Subject(s)
Lipodystrophy , Phenotype , Humans , Lipodystrophy/diagnosis , Lipodystrophy/epidemiology , Lipodystrophy/genetics , PrevalenceABSTRACT
Nearly 90 clinicians and researchers from around the world attended the first IMPROVE 2022 International Meeting on Pathway-Related Obesity. Delegates attended in person or online from across Europe, Argentina and Israel to hear the latest scientific and clinical developments in hyperphagia and severe, early-onset obesity, and set out a vision of excellence for the future for improving the diagnosis, treatment, and care of patients with melanocortin-4 receptor (MC4R) pathway-related obesity. The meeting co-chair Peter Kühnen, Charité Universitätsmedizin Berlin, Germany, indicated that change was needed with the rapidly increasing prevalence of obesity and the associated complications to improve the understanding of the underlying mechanisms and acknowledge that monogenic forms of obesity can play an important role, providing insights that can be applied to a wider group of patients with obesity. World-leading experts presented the latest research and led discussions on the underlying science of obesity, diagnosis (including clinical and genetic approaches such as the role of defective MC4R signalling), and emerging clinical data and research with targeted pharmacological approaches. The aim of the meeting was to agree on the questions that needed to be addressed in future research and to ensure that optimised diagnostic work-up was used with new genetic testing tools becoming available. This should aid the planning of new evidence-based treatment strategies for the future, as explained by co-chair Martin Wabitsch, Ulm University Medical Center, Germany.
Subject(s)
Obesity , Receptor, Melanocortin, Type 4 , Humans , Hyperphagia , Obesity/therapy , Receptor, Melanocortin, Type 4/genetics , Receptor, Melanocortin, Type 4/metabolism , Signal TransductionABSTRACT
Lipodystrophy syndromes are rare diseases primarily affecting the development or maintenance of the adipose tissue but are also distressing indirectly multiple organs and tissues, often leading to reduced life expectancy and quality of life. Lipodystrophy syndromes are multifaceted disorders caused by genetic mutations or autoimmunity in the vast majority of cases. While many subtypes are now recognized and classified, the disease remains remarkably underdiagnosed. The European Consortium of Lipodystrophies (ECLip) was founded in 2014 as a non-profit network of European centers of excellence working in the field of lipodystrophies aiming at promoting international collaborations to increase basic scientific understanding and clinical management of these syndromes. The network has developed a European Patient Registry as a collaborative research platform for consortium members. ECLip and ECLip registry activities involve patient advocacy groups to increase public awareness and to seek advice on research activities relevant from the patients perspective. The annual ECLip congress provides updates on the research results of various network groups members.
Subject(s)
Lipodystrophy , Humans , Europe , Italy , Lipodystrophy/therapy , Lipodystrophy/diagnosisABSTRACT
PURPOSE: Bi-allelic pathogenic leptin gene variants cause severe early onset obesity usually associated with low or undetectable circulating leptin levels. Recently, variants have been described resulting in secreted mutant forms of the hormone leptin with either biologically inactive or antagonistic properties. METHODS: We conducted a systematic literature research supplemented by unpublished data from patients at our center as well as new in vitro analyses to provide a systematic classification of congenital leptin deficiency based on the molecular and functional characteristics of the underlying leptin variants and investigated the correlation of disease subtype with severity of the clinical phenotype. RESULTS: A total of 28 distinct homozygous leptin variants were identified in 148 patients. The identified variants can be divided into three different subtypes of congenital leptin deficiency: classical hormone deficiency (21 variants in 128 patients), biologically inactive hormone (3 variants in 12 patients) and antagonistic hormone (3 variants in 7 patients). Only 1 variant (n=1 patient) remained unclassified. Patients with biological inactive leptin have a higher percentage of 95th BMI percentile (%BMIp95) compared to patients with classical hormone deficiency. While patients with both classical hormone deficiency and biological inactive hormone can be treated with the same starting dose of metreleptin, patients with antagonistic hormone need a variant-tailored treatment approach to overcome the antagonistic properties of the variant leptin. MAIN CONCLUSIONS: Categorization of leptin variants based on molecular and functional characteristics helps to determine the most adequate approach to treatment of patients with congenital leptin deficiency.
ABSTRACT
Bardet-Biedl syndrome (BBS) is a rare, autosomal recessive multisystem disease. The pathophysiological origin is a dysfunction of the primary cilium. Clinical symptoms are heterogeneous and variable: retinal dystrophy, obesity, polydactyly, kidney abnormalities, hypogenitalism and developmental delays are the most common features. By the approval of the melanocortin 4 receptor agonist setmelanotide, a drug therapy for BBS-associated hyperphagia and obesity can be offered for the first time. Hyperphagia and severe obesity represent a considerable burden and are associated with comorbidity and increased mortality risk. Due to the limited experience with setmelanotide in BBS, a viable comprehensive therapy concept is to be presented. Therapy decision and management should be conducted in expert centers. For best therapeutic effects with setmelanotide adequate information of the patient about the modalities of the therapy (daily subcutaneous injection) and possible adverse drug events are necessary. Furthermore, the involvement of psychologists, nutritionists and nursing services (support for the application) should be considered together with the patient. The assessment of therapy response should be carried out with suitable outcome measurements and centrally reported to an adequate register.
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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.
Subject(s)
Bariatric Surgery , Obesity, Morbid , Adolescent , Female , Humans , Young Adult , Bariatric Surgery/methods , Cohort Studies , Follow-Up Studies , Obesity/surgery , Obesity, Morbid/surgery , MaleABSTRACT
Hormone absence or inactivity is common in congenital disease, but hormone antagonism remains controversial. Here, we characterize two novel homozygous leptin variants that yielded antagonistic proteins in two unrelated children with intense hyperphagia, severe obesity, and high circulating levels of leptin. Both variants bind to the leptin receptor but trigger marginal, if any, signaling. In the presence of nonvariant leptin, the variants act as competitive antagonists. Thus, treatment with recombinant leptin was initiated at high doses, which were gradually lowered. Both patients eventually attained near-normal weight. Antidrug antibodies developed in the patients, although they had no apparent effect on efficacy. No severe adverse events were observed. (Funded by the German Research Foundation and others.).
Subject(s)
Leptin , Obesity, Morbid , Child , Humans , Antibodies , Homozygote , Leptin/genetics , Obesity, Morbid/genetics , Signal TransductionABSTRACT
BACKGROUND: Metreleptin, a recombinant analog of human leptin, is an approved therapy, adjunct to diet, to treat the metabolic complications of leptin deficiency in patients with lipodystrophy - a group of rare diseases characterized by a paucity of adipose tissue. MEASuRE (Metreleptin Effectiveness And Safety Registry) is a post-authorization, voluntary registry that gathers long-term safety and effectiveness data on metreleptin. Here, we present the aims and evolution of MEASuRE. METHODS: MEASuRE was established to collect data from patients receiving commercially supplied metreleptin in the United States (US) and European Union (EU). MEASuRE aims to determine the incidence and severity of safety events and describe the clinical characteristics and therapeutic outcomes in the metreleptin-treated population. A key feature of MEASuRE is that it accumulates data from different sources to meet post-authorization objectives. US data are received directly from treating physicians via a contract research organization-mediated electronic data capture system. In the EU, data are received via the European Registry of Lipodystrophies managed by the European Consortium of Lipodystrophies (ECLip), a platform established by researchers and physicians to advance the knowledge of lipodystrophy. MEASuRE complies with applicable regulatory requirements governing privacy, and the storage, management, and access of data. RESULTS: Leveraging processes, infrastructure, and data from the ECLip registry presented several challenges that were addressed during MEASuRE's development, including the expansion of the ECLip registry to accommodate MEASuRE-specific data elements, extensive data matching processes to ensure data consistency regardless of source, and rigorous data validation following the amalgamation of global data. Through the support of ECLip, MEASuRE is now a fully operational registry with the capacity for gathering and integrating standardized US- and EU-derived data. As of 31st October 2022, 15 US and four EU sites have participated in the MEASuRE, enrolling 85 patients globally. CONCLUSIONS: Our experiences show that a post-authorization product registry can be successfully integrated into an existing patient registry. We propose that, through collaboration with existing registries and use of their established resources, patient enrolment timelines and data collection for new registries can be expedited. The learnings presented here may be applicable to other registries with similar objectives. TRIAL REGISTRATION: NCT02325674; Registered 25 December 2014 - Retrospectively registered'. https://clinicaltrials.gov/ct2/show/NCT02325674 .
Subject(s)
Leptin , Lipodystrophy , Humans , Lipodystrophy/drug therapy , Adipose Tissue/metabolism , RegistriesABSTRACT
BACKGROUND: States of starvation are characterized by reduced physical activity and social withdrawal. This has been suggested to be mediated at least in part via reduced leptin concentrations. OBJECTIVE: We therefore aimed to ascertain if leptin substitution in patients with congenital leptin deficiency (CLD) can improve physical activity and mood. METHODS: Seven patients with CLD were filmed prior to and after short- and long-term substitution (2-21 days; 3-4 months) in a play situation. Six independent, blinded investigators ranked each video according to specifically developed scales concerning motor activity, social interaction, emotionality, and mood with higher scores representing improvements. RESULTS: Short term metreleptin substitution significantly increased mean total score from 17.7 ± 4.1 to 22.6 ± 6.6 (p = 0.039), and mean scores for motor activity (4.1 ± 1.1 to 5.1 ± 1.5, p = 0.023) and social interaction (4.6 ± 1.1 to 6.2 ± 1.7, p = 0.016). After long term substitution means of all four single scales and of total score were even higher than at short-term follow-up. During a treatment pause of 3 months in two children, all four scale scores fell below substitution levels and rose again after restart. CONCLUSIONS: Metreleptin substitution improved indices of physical activity and psychological wellbeing in patients with CLD. This suggests that reduced leptin concentrations might be in part responsible for emotional and behavioural changes seen during starvation.
Subject(s)
Leptin , Child , HumansABSTRACT
Lipodystrophy syndromes are rare diseases with defects in the development or maintenance of adipose tissue, frequently leading to severe metabolic complications. They may be genetic or acquired, with variable clinical forms, and are largely underdiagnosed. The European Consortium of Lipodystrophies, ECLip, is a fully functional non-profit network of European centers of excellence working in the field of lipodystrophies. It provides a favorable environment to promote large Europe-wide and international collaborations to increase the basic scientific understanding and clinical management of these diseases. It works with patient advocacy groups to increase public awareness. The network also promotes a European Patient Registry of lipodystrophies, as a collaborative research platform for consortium members. The annual congress organized gives an update of the findings of network research groups, highlighting clinical and fundamental aspects. The talks presented during the meeting in Cambridge, UK, in 2022 are summarized in these minutes.
Subject(s)
Lipodystrophy , Humans , Adipose Tissue , Lipodystrophy/therapy , Lipodystrophy/genetics , Syndrome , United KingdomABSTRACT
Two psychiatric interviews of a 39-year old female with congenital leptin deficiency were conducted to define psychological changes 14 and 165 days after initiation of treatment with human recombinant leptin (metreleptin). The most pronounced initial experience related to the reduced preoccupation with food. An improved mood was reported by the patient, which she associated with this reduced preoccupation. Her mood remained elevated upon recontact, whereas she was no longer preoccupied with food. Overall, the interviews provide a vivid account of the subjective experiences upon the initiation of treatment. Some of the findings bear a resemblance to those reported recently in patients with anorexia nervosa who were treated with metreleptin for 1-3 weeks. This case report provides further evidence that metreleptin has strong psychopharmacological effects in patients with absolute or relative leptin deficiency. We strongly recommend profound psychological examinations of patients with congenital leptin deficiency at baseline and after intitiation of treatment with human recombinant leptin to gain further insight into the functions affected by this hormone.
Subject(s)
Food , Leptin , Humans , Female , AdultABSTRACT
BACKGROUND: Hyperphagia is a key symptom in patients with monogenic obesity, but the assessment is challenging. OBJECTIVES: We aimed to investigate the applicability of Dykens' Hyperphagia Questionnaire in patients with monogenic and syndromic obesity to assess the quality and severity of hyperphagia, and to compare our results with those reported in the literature. METHODS: Patients with biallelic leptin receptor variants (LEPR, n = 8), heterozygous melanocortin-4 receptor variants (MC4R, n = 7) and 16p11.2 deletions, leading to a deletion of the Src homology 2B adaptor protein gene (n = 5) were included in the study. Hyperphagia was assessed by the parent-based, 13-item hyperphagia questionnaire from Dykens et al. (2007). A literature research was performed to identify published hyperphagia scores assessed by Dykens' Hyperphagia Questionnaire. RESULTS: The total hyperphagia scores were similar in patients with biallelic LEPR and monoallelic MC4R variants (32.0 ± 9.3 vs. 31.4 ± 5.4), but significantly lower in patients with 16p11.2 deletions (21.4 ± 5.5, p < 0.05). Compared to patients with syndromic obesity (27.6 ± 9.0) from the literature, patients with LEPR and MC4R variants had higher total hyperphagia scores. Total hyperphagia scores in patients with 16p11.2 deletions were lower than for patients with other syndromic obesity forms (21.4 ± 5.5 vs. 24.6 ± 8.1), but similar to those for individuals with obesity without a genetic cause (22.9 ± 7.2). CONCLUSIONS: Dykens' Hyperphagia Questionnaire seems to be a useful tool to assess hyperphagic behaviour in patients with monogenic and syndromic obesity.
Subject(s)
Hyperphagia , Obesity , Autistic Disorder , Chromosome Deletion , Chromosome Disorders , Chromosomes, Human, Pair 16 , Humans , Hyperphagia/genetics , Intellectual Disability , Obesity/genetics , Obesity/metabolismABSTRACT
Background: While for individuals with obesity an association between hyperleptinemia and an increased risk of non-alcoholic fatty liver disease (NAFLD) is assumed, a leptin deficiency is also related to the development of NAFLD early in life in ob/ob mice, in patients with leptin deficiency due to biallelic likely pathogenic variants in the leptin gene, and in patients with lipodystrophy. Objectives: To investigate the association of circulating leptin levels in pre-pubertal children with obesity and steatosis hepatis. Methods: The cross-sectional study consisted data of n=97 (nmale=76) pre-pubertal children (11.8 ± 1.5 years) with obesity (BMIz: 2.4 ± 0.4). Fasting concentrations of cardiometabolic parameters were measured: insulin, c-peptide, glucose, triglyceride, cholesterol, HDL, LDL, AST, ALT, GGT, leptin. Steatosis hepatis was diagnosed by an ultrasound examination (mild, moderate or severe). Patients were categorized into two groups: low z-score of circulating leptin levels (≤25th percentile) vs. normal z-score of circulating leptin levels. Results: One-third of the children with obesity were diagnosed with steatosis hepatis (I°: 63.6%, II°/III°: 36.4%). Children with steatosis hepatis had significantly lower z-scores of circulating leptin levels compared to children with an unremarkable liver ultrasonography (-2.1 ± 0.8 vs. -0.7 ± 0.6). Z-scores of circulating leptin levels correlate negatively with degree of steatosis hepatis. Children with low z-scores of circulating leptin levels had significantly higher triglyceride, fasting insulin and c-peptide levels compared to children with normal z-scores of circulating leptin levels. Conclusion: Prepubertal children with NAFLD and obesity and partial leptin deficiency might be defined as a clinical subgroup.
Subject(s)
Leptin , Non-alcoholic Fatty Liver Disease , Pediatric Obesity , Body Mass Index , C-Peptide , Child , Cross-Sectional Studies , Female , Humans , Insulin , Leptin/blood , Male , Non-alcoholic Fatty Liver Disease/complications , Non-alcoholic Fatty Liver Disease/pathology , Pediatric Obesity/complications , TriglyceridesABSTRACT
INTRODUCTION: Individuals with proopiomelanocortin (POMC) or leptin receptor (LEPR) deficiency are young and experience severe obesity, hyperphagia, and comorbidities, which can impair quality of life (QOL). METHODS: Two pivotal Phase 3 trials explored the effect of setmelanotide on body weight and hunger in individuals with obesity due to POMC (NCT02896192) or LEPR (NCT03287960) deficiency. QOL and depression were investigated in parallel using the disease-specific, age-appropriate Impact of Weight on Quality of Life-Lite (IWQOL-Lite), Pediatric Quality of Life Inventory (PedsQL), and Patient Health Questionnaire-9 (PHQ-9). RESULTS: In total, the POMC and LEPR trials enrolled 21 patients. Adults (≥ 18 years old; n = 7) had moderate-to-severe impairment in QOL at baseline, with mean (standard deviation [SD]) IWQOL-Lite total score 60.3 (13.2; maximum IWQOL-Lite total score = 100). The effect of setmelanotide on IWQOL-Lite total score was observed as soon as Week 5. Among those with scores at Week 52, 5 of 6 adults experienced a clinically meaningful improvement, with mean (SD) total scores increased from baseline by 24.2 (12.1) points. Children (6-12 years old; n = 2) and adolescents (13-17 years old; n = 4) had impaired QOL at baseline, with mean (SD) self-reported PedsQL total scores 53.3 (6.2) and 63.3 (29.1), respectively (maximum PedsQL total score = 100). Three of 5 patients experienced clinically meaningful improvement in PedsQL, with 2 children whose PedsQL total score increased by 28.3 and 3.3 points and 3 adolescents whose mean (SD) total score increased from baseline by 5.8 (18.3) points. Baseline mean (SD) PHQ-9 score (in those ≥ 12 years old) was 5.3 (3.8) and was generally maintained through Week 52. CONCLUSIONS: Patients with POMC or LEPR deficiency had impaired, and in some cases severely impaired, QOL before setmelanotide treatment. Setmelanotide improved QOL in patients as early as Week 5, with some patients no longer experiencing impaired QOL at Week 52. Improvements in QOL may be related to a reduction in hunger and body weight associated with setmelanotide. Because of the highly complex psychological consequences of rare genetic diseases of obesity, some patients may require a long period of treatment to improve QOL and benefit from interdisciplinary care.
Subject(s)
Pro-Opiomelanocortin , Quality of Life , Adolescent , Adult , Child , Humans , Obesity/drug therapy , Receptors, Leptin , Surveys and Questionnaires , alpha-MSH/analogs & derivativesABSTRACT
INTRODUCTION: Genetic obesity is rare and quite challenging for pediatricians in terms of early identification. Src-homology-2 (SH2) B adapter protein 1 (SH2B1) is an important component in the leptin-melanocortin pathway and is found to play an important role in leptin and insulin signaling and therefore in the pathogenesis of obesity and diabetes. Microdeletions in chromosome 16p11.2, encompassing the SH2B1 gene, are known to be associated with obesity, insulin resistance, hyperphagia, and developmental delay. The aim of our study is to report on a case series of young individuals with 16p11.2 microdeletions, including the SH2B1 gene, and provide detailed information on body mass index (BMI) development and obesity-associated comorbidities. In this way, we want to raise awareness of this syndromic form of obesity as a differential diagnosis of genetic obesity. METHODS: We describe the phenotype of 7 children (3 male; age range: 2.8-18.0 years) with 16p11.2 microdeletions, encompassing the SH2B1 gene, and present their BMI trajectories from birth onward. Screening for obesity-associated comorbidities was performed at the time of genetic diagnosis. RESULTS: All children presented with severe, early-onset obesity already at the age of 5 years combined with variable developmental delay. Five patients presented with elevated fasting insulin levels, 1 patient developed diabetes mellitus type 2, 4 patients had dyslipidemia, and 4 developed nonalcoholic fatty-liver disease. DISCUSSION/CONCLUSION: Chromosomal microdeletions in 16p11.2, including the SH2B1 gene, in children are associated with severe, early-onset obesity and comorbidities associated with insulin resistance. Early genetic testing in suspicious patients and early screening for comorbidities are recommended.
Subject(s)
Adaptor Proteins, Signal Transducing , Pediatric Obesity , Adaptor Proteins, Signal Transducing/genetics , Adolescent , Body Mass Index , Child , Child, Preschool , Female , Gene Deletion , Humans , Insulin/metabolism , Insulin Resistance/genetics , Leptin/metabolism , Male , Pediatric Obesity/diagnosis , Pediatric Obesity/geneticsABSTRACT
Leptin (LEP) and leptin receptor (LEPR) play a major role in energy homeostasis, metabolism, and reproductive function. While effects of biallelic likely pathogenic variants (-/-) on the phenotype are well characterized, effects of mono-allelic likely pathogenic variants (wt/-) in the LEP and LEPR gene on the phenotype compared to wild-type homozygosity (wt/wt) have not been systematically investigated. We identified in our systematic review 44 animal studies (15 on Lep, 29 on Lepr) and 39 studies in humans reporting on 130 mono-allelic likely pathogenic variant carriers with 20 distinct LEP variants and 108 heterozygous mono-allelic likely pathogenic variant carriers with 35 distinct LEPR variants. We found indications for a higher weight status in carriers of mono-allelic likely pathogenic variant in the leptin and in the leptin receptor gene compared to wt/wt, in both animal and human studies. In addition, animal studies showed higher body fat percentage in Lep and Lepr wt/- vs wt/wt. Animal studies provided indications for lower leptin levels in Lep wt/- vs. wt/wt and indications for higher leptin levels in Lepr wt/- vs wt/wt. Data on leptin levels in human studies was limited. Evidence for an impaired metabolism in mono-allelic likely pathogenic variants of the leptin and in leptin receptor gene was not conclusive (animal and human studies). Mono-allelic likely pathogenic variants in the leptin and in leptin receptor gene have phenotypic effects disposing to increased body weight and fat accumulation.
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BACKGROUND: Evidence from in vitro and rodent studies suggests that leptin, a key signal of long-term energy reserves, promotes IGF1 synthesis and linear growth. This effect of leptin has not been fully investigated in humans. The aim of our study was to investigate the effect of leptin substitution on growth factors and linear growth in children with congenital leptin deficiency (CLD). METHODS: In this cohort study we included eight pediatric patients (six males), age 0.9-14.8 years, who were diagnosed with CLD and received leptin substitution at our University Medical Center. We calculated standard deviation scores (SDS) for serum levels of IGF1 and IGFBP3, IGF1/IGFBP3 molar ratio, and height at baseline (T0) and 12 months (T12) after the initiation of substitution with metreleptin. RESULTS: All patients had severe obesity (BMI-SDS mean ± SD: 4.14 ± 1.51) at T0 and significant BMI-SDS reduction to 2.47 ± 1.05 at T12. At T0, all patients were taller than the mid-parental median, yet had low IGF1 and IGF1/IGFBP3 molar ratios (IGF1-SDS[Formula: see text]T0: -1.58 ± 0.92, IGF1/IGFBP3 molar ratio-SDS[Formula: see text]T0: -1.58 ± 0.88). At T12, IGF1-SDS increased significantly (∆T0-12: 1.63 ± 1.40, p = 0.01), and IGFBP3-SDS and IGF1/IGFBP3 molar ratio-SDS showed a trend toward an increase. In the three children within the childhood growth period (post-infancy, pre-puberty) height-SDS increased (∆height-SDST0-12: 0.57 ± 0.06, p = 0.003) despite substantial weight loss. CONCLUSIONS: These results in CLD patients are contrary to observations in children with idiopathic obesity who typically have above-mean IGF1 levels that decrease with weight loss, and therefore suggest that leptin increases IGF1 levels and promotes linear growth.
Subject(s)
Deficiency Diseases , Insulin-Like Growth Factor I/analysis , Leptin , Adolescent , Child , Child, Preschool , Cohort Studies , Deficiency Diseases/blood , Deficiency Diseases/drug therapy , Deficiency Diseases/genetics , Deficiency Diseases/physiopathology , Female , Humans , Infant , Leptin/administration & dosage , Leptin/deficiency , Leptin/therapeutic use , MaleABSTRACT
Survivors of childhood cancer are at high risk of developing metabolic diseases in adulthood. Recently, several patients developing partial lipodystrophy following hematopoietic stem cell transplantation (HSCT) have been described. In this review, we summarize the cases described so far and discuss potential underlying mechanisms of the disease. The findings suggest that HSCT-associated lipodystrophies may be seen as a novel form of acquired lipodystrophy.
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BACKGROUND: Rare genetic variations in the leptin-melanocortin signalling pathway can severely impair appetite regulation and cause extreme obesity in early childhood. CASE PRESENTATION: Our case reports describe the diagnostic and therapeutic procedures in a girl as well as in a non-related boy of non-consanguineous, German parents with severe early-onset obesity, pronounced hyperphagia, and permanent food-seeking behaviour. Excessive weight gain within the first year of life initiated extensive diagnostics without finding a causal diagnosis. Furthermore, a wide range of intensive, interdisciplinary, and behavioural therapies for weight control were unsuccessful. Prior to bariatric surgery, the 18-year-old girl and the 14-year-old boy reached a BMI of 67.7 kg/m2 and 55.2 kg/m2, respectively. However, even surgical outcomes were unsatisfactory. A subsequently initiated genetic analysis including sequencing of the leptin receptor gene revealed compound heterozygous variants as a cause of the severe early-onset obesity in both patients (c.2598-3_2607delTAGAATGAAAAAG and c.2227 T>C; c.1874G>A and c.2051A>C). Both patients were enrolled in the clinical study RM-493-015 and treated with melanocortin receptor agonist setmelanotide. Currently, they are still on setmelanotide treatment in the extension trial RM-493-022. CONCLUSION: Our case report illustrates the urgent necessity of early genetic diagnostics in children with severe early-onset obesity to avoid frustrating and potentially damaging therapies. Thus, genetic examination should precede bariatric surgery. In the future, several pharmacological therapies will be available for some forms of monogenetic obesity.
ABSTRACT
Background Severe early-onset obesity (SEOO) in children is a common feature of monogenic obesity. Gene defects of the leptin-melanocortin pathway can be analysed biochemically and genetically. The aim of this study was to search for children with leptin deficiency or biologically inactive leptin in a cohort of children with SEOO and to study associations between leptin parameters and anthropometric data. Methods The cohort included n = 50 children with SEOO (22 boys) who were recruited at one of four study centres (Germany: Ulm; Poland: Katowice, Szczecin, Rzeszow) between October 2015 and October 2017. Weight (kg) and height (m) were measured, Tanner stage was obtained and a fasting serum blood sample was taken. Serum levels of total leptin (LEP, ng/mL), biologically active leptin (bioLEP, ng/mL) and soluble leptin receptor (sLEPR, ng/mL) were measured. The body mass index (BMI [kg/m2]), BMI z-score (World Health Organization [WHO]), quotient of bioLEP/LEP and leptin-standard deviation score (LEP-SDS) (Tanner stage, BMI and sex-adjusted) were calculated. Results We did not find any child with leptin deficiency or biologically inactive leptin in our cohort. The serum LEP and bioLEP levels were strongly correlated with age (r = 0.50, p < 0.05) and BMI (r = 0.70; p < 0.0001). Girls had higher LEP and bioLEP levels (49.7 ± 35.9 vs. 37.1 ± 25.5 ng/mL, p > 0.05) as well as lower LEP-SDS than boys (-1.77 ± 2.61 vs. -1.40 ± 2.60, p > 0.05). sLEPR levels were negatively correlated with BMI values (r = -0.44; p < 0.05), LEP (r = -0.39; p < 0.05) and bioLEP levels (r = -0.37; p < 0.05). Interestingly, there was a strong inverse relationship between LEP-SDS and BMI (r = -0.72, p < 0.001). Conclusions In this cohort with SEOO, we identified no new cases of children with leptin deficiency or bioinactive leptin. A strong negative correlation between the LEP-SDS and BMI values could be interpreted as relative leptin deficiency in children with SEOO. In case this hypothesis can be confirmed, these children would benefit from a substitution therapy with methionyl human leptin (metreleptin™).