Association between smartphone usage and health outcomes of adolescents: A propensity analysis using the Korea youth risk behavior survey.

OBJECTIVES: We aimed to investigate the association between smartphone use and adverse behavioral health outcomes using nationwide Korea Youth Risk Behavior Web-based Survey data for 2017 and 2020. METHODS: The 2020 data (N = 54,809) were used to analyze the relationships between daily smartphone usage time (non-user, 0-2 h [hour], 2-4 h, 4-6 h, 6-8 h, and > 8 h), and adverse health outcomes (stress, sleep, depression, suicide, substance use, and smartphone overdependence). A 1:1 propensity score matching (PSM) was used to control for confounding variables. RESULTS: A total of 40,998 adolescents with < 4 h/day and > 4 h/day of usage were included. Adolescents' mean smartphone usage time in 2020 increased compared to that in 2017 (weighted % of > 2 h/day; 64.3% vs. 85.7%). The curvilinear relationships between smartphone usage time and adverse health outcomes were prominent after > 4 h/day. Adolescents using smartphones 2-4 h/day showed no increased adverse health outcomes compared to non-users, except for smartphone overdependence. Using a smartphone > 4 h/day was significantly associated with stress perception (1.16; 1.11-1.22), suicidal ideation (1.22; 1.13-1.31), and substance use (alcohol, 1.66; 1.57-1.75) after PSM. CONCLUSIONS: Our study demonstrated the curvilinear relationship between smartphone usage time and adverse health outcomes in adolescents. Our findings can help establish smartphone usage guidelines for adolescents.

Feeding practice during infancy is associated with attention-deficit/hyperactivity disorder and autism spectrum disorder: a population-based study in South Korea.

Attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are representative neurodevelopmental disorders. Using a nationwide database, we aimed to investigate whether feeding practices in infancy (breastfeeding and the timing of supplementary food introduction) could impact ADHD or ASD development. We evaluated 1,173,448 children aged 4-6 months who were included in the National Screening Program for Infants and Children (NHSPIC) between 2008 and 2014. We observed individuals until 6-7 years of age. Data on feeding type (milk feeding: exclusive breastfeeding [EBF], partial breastfeeding [PBF], exclusive formula feeding [EFF] at 4-6 months of age; supplementary food introduction: < 6 or > 6 months of age) were obtained from the NHSPIC, and diagnoses were based on the International Classification of Diseases, Tenth Revision. In a generalized linear model, children who received EBF had significantly lower incidence of both ADHD (odds ratio [OR]: 0.77, 95% confidence interval [CI]: 0.72-0.82) and ASD (OR: 0.64, 95% CI: 0.60-0.67) than that of children who received EFF. PBF also had a significant protective effect on both ADHD (0.91; 0.85-0.98), and ASD (0.89; 0.83-0.95). The timing of supplementary food introduction was not associated with either ADHD or ASD, although there was an increased risk of ASD in the EFF infants who had supplementary food introduced at > 6 months of age.  Conclusion: Our study strengthens and supports the beneficial effect of breastfeeding on neurodevelopmental disorders in children. Breastfeeding should be encouraged and recommended to promote desirable neurodevelopmental outcomes. What is Known: • Breastfeeding is beneficial for the overall health of children, including neurodevelopmental outcomes and cognitive functions. What is New: • Breastfeeding, especially exclusive breastfeeding, was protective against neurodevelopmental disorders. • The effect of the timing of supplementary food introduction was limited.

Protective Effect of Breastfeeding Against Febrile Seizure: A Nationwide Study in Korea.

BACKGROUND: Breastfeeding is known to protect against febrile seizure (FS). Whether its impact continues throughout the childhood period is still controversial. Our objective was to investigate the protective effect of breastfeeding against FS stratified by age. METHODS: We included children who participated in the National Health Screening Program for Infants and Children (NHSPIC) aged between four and six months between 2008 and 2014. Feeding type was confirmed based on the NHSPIC questionnaire, and data from the Korean National Health Insurance Service were used to determine FS cases during a five-year follow-up period. RESULTS: Among the 1,791,335 children, the most prevalent feeding type was exclusive breastfeeding (EB) (42.3%). FS occurred most frequently in the exclusive formula feeding (EF) group (12.2%), followed by the partial breastfeeding (PB) (11.3%) and EB groups (10.7%). Compared with the EF group, the adjusted odds ratio for FS was 0.87 (95% confidence interval, 0.86 to 0.88, P < 0.001) and 0.93 (0.92 to 0.94, P < 0.001) in the EB and PB groups, respectively. The protective effect by age 2.5 years was significant in both the EB (0.85; 0.84 to 0.86, P < 0.001) and PB (0.92; 0.90 to 0.93, P < 0.001) groups. In contrast, the protective effect was not significant in the PB group and inconsistent in the EB group after 2.5 years. CONCLUSION: Breastfeeding has a protective effect against FS in the most prevalent age period, from 0 to 2.5 years. Despite the limited effect after age 2.5 years, we support the current recommendation for prolonged breastfeeding to promote childhood health.

Development of the Parental Questionnaire for Cerebral Visual Impairment in Children Younger than 72 Months.

BACKGROUND AND PURPOSE: Cerebral visual impairment (CVI) is an underdiagnosed condition in children, and its assessment tools have focused on older children. We aimed to develop a parental questionnaire for cerebral visual impairment (PQCVI) for screening CVI in young children. METHODS: The PQCVI comprised 23 questions based on a modified version of Houliston and Dutton's questionnaire for older children. The PQCVI with neurocognitive function tests was applied to 201 child-parent pairs with typically developing children younger than 72 months (age 32.4±20.1 months, mean±standard deviation). The children were classified into six age groups. The normative data, cutoff scores, and internal reliability were assessed and item analysis was performed. We referred to the total score for all questions as the cerebral visual function (CVF) score. RESULTS: The normative data showed that the CVF score and the scores corresponding to ventral-stream and dorsal-stream visual functions plausibly increased with age. The scores rapidly reached 90% of their maximum values up to the age of 36 months, after which they increased slowly. Cronbach's alpha for all questions across all age groups was 0.97, showing excellent consistency. The item difficulty and item discrimination coefficients showed that the questions were generally adequate for this age stage. CONCLUSIONS: The PQCVI items produced reliable responses in children younger than 72 months. The rapid increase in scores before the age of 3 years supports the importance of early identification of CVI. Following additional clinical verification, the PQCVI may be useful for CVI screening.

Increased sensitization rates to tree pollens in allergic children and adolescents and a change in the pollen season in the metropolitan area of Seoul, Korea.

INTRODUCTION: Children with allergies are at greater risk of becoming sensitized to allergenic pollens in response to environmental changes. This study investigated the relationship between changes in pollination associated with meteorologic changes and the sensitization rates of children to tree pollen allergens in the metropolitan area of Seoul, Korea. METHODS: The study population consisted of 8,295 children who visited the pediatric allergy clinics at Hanyang University Seoul and Guri Hospital for allergy symptoms between January 1, 1998, and December 31, 2019. Pollen was collected at the two hospitals during the study using a Burkard 7-day sampler. Meteorologic data were obtained from the National Weather Service. RESULTS: Among the major tree pollens, the largest increase in allergic sensitization was to oak, hazel, and alder pollens (0.28% annually). The pollen-sensitization rates increased annually within younger age groups. The duration of the pollen season was 98 days in 1998 and 140 days in 2019. Positive correlations were determined between the duration of the pollen season and the rates of sensitization to tree pollens, as well as between the pollen-sensitization rates and increasing temperature. CONCLUSIONS: This study demonstrated the correlation between weather changes and the resulting changes in the pollen season with sensitization rates to allergenic pollens in children living in the Seoul metropolitan area. An annual increase in sensitization rates in younger children was determined. This pattern is expected to continue due to continuing climate change.

Severe Fever With Thrombocytopenia Syndrome With Q Fever Coinfection in an 8-Year-Old Girl.

We report a case of an 8-year-old Korean girl diagnosed with severe fever with thrombocytopenia syndrome with Q fever coinfection after playing with a dog and being bitten by a tick in a suburb in South Korea. The clinical findings and treatment were summarized. To the best of our knowledge, this case is the youngest patient reported to have been diagnosed with severe fever with thrombocytopenia syndrome and Q fever from South Korea.

Health effects of electromagnetic fields on children.

In today's world, most children are exposed to various manmade electromagnetic fields (EMFs). EMFs are electromagnetic waves less than 300 GHz. A developing child's brain is vulnerable to electromagnetic radiation; thus, their caregivers' concerns about the health effects of EMFs are increasing. EMF exposure is divided into 2 categories: extremely low frequencies (ELFs; 3-3,000 Hz), involving high-voltage transmission lines and in-house wiring; and radiofrequencies (RFs; 30 kHz to 300 GHz), involving mobile phones, smart devices, base stations, WiFi, and 5G technologies. The biological effects of EMFs on humans include stimulation, thermal, and nonthermal, the latter of which is the least known. Among the various health issues related to EMFs, the most important issue is human carcinogenicity. According to the International Agency for Research on Cancer's (IARC's) evaluation of carcinogenic risks to humans, ELFs and RFs were evaluated as possible human carcinogens (Group 2B). However, the World Health Organization's (WHO's) view of EMFs remains undetermined. This article reviews the current knowledge of EMF exposure on humans, specifically children. EMF exposure sources, biological effects, current WHO and IARC opinions on carcinogenicity, and effects of EMF exposures on children will be discussed. As well-controlled EMF experiments in children are nearly impossible, scientific knowledge should be interpreted objectively. Precautionary approaches are recommended for children until the potential health effects of EMF are confirmed.

Analysis of Somatostatin-Secreting Gastric Delta Cells according to Upper Abdominal Symptoms and Helicobacter pylori Infection in Children.

PURPOSE: Gastric delta cells (D-cells), which are somatostatin-secreting cells, are the main paracrine inhibitor of acid secretion. The number of D-cells was studied in children presenting with upper gastrointestinal (UGI) disease. METHODS: We retrospectively investigated the number of D-cells in the gastric body and antrum through immunofluorescence examinations according to symptoms, endoscopic findings, and Helicobacter pylori infection in 75 children who visited Hanyang University Hospital Pediatrics. RESULTS: The mean patient age was 12.2±3.3 years. The male-to-female ratio was 1:1.4. The mean D-cell number per high-power field in the antrum and body was 20.5 and 12 in children with substernal pain, 18.3 and 10.3 in vomiting, 22.3 and 6 in diarrhea, and 9.3 and 6 in abdominal pain, respectively (p>0.05). According to endoscopic findings, the mean D-cell number in the antrum and body was 14.3 and 6 with gastritis, 14 and 9.3 with reflux esophagitis, 16.7 and 8.7 with duodeno-gastric reflux, 19.3 and 12.7 with gastric ulcer, 16 and 13.7 with duodenitis, and 12.3 and 4 with duodenal ulcer, respectively (p>0.05). The D-cell number in the gastric body was 2.7 and 8.7 in children with current H. pylori infection and non-infected children, respectively (p=0.01), while those in the antrum were 15.5 and 14, respectively, with no statistical significance. CONCLUSION: The D-cell number was lower in the gastric body of children with current H. pylori infection. Further studies concerning peptide-secreting cells with a control group would provide information about the pathogenic pathways of UGI disorder.

Visual Hyper-vigilance But Insufficient Mental Representation in Children with Overweight/Obesity: Event-related Potential Study with Visual Go/NoGo Test.

PURPOSE: The neural processing of children with overweight/obesity (CWO), may affect their eating behavior. We investigated the visual information processing of CWO under response control condition, by event-related potential (ERP) study, an electrophysiologic study for cognitive mechanism. METHODS: Seventeen CWO (mean age: 10.6±1.9), and 17 age-matched non-obese children (NOC), participated in the study. Neurocognitive function tests and visual ERP under Go/NoGo conditions, were implemented. Area amplitudes of major ERP components (P1, N1, P2, N2, and P3) from four scalp locations (frontal, central, parietal, and occipital), were analyzed. RESULTS: For Go and NoGo conditions, CWO had significantly greater occipital P1, fronto-central N1, and P2 amplitudes compared with NOC. P2 amplitude was significantly greater in CWO, than in NOC, at the frontal location. N2 amplitude was not significantly different, between CWO and NOC. For CWO and NOC, Go P3 amplitude was highest at the parietal location, and NoGo P3 amplitude was highest at the frontal location. In Go and NoGo conditions, P3 amplitude of CWO was significantly less than in NOC. CONCLUSION: The greater P1, N1, and P2 suggested hyper-vigilance to visual stimuli of CWO, but the smaller P3 suggested insufficient mental representation of them. Such altered visual processing, may affect the eating behavior of CWO.

Smart device usage in early childhood is differentially associated with fine motor and language development.

AIM: We evaluated the relationships between the use of smart devices, such as smartphones and tablet computers, and the development levels and language scores in young children. METHODS: A cross-sectional analysis with 117 children aged three to five years was conducted. The participants were recruited from kindergartens in South Korea between November 2015 and April 2016. Parental questionnaires to assess smart device usage status by children, developmental screening test and receptive-expressive language scale were administered; metrics included smart device usage frequency and usage time, appropriate smart device usage level, developmental levels and language scores. RESULTS: Smart device usage frequency was significantly positively correlated with fine motor skill development [Spearman's correlation coefficient (rs ) = 0.426] in three-year-old children. Appropriate smart device usage level was also positively correlated with social development (rs  = 0.466). However, smart device usage time was significantly negatively correlated with expressive language months (rs  = -0.481). There were no such correlations in children aged four to five years. For the subcategories of appropriate usage level, the suitability of social relationship was significantly positively correlated with social development in three-year-old children (rs  = 0.474). CONCLUSION: In three-year-old children, smart device usage was positively correlated with fine motor development and negatively correlated with language development.

Critical appraisal for low-carbohydrate diet in nonalcoholic fatty liver disease: Review and meta-analyses.

BACKGROUND & AIMS: Weight loss by lifestyle modification is the cornerstone therapy of Non Alcoholic Fatty Liver Disease. Low carbohydrate diet has showed favorable effects for body weight as well as hepatic fat content in several reports. In this meta-analysis, we review clinical studies article to date regarding the composition of the diet and analyzed the impact of low carbohydrate diet comparing to low calorie diet on hepatic fat change, AST and ALT using Forest plot. We aimed to investigate the efficacy of low carbohydrate diet on NAFLD. METHODS: We collected studies that were conducted with various amounts of carbohydrate and different methods for changing the hepatic fat and fibrosis. RESULTS: Eleven clinical studies (seven randomized controlled trials) were selected on the efficacy and safety of low carbohydrate diet on NAFLD patients. Four studies evaluated hepatic fat by magnetic resonance imaging and two evaluated hepatic fat using computed tomography. However, the pools of subjects were small, the criterion for low carbohydrate was variable, and there is yet an established standard method of evaluation of liver. In meta-analysis, there was no significant difference between low carbohydrate diet group and low fat diet group on the improvement of hepatic fat content and transaminases in NAFLD. CONCLUSION: So far there's little evidence that low-carbohydrate diet has more beneficial effect on NAFLD than low calorie diet in similar calorie intake.

Effects of Moderate Alcohol Drinking in Patients with Nonalcoholic Fatty Liver Disease.

Whether moderate alcohol intake is beneficial remains an unsolved issue. Recent studies have suggested that moderate alcohol consumption is associated with beneficial effects related to the prevention of cardiovascular diseases. Moderate alcohol consumption leads to a higher risk of hepatocellular carcinoma in patients with chronic viral liver diseases. However, the effects of moderate alcohol intake in patients with nonalcoholic fatty liver disease are unclear. In this review, we analyzed, from various perspectives, the effect of moderate alcohol consumption in patients with nonalcoholic fatty liver disease. We reviewed four cohort studies and seven cross-sectional studies. The results showed that moderate alcohol consumption was negatively related to the incidence of nonalcoholic steatohepatitis and liver fibrosis. However, moderate alcohol consumption was positively associated with the incidence of hepatocellular carcinoma in patients with nonalcoholic fatty liver disease. The results of the analysis of the relationship between moderate alcohol consumption and the levels of triglycerides, total cholesterol, high-density lipoprotein, and hypertension were diverse. More clinical data are needed to draw a conclusion about the effects of moderate alcohol consumption in patients with nonalcoholic fatty liver disease.

Respiratory syncytial virus-associated seizures in Korean children, 2011-2016.

PURPOSE: Respiratory syncytial virus (RSV) infection can cause various neurological complications. This study aimed to investigate the RSV-associated neurologic manifestations that present with seizures. METHODS: We retrospectively reviewed the medical records of patients aged less than 15 years with laboratory-confirmed RSV infections and seizures between January 2011 and December 2016 in a regional hospital in South Korea. RESULTS: During this period, 1,193 patients with laboratory-confirmed RSV infection were identified. Of these, 35 (35 of 1,193, 2.93%; boys, 19; girls, 16; mean age: 20.8±16.6 months) presented with seizures. Febrile seizure was the most common diagnosis (27 of 35, 77.1%); simple febrile seizure in 13 patients (13 of 27, 48.1%) and complex febrile seizure in 14 (14 of 27, 51.9%). Afebrile seizures without meningitis or encephalopathy were observed in 5 patients (5 of 35, 14.3%), seizures with meningitis in 2 (2 of 35, 5.7%), and seizure with encephalopathy in 1 (1 of 35, 2.9%) patient. Lower respiratory symptoms were not observed in 8 patients. In a patient with encephalopathy, brain diffusion-weighted magnetic resonance imaging revealed transient changes in white matter, suggesting cytotoxic edema as the mechanism underlying encephalopathy. Most patients recovered with general management, and progression to epilepsy was noted in only 1 patient. CONCLUSION: Although febrile seizure is the most common type of seizure associated with RSV infection, the proportion of patients with complex febrile seizure was higher than that of general febrile seizure. Transient cytotoxic edema may be a pathogenic mechanism in RSV-related encephalopathy with seizures.

Serial Changes of Cytokines in Children with Cerebral Palsy Who Received Intravenous Granulocyte-colony Stimulating Factor Followed by Autologous Mobilized Peripheral Blood Mononuclear Cells.

BACKGROUND: This study was performed to assess serial cytokine changes and their clinical impact in children with cerebral palsy (CP) who received granulocyte-colony stimulating factor (G-CSF) followed by infusion of autologous mobilized peripheral blood mononuclear cells (mPBMCs). METHODS: Peripheral blood (PB) samples were collected from 16 CP children at enrollment, and 1 month and 7 months after G-CSF infusion as well as at the end of the study. Cytokine levels were measured by enzyme-linked immunosorbent assays with plasma samples. RESULTS: There were no significant differences in cytokine levels between the mPBMC and placebo groups over 6 months. However, when clinical responders and non-responders were compared, interleukin (IL)-6 (P = 0.050) as well as G-CSF (P = 0.010) were higher in the responders than the non-responders at 1 month, while brain-derived neurotrophic factor (BDNF) (P = 0.030) and insulin-like growth factor (IGF)-1 (P = 0.001) were lower. In addition, BDNF was higher at baseline in the responders than the non-responders (P = 0.030). CONCLUSION: The changes of G-CSF itself, as well as G-CSF-induced cytokines such as IL-6, may be associated with the clinical improvement of neurologic functions. The G-CSF-induced changes of IL-6, BDNF and IGF-1, and BDNF levels before treatment, could be used as prognostic factors in G-CSF trials in CP children.

Rotavirus infection as a frequent cause of neonatal fever.

BACKGROUND: Fever rather than diarrhea or vomiting was the most common symptom of neonatal rotavirus (RV) infection in our previous study. We investigated whether RV infection is a major cause of neonatal fever and compared the clinical characteristics of bacterial infection, viral infection and unknown causes of neonatal fever. METHOD: We reviewed the electronic medical records of 48 newborns aged ≤28 days who were admitted to the Special Care Nursery of Hanyang University Guri Hospital for fever (≥38°C) from 2005 to 2009. All the newborns underwent complete blood count, urinalysis, C-reactive protein, cultures of blood, urine, and cerebrospinal fluid as well as stool RV enzyme-linked immunosorbent assay. Respiratory virus polymerase chain reaction for cough or rhinorrhea, and stool culture for diarrhea were also done. RESULTS: All the babies were term, with mean age 13 ± 8 days and peak body temperature 38.5 ± 0.5°C. The causes of neonatal fever were viral (44%), bacterial (10%) and unknown (46%). The viral infections included RV (n = 12), enterovirus (n = 6), respiratory syncytial virus (n = 2), and rhinovirus (n = 1). All the rotavirus genotypes were G4P[6]. Only three of 12 RV-infected febrile newborns had diarrhea. The bacterial infections included three cases of urinary tract infection (Escherichia coli, n = 2; Klebsiella pneumoniae, n = 1), and two cases of sepsis complicated with meningitis (all Streptococcus agalactiae). CONCLUSIONS: RV infection is the most common single cause of neonatal fever. It may be necessary to include stool RV tests for febrile newborns.

Investigation of Clinical and Pathological Relationships between Adult- and Pediatric-type NASH in Korean Children.

BACKGROUND: Histologically, nonalcoholic steatohepatitis (NASH) is categorized into adult-type (type 1) and pediatric-type (type 2). The origination of the histological difference between the two types and how they differ clinically remain uncertain. We aimed to understand the incidence and clinical characteristics of the two types of NASH in Korean children, and to investigate the association between their pathological type and clinical characteristics, using anthropometric and laboratory data. METHODS: In 38 children with confirmed NASH, we investigated hepatic pathological findings, and correlating factors between pathological type and laboratory and anthropometric data (weight percentile, body mass index (BMI) z-score, and blood pressure percentile). Adult-type NASH was noted in 21 patients and pediatric-type in 17 patients. RESULTS: Age, sex, BMI, transaminase levels, and insulin resistance were not significantly different between the two groups. Triglyceride (TG) levels were higher in adult-type NASH (P = 0.033). Hematocrit and albumin levels were lower in adult-type NASH (P = 0.016 and 0.013, respectively). Hepatic fibrosis was more common in pediatric-type. The fibrosis scores in patients with adult-type were mostly 0 and 1, whereas the score was 3 in patients with pediatric-type (P = 0.024, 0.004, and < 0.010, respectively). Anthropometric data, liver function, and insulin resistance scores did not differ between the two pathological NASH types. TG, hematocrit, and albumin may be potential factors to predict pathological types. Fibrosis was observed more frequently in pediatric-type NASH. CONCLUSION: Monitoring children with pediatric-type NASH for progression to fibrosis or cirrhosis is recommended.

Pathologic Impact of Insulin Resistance and Sensitivity on the Severity of Liver Histopathology in Pediatric Non-Alcoholic Steatohepatitis.

PURPOSE: Insulin resistance (IR) has an important role in the development of non-alcoholic steatohepatitis (NASH). We aimed to analyze the association between liver histopathology and IR in pediatric patients with NASH. MATERIALS AND METHODS: In 24 children with non-alcoholic fatty liver disease (NAFLD), we investigated whether the hepatic pathologic characteristics have relations with following three biochemical indices; IR index including homeostasis model assessment of IR (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), and insulin sensitivity indices-free fatty acid (ISI-FFA). RESULTS: Among 24 patients, 16 (66.6%) had a high NAFLD activity score (NAS), which is diagnostic of NASH. Higher serum triglyceride level was significantly correlated with a high NAS. Higher steatosis grades were significantly associated with low insulin sensitivity (p=0.023). In addition, severe lobular inflammation was associated with higher IR: HOMA-IR (p=0.014) and QUICKI (p=0.023). Severe fibrosis correlated with low insulin sensitivity and high IR indexes: ISI-FFA (p=0.049), HOMA-IR (p=0.028), and QUICKI (p=0.007). CONCLUSION: Patients with high IR had more severe lobular inflammation and hepatic fibrosis. Analyses of biochemical and endocrine parameters can be applied to determine the severity of the hepatic pathologic status in patients with NASH, especially in children who cannot undergo a liver biopsy.