High Prevalence of Positive Genetic Obesity Variants in Postoperative Bariatric Surgery Patients with Weight Regain Presenting for Medical Obesity Intervention

INTRODUCTION

Genetic obesity susceptibility in postoperative bariatric surgery weight regain (PBSWR) remains largely unexplored.

METHODS

A retrospective case series of adult (N = 27) PBSWR patients who had undergone genetic obesity testing was conducted between Sept. 2020 and March 2022.

PRIMARY OUTCOME

frequency of genetic variants in patients experiencing weight regain following bariatric surgery.

SECONDARY OUTCOMES

prevalence of obesity-related comorbidities, nadir BMI achieved post-bariatric surgery, and percent total body weight loss (%TBWL) achieved with obesity pharmacotherapies.

RESULTS

Heterozygous mutations were identified in 22 (81%) patients, with the most prevalent mutations occurring in CEP290, RPGR1P1L, and LEPR genes (3 patients each). Median age was 56 years (interquartile range (IQR) 46.8-65.5), 88% female. Types of surgery were 67% RYGB, 19% SG, 4% gastric band, and 13% revisions. Median nadir BMI postoperatively was 34.0 kg/m2 (IQR 29.0-38.5). A high prevalence of metabolic derangements was noted; patients presented median 80 months (IQR 39-168.5) postoperative for medical weight management with 40% weight regain. BMI at initiation of anti-obesity medication (AOMs) was 41.7 kg/m2 (36.8-44.4). All received AOM and required at least 3 AOMs for weight regain. Semaglutide (N = 21), topiramate (N = 14), and metformin (N = 12) were most prescribed. Median %TBWL for the cohort at the first, second, and third visit was 1.7, 5.0, and 6.5 respectively. Fourteen (52%) achieved 5%TBWL, 10 (37%) achieved 10%TBWL, and 4 (15%) achieved 15%TBWL with combination AOMs and supervised medical intervention.

CONCLUSION

An unusually high prevalence of genetic obesity variants in PBSWR was found, warranting further research.

Diagnostic challenge: A pediatric patient with severe obesity and complications of imminent death

Background

A 15-year-old patient suffering from severe obesity (400 pounds, BMI 71.6 kg/m2) with a clinical phenotype suggestive of syndromic obesity was hospitalized for severe heart failure and cardiogenic shock. The hospital admission prompted a palliative care and heart transplant consultation given end-stage-disease and poor prognosis. It further necessitated a pediatric inpatient obesity consult, which was complicated by several significant hurdles including lack of insurance coverage, FDA approvals, availability of medications, and inadequate knowledge among the medical community.

Methods

Innovative treatment, proactive, persistent advocacy, anti-obesity medication combination strategies modeled after diabetes and hypertension treatment algorithms, and latest evidence in obesity management were utilized to effectively and expeditiously overcome major challenges to care and the medical emergency.

Results

The patient was stabilized and ultimately discharged home, after -25.2% weight loss over 4 months (weight down to 299 pounds, BMI 49.9 kg/m2) through collaborative medical obesity intervention.

Conclusion

The typical delay in care sought by patients suffering from obesity, often due to stigma and lack of disease awareness, results in missed opportunities to prevent serious obesity-related complications. Skilled specialist expertise, fund of obesity-specific knowledge, and constant advocacy can be crucial in surmounting regulatory barriers to obesity care and in generating successful weight loss outcomes.

The Narrative of a Patient with Leptin Receptor Deficiency: Personalized Medicine for a Rare Genetic Obesity Disorder

Leptin receptor (LEPR) deficiency is a rare genetic disorder that affects the body's ability to regulate appetite and weight. For patients and their families, the disorder seriously disrupts daily life; however, little is published about this impact. We here report the experiences of a 10.5-year-old girl with leptin receptor deficiency and her family. The diagnosis of this rare genetic obesity had a deep impact on the life of the child and her family. It led to a better understanding of the cause of the impaired appetite regulation and early-onset obesity with subsequently less judgement by others and improved cooperation of their social network and school on maintaining a healthy lifestyle for this girl. A strict eating regimen and lifestyle measures resulted in the first year after diagnosis in a significantly decreased body mass index (BMI), followed by BMI stabilization, still categorized as obesity class three. However, the troublesome challenge of how to manage the disruptive behaviour due to hyperphagia remained. Eventually, due to treatment with targeted pharmacotherapy, i.e., melanocortin-4 receptor agonists, her BMI continued to decrease due to resolving hyperphagia. The daily routine of the family and the atmosphere at home positively changed as they were no longer dominated by the food-focused behaviour of the child and the adherence to the strict eating regimen. This case report demonstrates the importance and impact of a rare genetic obesity disorder diagnosis in a family. Additionally, it highlights the value of genetic testing in patients with a high suspicion of a genetic obesity disorder as it can eventually lead to personalized treatment, such as guidance by specialized healthcare professionals and educated caregivers or targeted pharmacotherapy.

Genetic Contributors to Obesity

Genetic forms of obesity contribute to ∼7% of severe obesity in children and adolescents. The exact global prevalence of monogenic and syndromic forms of obesity is not well established, most likely due to missed or delayed diagnosis. The challenge in determining the prevalence can be attributed to the lack of consensus on identifying and evaluating symptoms of genetic defects in a timely manner and hence a vastly undertested patient population. Further large-scale and long-term studies are needed to advance the understanding of this unique phenotype of obesity and effective treatment options."

Current Treatments for Patients with Genetic Obesity

Obesity derives from impaired central control of body weight, implying interaction between environment and an individual genetic predisposition. Genetic obesities, including monogenic and syndromic obesities, are rare and complex neuro-endocrine pathologies where the genetic contribution is predominant. Severe and early-onset obesity with eating disorders associated with frequent comorbidities make these diseases challenging. Their current estimated prevalence of 5-10% in severely obese children is probably underestimated due to the limited access to genetic diagnosis. A central alteration of hypothalamic regulation of weight implies that the leptin-melanocortin pathway is responsible for the symptoms. The management of genetic obesity has so far been only based, above all, on lifestyle intervention, especially regarding nutrition and physical activity. New therapeutic options have emerged in the last years for these patients, raising great hope to manage their complex situation and improve quality of life. Implementation of genetic diagnosis in clinical practice is thus of paramount importance to allow individualized care. This review describes the current clinical management of genetic obesity and the evidence on which it is based. Some insights will also be provided into new therapies under evaluation.

Quality of life improvements following one year of setmelanotide in children and adult patients with Bardet-Biedl syndrome: phase 3 trial results

BACKGROUND

Bardet-Biedl syndrome is a rare genetic disease associated with hyperphagia and early-onset, severe obesity. There is limited evidence on how hyperphagia and obesity affect health-related quality of life in patients with Bardet-Biedl syndrome, and on how management of these symptoms may influence disease burden. This analysis evaluated changes in health-related quality of life in adults and children with Bardet-Biedl syndrome in a Phase 3 trial following 1 year of setmelanotide treatment (ClinicalTrials.gov identifier: NCT03746522).

METHODS

Patients with Bardet-Biedl syndrome and obesity received 52 weeks of treatment with setmelanotide and completed various self-reported health-related quality of life measures. Patients aged < 18 years or their caregiver completed the Pediatric Quality of Life Inventory (PedsQL; meaningful improvement, 4.4-point change); adults aged ≥ 18 years completed the Impact of Weight on Quality of Life Questionnaire-Lite (IWQOL-Lite; meaningful improvement range, 7.7-12-point change). Descriptive outcomes were reported in patients with data both at active treatment baseline and after 52 weeks of treatment.

RESULTS

Twenty patients (< 18 years, n = 9; ≥ 18 years, n = 11) reported health-related quality of life at baseline and 52 weeks. For children and adolescents, PedsQL score mean change from baseline after 52 weeks was + 11.2; all patients with PedsQL impairment at baseline (n = 4) experienced clinically meaningful improvement. In adults, IWQOL-Lite score mean change from baseline was + 12.0. Of adults with IWQOL-Lite impairment at baseline (n = 8), 62.5% experienced clinically meaningful improvement. In adults, IWQOL-Lite score was significantly correlated with changes in percent body weight (P = 0.0037) and body mass index (P = 0.0098).

CONCLUSIONS

After 1 year of setmelanotide, patients reported clinically meaningful improvements across multiple health-related quality of life measures. This study highlights the need to address the impaired health-related quality of life in Bardet-Biedl syndrome, and supports utility of setmelanotide for reducing this burden. Trial Registration NCT03746522. Registered November 19, 2018, https://clinicaltrials.gov/ct2/show/NCT03746522 .

Body composition and obstructive sleep apnoea assessment in adult patients with Prader-Willi syndrome: a case control study

INTRODUCTION

In Prader-Willi syndrome (PWS) adult patients, sleep-breathing disorders, especially obstructive sleep apnoea syndrome (OSAS), are very common, whose missed or delayed diagnosis can contribute to further increase cardiovascular morbidity and mortality.

PURPOSE

The aim of this cross-sectional study was to evaluate differences in sleep-breathing parameters obtained by overnight cardiorespiratory polygraphy in 13 adult PWS patients and 13 individuals with non-syndromic obesity as controls matched by age, sex, and BMI.

METHODS

In all subjects' anthropometric parameters, body composition using bioimpedance analysis and overnight cardiorespiratory monitoring parameters were obtained.

RESULTS

Ten (76.9%) PWS patients were diagnosed with OSAS, most notably nine (69.2%) and one PWS (7.7%) with mild and severe OSAS, respectively. Compared with the control group, PWS patients had evidence of higher apnoea-hypopnea index (AHI) (p = 0.04) and oxyhaemoglobin desaturation index (ODI) (p = 0.009). However, no differences were found between the two groups regarding OSAS categories or diagnosis of nocturnal respiratory failure. In the PWS group, there were no significant correlations among AHI, ODI and hypoxemia index (T90) and anthropometric measurements, fat mass (FM), and FM percentage (%). Conversely, in the control group, the sleep-related respiratory indices evaluated correlated positively with BMI, waist circumference, FM and FM%.

CONCLUSIONS

This study confirmed that AHI and ODI indices were worse in PWS than in age, sex and BMI-matched controls. The lack of their significant association with the anthropometric parameters and FM supported the existence of PWS-related mechanisms in OSAS pathophysiology that are independent of visceral obesity and FM.

Genetic obesity: an update with emerging therapeutic approaches

Based on the genetic contribution, childhood obesity can be classified into 3 groups: common polygenic obesity, syndromic obesity, and monogenic obesity. More genetic causes of obesity are being identified along with the advances in the genetic testing. Genetic obesities including syndromic and monogenic obesity should be suspected and evaluated in children with early-onset morbid obesity and hyperphagia under 5 years of age. Patients with syndromic obesity have early-onset severe obesity associated specific genetic syndromes including Prader-Willi syndrome, Bardet-Biedle syndrome, and Alstrom syndrome. Syndromic obesity is often accompanied with neurodevelopmental delay or dysmorphic features. Nonsyndromic monogenic obesity is caused by variants in single gene which are usually involved in the regulation of hunger and satiety associated with the hypothalamic leptin-melanocortin pathway in central nervous system. Unlike syndromic obesity, patients with monogenic obesity usually show normal neurodevelopment. They would be presented with hyperphagia and early-onset severe obesity with additional clinical symptoms including short stature, red hair, adrenal insufficiency, hypothyroidism, hypogonadism, pituitary insufficiencies, diabetes insipidus, increased predisposition to infection or intractable recurrent diarrhea. Identifying patients with genetic obesity is critical as new innovative therapies including melanocortin 4 receptor agonist have become available. Early genetic evaluation enables to identify treatable obesity and provide timely intervention which may eventually achieve favorable outcome by establishing personalized management.

Effects of Heterozygous Variants in the Leptin-Melanocortin Pathway on Roux-en-Y Gastric Bypass Outcomes: a 15-Year Case-Control Study

INTRODUCTION

Heterozygous variants in the leptin-melanocortin pathway are associated with obesity. However, their effect on the long-term outcomes after Roux-en-Y gastric bypass (RYGB) is still unknown.

METHODS

In this matched case-control study, 701 participants from the Mayo Clinic Biobank with a history of RYGB were genotyped. Sixty-three patients had a heterozygous variant in the leptin-melanocortin pathway. After excluding patients with potential confounders, carriers were randomly matched (on sex, age, body mass index [BMI], and years since surgery) with two non-carrier controls. The electronic medical record of carriers and matched non-carriers was reviewed for up to 15 years after RYGB.

RESULTS

A total of 50 carriers and 100 matched non-carriers with a history of RYGB were included in the study. Seven different genes (LEPR, PCSK1, POMC, SH2B1, SRC1, MC4R, and SIM1) in the leptin-melanocortin pathway were identified. At the time of surgery, the mean age was 50.8 ± 10.6 years, BMI 45.6 ± 7.3 kg/m², and 79% women. There were no differences in postoperative years of follow-up, Roux limb length, or gastric pouch size between groups. Fifteen years after RYGB, the percentage of total body weight loss (%TBWL) in carriers was - 16.6 ± 10.7 compared with - 28.7 ± 12.9 in non-carriers (diff = 12.1%; 95% CI, 4.8 to 19.3) and the percentage of weight regain after maximum weight loss was 52.7 ± 29.7 in carriers compared with 29.8 ± 20.7 in non-carriers (diff = 22.9%; 95% CI, 5.3 to 40.5). The nadir %TBWL was lower - 32.1 ± 8.1 in carriers compared with - 36.8 ± 10.4 in non-carriers (diff = 4.8%; 95% CI 1.8 to 7.8).

CONCLUSIONS

Carriers of a heterozygous variant in the leptin-melanocortin pathway have a progressive and significant weight regain in the mid- and long-term after RYGB. Genotyping patients experiencing significant weight regain after RYGB could help implement multidisciplinary and individualized weight loss interventions to improve weight maintenance after surgery.

Kisspeptin and the Genetic Obesity Interactome

BACKGROUND

Kisspeptin (encoded by the KISS1 gene in humans) is an excitatory neuromodulatory peptide implicated in multiple homeostatic systems, including anti-oxidation, glucose homeostasis, nutrition, locomotion, etc. Therefore, in the current obesity epidemic, kisspeptin is gaining increasing interest as a research objective.

AIM

To construct an updated interactome of genetic obesity, including the kisspeptin signal transduction pathway.

METHODS

Kisspeptin and obesity-related genes or gene products were extracted from the biomedical literature, and a network of functional associations was created.

RESULTS

The generated network contains 101 nodes corresponding to gene/gene products with known and/or predicted interactions. In this interactome, KISS1 and KISS1R are connected directly to the luteinizing hormone receptor (LHCGR), gonadotropin-releasing hormone receptor (GNRH1), and indirectly, through the latter, to proopiomelanocortin (POMC), glucagon, leptin (LEP), and/or pro-protein convertase subtilisin/kexin-type 1 (PCSK1), all of which are critically implicated in obesity disorders.

CONCLUSIONS

Our updated obesidome includes kisspeptin and its connections to the genetic obesity signalosome with 12 major hubs: glucagon (GCG), insulin (INS), arginine vasopressin (AVP), G protein subunit beta 1 (GNB1) and proopiomelanocortin (POMC), melanocortin 4 receptor (MC4R), leptin (LEP), gonadotropin-releasing hormone 1 (GNRH1), adrenoceptor beta 2 and 3 (ADRB2-3), glucagon-like peptide 1 receptor (GLP1R), and melanocortin 3 receptor (MC3R) genes were identified as major "hubs" for genetic obesity, providing novel insight into the body's energy homeostasis.

Effects of the COVID-19 pandemic and lockdown on the mental and physical health of adults with Prader-Willi syndrome

Background

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder with hypothalamic dysfunction leading to obesity and behavioral disabilities, including eating disorders (EDs). We evaluated the effects of the COVID-19 infection and lockdown on mental and physical health in PWS. At the end of April, 85 adults with PWS completed a self-administered questionnaire, including lockdown conditions, physical activity (PA), ED, and medical and behavioral outcomes. Body weight was measured at home and self-reported.

Results

Patients (52.9% women, 44.8% disomic) were assessed, with a mean age of 28.05 ± 8.73 years and body mass index (BMI) of 36.76 ± 10.74 kg/m². Seventy percent lived in the Paris region (France) and were confined with their parents. The mean weight change was 0.96 ± 3.28 kg. We compared patients showing weight loss (n = 39, − 3.30 ± 2.93 kg) to patients showing weight gain (n = 22, + 2.35 ± 1.54 kg): the BMI was lower (34.60 ± 9.18 versus 40.45 ± 9.45 kg/m², p = 0.02), PA increased (25.6% versus 4.5%, p = 0.04), and EDs improved (51.3% versus 13.6%, p = 0.005). Behavioral disorders increased for 12.9% of the cohort. Three individuals (3.5%) were diagnosed with non-severe COVID-19.

Conclusion

Lockdown during the COVID-19 pandemic was associated with positive effects for most French adults with PWS, with weight loss probably associated with a more favourable environment during this period. We observed no severe forms of COVID-19.

Clinical management of patients with genetic obesity during COVID-19 pandemic: position paper of the ESE Growth & Genetic Obesity COVID-19 Study Group and Rare Endo-ERN main thematic group on Growth and Obesity

This article aims to provide guidance on prevention and treatment of COVID-19 in patients with genetic obesity. Key principals of the management of patients with genetic obesity during COVID-19 pandemic for patients that have contracted COVID-19 are to be aware of: possible adrenal insufficiency (e.g., POMC deficiency, PWS); a more severe course in patients with concomitant immunodeficiency (e.g., LEP and LEPR deficiency), although defective leptin signalling could also be protective against the pro-inflammatory phenotype of COVID-19; disease severity being masked by insufficient awareness of symptoms in syndromic obesity patients with intellectual deficit (in particular PWS); to adjust medication dose to increased body size, preferably use dosing in m2; the high risk of malnutrition in patients with Sars-Cov2 infection, even in case of obesity. Key principals of the obesity management during the pandemic are to strive for optimal obesity management and a healthy lifestyle within the possibilities of the regulations to prevent weight (re)gain and to address anxiety within consultations, since prevalence of anxiety for COVID-19 is underestimated.

A Targeted Next Generation Sequencing Panel for Non-syndromic Early Onset Severe Obesity and Identification of Novel Likely -Pathogenic Variants in the MC4R and LEP Genes

OBJECTIVES

To screen for variants in the MC4R and LEP genes in 46 patients with clinical suspicion of non-syndromic early onset severe obesity (NEOSO).

METHODS

Children with early onset obesity satisfying WHO criteria of obesity were studied. The MC4R and LEP genes were sequenced using a PCR amplicon based NGS on Illumina MiSeq next generation sequencer using an in-house developed protocol.

RESULTS

Of the 46 children tested, four were found to have novel pathogenic/likely-pathogenic variants (one in the MC4R gene and three in the LEP gene). In three out of the 4 families, the presence of the variants was confirmed using standard bidirectional capillary sequencing in the probands.

CONCLUSIONS

Four children with novel likely pathogenic variants in the MC4R and LEP genes are reported. Genetic analysis is crucial in children with early onset obesity and should be considered.

Genetics of Obesity

Obesity is caused by an imbalance between energy intake and output, influenced by numerous environmental, biological, and genetic factors. Only a minority of people with obesity have a genetic defect that is the main cause of their obesity. A key symptom for most of these disorders is early-onset obesity and hyperphagia. For some genetic obesity disorders, the hyperphagia is the main characteristic, often caused by disruptions of the leptin-melanocortin pathway, the central pathway that regulates the body's satiety and energy balance. For other disorders, obesity is part of a distinct combination of other clinical features such as intellectual disability, dysmorphic facial features, or organ abnormalities. This chapter focuses on genetic obesity disorders and also summarizes the present knowledge on the genetics of the more common polygenic/multifactorial obesity.

Maternal Uniparental Disomy 14 (Temple Syndrome) as a Result of a Robertsonian Translocation

Maternal uniparental disomy of chromosome 14 (upd(14)mat) or Temple syndrome is an imprinting disorder associated with a relatively mild phenotype. The absence of specific congenital malformations makes this condition underdiagnosed in clinical practice. A boy with a de novo robertsonian translocation 45,XY,rob(13;14)(q10;q10) is reported; a CGH/SNP array showed a loss of heterozygosity in 14q11.2q13.1. The final diagnosis of upd(14)mat was made by microsatellite analysis, which showed a combination of heterodisomy and isodisomy for different regions of chromosome 14. Obesity after initial failure to thrive developed, while compulsive eating habits were not present, which was helpful for the clinical differential diagnosis of Prader-Willi syndrome. In addition, the boy presented with many phenotypic features associated with upd(14)mat along with hypoesthesia to pain, previously unreported in this disorder, and bilateral cryptorchidism, also rarely described. These features, as well as other clinical manifestations (i.e., truncal obesity, altered pubertal timing), may suggest a hypothalamic-pituitary involvement. A detailed cytogenetic and molecular characterization of the genomic rearrangement is presented. Early genetic diagnosis permits a specific follow-up of children with upd(14)mat in order to optimize the long-term outcome.