Longitudinal analysis of vitamin D levels considering sunshine duration and suggestion for a standardised approach for vitamin D supplementation in children and adolescents with obesity.

BACKGROUND: Children with obesity have low 25 hydroxy-vitamin D (25-OH-D3) levels compared to lean children. Recommendations on when to start vitamin D supplementation differ largely between countries. Longitudinal data on 25-OH-D3 levels to guide treatment decisions are scarce since they are largely influenced by solar radiation and are difficult to compare. METHODS: We carried out a retrospective analysis of multiple 25-OH-D3 and parathyroid hormone (PTH) measurements in a cohort of 543 patients without vitamin D supplementation. All measurements were taken at the local paediatric obesity clinic as documented in the German-Austrian-Swiss APV (Prospective Documentation of Overweight Children and Adolescents) registry from 2009 to 2019. Serial 25-OH-D3 and PTH levels were adjusted for sunshine duration over the last 30 days to account for seasonal variation, as well as for sex and body mass index (BMI). We further performed an exploratory analysis of the association of sunshine duration, sex, BMI SDS (standard deviation score), abnormal lipid levels or dysglycemia with the 25-OH-D3 trend. RESULTS: 229 obese patients (mean BMI SDS: 2,58 (± 0,56), 53% females, mean age: 12 (± 3) years, range: 2-21 years) with two, 115 with three and 96 with four repeated 25-OH-D3 measurements were identified. Mean adjusted 25-OH-D3 (48.2 nmol/l) and PTH (34.9 ng/l) levels remained stable over 120 weeks. 5% of the patients had an elevated PTH > 65 ng/l. High total cholesterol ≥ 200 mg/dl and high triglycerides ≥ 130 mg/dl were associated with higher 25-OH-D3 levels. CONCLUSION: We propose a simple method to include sunshine duration in the analysis of 25-OH-D3 levels to minimise the bias of seasonal variation. Based on our data we established the pragmatic strategy of limiting vitamin D supplementation to patients with biochemical signs of mineralisation disorders such as elevated PTH and alkaline phosphatase (AP). In children with normal PTH and AP we recommend adjustment of calcium intake and increase of outdoor activity instead.

Twelve-Month Outcomes after Metabolic and Bariatric Surgery among Youths Participating in a Structured Preparation and Follow-Up Program: Results of the Youth with Extreme Obesity Study.

INTRODUCTION: While invasive and associated with risks, metabolic and bariatric surgery (MBS) can promote sustained weight loss and substantial health benefits in youths with extreme obesity. The path toward informed decision making for or against MBS is poorly characterized and postoperative follow-up to assess risks and benefits is inconsistent. In youths with extreme obesity, we aimed to evaluate decision making toward MBS, as well as MBS outcomes and adherence with follow-up and recommendations in the setting of a structured pre- and post-MBS program. METHODS: Participants were recruited in the setting of the multicenter "Youth with Extreme Obesity Study" (YES). YES is a cohort study in adolescents and young adults aged 14-24 years with obesity (BMI ≥30.0 kg/m2) who were recruited at four medical centers and one job center in Germany between 2012 and 2018. Participants at two medical centers with BMI ≥35 kg/m2, aged 14-24 years, and interested in pursuing MBS were included in the subproject 3 "Safety and effectiveness of weight loss surgery in adolescents with severe obesity within a structured pre- and post-surgery treatment program - an observational study" that comprised a 2-months pre- and 12-months post-MBS program. RESULTS: Twenty-eight of 169 youths (17%) with BMI ≥35 kg/m2 were interested in MBS. Twenty-six fulfilled published eligibility criteria for MBS and participated in the structured pre-MBS preparation program. Of these, 9 participants (2 females) decided against, and 17 (n = 11 females) decided for MBS (sleeve gastrectomy). The 12-month follow-up rate was high (16/17 [94%]) and all participants achieved significant weight reduction (ΔBMI: -16.1 ± 5.6 kg/m2). Eleven of 16 participants (69%) reported taking the prescribed dietary supplements in the first year after MBS, but only five of them (31%) did so daily. In contrast to the high 12-month retention rate, follow-up after completion of the structured program was low at 24-months (9/16 [56%]) and at 36-months (5/15 [36%]), respectively. CONCLUSION: Participants demonstrated active decision making for or against MBS and high adherence with the structured pre- and 12 months post-MBS program, but participation was low thereafter. These findings endorse the need for longer term structured post-MBS programs to capture long-term outcomes and provide adequate care in this vulnerable group at the transition to adulthood.

Alterations of Central Liver Metabolism of Pediatric Patients with Non-Alcoholic Fatty Liver Disease.

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in children and is associated with overweight and insulin resistance (IR). Almost nothing is known about in vivo alterations of liver metabolism in NAFLD, especially in the early stages of non-alcoholic steatohepatitis (NASH). Here, we used a complex mathematical model of liver metabolism to quantify the central hepatic metabolic functions of 71 children with biopsy-proven NAFLD. For each patient, a personalized model variant was generated based on enzyme abundances determined by mass spectroscopy. Our analysis revealed statistically significant alterations in the hepatic carbohydrate, lipid, and ammonia metabolism, which increased with the degree of obesity and severity of NAFLD. Histologic features of NASH and IR displayed opposing associations with changes in carbohydrate and lipid metabolism but synergistically decreased urea synthesis in favor of the increased release of glutamine, a driver of liver fibrosis. Taken together, our study reveals already significant alterations in the NASH liver of pediatric patients, which, however, are differently modulated by the simultaneous presence of IR.

Surgery for the treatment of obesity in children and adolescents.

BACKGROUND: Child and adolescent overweight and obesity have increased globally and are associated with significant short- and long-term health consequences. OBJECTIVES: To assess the effects of surgery for treating obesity in childhood and adolescence. SEARCH METHODS: For this update, we searched Cochrane Central Register of Controlled Trials, MEDLINE, Latin American and Caribbean Health Science Information database (LILACS), World Health Organization International Clinical Trials Registry Platform (ICTRP)and ClinicalTrials.gov on 20 August 2021 (date of the last search for all databases). We did not apply language restrictions. We checked references of identified studies and systematic reviews. SELECTION CRITERIA: We selected randomised controlled trials (RCTs) of surgical interventions for treating obesity in children and adolescents (age < 18 years) with a minimum of six months of follow-up. We excluded interventions that specifically dealt with the treatment of eating disorders or type 2 diabetes, or which included participants with a secondary or syndromic cause of obesity, or who were pregnant. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Two review authors independently extracted data and assessed the risk of bias using the Cochrane Risk of Bias 2.0 tool. Where necessary, we contacted authors for additional information. MAIN RESULTS: With this update, we did not find any new RCTs. Therefore, this updated review still includes a single RCT (a total of 50 participants, 25 in both the intervention and comparator groups). The intervention focused on laparoscopic adjustable gastric banding surgery, which was compared to a control group receiving a multi-component lifestyle programme. The participating population consisted of Australian adolescents (a higher proportion of girls than boys) aged 14 to 18 years, with a mean age of 16.5 and 16.6 years in the gastric banding and lifestyle groups, respectively. The trial was conducted in a private hospital, receiving funding from the gastric banding manufacturer. For most of the outcomes, we identified a high risk of bias, mainly due to bias due to missing outcome data. Laparoscopic gastric banding surgery may reduce BMI by a mean difference (MD) of -11.40 kg/m2 (95% CI -13.22 to -9.58) and weight by -31.60 kg (95% CI -36.66 to -26.54) compared to a multi-component lifestyle programme at two years follow-up. The evidence is very uncertain due to serious imprecision and a high risk of bias. Adverse events were reported in 12/25 (48%) participants in the intervention group compared to 11/25 (44%) in the control group. A total of 28% of the adolescents undergoing gastric banding required revisional surgery. The evidence is very uncertain due to serious imprecision and a high risk of bias. At two years of follow-up, laparoscopic gastric banding surgery may increase health-related quality of life in the physical functioning scores by an MD of 16.30 (95% CI 4.90 to 27.70) and change in health scores by an MD of 0.82 (95% CI 0.18 to 1.46) compared to the lifestyle group. The evidence is very uncertain due to serious imprecision and a high risk of bias. No data were reported for all-cause mortality, behaviour change, participants' views of the intervention and socioeconomic effects. Finally, we have identified three ongoing RCTs that are evaluating the efficacy and safety of metabolic and bariatric surgery in children and adolescents. AUTHORS' CONCLUSIONS: Laparoscopic gastric banding led to greater body weight loss compared to a multi-component lifestyle program in one small study with 50 participants. These results have very limited application, primarily due to more recent recommendations derived from observation studies to avoid the use of banding in youth due to long-term reoperation rates. This systematic review update still highlights the lack of RCTs in this field. The authors are concerned that there may be ethical barriers to RTCs in this field, despite the lack of other effective therapies for severe obesity in children and adolescents and the significant morbidity and premature mortality caused by childhood obesity. Nevertheless, future studies, whether pre-registered and planned non-randomised or pragmatic randomised trials, should assess the impact of the surgical procedure and post-operative care to minimise adverse events, including the need for post-operative adjustments and revisional surgery. Long-term follow-up is also critical to comprehensively assess the impact of surgery as participants enter adulthood.

Comparison of two methods of cardiopulmonary exercise testing for assessing physical fitness in children and adolescents with extreme obesity.

It is well-known that children and adolescents with obesity have increased over recent decades which in turn carries greater risk of co-morbidities and poses a preventive as well as a therapeutic challenge. Currently, there are limited recommendations available on proven methods for recording physical fitness in children and adolescents presenting with extreme obesity. In this study, twenty participants, aged 12-17 years, with a body mass index (BMI) above the 99.5th percentile, were comparatively assessed, using a correlation between their physical fitness on a bicycle (BC) and treadmill (TM) cardiopulmonary exercise testing (CPET) with a lactate diagnostic. The results of the BC and the TM were as follows: maximum heart rate (HRmax) 186.4 ± 8.6 beats per minute (bpm) vs. 190.8 ± 8.8 bpm, peak oxygen consumption (VO2peak/kg) 23.5 ± 2.9 ml/min/kg vs. 25.4 ± 3.1 ml/min/kg, and maximum lactate (Lamax) 6.4 ± 1.6 mmol/l vs. 5.6 ± 1.4 mmol/l. The values of HRmax and VO2peak/kg were significantly higher for adolescents tested on the TM. However, no significant difference was observed in either Lamax values or between the genders.    Conclusions: The higher values of HRmax and VO2peak/kg could be attributed to the activation of a higher percentage of muscle mass on the TM. Lower Lamax values on the TM suggest maximum physical exertion was not achieved. This could be due to the extreme body weight carried by the participants. Both the BC and the TM CPET could be used for assessing physical fitness in children and adolescents with extreme obesity but should not be used interchangeably. What is Known: • Currently, there are only limited recommendations available on proven methods for recording physical fitness in children and adolescents with extreme obesity available. What is New: • Cardiopulmonary exercise testing with maximum physical exertion has been shown to be feasible in children and adolescents with extreme obesity. The results obtained from this study demonstrated that both a bicycle and a treadmill can be effectively used for assessing the physical fitness levels in children and adolescents with extreme obesity.

Long-term outcomes of bariatric surgery in patients with bi-allelic mutations in the POMC, LEPR, and MC4R genes.

BACKGROUND: Gene mutations in the leptin-melanocortin signaling cascade lead to hyperphagia and severe early onset obesity. In most cases, multimodal conservative treatment (increased physical activity, reduced caloric intake) is not successful to stabilize body weight and control hyperphagia. OBJECTIVES: To examine bariatric surgery as a therapeutic option for patients with genetic obesity. SETTING: Three major academic, specialized medical centers. METHODS: In 3 clinical centers, we retrospectively analyzed the outcomes of bariatric surgery performed in 8 patients with monogenic forms of obesity with bi-allelic variants in the genes LEPR (n = 5), POMC (n = 2), and MC4R (n = 1). RESULTS: In this group of patients with monogenic obesity, initial bariatric surgery was performed at a median age of 19 years (interquartile range [IQR], 16-23.8 yr). All patients initially experienced weight loss after each bariatric surgery, which was followed by substantial weight regain. In total, bariatric surgery led to a median maximum reduction of body weight of -21.5 kg (IQR, -36.3 to -2.9 kg), median percent excess weight loss (%EWL) of -47.5 %EWL (IQR, -57.6 to -28.9 %EWL). This body weight reduction was followed by median weight regain of 24.1 kg (IQR: 10.0 to 42.0 kg), leading to a final weight change of -24.2 % EWL (IQR: -37.6 to -5.4 %EWL) after a maximum duration of 19 years post surgery. In one patient, bariatric surgery was accompanied by significant complications, including vitamin deficiencies and hernia development. CONCLUSION: The indication for bariatric surgery in patients with monogenic obesity based on bi-allelic gene mutations and its benefit/risk balance has to be evaluated very cautiously by specialized centers. Furthermore, to avoid an unsuccessful operation, preoperative genetic testing of patients with a history of early onset obesity might be essential, even more since novel pharmacological treatment options are expected.

A Melanocortin-4 Receptor Agonist Induces Skin and Hair Pigmentation in Patients with Monogenic Mutations in the Leptin-Melanocortin Pathway.

BACKGROUND AND OBJECTIVES: Gene mutations within the leptin-melanocortin signaling pathway lead to severe early-onset obesity. Recently, a phase 2 trial evaluated new pharmacological treatment options with the MC4R agonist setmelanotide in patients with mutations in the genes encoding proopiomelanocortin (POMC) and leptin receptor (LEPR). During treatment with setmelanotide, changes in skin pigmentation were observed, probably due to off-target effects on the closely related melanocortin 1 receptor (MC1R). Here, we describe in detail the findings of dermatological examinations and measurements of skin pigmentation during this treatment over time and discuss the impact of these changes on patient safety. METHODS: In an investigator-initiated, phase 2, open-label pilot study, 2 patients with loss-of-function POMC gene mutations and 3 patients with loss-of-function variants in LEPR were treated with the MC4R agonist setmelanotide. Dermatological examination, dermoscopy, whole body photographic documentation, and spectrophotometric measurements were performed at screening visit and approximately every 3 months during the course of the study. RESULTS: We report the results of a maximum treatment duration of 46 months. Skin pigmentation increased in all treated patients, as confirmed by spectrophotometry. During continuous treatment, the current results indicate that elevated tanning intensity levels may stabilize over time. Lips and nevi also darkened. In red-haired study participants, hair color changed to brown after initiation of setmelanotide treatment. DISCUSSION: Setmelanotide treatment leads to skin tanning and occasionally hair color darkening in both POMC- and LEPR-deficient patients. No malignant skin changes were observed in the patients of this study. However, the results highlight the importance of regular skin examinations before and during MC4R agonist treatment.

Comparison of cardiovascular risk factors between children and adolescents with classes III and IV obesity: findings from the APV cohort.

OBJECTIVE: Obesity is associated with many cardiovascular risk factors (CVRF) in childhood. There is an ongoing discussion whether there is a linear relationship between degree of overweight and deterioration of CVRFs justifying body mass index (BMI) cut-offs for treatment decisions. METHODS: We studied the impact of BMI-SDS on blood pressure, lipids, and glucose metabolism in 76,660 children (aged 5-25 years) subdivided in five groups: overweight (BMI-SDS 1.3 to <1.8), obesity class I (BMI-SDS 1.8 to <2.3), class II (BMI-SDS 2.3-2.8), class III (BMI-SDS > 2.8-3.3), and class IV (BMI-SDS > 3.3). Analyses were stratified by age and sex. RESULTS: We found a relationship between BMI-SDS and blood pressure, triglycerides, HDL cholesterol, liver enzymes, and the triglycerides-HDL-cholesterol ratio at any age and sex. Many of these associations lost significance when comparing children with obesity classes III and IV: In females < 14 years and males < 12 years triglycerides and glucose parameters did not differ significantly between classes IV and III obesity. Prevalence of dyslipidemia was significantly higher in class IV compared to class III obesity only in females ≥ 14 years and males ≥ 12 years but not in younger children. In girls < 14 years and in boys of any age, the prevalences of type 2 diabetes mellitus did not differ between classes III and IV obesity. CONCLUSIONS: Since a BMI above the highest BMI cut-off was not associated consistently with dyslipidemia and disturbed glucose metabolism in every age group both in boys and girls, measurements of CVRFs instead of BMI cut-off seem preferable to guide different treatment approaches in obesity such as medications or bariatric surgery.

How histopathologic changes in pediatric nonalcoholic fatty liver disease influence in vivo liver stiffness.

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in children and adolescents. About 30% of patients with NAFLD progress to the more severe condition of nonalcoholic steatohepatitis (NASH), which is typically diagnosed using liver biopsy. Liver stiffness (LS) quantified by elastography is a promising imaging marker for the noninvasive assessment of NAFLD and NASH in pediatric patients. However, the link between LS and specific histopathologic features used for clinical staging of NAFLD is not well defined. Furthermore, LS data reported in the literature can vary greatly due to the use of different measurement techniques. Uniquely, time-harmonic elastography (THE) based on ultrasound and magnetic resonance elastography (MRE) use the same mechanical stimulation, allowing us to compare LS in biopsy-proven NAFLD previously determined by THE and MRE in 67 and 50 adolescents, respectively. In the present work, we analyzed the influence of seven distinct histopathologic features on LS, including septal infiltration, bridging fibrosis, pericellular fibrosis, hepatocellular ballooning, portal inflammation, lobular inflammation, and steatosis. LS was highly correlated with periportal and lobular fibrosis as well as hepatocellular ballooning while no independent association was found for inflammation and steatosis. Based on this analysis, we propose a composite elastography score (CES) which includes the four key histopathologic features identified as mechanically relevant. Interestingly, CES-relevant histopathologic features were associated with zonal distribution patterns of pediatric NAFLD. Mechano-structural changes associated with NAFLD progression can be histopathologically staged using the CES, which is easily determined noninvasively based on LS measured by time-harmonic elastography.

Hepatocyte-specific NRF2 activation controls fibrogenesis and carcinogenesis in steatohepatitis.

BACKGROUND & AIMS: In chronic liver diseases, inflammation induces oxidative stress and thus may contribute to the progression of liver injury, fibrosis, and carcinogenesis. The KEAP1/NRF2 axis is a major regulator of cellular redox balance. In the present study, we investigated whether the KEAP1/NRF2 system is involved in liver disease progression in humans and mice. METHODS: The clinical relevance of oxidative stress was investigated by liver RNA sequencing in a well-characterized cohort of patients with non-alcoholic fatty liver disease (n = 63) and correlated with histological and clinical parameters. For functional analysis, hepatocyte-specific Nemo knockout (NEMOΔhepa) mice were crossed with hepatocyte-specific Keap1 knockout (KEAP1Δhepa) mice. RESULTS: Immunohistochemical analysis of human liver sections showed increased oxidative stress and high NRF2 expression in patients with chronic liver disease. RNA sequencing of liver samples in a human pediatric NAFLD cohort revealed a significant increase of NRF2 activation correlating with the grade of inflammation, but not with the grade of steatosis, which could be confirmed in a second adult NASH cohort. In mice, microarray analysis revealed that Keap1 deletion induces NRF2 target genes involved in glutathione metabolism and xenobiotic stress (e.g., Nqo1). Furthermore, deficiency of one of the most important antioxidants, glutathione (GSH), in NEMOΔhepa livers was rescued after deleting Keap1. As a consequence, NEMOΔhepa/KEAP1Δhepa livers showed reduced apoptosis compared to NEMOΔhepa livers as well as a dramatic downregulation of genes involved in cell cycle regulation and DNA replication. Consequently, NEMOΔhepa/KEAP1Δhepa compared to NEMOΔhepa livers displayed decreased fibrogenesis, lower tumor incidence, reduced tumor number, and decreased tumor size. CONCLUSIONS: NRF2 activation in patients with non-alcoholic steatohepatitis correlates with the grade of inflammation, but not steatosis. Functional analysis in mice demonstrated that NRF2 activation in chronic liver disease is protective by ameliorating fibrogenesis, initiation and progression of hepatocellular carcinogenesis. LAY SUMMARY: The KEAP1 (Kelch-like ECH-associated protein-1)/NRF2 (erythroid 2-related factor 2) axis has a major role in regulating cellular redox balance. Herein, we show that NRF2 activity correlates with the grade of inflammation in patients with non-alcoholic steatohepatitis. Functional studies in mice actually show that NRF2 activation, resulting from KEAP1 deletion, protects against fibrosis and cancer.

[Innovative medical care concepts for adolescents with severe obesity]. / Innovative medizinische Betreuungskonzepte für Jugendliche mit extremer Adipositas.

There is no convincing, science-based treatment or care concept for adolescents with severe obesity in Germany or other countries. The affected young people have an increased risk of numerous somatic comorbidities (e.g. type 2 diabetes mellitus, orthopaedic disorders and sleep apnoea syndrome), mental disorders (e.g. depression and anxiety disorders, social phobia and self-harming behaviour), as well as social isolation (e.g. avoidance of school and unemployment), which develops due to functional impairments and stigmatisation. Despite the negative effects of severe obesity in adolescence, these young people are medically difficult to reach and treat. Only a small percentage of patients actively seek treatment.Aware of these difficulties, the German multi-centre Youth with Extreme Obesity (YES) Study (funded by the German Ministry of Education and Science; 01 GI 1120 A and B) was carried out between 2012 and 2019 with the aim of improving care concepts for this neglected group of young people. In our article, we show possible supply routes. These consist of accompanying the adolescents and treating their comorbidities, sustainable lifestyle interventions in a protected environment and treatment for weight reduction through bariatric surgery. The overriding goals for patients are an increase in self-esteem, early diagnosis and treatment of secondary diseases and integration into the training and labour market.

Associations between circulating inflammatory markers, diabetes type and complications in youth.

BACKGROUND: Inflammation is implicated in the pathogenesis of diabetes and its complications in adults. Little is known about the relative contribution of inflammation in common types of diabetes in youth: type 1 diabetes (T1D), type 2 diabetes (T2D), and cystic fibrosis-related diabetes (CFRD). This study investigates inflammatory markers by diabetes type and complication status, and assesses indicators of inflammation and complications. METHODS: A cross-sectional study of 134 T1D, 32 T2D, 32 CFRD and 48 subjects without diabetes (including 11 with CF and normal glucose tolerance) was undertaken. Inflammation was assessed by sE-selectin by ELISA, hsCRP by turbidimetry, WCC and ESR. Nephropathy was defined by albuminuria, autonomic neuropathy by heart rate variability, and peripheral neuropathy by vibration and thermal threshold testing and retinopathy by seven-field stereoscopic fundus photography. Descriptive statistics, parametric and non-parametric ANOVA and regression analyses were performed, with significance at P < .05. RESULTS: Of 198 diabetic participants; 49% female, mean (SD) age, median diabetes duration and median HbA1c were 16 (2.5) and 6 (3-9) years, and 8.1 (6.9-9.3)%, respectively. All inflammatory markers were lower in T1D than in other diabetes groups (P < .05) but higher than in non-diabetic controls. T2D (n = 32) and CFRD (n = 32) subjects had comparable elevated levels of inflammation. Body mass index (BMI) was a strong independent explanatory variable of inflammation. In multivariate analysis, hsCRP and ESR were associated with complications in addition to HbA1c, BMI, and diastolic BP. CONCLUSIONS: Circulating inflammatory markers are elevated in adolescents with diabetes, being higher and comparable in T2D and CFRD than in T1D. Inflammation is independently associated with diabetes complications, consistent with inflammation driving vascular pathology in diabetes.

Evaluation of a rare glucose-dependent insulinotropic polypeptide receptor variant in a patient with diabetes.

AIMS: Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone that augments insulin secretion in pancreatic ß-cells via its glucose-dependent insulinotropic polypeptide receptor (GIPR). Recent genome-wide association studies identified a single nucleotide variant (SNV) in the GIPR encoding gene (GIPR), rs1800437, that is associated with obesity and insulin resistance. In the present study, we tested whether GIPR variants contribute to obesity and disturb glucose homeostasis or diabetes in specific patient populations. MATERIALS AND METHODS: Exon sequencing of GIPR was performed in 164 children with obesity and insulin resistance and in 80 children with paediatric-onset diabetes of unknown origin. The Study of Health in Pomerania (SHIP) cohort, comprising 8320 adults, was screened for the GIPR variant Arg217Leu. GIPR variants were expressed in COS-7 cells and cAMP production was measured upon stimulation with GIP. Cell surface expression was determined by ELISA. Protein homology modelling of the GIPR variants was performed to extract three-dimensional information of the receptor. RESULTS: A heterozygous missense GIPR variant Arg217Leu (rs200485112) was identified in a patient of Asian ancestry. Functional characterization of Arg217Leu revealed reduced surface expression and signalling after GIP challenge. The homology model of the GIPR structure supports the observed functional relevance of Arg217Leu. CONCLUSION: In vitro functional studies and protein homology modelling indicate a potential relevance of the GIPR variant Arg217Leu in receptor function. The heterozygous variant displayed partial co-segregation with diabetes. Based on these findings, we suggest that GIPR variants may play a role in disturbed glucose homeostasis and may be of clinical relevance in homozygous patients.

Tomoelastography for the Evaluation of Pediatric Nonalcoholic Fatty Liver Disease.

OBJECTIVES: Today, nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in children and adults alike. Yet, the noninvasive evaluation of disease severity remains a diagnostic challenge. In this study, we apply multifrequency magnetic resonance elastography (mMRE) for the quantification of liver steatosis and fibrosis in adolescents with NAFLD. METHODS: Fifty adolescents (age range, 10-17 years; mean BMI, 33.9 kg/m; range, 21.4-42.1 kg/m) with biopsy-proven NAFLD were included in this prospective study. Multifrequency magnetic resonance elastography was performed using external multifrequency vibrations of 30 to 60 Hz and tomoelastography postprocessing, resulting in penetration rate (a) and shear wave speed (c). Hepatic fat fraction was determined using Dixon method. The diagnostic accuracy of mMRE in grading liver steatosis and staging liver fibrosis was assessed by receiver operating characteristic curve analysis. RESULTS: Multifrequency magnetic resonance elastography parameters c and a were independently sensitive to fibrosis and steatosis, respectively, providing area under the receiver operating characteristic values of 0.79 (95% confidence interval [CI], 0.66-0.92), 0.91 (95% CI, 0.83-0.99), and 0.90 (95% CI, 0.80-0.99) for the detection of any (≥F1), moderate (≥F2), and advanced (≥F3) fibrosis, and 0.87 (95% CI, 0.76-0.97) and 0.87 (95% CI, 0.77-0.96) for the detection of moderate (≥S2) and severe (S3) steatosis. CONCLUSIONS: One mMRE measurement provides 2 independent parameters with very good diagnostic accuracy in detecting moderate and advanced fibrosis as well as moderate and severe steatosis in pediatric NAFLD.

Genetic determinants of steatosis and fibrosis progression in paediatric non-alcoholic fatty liver disease.

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in children and adolescents today. In comparison with adult disease, paediatric NAFLD may show a periportal localization, which is associated with advanced fibrosis. This study aimed to assess the role of genetic risk variants for histological disease pattern and severity in childhood NAFLD. METHODS: We studied 14 single nucleotide polymorphisms (SNP) in a cohort of 70 adolescents with biopsy-proven NAFLD. Genotype was compared to an adult control cohort (n = 200) and analysed in relation to histological disease severity and liver tissue proteomics. RESULTS: Three of the 14 SNPs were significantly associated with paediatric NAFLD after FDR adjustment, rs738409 (PNPLA3, P = 2.80 × 10-06 ), rs1044498 (ENPP1, P = 0.0091) and rs780094 (GCKR, P = 0.0281). The severity of steatosis was critically associated with rs738409 (OR=3.25; 95% CI: 1.72-6.52, FDR-adjusted P = 0.0070). The strongest variants associated with severity of fibrosis were rs1260326, rs780094 (both GCKR) and rs659366 (UCP2). PNPLA3 was associated with a portal pattern of steatosis, inflammation and fibrosis. Proteome profiling revealed decreasing levels of GCKR protein with increasing carriage of the rs1260326/rs780094 minor alleles and downregulation of the retinol pathway in rs738409 G/G carriers. Computational metabolic modelling highlighted functional relevance of PNPLA3, GCKR and UCP2 for NAFLD development. CONCLUSIONS: This study provides evidence for the role of PNPLA3 as a determinant of portal NAFLD localization and severity of portal fibrosis in children and adolescents, the risk variant being associated with an impaired hepatic retinol metabolism.

US Time-Harmonic Elastography: Detection of Liver Fibrosis in Adolescents with Extreme Obesity with Nonalcoholic Fatty Liver Disease.

Purpose To measure in vivo liver stiffness by using US time-harmonic elastography in a cohort of pediatric patients who were overweight to extremely obese with nonalcoholic fatty liver disease (NAFLD) and to evaluate the diagnostic value of time-harmonic elastography for differentiating stages of fibrosis associated with progressive disease. Materials and Methods In this prospective study, 67 consecutive adolescents (age range, 10-17 years; mean body mass index, 34.7 kg/m2; range, 21.4-50.4 kg/m2) with biopsy-proven NAFLD were enrolled. Liver stiffness was measured by using time-harmonic elastography based on externally induced continuous vibrations of 30 Hz to 60 Hz frequency and real-time B-mode-guided wave profile analysis covering tissue depths of up to 14 cm. The diagnostic accuracy of time-harmonic elastography in staging liver fibrosis was assessed with area under the receiver operating characteristic curve (AUC) analysis. Liver stiffness cutoffs for the differentiation of fibrosis stages were identified based on the highest Youden index. Results Time-harmonic elastography was feasible in all patients (0% failure rate), including 70% (n = 47) of individuals with extreme obesity (body mass index above the 99.5th percentile). AUC analysis for the detection of any fibrosis (≥ stage F1), moderate fibrosis (≥ stage F2), and advanced fibrosis (≥ stage F3) was 0.88 (95% confidence interval [CI]: 0.80, 0.96), 0.99 (95% CI: 0.98, 1.00), and 0.88 (95% CI: 0.80, 0.96), respectively. The best liver stiffness cutoffs were 1.52 m/sec for at least stage F1, 1.62 m/sec for at least stage F2, and 1.64 m/sec for at least stage F3. Conclusion US time-harmonic elastography allows accurate detection of moderate fibrosis even in pediatric patients with extreme obesity. Larger clinical trials are warranted to confirm the accuracy of US time-harmonic elastography.

MC4R agonism promotes durable weight loss in patients with leptin receptor deficiency.

Genetic defects underlying the melanocortin-4 receptor (MC4R) signaling pathway lead to severe obesity. Three severely obese LEPR-deficient individuals were administered the MC4R agonist setmelanotide, resulting in substantial and durable reductions in hyperphagia and body weight over an observation period of 45-61 weeks. Compared to formerly developed and tested MC4R agonists, setmelanotide has the unique capability of activating nuclear factor of activated T cell (NFAT) signaling and restoring function of this signaling pathway for selected MC4R variants. Our data demonstrate the potency of setmelanotide in treatment of individuals with diverse MC4R-related pathway deficiencies.

[Current literature overview on the therapy of obesity in children and adolescents]. / Aktuelle Literaturübersicht zur Therapie der Adipositas bei Kindern und Jugendlichen.

BACKGROUND: Obesity is a chronic disease due to the comorbidity associated with it and the need for long-term medical care. Therapeutic intervention is possible at every stage of pathophysiology. AIM: The aim of the study is to demonstrate the effect of multimodal lifestyle interventions not only on the BMI/BMI-SDS, but also on (secondary) outcomes such as comorbidities, quality of life as well as the nutritional and movement behavior. MATERIALS AND METHODS: The literature database PubMed has been searched for internationally clinical studies on lifestyle interventions among 0 to 18-year-olds with overweight and obesity in the period from 01/01/2009 to 01/01/2016. RESULTS: 64 publications with data from 55 studies were included in this overview. Through multimodal lifestyle interventions, many improvements have been achieved in the fields of comorbidity, quality of life, diet and exercise. DISCUSSION: The use of obesity therapy goes far beyond a weight reduction, which is why other parameters should be regularly recorded as therapeutic targets. Thus the improvement of comorbidities, the quality of life as well as the movement and nutritional behavior for a long-term healthy lifestyle are at least as important and reduce the risk of regain after initial weight reduction.

Diabetes screening in overweight and obese children and adolescents: choosing the right test.

Type 2 diabetes can occur without any symptoms, and health problems associated with the disease are serious. Screening tests allowing an early diagnosis are desirable. However, optimal screening tests for diabetes in obese youth are discussed controversially. We performed an observational multicenter analysis including 4848 (2668 female) overweight and obese children aged 7 to 17 years without previously known diabetes. Using HbA1c and OGTT as diagnostic criteria, 2.4% (n = 115, 55 female) could be classified as having diabetes. Within this group, 68.7% had HbA1c levels ≥48 mmol/mol (≥6.5%). FPG ≥126 mg/dl (≥7.0 mmol/l) and/or 2-h glucose levels ≥200 mg/dl (≥11.1 mmol/l) were found in 46.1%. Out of the 115 cases fulfilling the OGTT and/or HbA1c criteria for diabetes, diabetes was confirmed in 43.5%. For FPG, the ROC analysis revealed an optimal threshold of 98 mg/dl (5.4 mmol/l) (sensitivity 70%, specificity 88%). For HbA1c, the best cut-off value was 42 mmol/mol (6.0%) (sensitivity 94%, specificity 93%). CONCLUSIONS: HbA1c seems to be more reliable than OGTT for diabetes screening in overweight and obese children and adolescents. The optimal HbA1c threshold for identifying patients with diabetes was found to be 42 mmol/mol (6.0%). What is Known: • The prevalence of obesity is increasing and health problems related to type 2 DM can be serious. However, an optimal screening test for diabetes in obese youth seems to be controversial in the literature. What is New: • In our study, the ROC analysis revealed for FPG an optimal threshold of 98 mg/dl (5.4 mmol/l, sensitivity 70%, specificity 88%) and for HbA1c a best cut-off value of 42 mmol/mol (6.0%, sensitivity 94%, specificity 93%) to detect diabetes. Thus, in overweight and obese children and adolescents, HbA1c seems to be a more reliable screening tool than OGTT.

Proopiomelanocortin Deficiency Treated with a Melanocortin-4 Receptor Agonist.

Patients with rare defects in the gene encoding proopiomelanocortin (POMC) have extreme early-onset obesity, hyperphagia, hypopigmentation, and hypocortisolism, resulting from the lack of the proopiomelanocortin-derived peptides melanocyte-stimulating hormone and corticotropin. In such patients, adrenal insufficiency must be treated with hydrocortisone early in life. No effective pharmacologic treatments have been available for the hyperphagia and obesity that characterize the condition. In this investigator-initiated, open-label study, two patients with proopiomelanocortin deficiency were treated with setmelanotide, a new melanocortin-4 receptor agonist. The patients had a sustainable reduction in hunger and substantial weight loss (51.0 kg after 42 weeks in Patient 1 and 20.5 kg after 12 weeks in Patient 2).