Metabolic syndrome in pediatrics: old concepts revised, new concepts discussed

Comparison of Metabolic Response to Colonic Fermentation in Lean Youth vs Youth With Obesity

Importance

Pediatric obesity is a growing health care burden. Understanding how the metabolic phenotype of youth with obesity may modify the effect of intestinal fermentation on human metabolism is key to designing early intervention.

Objective

To assess whether adiposity and insulin resistance in youth may be associated with colonic fermentation of dietary fibers and its production of acetate, gut-derived hormone secretion, and adipose tissue lipolysis.

Design, Setting, and Participants

Cross-sectional study of youths aged 15 to 22 years with body mass index in the 25th to 75th percentile or higher than the 85th percentile for age and sex throughout the New Haven County community in Connecticut. Recruitment, studies, and data collection occurred from June 2018 to September 2021. Youths were assigned to a lean, obese insulin sensitive (OIS), or obese insulin resistant (OIR) group. Data were analyzed from April 2022 to September 2022.

Exposure

Participants consumed 20 g of lactulose during a continuous 10-hour sodium d3-acetate intravenous infusion to measure the rate of appearance of acetate in plasma.

Main Outcomes and Measures

Plasma was obtained hourly to measure acetate turnover, peptide tyrosine tyrosine (PYY), ghrelin, active glucagon-like peptide 1 (GLP-1), and free fatty acids (FFA).

Results

A total of 44 youths participated in the study (median [IQR] age, 17.5 [16.0-19.3] years; 25 [56.8%] were female; 23 [52.3%] were White). Consequent to lactulose ingestion, there was a reduction of plasma FFA, an improvement of adipose tissue insulin sensitivity index, an increase in colonic acetate synthesis, and an anorexigenic response characterized by an increased plasma concentration of PYY and active GLP-1 and a reduction of ghrelin in the subgroups. Compared with the lean and OIS groups, the OIR group showed a less marked median (IQR) rate of acetate appearance (OIR: 2.00 [-0.86 to 2.69] μmol × kg-1 × min-1; lean: 5.69 [3.04 to 9.77] μmol × kg-1 × min-1; lean vs OIR P = .004; OIS: 2.63 [1.22 to 4.52] μmol × kg-1 × min-1; OIS vs OIR P = .09), a blunted median (IQR) improvement of adipose insulin sensitivity index (OIR: 0.043 [ 0.006 to 0.155]; lean: 0.277 [0.220 to 0.446]; lean vs OIR P = .002; OIS: 0.340 [0.048 to 0.491]; OIS vs OIR P = .08), and a reduced median (IQR) PYY response (OIR: 25.4 [14.8 to 36.4] pg/mL; lean: 51.3 [31.6 to 83.3] pg/mL; lean vs OIR P = .002; OIS: 54.3 [39.3 to 77.2] pg/mL; OIS vs OIR P = .011).

Conclusions and Relevance

In this cross-sectional study, lean, OIS, and OIR youth demonstrated different associations between colonic fermentation of indigestible dietary carbohydrates and the metabolic response, with OIR youth showing minimal metabolic modifications as compared with the other 2 groups.

Trial Registration

ClinicalTrials.gov Identifier: NCT03454828.

Clinical features and metabolic complications for non-alcoholic fatty liver disease (NAFLD) in youth with obesity

Pediatric obesity has become in the last forty years the most common metabolic disease in children and adolescents affecting about 25% of the pediatric population in the western world. As obesity worsens, a whole-body insulin resistance (IR) occurs. This phenomenon is more pronounced during adolescence, when youth experience a high degree of insulin resistance due the production of growth hormone. As IR progresses, the blunted control of insulin on adipose tissue lipolysis causes an increased flux of fatty acids with FFA deposition in ectopic tissues and organs such as the liver, leading to the development of NAFLD. In this brief review, we will discuss the clinical implications of IR and NAFLD in the context of pediatric obesity. We will review the pathogenesis and the link between these two entities, the major pathophysiologic underpinnings, including the role of genetics and metagenomics, how these two entities lead to the development of type 2 diabetes, and which are the therapeutic options for NAFLD in youth.

The role of oxidized lipid species in insulin resistance and NASH in children

During the last two decades, nonalcoholic fatty liver disease (NAFLD) has emerged as the most common hepatic disease in pediatrics, mainly owing to the rising prevalence of pediatric obesity. Epidemiological studies have shown that the progressive increase in NAFLD prevalence is associated not only with obesity but also with changes in dietary habits experienced by all age groups, characterized by the increased intake of added sugars and certain fatty acids. In this review article, we focus on the effect of oxidized fatty acids deriving from linoleic acid and arachidonic acid on the pathogenesis and progression of NAFLD in youth.

Insights from shotgun metagenomics into bacterial species and metabolic pathways associated with NAFLD in obese youth

Nonalcoholic fatty liver disease (NAFLD) is the most common form of liver disease and is often the precursor for more serious liver conditions such as nonalcoholic steatohepatitis and cirrhosis. Although the gut microbiome has been implicated in the development of NAFLD, the strong association of obesity with NAFLD and its effect on microbiome structure has made interpreting study outcomes difficult. In the present study, we examined the taxonomic and functional differences between the microbiomes of youth with obesity and with and without NAFLD. Shotgun metagenome sequencing was performed to profile the microbiomes of 36 subjects, half of whom were diagnosed with NAFLD using abdominal magnetic resonance imaging. Beta diversity analysis showed community-wide differences between the groups (p = 0.002). Specific taxonomic differences included increased relative abundances of the species Fusicatenibacter saccharivorans (p = 0.042), Romboutsia ilealis (p = 0.046), and Actinomyces sp. ICM47 (p = 0.0009), and a decrease of Bacteroides thetaiotamicron (p = 0.0002), in the NAFLD group as compared with the non-NAFLD group. At the phylum level, Bacteroidetes (p < 0.0001) was decreased in the NAFLD group. Functionally, branched-chain amino acid (p = 0.01343) and aromatic amino acid (p = 0.01343) synthesis pathways had increased relative abundances in the NAFLD group along with numerous energy use pathways, including pyruvate fermentation to acetate (p = 0.01318). Conclusion: Community-wide differences were noted based on NAFLD status, and individual bacterial species along with specific metabolic pathways were identified as potential drivers of these differences. The results of the present study support the idea that the NAFLD phenotype displays a differentiated microbial and functional signature from the obesity phenotype.

Growth differentiation factor 15 (GDF15) is associated with non-alcoholic fatty liver disease (NAFLD) in youth with overweight or obesity

OBJECTIVE

Growth differentiation factor 15 (GDF15) has been associated with food intake and weight regulation in response to metabolic stress. In animal models, it has been noted that it may play a role in the progression of non-alcoholic fatty liver disease (NAFLD), the leading cause of chronic liver disease in children.

DESIGN

In the current study, we explored the association of circulating plasma concentrations of GDF15 with NAFLD in youth with overweight/obesity, and whether changes in plasma concentrations in GDF15 parallel the changes in intrahepatic fat content (HFF%) over time.

METHODS

Plasma GDF15 concentrations were measured by ELISA in 175 youth with overweight/obesity who underwent an oral glucose tolerance test (OGTT) and magnetic resonance imaging (MRI) to assess intrahepatic, visceral, and subcutaneous fat. Baseline fasting GDF15 concentrations were measured in twenty-two overweight/obese youth who progressed (n = 11) or regressed (n = 11) in HFF% by more than 30% of original over a 2-year period.

RESULTS

Youth with NAFLD had significantly higher plasma concentrations of GDF15 than those without NAFLD, independent of age, sex, ethnicity, BMI z-score (BMIz), and visceral fat (P = 0.002). During the OGTT, there was a decline in plasma GDF15 concentrations from 0 to 60 min, but GDF15 concentrations returned to basal levels by the end of the study. There was a statistically significant association between change in HFF% and change in GDF15 (P = 0.008; r2 = 0.288) over ~2 years of follow-up.

CONCLUSIONS

These data suggest that plasma GDF15 concentrations change with change in intrahepatic fat content in youth with overweight/obesity and may serve as a biomarker for NAFLD in children.

Associations Between Single-Child Status and Metabolic Syndrome in Children and Adolescents in China

Objective: To evaluate the associations between single-child status and metabolic syndrome (MS) and to identify the highest risk group of MS among single children. Methods: Differences in participants' characteristics by sex were examined by Student's t-test for continuous variables and Pearson's chi-squared test for categorical variables. Multivariate logistic regression analysis was performed to estimate the odds ratios (OR) and 95% confidence intervals (CI) for MS and its components according to the single-child status. Radar maps were used to compare the composition of different components in MS. Results: In total, 11,784 (5,880 boys) children and adolescents were included in this study, with a mean age of (11.3 ± 3.1) years. MS was observed in 7.1% of participants, with a higher prevalence in boys (8.2%) than girls (5.9%) (P < 0.05). The prevalence of MS, elevated blood pressure and abdominal obesity in single children were higher than that in children with siblings, particularly in boys (P < 0.001). Elevated risk of abdominal obesity was observed in single children [boys (1.56, 95% CI: 1.31, 1.85), girls (1.40, 95% CI: 1.19, 1.63)], however, increased ORs of elevated blood pressure and metabolic syndrome were observed in single-child boys only (1.19, 95% CI: 1.01, 1.40 and 1.76, 95% CI: 1.34, 2.31, respectively). Results showed that a statistically significant association between single child status and MS was mainly observed in urban boys (2.04, 95% CI: 1.33, 3.12) and rural boys (1.50, 95% CI: 1.05, 2.15), but not in girls. Among all the combinations of MS, two combinations were significantly associated with the single-child status, including the combination of elevated blood pressure, abdominal and low HDL-C (1.45, 1.04, 2.04) and the combination of elevated blood pressure, abdominal obesity, low HDL-C and hypertriglyceridemia (2.04, 1.40, 3.06) (P < 0.05). Conclusions: The present study found that single children and adolescents had a higher risk of MS, elevated blood pressure and abdominal obesity. The associations were stronger in urban boys. Further attention should be directed to the prevention and control strategies targeting the high-risk population of MS.

Association of the T130I Variant of the HNF4A Gene with Metabolic Syndrome and Its Components in Mexican Children

Background: Metabolic syndrome (MetS), a cluster of risk factors, leads to cardiovascular disease (CVD) and type 2 diabetes (T2D). The second leading cause of mortality in Mexico is T2D. Genetic factors participate in the pathogenesis of MetS. The HNFA gene encodes a transcription factor that plays a crucial role in energy homeostasis by regulating the metabolism of glucose and lipids. This study aimed to investigate the association of the T130I variant of the HNF4A gene in Mexican children with MetS and its constituent components. Methods: The study was performed in 477 children from elementary schools. MetS was classified according to the de Ferranti definition. Biochemical parameters were measured and genotyping was performed. Logistic regression under a dominant genetic model was used to analyze the association of the T130I variant of the HNF4A gene with MetS and with its components separately. Results: The prevalence of MetS was 25.4%, and 18.9% in children who presented insulin resistance. Interestingly, this is the first time that a significant association between the T130I variant of the HNF4A gene and MetS has been reported [odds ratios (OR) = 2.31; 95% confidence interval (CI) 1.10-4.83; P = 0.026]. Moreover, carriers of the risk allele show higher abdominal obesity (OR = 1.20; 95% CI 1.09-4.50; P = 0.029). These findings highlight the active role of genetic variants in the pathogenesis of MetS in Mexican children. Conclusions: The high prevalence of children with MetS and insulin resistance places this population at an elevated risk of early CVD and T2D. The Clinical Trial Registration Number is HJM2315/14C.

Demographics and anthropometrics impact benefits of health intervention: data from the Reduce Obesity and Diabetes Project

OBJECTIVE

To determine the efficacy of a 4-month school-based health, nutrition and exercise intervention on body fatness and examine possible effects of demographic and anthropometric covariates.

METHODS

Height, weight, waist circumference and body composition were measured in a diverse population of 644 NYC middle school students (mean ± SD age 12.7 ± 0.9 years; 46% male; 38% Hispanic, 17% East Asian, 15% South Asian, 13.5% African American, 8.5% Caucasian, 8% other) during the fall and spring semesters. Year 1 participants (n = 322) were controls. Experimental participants (year 2, n = 469) received a 12-session classroom-based health and nutrition educational programme with an optional exercise intervention.

RESULTS

Groups were demographically and anthropometrically similar. The intervention resulted in significant reductions in indices of adiposity (ΔBMI z-scores [-0.035 ± 0.014; p = 0.01], Δ% body fat [-0.5 ± 0.2; p < 0.0001] and Δwaist circumference [-0.73 ± 0.30 cm; p < 0.0001]). Intervention effects were greater (p = 0.01) in men (ΔBMI z-score = -0.052 ± 0.015) versus women (0.022 ± 0.018), participants who were obese (ΔBMI z-score -0.083 ± 0.022 kg m-2) versus lean (-0.0097 ± 0.020 kg m-2) and South Asians (Δ% body fat -1.03 ± 0.35) versus total (-0.49 ± 0.20%) participants (p = 0.005).

CONCLUSION

A 4-month school-based health intervention was effective in decreasing measures of adiposity in middle school students, particularly in men, participants who were obese and South Asians.

Oxidized Derivatives of Linoleic Acid in Pediatric Metabolic Syndrome: Is Their Pathogenic Role Modulated by the Genetic Background and the Gut Microbiota?

We tested whether oxidized linoleic acid metabolites (OXLAM) are associated with pediatric metabolic syndrome (MetS) and a proatherogenic lipoprotein profile in 122 obese adolescents. Furthermore, we examined whether genetic and metagenomic factors can modulate plasma OXLAM concentrations by genotyping the fatty acid desaturase 1/2 (FADS) gene and by characterizing the gut microbiota. Subjects with MetS (n = 50) showed higher concentrations of 9- and 13-oxo-octadecadienoic acid (9- and 13-oxo-ODE) than subjects without MetS (n = 72). Both metabolites were associated with an adverse lipoprotein profile that was characterized by elevated very small-dense low-density lipoprotein (p < 0.005) and large very low-density lipoprotein particles (p = 0.01). Plasma 9- and 13-oxo-ODE were higher in subjects carrying the haplotype AA of the FADS gene cluster (p = 0.030 and p = 0.048, respectively). Furthermore, the reduced gut bacterial load was associated with higher 9-oxo-ODE concentrations (p = 0.035). This is the first study showing that high plasma OXLAM concentrations are associated with MetS and suggesting that the leading factors for high plasma concentrations of OXLAM might be the genetic background and the composition of the gut microbiota. In conclusion, high concentrations of 9- and 13-oxo-ODE, which may be the result of a genetic predisposition and a reduced gut bacterial load, are associated with MetS and with a proatherogenic lipoprotein profile in obese adolescents.

A low visceral fat proportion, independent of total body fat mass, protects obese adolescent girls against fatty liver and glucose dysregulation: a longitudinal study

BACKGROUND

The relative proportion of visceral fat (VAT) to subcutaneous fat (SAT) has been described as a major determinant of insulin resistance (IR). Our study sought to evaluate the effect of body fat distribution on glucose metabolism and intrahepatic fat content over time in a multiethnic cohort of obese adolescents.

SUBJECTS/METHODS

We examined markers of glucose metabolism by oral glucose tolerance test, and body fat distribution by abdominal MRI at baseline and after 19.2 ± 11.4 months in a cohort of 151 obese adolescents (88 girls, 63 boys; mean age 13.3 ± 3.4 years; mean BMI z-score 2.15 ± 0.70). Hepatic fat content was assessed by fast-gradient MRI in a subset of 93 subjects. We used the median value of VAT/(VAT + SAT) ratio within each gender at baseline to stratify our sample into high and low ratio groups (median value 0.0972 in girls and 0.118 in boys).

RESULTS

Female subjects tended to remain in their VAT/(VAT + SAT) category over time (change over follow-up P = 0.14 among girls, and P = 0.04 among boys). Baseline VAT/(VAT + SAT) strongly predicted the hepatic fat content, fasting insulin, 2-h glucose, and whole-body insulin sensitivity index at follow-up among girls, but not in boys.

CONCLUSIONS

The VAT/(VAT + SAT) ratio is a major determinant of impaired glucose metabolism and hepatic fat accumulation over time, and its effects are more pronounced in girls than in boys.

[Metabolic syndrome in children aged 6 to 12 years with obesity in public schools of seven municipalities in the State of Mexico]

OBJECTIVE

To estimate the prevalence of Metabolic Syndrome (MS), its components and its association with obesity and cardiovascular risk in school age children.

MATERIALS AND METHODS

A cross-sectional study of 1,017 children from 6 to 12 years of age. Anthropometric information, blood pressure, glucose, insulin, cholesterol, HDLc, LDLc and triglycerides were collected. The presence of MS and its components were determined by criteria of Cook et. al. (2003), modified for children and adolescents. In the analysis, the children were grouped by aged group of 6 to 9 and 10 to 12 years. The association between MS, obesity and cardiovascular risk was estimated using Student's t-test and Mann-Whitney U test, Chi-square test and logistic regression.

RESULTS

The MS was present with 54.6% in obese children. Obesity was the characteristic of greater association to suffer from MS with an OR=8.62 p<0.001.

CONCLUSIONS

MS is high among children with obesity, and is mostly associated with insulin resistance and atherogenic risk.

The rs626283 Variant in the MBOAT7 Gene is Associated with Insulin Resistance and Fatty Liver in Caucasian Obese Youth

OBJECTIVES

Non alcoholic fatty liver disease (NAFLD) is a leading cause of liver damage in childhood, its occurrence is influenced by genetic and environmental factors. Recently, the rs626283 polymorphism in the MBOAT7 gene has been found to be associated with alcoholic liver disease and NAFLD in adults.

METHODS

In a multiethnic cohort of obese children and adolescents we genotyped the rs626283 polymorphism in the MBOAT7 gene, evaluated insulin sensitivity by an oral glucose tolerance test, and measured the intra-hepatic fat content (HFF%) by magnetic resonance imaging.

RESULTS

In Caucasian youth, the minor allele (C) was associated with HFF% in (P=0.003), fasting insulin (P=0.03), area under the curve of glucose (P=0.03), and lower degree of whole-body insulin sensitivity (P=0.01) independent of age, gender, and body mass index z-score. A partial correlation showed that the association between the rs626283 variant and insulin resistance was driven by the presence of hepatic steatosis (P=0.009). However, there was no association between the rs626283 and hepatic steatosis among Hispanic and African American children and youth. The association between the rs626283 in the MBOAT7 gene among Caucasians was independent of the PNPLA3 rs738409, GCKR 1260326, and TM6SF2 rs58542926 (P=0.01). The four polymorphisms combined explained~19% of the HFF% in Caucasian obese children and adolescents.

CONCLUSIONS

The rs626283 variant in the MBOAT7 gene is associated with NAFLD and may affect glucose metabolism by modulating intra-hepatic fat content in Caucasian obese children and adolescents.

Trends of childhood diabetes in Southern Thailand: 20-year experience in a tertiary medical center

BACKGROUND

The incidence and/or prevalence of both childhood diabetes and the percent of type 2 diabetes mellitus (T2DM) cases in children and young adolescents have been increasing worldwide. This study aimed to examine the 20-year trends of childhood diabetes in a single tertiary medical center in Southern Thailand.

METHODS

The medical records of pediatric diabetic patients, aged 0-15 years, diagnosed at Songklanagarind Hospital from 1995 to 2014 were retrospectively reviewed.

RESULTS

During the 20-year period, 156 children were diagnosed with DM: 99 (63.4%) with T1DM, 43 (27.6%) with T2DM, 2 (1.3%) with neonatal diabetes, and 12 (7.7%) with secondary diabetes. The estimated incidence of new patients with diabetes per 100 000 per year doubled from 0.12 in 1995-2000, to 0.24-0.28 in 2001-2004, and further increased to 0.39-0.48 in 2005-2012 and 0.59-0.64 in 2013-2014; and also the proportion of T2DM cases increased from 10%-15% during 1995-2003 to 25%-30% during 2004-2008, and 35%-40% during 2009-2014. At the time of diagnosis, the fasting plasma glucose and glycated hemoglobin levels were significantly greater in T1DM than T2DM patients while the lipid profiles were more abnormal in T2DM than T1DM patients.

CONCLUSIONS

The estimated incidences of both T1DM and T2DM in pediatric patients have increased markedly over the 20-year period, and also the percentage of T2DM cases, from 10%-15% in 1995 to 35%-40% in 2014.

Elevated α-Hydroxybutyrate and Branched-Chain Amino Acid Levels Predict Deterioration of Glycemic Control in Adolescents

CONTEXT

Traditional risk factors for type 2 diabetes mellitus are weak predictors of changes in glucose tolerance and insulin sensitivity in youth.

OBJECTIVE

To identify early metabolic features of insulin resistance (IR) in youth and whether they predict deterioration of glycemic control.

DESIGN AND SETTING

A cross-sectional and longitudinal study was conducted at the Yale Pediatric Obesity Clinic.

PATIENTS AND INTERVENTION

Concentrations of α-hydroxybutyrate, β-hydroxybutyrate, lactate, and branched-chain amino acids (BCAAs) were measured by nuclear magnetic resonance spectroscopy in 78 nondiabetic adolescents during an oral glucose tolerance test (OGTT). Associations between baseline metabolic alterations and longitudinal changes in glucose control were tested in 16 subjects after a mean follow-up of 2.3 years.

MAIN OUTCOME MEASURES

The relationship between metabolite levels, parameters of IR, and glycemic control, and their progression over time.

RESULTS

Elevated fasting α-hydroxybutyrate levels were observed in adolescents with reduced insulin sensitivity after adjusting for age, sex, ethnicity, Tanner stage, and body mass index z-score (P = 0.014). Plasma α-hydroxybutyrate and BCAAs were increased throughout the course of the OGTT in this group (P < 0.03). Notably, borderline IR was associated with a progressive α-hydroxybutyrate decrease from elevated baseline concentrations to normal levels (P = 0.02). Increased baseline α-hydroxybutyrate concentrations were further associated with progressive worsening of glucose tolerance and disposition index.

CONCLUSION

α-Hydroxybutyrate and BCAA concentrations during an OGTT characterize insulin-resistant youth and predict worsening of glycemic control. These findings provide potential biomarkers for risk assessment of type 2 diabetes and new insights into IR pathogenesis.

The Association between Pediatric NAFLD and Common Genetic Variants

Non-alcoholic fatty liver disease (NAFLD) is one of the most common complications of obesity. Several studies have shown that genetic predisposition probably plays an important role in its pathogenesis. In fact, in the last few years a large number of genetic studies have provided compelling evidence that some gene variants, especially those in genes encoding proteins regulating lipid metabolism, are associated with intra-hepatic fat accumulation. Here we provide a comprehensive review of the gene variants that have affected the natural history of the disease.

Metabolic syndrome's risk factors and its association with nutritional status in schoolchildren

The metabolic risk factors (RF) to the diagnosis of metabolic syndrome (MetS) have been evidenced at early ages, including children. The aim of the present study was to identify the prevalence of RF to the diagnosis of MetS and its association with nutritional status of schoolchildren from 6 to 10 years old. A cross-sectional study was carried out in 505 students of municipal schools in Macae, Brazil, conducted from 2013 to 2014. The RF evaluated were: blood pressure (mm Hg), triglycerides (mmol/L), HDL-cholesterol (mmol/L) fasting glucose (mmol/L) and waist circumference (cm). At least one RF was present in 61% (n = 308) of the sample. By nutritional status, there was higher prevalence of RF in overweight/obese schoolchildren compared to those with normal weight, except in the concentration of HDL-c. The prevalence of one, two and three RF (MetS) were 34.7% (n = 175), 21.0% (n = 106) and 5.3% (n = 27), respectively. Two RF were more present in overweight (28.2% 95%CI 19.0; 39.0) and obese (41.5% 95%CI 31.4; 52.1) compared to normal weight children (13.5% 95%CI 9.9; 17.8). Three or more RF were more frequent among obese (25.5% 95%CI 17.0; 35.5) in relation to overweight (2.4% 95%CI 0.2; 8.2) and normal weight children (0.3% 95%CI 0; 1.7). The data indicate high prevalence of RF and its relationship with the magnitude of body weight excess. Therefore, the identification and early treatment of these RF might minimize the risk of MetS and related diseases.

Comparison of definitions for the metabolic syndrome in adolescents. The HELENA study

Various definitions are used to define metabolic syndrome in adolescents. This study aimed to compare, in terms of prevalence and differences, five frequently used definitions for this population: International Diabetes Federation, National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP) modified by Cook, pediatric American Heart Association (AHA), World Health Organization, and Jolliffe and Janssen. A sample of 1004 adolescents (12.5-17.0 years) from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study was considered. The components of the definitions (waist circumference/BMI, plasma lipids, glycemia, and blood pressure) were applied, and definitions were compared by using crosstabs, sensitivity, specificity, and kappa coefficient. The prevalence of metabolic syndrome varied from 1.6 to 3.8% depending on the used definitions. Crosstabs comparing the definitions showed the fewest cases being misclassified (having metabolic syndrome or not) between NCEP-ATP and AHA. Analyses for kappa coefficient, sensitivity, and specificity confirmed this finding.

CONCLUSION

The different definitions do not classify the same adolescents as having MS and prevalence varied between diagnostic methods. The modified NCEP-ATP and the AHA definitions were most analogous in defining subjects as having metabolic syndrome or not. What is known? • Metabolic syndrome is not only a problem of adulthood but is already present in children and adolescents. • Several diagnostic methods are used to define metabolic syndrome in adolescents. What is new? • Comparing the most frequently used definitions of metabolic syndrome in adolescents showed that they do not indicate the same adolescents as having metabolic syndrome. • The modified National Cholesterol Education Program Adult Treatment Panel III and the pediatric American Heart Association definitions were most analogous in defining subjects as having metabolic syndrome or not.

Components of the metabolic syndrome in early childhood in very-low-birth-weight infants and term small and appropriate for gestational age infants

BACKGROUND

Term small-for-gestational-age (SGA) and preterm born infants have an increased prevalence of metabolic syndrome components already in childhood. Our recent study in 2-y-old very-low-birth-weight (VLBW) infants was limited by the absence of a control group of term born children. We compared the metabolic syndrome components in early childhood in VLBW and term SGA infants to term appropriate for gestational age (AGA) infants.

METHODS

We included 38 VLBW children and 82 term born children (64 AGA/18 SGA). HDL cholesterol, triglycerides, glucose, and insulin were measured in blood samples taken at 1 y (term children) and 2 y (all children) of (corrected) age.

RESULTS

At 2 y corrected age, VLBW children have lower BMI and higher glucose level compared to AGA children. SGA children have lower BMI at 1 and 2 y of age and a high prevalence of high triglyceride levels at 1 y of age compared to AGA children. Total body fat is a significant determinant of HDL cholesterol and triglycerides and birth weight is a significant determinant of glucose at 2 y corrected age.

CONCLUSION

In early childhood, VLBW and term SGA children already have a high prevalence of some metabolic syndrome components compared to term AGA children.

Insulin Resistance, Metabolic Syndrome, and Polycystic Ovary Syndrome in Obese Youth

School nurses are well aware of the childhood obesity epidemic in the United States, as one in three youth are overweight or obese. Co-morbidities found in overweight or obese adults were not commonly found in youth three decades ago but are now increasingly "normal" as the obesity epidemic continues to evolve. This article is the second of six related articles discussing the co-morbidities of childhood obesity and discusses the complex association between obesity and insulin resistance, metabolic syndrome, and polycystic ovary syndrome. Insulin resistance increases up to 50% during puberty, which may help to explain why youth are more likely to develop co-morbidities as teens. Treatment of these disorders is focused on changing lifestyle habits, as a child cannot change his or her pubertal progression, ethnicity, or family history. School nurses and other personnel can assist youth with insulin resistance, metabolic syndrome, and polycystic ovary syndrome by supporting their efforts to make changes, reinforcing that insulin resistance is not necessarily type 2 diabetes even if the child is taking medication, and intervening with negative peer pressure.

Components of the metabolic syndrome in early childhood in very-low-birth-weight infants

BACKGROUND/AIMS

Term small-for-gestational-age and preterm born infants have an increased prevalence of metabolic syndrome components already in childhood. Data in very-low-birth-weight (VLBW) children are limited. We investigated the prevalence of metabolic syndrome components in VLBW infants at 2 years of corrected age.

METHODS

We included 38 children, participating in the Neonatal Insulin Replacement Therapy in Europe (NIRTURE) trial, a randomized controlled trial of early insulin therapy in VLBW infants. Metabolic syndrome components were defined as: body mass index SDS >2; blood pressure (systolic and/or diastolic) ≥ 90th percentile; triglycerides ≥ 0.98 mmol/l; high-density lipoprotein (HDL) cholesterol ≤ 1.03 mmol/l; glucose ≥ 5.6 mmol/l.

RESULTS

Two children (5%) had three metabolic syndrome components, 13 children (34%) had two components, and 11 children (29%) one component. 63% had raised blood pressure (prevalence higher in boys), 32% low HDL, and 30% high triglycerides (prevalence lower in early insulin group). In children with body mass index SDS <0, insulin-treated children had higher HDL than children with standard care. Systolic blood pressure was correlated with growth between term and 2 years of corrected age.

CONCLUSIONS

VLBW infants already have a high prevalence of metabolic syndrome components at 2 years of corrected age. Early insulin treatment could have long-term benefits for some of these components.

Obesity and the metabolic syndrome in pediatric psoriasis

Psoriasis is a common, chronic inflammatory dermatosis that often has its onset during childhood. There is increasing evidence that psoriasis in adults is associated with obesity, the metabolic syndrome, and associated comorbidities, including insulin resistance/type 2 diabetes, dyslipidemia, hypertension, and cardiovascular disease. This association is postulated to arise, at least in part, as a result of a systemic proinflammatory state that is mediated by adipose tissue. Several recent observational studies suggest that children and adolescents with psoriasis may be at increased risk of being overweight and obese as well as having an increased risk for features of the metabolic syndrome. Such an association raises concern with regards to the long-term health implications for children and adolescents with psoriasis and suggests that better awareness, evaluation, and management of overweight and obese patients and associated metabolic disease are warranted in this population.

Oxidized fatty acids: A potential pathogenic link between fatty liver and type 2 diabetes in obese adolescents?

In this study, we sought to investigate the putative association of the oxidized metabolites derived from linoleic acid (OXFAs) with pediatric nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2D). We studied 80 obese adolescents (age 13.3 ± 3.31 years; body mass index 33.0 ± 6.79 kg/m(2)), who underwent an oral glucose tolerance test, a magnetic resonance imaging (MRI) to measure the hepatic fat content, and the measurement of OXFAs and caspase-cleaved Citokeratin18 fragment (CK-18), a robust biomarker of liver injury. In this study, we show that only in subjects with hepatic steatosis, the OXFAs are associated with the CK-18 and that this association is modulated by the PNPLA3 rs738409 variant. We also show that most of the OXFAs are associated with a lower insulin secretion and that adolescents with T2D have higher levels of OXFAs than subjects with impaired or normal glucose tolerance. These observations lead to the hypothesis that the OXFAs may be the pathogenic link between liver injury and T2D and that the novel therapeutic opportunities targeting the OXFAs are possible in adolescents with early-onset NAFLD and T2D.

Enhanced production of erythritol by Yarrowia lipolytica on glycerol in repeated batch cultures

Erythritol is an important natural sweetener, industrially produced only by fermentation on glucose media. Glycerol is an important renewable feedstock as it is the major by-product of the biodiesel production process; here we present an alternative way to convert this low-cost substrate into value-added products, such as erythritol. Repeated batch cultures (RBC) were performed to improve the productivity of erythritol from pure and crude glycerol. An acetate negative mutant of Yarrowia lipolytica Wratislavia K1 was found to be applicable for the production of high amounts of erythritol in RBC. When 20 % of fresh replaced medium was added, the strain Wratislavia K1 was able to produce 220 g l (-1) erythritol, which corresponded to a 0.43 g g(-1) yield and a productivity of 0.54 g l(-1) h(-1). Additionally, the activity of the culture remained stable for more than 1,000 h, i.e., 11 cycles of the repeated batch bioreactors.

Metabolic syndrome in youth: current insights and novel serum biomarkers

Paralleling the worldwide epidemic in childhood obesity, in the last decade we have observed a rise in the prevalence of metabolic syndrome (MetS) in pediatrics. The MetS comprises a cluster of cardiovascular risk factors. Multiple definitions have been proposed for the syndrome in the pediatric age group, but they are very difficult to test and validate. Thus, in this paper we will discuss the current knowledge in pediatric MetS and the potential role of novel biomarkers in the pathogenesis and diagnosis of MetS.

The human gut microbiome and body metabolism: implications for obesity and diabetes

BACKGROUND

Obesity, metabolic syndrome, and type 2 diabetes are major public health challenges. Recently, interest has surged regarding the possible role of the intestinal microbiota as potential novel contributors to the increased prevalence of these 3 disorders.

CONTENT

Recent advances in microbial DNA sequencing technologies have resulted in the widespread application of whole-genome sequencing technologies for metagenomic DNA analysis of complex ecosystems such as the human gut. Current evidence suggests that the gut microbiota affect nutrient acquisition, energy harvest, and a myriad of host metabolic pathways.

CONCLUSION

Advances in the Human Microbiome Project and human metagenomics research will lead the way toward a greater understanding of the importance and role of the gut microbiome in metabolic disorders such as obesity, metabolic syndrome, and diabetes.

Obesity is positively associated with dehydroepiandrosterone sulfate concentrations at 7 y in Chilean children of normal birth weight

BACKGROUND

In low-birth-weight girls, obesity increases the risk of premature adrenarche and metabolic complications. However, the consistency of this association in normal-birth-weight children and its potential mediators remain unknown.

OBJECTIVES

The objectives were to assess the associations between obesity indicators and dehydroepiandrosterone sulfate (DHEAS) at 7 y of age and to evaluate the role of hormonal markers on these associations.

DESIGN

We assessed in 969 participants (6.9 y; 48% girls; all Tanner I) in the Growth and Obesity Chilean Cohort Study the associations between DHEAS and weight, BMI, waist circumference (WC), waist-to-height ratio, skinfold thickness, and percentage total fat (bioimpedance) and determined whether these associations were related to insulin, insulin-like growth factor I (IGF-I), and leptin. We also compared BMI and height growth from 0 to 7 y of age in nonobese and obese children with normal and high DHEAS (≥75th percentile) at 7 y.

RESULTS

DHEAS concentrations were similar between girls (30.3 ±1.86 μg/dL) and boys (29.4 ±1.73 μg/dL) (P > 0.05); 17.3% of children were obese (BMI-for-age z score ≥2 SD). Adiposity indicators were positively and similarly associated with DHEAS [ie, BMI, β standardized regression coefficient: 0.23 (95% CI: 0.17, 0.29); WC, β standardized regression coefficient: 0.23 (95% CI: 0.16, 0.30)]; these associations were only partially related to IGF-I and leptin. Obese children had twice the risk of high DHEAS (OR: 2.16; 95% CI: 1.51, 3.09); at 7 y, obese children with high DHEAS were fatter and more centrally obese than their counterparts (P < 0.05), although their previous growth was similar (P > 0.05). None of the results differed by sex (P > 0.05).

CONCLUSION

In children of normal birth weight, obesity is positively associated with DHEAS at 7 y of age.

Management of psychotropic medication side effects in children and adolescents

This article is a review of several of the most concerning side effects of psychotropic medications in children and adolescents. An emphasis is placed on review of the prevalence, presentation, monitoring, and evidence-based management of these side effects.