 years. The distribution of HbA1c levels was evaluated according to age with subgroups divided by gender, use of continuous glucose monitoring (CGM), and the presence of complications. RESULTS: HbA1c levels were highest at the age of 1 year and then declined until age 4, followed by a significant increase, reaching a maximum at ages 15-16 years. The levels subsequently gradually decreased until early adulthood. This pattern was observed in both sexes, but it was more pronounced in females. Additionally, HbA1c levels were higher in CGM nonusers compared with CGM users; however, regardless of CGM usage, an age-dependent pattern was observed. Furthermore, diabetic complications occurred in 26.8% of individuals, and the age-dependent pattern was observed irrespective of diabetic complications, although HbA1c levels were higher in individuals with diabetic complications. CONCLUSION: HbA1c levels vary throughout the lifespan, with higher levels during adolescence. This trend is observed regardless of sex and CGM usage, potentially due to physiological IR observed during adolescence. Hence, physiological IR should be considered when interpretating HbA1c levels during adolescence.

Bioelectrical impedance parameters add incremental value to waist-to-hip ratio for prediction of metabolic dysfunction associated steatotic liver disease in youth with overweight and obesity.

Introduction: Metabolic dysfunction-associated steatotic liver disease (MASLD) presents a growing health concern in pediatric populations due to its association with obesity and metabolic syndrome. Bioelectrical impedance analysis (BIA) offers a non-invasive and potentially effective alternative for identifying MASLD risk in youth with overweight or obesity. Therefore, this study aimed to assess the utility of BIA for screening for MASLD in the youth. Method: This retrospective, cross-sectional study included 206 children and adolescents aged <20 years who were overweight and obese. The correlations between anthropometric measurements and BIA parameters and alanine aminotransferase (ALT) levels were assessed using Pearson's correlation analysis. Logistic regression analysis was performed to examine the associations between these parameters and ALT level elevation and MASLD score. Receiver operating characteristic (ROC) curves were generated to assess the predictive ability of the parameters for MASLD. Results: Pearson's correlation analysis revealed that waist-to-hip ratio (WHR), percentage body fat (PBF), and BIA parameters combined with anthropometric measurements were correlated with ALT level. Logistic regression revealed that WHR, skeletal muscle mass/WHR, PBF-WHR, fat-free mass/WHR, and appendicular skeletal muscle mass/WHR were correlated with ALT level elevation after adjusting for age, sex, and puberty. WHR, PBF-WHR, and visceral fat area (VFA)-WHR were positively correlated with the MASLD score in the total population after adjusting for age, sex, and puberty. PBF-WHR and VFA-WHR were correlated with the MASLD score even in youth with a normal ALT level. The cutoff points and area under the ROC curves were 34.6 and 0.69 for PBF-WHR, respectively, and 86.6 and 0.79 for VFA-WHR, respectively. Discussion: This study highlights the utility of combining BIA parameters and WHR in identifying the risk of MASLD in overweight and obese youth, even in those with a normal ALT level. BIA-based screening offers a less burdensome and more efficient alternative to conventional MASLD screening methods, facilitating early detection and intervention in youth at risk of MASLD.

Effectiveness and safety of pamidronate treatment in nonambulatory children with low bone mineral density.

PURPOSE: Nonambulatory pediatric patients may have low bone mineral density (BMD) and increased risk of pathologic fractures. Though bisphosphonate therapy is the mainstream medical intervention in these children, clinical data regarding this treatment are limited. Therefore, this study aimed to evaluate the effectiveness and safety of bisphosphonate therapy in such children. METHODS: We conducted a retrospective study of 21 nonambulatory children (Gross Motor Function Classification System level V) with BMD z-score ≤ -2.0 who were treated with intravenous pamidronate for at least 1 year. These patients received pamidronate every 4 months at a dose of 1.0 to 3.0 mg/kg for each cycle and had regular follow-ups for at least 1 year. The main outcome measures were changes in BMD, risk rate of fracture, biochemical data, and adverse events. RESULTS: The average duration of pamidronate treatment was 2.0±0.9 years, and the mean cumulative dose of pamidronate according to body weight was 7.7±2.5 mg/kg/yr. After treatment, the mean lumbar spine bone mineral content, BMD, and height-for-age-z-score-adjusted BMD z-score (BMDhazZ) significantly improved. The relative risk of fracture after treatment was 0.21 (p=0.0032), suggesting that pamidronate treatment reduced fracture incidence significantly. The increase in the average dose per body weight in each cycle significantly increased the changes in BMDhazZ. CONCLUSION: Pamidronate treatment improved the bone health of nonambulatory children with low bone density without any significant adverse events. Independent of cumulative dosage and duration of treatment, the effectiveness of pamidronate increased significantly with an increase in the average dose per body weight in subsequent cycles.

Effects of Early Wake-Up Time on Obesity in Adolescents.

Background: Although numerous studies have reported that obesity in adolescents is related to shorter sleep duration, few studies have reported the effect of sleep timing, particularly early wake-up time, on obesity. Objectives: To investigate the association between wake-up time and adolescent obesity. Methods: Using the Korean National Health and Nutrition Examination Survey VII data, 1301 middle school and high school students were selected and grouped according to BMI. Sleep timing and lifestyle factors were evaluated using self-reported questionnaires. Results: The mean bedtime and wake-up time were 00:09 am and 07:06 am, respectively. Despite similar bedtimes, the group with overweight/obesity woke up earlier than the group with underweight/normal weight. The BMI z-score and the overweight/obesity relative risk decreased as the wake-up time was delayed, even after adjustment for covariates. Participants who woke up before 06:50 am had a 1.82-fold higher risk of having overweight/obesity than those who woke up after 07:30 am. Participants who woke up late tended to sleep longer than those who woke up early. Conclusions: Waking up early is significantly associated with an increased BMI z-score in adolescents and may be a risk factor for overweight/obesity.

Comparison of agranulocytosis and anti-neutrophil cytoplasmic antibody-associated vasculitis caused by two antithyroid drugs: A pharmacovigilance study using the WHO international database.

BACKGROUND: Methimazole (MMI) and propylthiouracil (PTU) are commonly used for patients with thyrotoxicosis. Agranulocytosis and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is associated with high morbidity and mortality, requiring appropriate interventions. In this study, we compared adverse drug effects associated with MMI and PTU using a real-world large pharmacovigilance database. METHODS: We searched all Individual Case Safety Reports reported to be associated with MMI and PTU, from VigiBase between 1967 and June 2, 2021. We conducted disproportionality analysis (case/non-case analysis) to analyze the difference in reported adverse drug reactions (ADRs) between antithyroid drugs (case) and the entire database (non-cases). We further analyzed information for the cases of agranulocytosis and AAV. RESULTS: Among 11 632 cases of ADRs reported after MMI intake, agranulocytosis occurred in 1633 cases and AAV occurred in 41 cases. For 5055 cases of ADRs reported after PTU intake, agranulocytosis occurred in 459 cases and AAV occurred in 110 cases. Agranulocytosis occurred after a median of 28 days after PTU intake and 33 days after MMI intake. More than 95% of the agranulocytosis cases were classified as serious, but most of them (65.1% for PTU and 70.4% for MMI) were reported to have recovered after dechallenge actions; mostly drug withdrawal. AAV occurred after a median of 668 days after PTU intake, and 1162 days after MMI intake. CONCLUSIONS: This is a pharmacoepidemiological study investigating agranulocytosis and AAV caused by MMI and PTU. Through this research, we could provide more specific insights into a safe prescription of antithyroid drugs in a real-world setting.

Establishment of IGF-1 and IGFBP-3 continuous reference percentiles from data of healthy children using three kinds of immunoassay systems.

Background and aims: Appropriate continuous reference intervals (RIs) for serum insulin-like growth factor 1 (IGF-1) and insulin-like growth factor-binding protein 3 (IGFBP-3) are important for diagnosing growth hormone deficiency or excess. Material and methods: We retrospectively reviewed serum IGF-1 and IGFBP-3 levels in Korean children aged 0-17 years who were diagnosed as healthy during a short stature workup in the outpatient clinics of three hospitals. IGF-1 and IGFBP-3 levels were measured using various immunoassays, including Liaison XL for IGF-1, an immunoradiometric assay (IRMA) for IGFBP-3 (n = 5522), and Immulite 2000 (n = 3036) and cobas e801 (n = 314). We established RIs from the 2.5th to 97.5th percentile RI curves using the lambda-mu-sigma (LMS) method for each sex group. Results: Pediatric serum continuous IGF-1 and IGFBP-3 reference percentiles by LMS method were found to be immunoassay method-dependent, but aligned relatively well with the manufacturers' RIs. IGFBP-3 levels displayed notable discrepancies among the different immunoassay methods. Conclusion: Age- and sex-specific pediatric LMS based continuous reference intervals are method dependent and they should be calculated for dynamic parameters that show variations throughout childhood.

Prediction of insulin resistance and elevated liver transaminases using serum uric acid and derived markers in children and adolescents.

OBJECTIVE: To investigate the relationship of serum uric acid (Uacid) and derived parameters as predictors of insulin resistance (IR) and elevated liver transaminases in children and adolescents METHODS: Data of 1648 participants aged 10-18 years was analyzed using nationwide survey. Logistic regression analysis was performed with IR and elevated liver transaminases as dependent variables, and odds ratios (ORs) and 95% confidence intervals (CIs) for tertiles 2 and 3 of each parameter in comparison to tertile 1, which served as the reference. Receiver operating characteristic (ROC) curves were generated to assess predictability of the parameters for IR and elevated liver transaminases. RESULTS: Hyperuricemia, IR, and elevated liver transaminases were significantly associated with each other. All Uacid and derived markers showed continuous increase in ORs and 95% CIs for IR and elevated liver transaminases across the tertiles of several biochemical and metabolic variables of interest (all p < 0.001), and were also significantly predictive in ROC curve. Overall, Uacid combined with obesity indices showed higher ORs and area under the curve (AUC) compared to Uacid alone. Uacid-body mass index (BMI) standard deviation score presented the largest AUC for IR. For elevated liver transaminases, Uacid-BMI and Uacid-waist-to-height ratio showed the largest AUC. CONCLUSIONS: Uacid combined with obesity indices are robust markers for prediction of IR and elevated liver transaminases in children and adolescents. Uacid and derived markers have potential as simple markers which do not require fasting for screening of IR and elevated liver transaminases in children and adolescents.

Nonalcoholic fatty liver disease and insulin resistance in children.

Nonalcoholic fatty liver disease (NAFLD), a spectrum of liver diseases characterized by excessive fat accumulation, is the leading cause of chronic liver disease. The global prevalence of NAFLD is increasing in both adults and children. In Korea, the prevalence of pediatric NAFLD increased from 8.2% in 2009 to 12.1% in 2018 according to a national surveillance study. For early screening of pediatric NAFLD, laboratory tests including aspartate aminotransferase and alanine aminotransferase; biomarkers including hepatic steatosis index, triglyceride glucose index, and fibrosis-4 index; and imaging studies including ultrasonography and magnetic resonance imaging are required. Insulin resistance plays a major role in the pathogenesis of NAFLD, which promotes insulin resistance. Thus, the association between NAFLD and insulin resistance, diabetes mellitus, and metabolic syndrome has been reported in many studies. This review addresses issues related to the epidemiology and investigation of NAFLD as well as the association between NAFLD and insulin resistance and metabolic syndrome with focus on pediatric NAFLD.

The influence of pituitary volume on the growth response in growth hormone-treated children with growth hormone deficiency and idiopathic short stature.

Purpose: Magnetic resonance imaging (MRI) can be used for assessing the morphology of pituitary gland. The purpose of this study was 1) to determine whether the pituitary volume (PV) distinguish growth hormone (GH) deficiency from idiopathic short stature (ISS) and 2) to validate an association between PV and severity of GH deficiency and 3) to compare the PV between good and poor response groups in children with GH deficiency and ISS. Methods: Data were collected from the medical records of 152 children with short stature who underwent GH stimulation test, sella MRI, and GH treatment. Estimated PV were calculated using the formula of an ellipsoid. We compared the PV in patients with GH deficiency with that of patients with ISS. In addition, we assessed the association between PV and severity of GH deficiency, and growth response after treatment. Results: No difference was observed in the PV between patients with GH deficiency and ISS. The PV seemed to be smaller as the degree of GH deficiency was severe (P=0.082). The PV in good response group was smaller than that in poor response group in patients with GH deficiency (P< 0.005). The PV showed no association with responsiveness to GH treatment in patients with ISS (P=0.073). Conclusions: The measurement of PV cannot be used for differential diagnosis between GH deficiency and ISS. In patients with GH deficiency, the PV tend to be smaller as the severity of GH deficiency even though no statistical significance, and may be a good response predictor for GH treatment.

Change in Prevalence of Hypertension among Korean Children and Adolescents during the Coronavirus Disease 2019 (COVID-19) Outbreak: A Population-Based Study.

During the coronavirus disease 2019 (COVID-19) outbreak, the prevalence of obesity increased globally; this may be associated with hypertension incidence. However, investigations on the changes in the prevalence of hypertension among children and adolescents are limited. This cross-sectional study investigated the prevalence of hypertension among 1428 youths aged 10-18 years using data from the Korea National Health and Nutrition Examination Survey 2018-2020. We assessed the prevalence of hypertension according to sex, age, body mass index (BMI), and residential district. The prevalence of hypertension increased from 7.1% to 12.5% in all participants. In the sex-specific analysis, the prevalence was found to be increased in boys. In the age-specific analysis, the prevalence was found to be increased in youths aged 13-15 years. In the BMI-specific analysis, an increase in the prevalence was prominent in the normal BMI group. In the residential district-specific analysis, the prevalence of hypertension among youth increased in urban areas. Our results show that the prevalence of hypertension increased among Korean children and adolescents during the COVID-19 outbreak. These findings suggest the importance of close monitoring of hypertension among youth during the COVID-19 pandemic.

Association of maternal mental health and drinking/smoking with adolescents' mental health based on the Korea National Health and Nutrition Examination Survey.

Introduction: Depression is one of the major concerns in adolescence, with a global prevalence of approximately 5%. Diverse environmental factors can affect the development of depression depending on the individual developmental stage. Methods: Using data from the Korea National Health and Nutrition Examination Survey (KNHANES), we aimed to investigate the association between socioeconomic factors and mental health in a population of non-clinically ill adolescents in Korea totaling 6,261 adolescents aged 12-18 years. Results: Drinking, smoking, stress, depressed mood, suicidal ideation in adolescents, and stress, depressed mood, and suicidal ideation in mothers were identified as factors associated with adolescent depression. In addition to depressed mood and suicidal ideation, the higher perception of stress in mothers was related to higher stress perception, depressed mood, and suicidal ideation in adolescents. The association of adolescents' mental health with fathers' mental health was weaker than that with mothers' mental health. Additionally, increased smoking and drinking were commonly reported in adolescents with higher stress perception, depressed mood, and suicidal ideation. Discussion: We conclude that close monitoring of mental health is required for adolescents with drinking and smoking habits and mothers with mental health problems.

Changes in the Prevalences of Obesity, Abdominal Obesity, and Non-Alcoholic Fatty Liver Disease among Korean Children during the COVID-19 Outbreak.

PURPOSE: We aimed to investigate the prevalences of obesity, abdominal obesity, and non-alcoholic fatty liver disease (NAFLD) among children and adolescents during the coronavirus disease 2019 (COVID-19) outbreak. MATERIALS AND METHODS: This population-based study investigated the prevalences of obesity, abdominal obesity, and NAFLD among 1428 children and adolescents between 2018-2019 and 2020. We assessed the prevalences of obesity, abdominal obesity, and NAFLD according to body mass index, age, sex, and residential district. Logistic regression analyses were performed to determine the relationships among obesity, abdominal obesity, and NAFLD. RESULTS: In the obese group, the prevalence of abdominal obesity increased from 75.55% to 92.68%, and that of NAFLD increased from 40.68% to 57.82%. In age-specific analysis, the prevalence of abdominal obesity increased from 8.25% to 14.11% among participants aged 10-12 years and from 11.70% to 19.88% among children aged 13-15 years. In residential district-specific analysis, the prevalence of both abdominal obesity and NAFLD increased from 6.96% to 15.74% in rural areas. In logistic regression analysis, the odds ratio of abdominal obesity for NAFLD was 11.82. CONCLUSION: Our results demonstrated that the prevalences of abdominal obesity and NAFLD increased among obese Korean children and adolescents and in rural areas during the COVID-19 outbreak. Additionally, the prevalence of abdominal obesity increased among young children. These findings suggest the importance of closely monitoring abdominal obesity and NAFLD among children during COVID-19, focusing particularly on obese young children and individuals in rural areas.

Comparison of the effect of gonadotropin-releasing hormone agonist dosage in girls with central precocious puberty.

PURPOSE: There are no definite guidelines on the optimal dosage of gonadotropin-releasing hormone (GnRH) agonist for treatment of central precocious puberty (CPP). We compared growth outcomes of GnRH agonist at different dosages in girls with idiopathic CPP to assess the optimal dosage. METHODS: This retrospective study included 86 girls with idiopathic CPP who had been treated with GnRH agonist for at least one year and had attained their final adult height. Leuprolide was given as fixed dosage (3.75 mg every 4 weeks in body weight >20 kg, n=72) or weight-based dosage (60-85 µg/kg every 4 weeks, n=14). We compared suppression of advanced puberty and treatment response between the 2 groups. RESULTS: Peak estradiol and luteinizing hormone and bone age (BA)/chronological age after injection of GnRH agonist were effectively suppressed in both groups. In both groups, the height standard deviation score (SDS) for BA increased after treatment. Final adult height (FAH) (fixed dosage group,160.8±4.1 cm and weight-based dosage group, 161.2±4.4 cm) was significantly higher than the initial predicted adult height (PAH) (155.5±3.3 and 156.1±3.6 cm, respectively) (both P<0.001) and similar to midparental height (159.8±3.3 and 160.6±3.7 cm, respectively). There were no differences in gain in height SDS for BA and gain in height (FAH-PAH at the start) between the 2 groups. CONCLUSION: There were no differences in treatment outcome between fixed dosage (3.75 mg/4 wk) and weight-based dosage (60-85 µg/kg/4wk) of GnRH agonist. Therefore, a fixed dosage of GnRH agonist can be used more conveniently for CPP treatment without growth oversuppression.

Effect of catch-up sleep on obesity in Korean adolescents: a nationwide cross-sectional study.

Background: Adolescents have weekday/weekend sleep discrepancies and may compensate for weekday sleep debt through sleep extension on weekends. Objective: We investigated the effects of total sleep duration on weekdays/weekends on obesity and determined if weekend catch-up sleep has an ameliorating effect on obesity in Korean adolescents. Methods: Using data from the KNHANES VII, 1,306 middle and high school students were assessed for total sleep duration on weekdays, weekends, and the entire week, as well as weekend sleep extension. Participants were classified into four groups according to weekend sleep extension. Results: Total sleep duration and weekend sleep duration were negatively associated with body mass index z-score. Increased weekend sleep duration and sleep extension on weekends decreased the relative risk of overweight/obesity with each 30 min increment, reducing the risk by a factor of 0.39 and 0.93, respectively. The risk of overweight/obesity in adolescents who slept less than 6 h on weekdays increased by a factor of 1.93 when they slept for less than 3 h on weekends. Conclusion: Weekend catch-up sleep had a negative dose-dependent association with obesity in Korean adolescents. Sleeping longer on weekends may be associated with a decreased risk of obesity, even if the adolescent obtains less sleep during weekdays. However, further prospective studies are needed to establish the causality between extended weekend sleep and obesity.

Parental metabolic syndrome and elevated liver transaminases are risk factors for offspring, even in children and adolescents with a normal body mass index.

Introduction: The parent-child correlation in metabolic syndrome (MetS) and elevated transaminases is sparsely researched. We assessed the correlation of parental MetS and elevated transaminase status with these conditions in their children. Methods: Data of 4,167 youths aged 10-18 years were analyzed in a population-based survey, and the parental characteristics were stratified by the presence or absence of MetS or alanine aminotransferase (ALT) elevation in their children. The prevalence of these conditions in children was analyzed according to their parents' status. Logistic regression analyses were performed with MetS and ALT elevation in youth as the dependent variables. Results: The proportions of MetS and ALT elevation were higher in parents of children with MetS and ALT elevation than in those without, even among youths without obesity. In logistic regression analyses, age, body mass index-standard deviation score (BMI-SDS), and ALT elevation were positively associated with MetS, whereas age, male sex, BMI-SDS, protein intake, and MetS were positively associated with ALT elevation. Higher protein intake was related to ALT elevation, whereas metabolic components and nutritional factors were closely related in parents and their children. Odds ratios (OR) of ALT elevation for MetS was 8.96 even after adjusting nutritional factors in the children. The OR was higher for ALT elevation in the children of parents with MetS and ALT elevation compared to those without. ORs for MetS and ALT elevation in the children of parents with MetS were higher than those of children of parents without MetS, even after adjusting for nutritional intake. ORs for ALT elevation were higher in the children of parents with ALT elevation than those without, even after adjusting for nutritional intake and BMI of parents as well as the nutritional intake, age, sex, and BMI-SDS of the children. Conclusion: MetS and elevated liver transaminase statuses in children were associated with those of their parents even after adjusting for nutritional factors, and the relationships were more prominent in the youth without obesity.