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Abstract Background Glutamate is a major neurotransmitter, although it causes cytotoxicity and inflammation in nonneuronal organs. This study aimed to investigate the metabolic disorders in which glutamate, associated with type 2 diabetes onset, is induced in the liver. Methods An analysis of Korean community‐based Ansan‐Ansung cohort study data as well as functional research using in vitro and mouse models were performed. Results Groups with high plasma glutamate levels (T2, T3) had a significantly increased risk of diabetes incidence after 8 years, compared to the group with relatively low glutamate levels (T1). Analysis of the effect of glutamate on diabetes onset in vitro showed that glutamate induces insulin resistance by increasing glucose‐related protein 78 (GRP78) and phosphoenolpyruvate carboxykinase (PEPCK) expression in SK‐Hep‐1 human liver cells. In addition, three different genes, FRMB4B, PLG, and PARD3, were significantly associated with glutamate and were identified via genome‐wide association studies. Among glutamate‐related genes, plasminogen (PLG) levels were most significantly increased in several environments in which insulin resistance was induced, and was also upregulated by glutamate. Glutamate‐induced increase in PLG in liver cells was caused by metabotropic glutamate receptor 5 activation, and PLG levels were also upregulated after extracellular secretion. Moreover, glutamate increased the expression of plasminogen activator inhibitor‐1 (PAI‐1). Thus, extracellular secreted PLG cannot be converted to plasmin (fibrinolytic enzyme) by increased PAI‐1. Conclusions Increased glutamate is closely associated with the development of diabetes, and it may cause metabolic disorders by inhibiting the fibrinolytic system, which plays an important role in determining blood clots, a hallmark of diabetes.

ObjectiveWe aimed to assess the effectiveness of the first 6 months of a 24 month multidisciplinary intervention program including circuit training and a balanced diet in children and adolescents with obesity.MethodsA quasi-experimental intervention trial included 242 participants (age [mean±standard deviation]: 11.3±2.06 years, 97 girls) of at least 85th percentile of age- and sex-specific body mass index (BMI). Participants were grouped into three to receive usual care (usual care group), exercise intervention with circuit training (exercise group), or intensive nutritional and feedback intervention with a balanced diet (nutritional group). Primary outcome was BMI z-score, while secondary outcomes included body composition, cardiometabolic risk markers, nutrition, and physical fitness.ResultsAmong the participants, 80.6% had a BMI ≥ the 97th percentile for age and sex. The BMI z-score of the overall completers decreased by about 0.080 after 6 months of intervention (p < 0.001). After the intervention, both exercise and nutritional groups had significantly lower BMI z-scores than the baseline data by about 0.14 and 0.075, respectively (p < 0.05). Significant group by time interaction effects were observed between exercise versus usual care group in BMI z-score (β, -0.11; 95% confidence interval (CI), -0.20 to -0.023) and adiponectin (β, 1.31; 95% CI, 1.08 to 1.58); and between nutritional versus usual care group in waist circumference (β, -3.47; 95% CI, -6.06 to -0.89). No statistically significant differences were observed in any of the other secondary outcomes assessed.ConclusionMultidisciplinary intervention including circuit training and a balanced diet for children and adolescents with obesity reduced the BMI z-score and improved cardiometabolic risk markers such as adiponectin and waist circumference.

Abstract Moderate alcohol consumption is generally associated with reduced risk of type 2 diabetes. However, this beneficial effects of alcohol intake remains controversial due to inconsistent results across studies. The analysis was performed using data from the Ansung-Ansan cohort study. We categorized the participants into four groups—based on the baseline (one-point measure; non-drinking,

The discovery of metabolomics-based biomarkers has been a focus of recent kidney dysfunction research. In the present study, we aimed to identify metabolites associated with chronic kidney disease (CKD) in the general population using a cross-sectional study design. At baseline, 6.5% of subjects had CKD. Pearson correlation analysis showed that 28 metabolites were significantly associated with estimated glomerular filtration rate (eGFR) after Bonferroni correction. Among these metabolites, 4 acylcarnitines, 12 amino acids, 4 biogenic amines, 1 phosphatidylcholine, and 1 sphingolipid were associated with CKD (p < 0.05). After eight years, 13.5% of subjects had CKD. Three amino acid metabolites were positively associated with new-onset CKD: citrulline [odds ratio (OR): 2.41, 95% confidence interval (CI): 1.26–4.59], kynurenine (OR: 1.98, 95% CI: 1.05–3.73), and phenylalanine (OR: 2.68, 95% CI: 1.00–7.16). The kynurenine:tryptophan ratio was also associated with CKD (OR: 3.20; 95% CI: 1.57–6.51). The addition of multiple metabolites significantly improved the CKD prediction by C statistics (0.756–0.85, p < 0.0001), and the net reclassification improvement was 0.84 (95% CI: 0.72–0.96). Elevated hs-C reactive protein (CRP) was associated with new-onset CKD (OR: 1.045, 95% CI: 1.005–1.086); however, this association disappeared following adjustment with the kynurenine:tryptophan ratio. The levels of citrulline and kynurenine and their ratio to tryptophan in CKD patients with proteinuria were worse than those with one or neither characteristic. Together, the results of this study demonstrate that amino acid metabolites are associated with CKD eight years after initial metabolite assessment. These results could improve the identification of subjects at high risk of CKD who have modified amino acid metabolism.

Liver enzyme elevations, as an indicator of liver function, are widely associated with metabolic diseases. Genome-wide population-based association studies have identified a genetic susceptibility to liver enzyme elevations and their related traits; however, the genetic architecture in childhood remains largely unknown. We performed a genome-wide association study to identify new genetic loci for liver enzyme levels in a Korean childhood cohort (n = 484). We observed three novel loci (rs4949718, rs80311637, and rs596406) that were multiply associated with elevated levels of alanine transaminase and aspartate transaminase. Although there are some limitations, including genetic power, additional replication and functional characterization will support the clarity on the genetic contribution that the ST6GALNAC3, ADAMTS9, and CELF2 genes have in childhood liver function.

Dyslipidemia, mainly characterized by high triglyceride (TG) and low high-density lipoprotein cholesterol (HDL-C) levels, is an important etiological factor in the development of cardiovascular disease (CVD). Considering the relationship between childhood obesity and CVD risk, it would be worthwhile to evaluate whether previously identified lipid-related variants in adult subjects are associated with lipid variations in a childhood obesity study (n = 482). In an association analysis for 16 genome-wide association study (GWAS)-based candidate loci, we confirmed significant associations of a genetic predisposition to lipoprotein concentrations in a childhood obesity study. Having two loci (rs10503669 at LPL and rs16940212 at LIPC) that showed the strongest association with blood levels of TG and HDL-C, we calculated a genetic risk score (GRS), representing the sum of the risk alleles. It has been observed that increasing GRS is significantly associated with decreased HDL-C (effect size, -1.13 ± 0.07) compared to single nucleotide polymorphism combinations without two risk variants. In addition, a positive correlation was observed between allelic dosage score and risk allele (rs10503669 at LPL) on high TG levels (effect size, 10.89 ± 0.84). These two loci yielded consistent associations in our previous meta-analysis. Taken together, our findings demonstrate that the genetic architecture of circulating lipid levels (TG and HDL-C) overlap to a large extent in childhood as well as in adulthood. Post-GWAS functional characterization of these variants is further required to elucidate their pathophysiological roles and biological mechanisms.

Obesity is an increasing public health concern worldwide. According to the latest Organization for Economic Co-operation and Development (OECD) report (2014), the incidence of child obesity in Korea has exceeded the OECD average. To better understand and control this condition, the present study examined the composition of the gut microbial community in normal and obese adolescents. Fecal samples were collected from 67 obese (body mass index [BMI] ≥ 30 kg/m2, or ≥ 99th BMI percentile) and 67 normal (BMI < 25 kg/m2 or < 85th BMI percentile) Korean adolescents aged 13-16 years and subjected to 16S rRNA gene sequencing. Analysis of bacterial composition according to taxonomic rank (genus, family, and phylum) revealed marked differences in the Bacteroides and Prevotella populations in normal and obese samples (p < 0.005) at the genus and family levels; however, there was no difference in the Firmicutes-to-Bacteroidetes (F/B) ratio between normal and obese adolescents samples at the phylum level (F/B normal = 0.50 ± 0.53; F/B obese = 0.56 ± 0.86; p = 0.384). Statistical analysis revealed a significant association between the compositions of several bacterial taxa and child obesity. Among these, Bacteroides and Prevotella showed the most significant association with BMI (p < 0.0001 and 0.0001, respectively). We also found that the composition of Bacteroides was negatively associated with triglycerides (TG), total cholesterol, and high-sensitive C-reactive protein (hs-crp) (p = 0.0049, 0.0023, and 0.0038, respectively) levels, whereas that of Prevotella was positively associated with TG and hs-crp levels (p = 0.0394 and 0.0150, respectively). We then applied the association rule mining algorithm to generate "rules" to identify the association between the populations of multiple bacterial taxa and obesity; these rules were able to discriminate obese from normal states. Therefore, the present study describes a systemic approach to identify the association between bacterial populations in the gut and childhood obesity.

Objective: The early identification of predictors related to cardiovascular disease risk factor clustering (CVD-RFC) can help prevent chronic disease. We aimed to identify the risk factors for CVD-RFC in adolescents.Methods: A prospective longitudinal cohort study design was used to obtain data included in these analyses from school-aged children who participated in the Korean Child-Adolescent Study 2008-2014. A total of 1309 children aged 6-15 years were enrolled. We compared the participants based on the presence or absence of CVD-RFC and examined the cumulative incidence of CVD-RFC.Results: Of the total 1309 children, 410 (31.32%) had CVD-RFC in adolescence. A higher average household income ≥3 million Korean Republic won (KRW)/month (3-5 million KRW/month: HR 0.75 (95% CI 0.58 to 0.97); ≥5 million KRW/month: HR 0.58 (95% CI 0.44 to 0.77)) was associated with a lower CVD-RFC incidence, while the presence of parental CVD history (HR 1.28 (95% CI 1.04 to 1.57)), overweight or obesity (HR 3.83 (95% CI 3.05 to 4.80)) and shorter sleep duration of 8-9 hour/day (HR 1.80 (95% CI 1.05 to 3.07)) and <8 hour/day (HR 1.93 (95% CI 1.11 to 3.34)) had higher CVD-RFC incidences.Conclusions: Obesity in childhood, short sleep duration and parental factors such as low socioeconomic status and parental history of CVD are significant risk factors for the development of CVD-RFC in adolescents. Efforts to create awareness regarding sufficient sleep duration in children via intervention programmes targeting cardiometabolic health in children and special attention to lifestyle modifications and socioeconomic components of the family should be considered. [ABSTRACT FROM AUTHOR]

Background A low serum level of high-density lipoprotein cholesterol (HDL-C) is a risk factor for cardiovascular disease. Proprotein convertase subtilisin/kexin type 5 (PCSK5) modulates HDL-C metabolism through the inactivation of endothelial lipase activity. Methods Therefore, we analysed the effects of PCSK5 on HDL-C and investigated the association between genetic variation in PCSK5 and dietary polyunsaturated fatty acids (PUFAs) intakes in Korean adults and children. This population-based study which was conducted in South Korea included 4205 adults (43% male) aged 40-69 years and 1548 children (48.6% boys) aged 8-13 years. Dietary intake was assessed using a semiquantitative food frequency questionnaire in adults and modified 3-day food records in children. Results After adjustments for age and body mass index, we identified a significant association between SNP rs1029035 of the PCSK5 gene and HDL-C concentrations specifically for men in both populations (adults, p=0.004; children, p=0.003; meta, p=7×10-4). Additionally, the interaction between the PCSK5 rs1029035 genotype and dietary polyunsaturated fatty acids intake influenced serum HDL-C concentrations in men (adults, p=0.001; children, p=0.008). The deleterious effect of the C allele on serum HDL-C was present only when dietary PUFA intake was less than the dichotomised median level (adults, p=0.011; children, p=0.001). Serum HDL-C concentrations were decreased in men with the C allele genotype and low consumption of dietary PUFA including n-3 and n-6. Conclusion According to these results, men carrying of the C allele were associated with low HDL-C concentrations and might exert beneficial effects on HDL-C concentrations following consumption of a high-PUFA diet. [ABSTRACT FROM AUTHOR]

Background/Aims Childhood obesity has been increased worldwide and many clinical and public interventions have been tried to reduce the morbidities. However, there was no reliable biomarkers to identify the high-risk groups or good response groups to specific interventions. The purpose of this study is to identify the metabolic signatures associated with interventions to control weight in obese children. Methods Forty obese children from "Intervention for Children and Adolescent Obesity via Activity and Nutrition study" were selected according to the response to the interventions. Half of the children were responders (n=20) and the others were non-responders (n=20). Physiological data and blood samples were collected at baseline, intervention after 6 months, and 18 months. Total 120 samples were collected and quantitative analysis of the metabolites of serum samples were applied using CE-TOFMS and the biocrates Absolute IDQ p180 kit with LC-TOFMS. Results Total 194 metabolites (111 metabolites in cation mode and 83 metabolites in anion mode) in 120 samples were detected on the basis of human metabolome technologies' standard library. Nine metabolites (1- or 3-Methylhistidine, 3-Hydroxypropionic acid, 8- or 2-Hydroxyoctanoic acid-1, alanine, asparagine, cystine, indole-3-acetic acid, N-acetylalanine, tyrosine) showed significant changes between baseline and 18months samples in responders and non-responders (p<0.05). Alanine, asparagine, cystine, indole- 3-acetic acid, tyrosine were also revealed relative areas of each metabolites in 0, 6, 18 months, respectively in metabolic pathway mapping. Conclusions Our study shows significantly different metabolomic profiling in responder and non-responder groups according to the interventions. This result calls for further researches about the biomarkers regarding to the responses to specific treatments or interventions to the larger group of obese children. [ABSTRACT FROM AUTHOR]

Abstract The superconductor-insulator transition induced by film thickness control is investigated for the optimally doped cuprate superconductor La1.85Sr0.15CuO4. Epitaxial thin films are grown on an almost exactly matched substrate LaAlO3 (001). Despite the wide thickness range of 6 nm to 300 nm, all films are grown coherently without significant relaxation of the misfit strain. Electronic transport measurement exhibits systematic suppression of the superconducting phase by reducing the film thickness, thereby inducing a superconductor-insulator transition at a critical thickness of ~10 nm. The emergence of a resistance peak preceding the superconducting transition is discussed based on the weak localization. X-ray photoelectron spectroscopy results show the possibility that oxygen vacancies are present near the interface.

Background: The current study aimed to screen for relationships and different potential metabolic biomarkers involved between metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO) in adolescents. Methods: The study included 148 obese adolescents aged between 14 and 16. The study participants were divided into MUO and MHO groups based on the age-specific adolescent metabolic syndrome (MetS) criteria of the International Diabetes Federation. The current study was conducted to investigate the clinical and metabolic differences between the MHO and MUO groups. Multivariate analyses were conducted to investigate the metabolites as independent predictors for the odds ratio and the presence of the MetS. Results: There were significant differences in the three acylcarnitines, five amino acids, glutamine/glutamate ratio, three biogenic amines, two glycerophospholipids, and the triglyceride-glucose index between the MUO group and those in the MHO group. Moreover, several metabolites were associated with the prevalence of MUO. Additionally, several metabolites were inversely correlated with MHO in the MUO group. Conclusions: In this study, the biomarkers found in this study have the potential to reflect the clinical outcomes of the MUO group. These biomarkers will lead to a better understanding of MetS in obese adolescents.

Childhood obesity has increased worldwide, and many clinical and public interventions have attempted to reduce morbidity. We aimed to determine the metabolomic signatures associated with weight control interventions in children with obesity. Forty children from the “Intervention for Children and Adolescent Obesity via Activity and Nutrition (ICAAN)” cohort were selected according to intervention responses. Based on changes in body mass index z-scores, 20 were responders and the remaining non-responders. Their serum metabolites were quantitatively analyzed using capillary electrophoresis time-of-flight mass spectrometry at baseline and after 6 and 18 months of intervention. After 18 months of intervention, the metabolite cluster changes in the responders and non-responders showed a difference on the heatmap, but significant metabolites were not clear. However, regardless of the responses, 13 and 49 metabolites were significant in the group of children with obesity intervention at 6 months and 18 months post-intervention compared to baseline. In addition, the top five metabolic pathways (D-glutamine and D-glutamate metabolism; arginine biosynthesis; alanine, aspartate, and glutamate metabolism; TCA cycle (tricarboxylic acid cycle); valine, leucine, and isoleucine biosynthesis) including several amino acids in the metabolites of obese children after 18 months were significantly changed. Our study showed significantly different metabolomic profiles based on time post obesity-related intervention. Through this study, we can better understand and predict childhood obesity through metabolite analysis and monitoring.