RNA sequencing unravels novel L cell constituents and mechanisms of GLP-1 secretion in human gastric bypass-operated intestine.

AIMS/HYPOTHESIS: Roux-en-Y gastric bypass surgery (RYGB) frequently results in remission of type 2 diabetes as well as exaggerated secretion of glucagon-like peptide-1 (GLP-1). Here, we assessed RYGB-induced transcriptomic alterations in the small intestine and investigated how they were related to the regulation of GLP-1 production and secretion in vitro and in vivo. METHODS: Human jejunal samples taken perisurgically and 1 year post RYGB (n=13) were analysed by RNA-seq. Guided by bioinformatics analysis we targeted four genes involved in cholesterol biosynthesis, which we confirmed to be expressed in human L cells, for potential involvement in GLP-1 regulation using siRNAs in GLUTag and STC-1 cells. Gene expression analyses, GLP-1 secretion measurements, intracellular calcium imaging and RNA-seq were performed in vitro. OGTTs were performed in C57BL/6j and iScd1-/- mice and immunohistochemistry and gene expression analyses were performed ex vivo. RESULTS: Gene Ontology (GO) analysis identified cholesterol biosynthesis as being most affected by RYGB. Silencing or chemical inhibition of stearoyl-CoA desaturase 1 (SCD1), a key enzyme in the synthesis of monounsaturated fatty acids, was found to reduce Gcg expression and secretion of GLP-1 by GLUTag and STC-1 cells. Scd1 knockdown also reduced intracellular Ca2+ signalling and membrane depolarisation. Furthermore, Scd1 mRNA expression was found to be regulated by NEFAs but not glucose. RNA-seq of SCD1 inhibitor-treated GLUTag cells identified altered expression of genes implicated in ATP generation and glycolysis. Finally, gene expression and immunohistochemical analysis of the jejunum of the intestine-specific Scd1 knockout mouse model, iScd1-/-, revealed a twofold higher L cell density and a twofold increase in Gcg mRNA expression. CONCLUSIONS/INTERPRETATION: RYGB caused robust alterations in the jejunal transcriptome, with genes involved in cholesterol biosynthesis being most affected. Our data highlight SCD as an RYGB-regulated L cell constituent that regulates the production and secretion of GLP-1.

Short-term effects of obesity surgery versus low-energy diet on body composition and tissue-specific glucose uptake: a randomised clinical study using whole-body integrated 18F-FDG-PET/MRI.

AIMS/HYPOTHESIS: Obesity surgery (OS) and diet-induced weight loss rapidly improve insulin resistance. We aim to investigate the impact of either Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) surgery compared with a diet low in energy (low-calorie diet; LCD) on body composition, glucose control and insulin sensitivity, assessed both at the global and tissue-specific level in individuals with obesity but not diabetes. METHODS: In this parallel group randomised controlled trial, patients on a waiting list for OS were randomised (no blinding, sealed envelopes) to either undergo surgery directly or undergo an LCD before surgery. At baseline and 4 weeks after surgery (n=15, 11 RYGB and 4 SG) or 4 weeks after the start of LCD (n=9), investigations were carried out, including an OGTT and hyperinsulinaemic-euglycaemic clamps during which concomitant simultaneous whole-body [18F]fluorodeoxyglucose-positron emission tomography (PET)/MRI was performed. The primary outcome was HOMA-IR change. RESULTS: One month after bariatric surgery and initiation of LCD, both treatments induced similar reductions in body weight (mean ± SD: -7.7±1.4 kg and -7.4±2.2 kg, respectively), adipose tissue volume (7%) and liver fat content (2% units). HOMA-IR, a main endpoint, was significantly reduced following OS (-26.3% [95% CI -49.5, -3.0], p=0.009) and non-significantly following LCD (-20.9% [95% CI -58.2, 16.5). For both groups, there were similar reductions in triglycerides and LDL-cholesterol. Fasting plasma glucose and insulin were also significantly reduced only following OS. There was an increase in glucose AUC in response to an OGTT in the OS group (by 20%) but not in the LCD group. During hyperinsulinaemia, only the OS group showed a significantly increased PET-derived glucose uptake rate in skeletal muscle but a reduced uptake in the heart and abdominal adipose tissue. Both liver and brain glucose uptake rates were unchanged after surgery or LCD. Whole-body glucose disposal and endogenous glucose production were not significantly affected. CONCLUSIONS/INTERPRETATION: The short-term metabolic effects seen 4 weeks after OS are not explained by loss of body fat alone. Thus OS, but not LCD, led to reductions in fasting plasma glucose and insulin resistance as well as to distinct changes in insulin-stimulated glucose fluxes to different tissues. Such effects may contribute to the prevention or reversal of type 2 diabetes following OS. Moreover, the full effects on whole-body insulin resistance and plasma glucose require a longer time than 4 weeks. TRIAL REGISTRATION: ClinicalTrials.gov NCT02988011 FUNDING: This work was supported by AstraZeneca R&D, the Swedish Diabetes Foundation, the European Union's Horizon Europe Research project PAS GRAS, the European Commission via the Marie Sklodowska Curie Innovative Training Network TREATMENT, EXODIAB, the Family Ernfors Foundation, the P.O. Zetterling Foundation, Novo Nordisk Foundation, the Agnes and Mac Rudberg Foundation and the Uppsala University Hospital ALF grants.

Ghrelin, CCK, GLP-1, and PYY(3-36): Secretory Controls and Physiological Roles in Eating and Glycemia in Health, Obesity, and After RYGB.

The efficacy of Roux-en-Y gastric-bypass (RYGB) and other bariatric surgeries in the management of obesity and type 2 diabetes mellitus and novel developments in gastrointestinal (GI) endocrinology have renewed interest in the roles of GI hormones in the control of eating, meal-related glycemia, and obesity. Here we review the nutrient-sensing mechanisms that control the secretion of four of these hormones, ghrelin, cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), and peptide tyrosine tyrosine [PYY(3-36)], and their contributions to the controls of GI motor function, food intake, and meal-related increases in glycemia in healthy-weight and obese persons, as well as in RYGB patients. Their physiological roles as classical endocrine and as locally acting signals are discussed. Gastric emptying, the detection of specific digestive products by small intestinal enteroendocrine cells, and synergistic interactions among different GI loci all contribute to the secretion of ghrelin, CCK, GLP-1, and PYY(3-36). While CCK has been fully established as an endogenous endocrine control of eating in healthy-weight persons, the roles of all four hormones in eating in obese persons and following RYGB are uncertain. Similarly, only GLP-1 clearly contributes to the endocrine control of meal-related glycemia. It is likely that local signaling is involved in these hormones' actions, but methods to determine the physiological status of local signaling effects are lacking. Further research and fresh approaches are required to better understand ghrelin, CCK, GLP-1, and PYY(3-36) physiology; their roles in obesity and bariatric surgery; and their therapeutic potentials.

Metabolic outcomes in obese mice undergoing one-anastomosis gastric bypass (OAGB) with a long or a short biliopancreatic limb.

One-anastomosis gastric bypass (OAGB) has gained importance as a simple, safe, and effective operation to treat morbid obesity. We previously found that Roux-en-Y gastric bypass surgery with a long compared with a short biliopancreatic limb (BPL) leads to improved weight loss and glucose tolerance in obese mice. However, it is not known whether a long BPL in OAGB surgery also results in beneficial metabolic outcomes. Five-week-old male C57BL/6J mice fed a high-fat diet (HFD) for 8 weeks underwent OAGB surgery with defined BPL lengths (5.5 cm distally of the duodenojejunal junction for short and 9.5 cm for long BPL), or sham surgery combined with caloric restriction. Weight loss, glucose tolerance, obesity-related comorbidities, endocrine effects, gut microbiota, and bile acids were assessed. Total weight loss was independent of the length of the BPL after OAGB surgery. However, a long BPL was associated with lower glucose-stimulated insulin on day 14, and an improved glucose tolerance on day 35 after surgery. Moreover, a long BPL resulted in reduced total cholesterol, while there were no differences in the resolution of metabolic dysfunction-associated steatotic liver disease (MASLD) and adipose tissue inflammation. Tendencies of an attenuated hypothalamic-pituitary-adrenal (HPA) axis and aldosterone were present in the long BPL group. With both the short and long BPL, we found an increase in primary conjugated bile acids (pronounced in long BPL) along with a loss in bacterial Desulfovibrionaceae and Erysipelotrichaceae and simultaneous increase in Akkermansiaceae, Sutterellaceae, and Enterobacteriaceae. In summary, OAGB surgery with a long compared with a short BPL led to similar weight loss, but improved glucose metabolism, lipid, and endocrine outcomes in obese mice, potentially mediated through changes in gut microbiota and related bile acids. Tailoring the BPL length in humans might help to optimize metabolic outcomes after bariatric surgery.NEW & NOTEWORTHY Weight loss following OAGB surgery in obese mice was not influenced by BPL length, but a longer BPL was associated with improved metabolic outcomes, including glucose and lipid homeostasis. These changes could be mediated by bile acids upon altered gut microbiota. Further validation of these findings is required through a randomized human study.

Bariatric-metabolic surgery versus lifestyle intervention plus best medical care in non-alcoholic steatohepatitis (BRAVES): a multicentre, open-label, randomised trial.

BACKGROUND: Observational studies suggest that bariatric-metabolic surgery might greatly improve non-alcoholic steatohepatitis (NASH). However, the efficacy of surgery on NASH has not yet been compared with the effects of lifestyle interventions and medical therapy in a randomised trial. METHODS: We did a multicentre, open-label, randomised trial at three major hospitals in Rome, Italy. We included participants aged 25-70 years with obesity (BMI 30-55 kg/m2), with or without type 2 diabetes, with histologically confirmed NASH. We randomly assigned (1:1:1) participants to lifestyle modification plus best medical care, Roux-en-Y gastric bypass, or sleeve gastrectomy. The primary endpoint of the study was histological resolution of NASH without worsening of fibrosis at 1-year follow-up. This study is registered at ClinicalTrials.gov, NCT03524365. FINDINGS: Between April 15, 2019, and June 21, 2021, we biopsy screened 431 participants; of these, 103 (24%) did not have histological NASH and 40 (9%) declined to participate. We randomly assigned 288 (67%) participants with biopsy-proven NASH to lifestyle modification plus best medical care (n=96 [33%]), Roux-en-Y gastric bypass (n=96 [33%]), or sleeve gastrectomy (n=96 [33%]). In the intention-to-treat analysis, the percentage of participants who met the primary endpoint was significantly higher in the Roux-en-Y gastric bypass group (54 [56%]) and sleeve gastrectomy group (55 [57%]) compared with lifestyle modification (15 [16%]; p<0·0001). The calculated probability of NASH resolution was 3·60 times greater (95% CI 2·19-5·92; p<0·0001) in the Roux-en-Y gastric bypass group and 3·67 times greater (2·23-6·02; p<0·0001) in the sleeve gastrectomy group compared with in the lifestyle modification group. In the per protocol analysis (236 [82%] participants who completed the trial), the primary endpoint was met in 54 (70%) of 77 participants in the Roux-en-Y gastric bypass group and 55 (70%) of 79 participants in the sleeve gastrectomy group, compared with 15 (19%) of 80 in the lifestyle modification group (p<0·0001). No deaths or life-threatening complications were reported in this study. Severe adverse events occurred in ten (6%) participants who had bariatric-metabolic surgery, but these participants did not require re-operations and severe adverse events were resolved with medical or endoscopic management. INTERPRETATION: Bariatric-metabolic surgery is more effective than lifestyle interventions and optimised medical therapy in the treatment of NASH. FUNDING: Fondazione Policlinico Universitario A Gemelli, Policlinico Universitario Umberto I and S Camillo Hospital, Rome, Italy.

Distributed Cox proportional hazards regression using summary-level information.

Individual-level data sharing across multiple sites can be infeasible due to privacy and logistical concerns. This article proposes a general distributed methodology to fit Cox proportional hazards models without sharing individual-level data in multi-site studies. We make inferences on the log hazard ratios based on an approximated partial likelihood score function that uses only summary-level statistics. This approach can be applied to both stratified and unstratified models, accommodate both discrete and continuous exposure variables, and permit the adjustment of multiple covariates. In particular, the fitting of stratified Cox models can be carried out with only one file transfer of summary-level information. We derive the asymptotic properties of the proposed estimators and compare the proposed estimators with the maximum partial likelihood estimators using pooled individual-level data and meta-analysis methods through simulation studies. We apply the proposed method to a real-world data set to examine the effect of sleeve gastrectomy versus Roux-en-Y gastric bypass on the time to first postoperative readmission.

Transoral Outlet Reduction: Expert Tips, Tricks, and Troubleshooting.

Transoral outlet reduction (TORe) is an incisionless, endoscopic procedure to address weight recurrence after Roux-en-Y gastric bypass. Given the chronic, progressive nature of obesity and the minimally invasive, anatomy preserving technique of TORe, the procedure is expected to be met with high patient acceptance and widening clinical adoption. Nevertheless, the approach to TORe has been heterogeneous. As endoscopic bariatric therapies are increasingly incorporated into the multidisciplinary management of obesity, it is crucial to have a standardized, evidence-based framework for their implementation. In this review, based on the available literature and the authors' combined experience of over 1,000 TORe procedures, we present our approach to patient selection, procedural technique, troubleshooting, and patient aftercare unique to TORe.

Bone mineral density in young adults 5 to 11 years after adolescent metabolic and bariatric surgery for severe obesity compared to peers.

OBJECTIVE: Metabolic and bariatric surgery (MBS) is associated with decreased bone mineral density (BMD) in adults. The long-term impact of MBS during adolescence on BMD is unknown. We report bone health status 5 to 11 years after Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) from the Teen-LABS study cohort. METHODS: Between 2016 and 2022, BMD was measured by dual energy x-ray absorptiometry (DXA) in 106 young adults who had undergone MBS as adolescents. Volumetric BMD by peripheral quantitative computed tomography was measured on a subset. Ninety-one controls who had not undergone MBS were recruited for comparison. RESULTS: In cases (RYGB: mean age 26.8 ± 1.9 years, mean BMI 42.1 ± 9.9 kg/m2, VSG: mean age 25.1 ± 2.1 years, mean BMI 37.1 ± 8.4 kg/m2), compared to controls (mean age 26.5 ± 2.7 years, mean BMI 40.2 ± 8.7 kg/m2) (age p < 0.001, BMI p = 0.02), adjusted mean DXA-BMD (g/cm2) of the RYGB (n = 58) and VSG (n = 48) groups were lower at the hip (-10.0% and -6.3%), femoral neck (-9.6% and -5.7%) and ultra-distal radius (-7.9% and -7.0%; all p < 0.001), respectively. DXA-BMD did not differ between RYGB and VSG groups. Trabecular volumetric BMD at the radius and tibia were lower in the RYGB (-30% and -26%) and VSG (-15% and -14%) groups compared to the control group (p < 0.001). Greater time since MBS was associated with lower BMD Z-scores at the hip (p = 0.05) and femoral neck (p = 0.045). Percent change in body mass index (BMI) from baseline or in the first year after MBS were not associated with bone measures at a median of 9.3 years post MBS. CONCLUSION: BMD, especially of the hip and femoral neck, was lower in young adults who underwent MBS during adolescence compared to matched peers who had not undergone MBS. BMD Z-scores of the femoral neck were inversely associated with time since MBS but were not associated with BMI change.

The effect of bariatric surgery type on cardiac reverse remodelling.

INTRODUCTION: Bariatric surgery is effective in reversing adverse cardiac remodelling in obesity. However, it is unclear whether the three commonly performed operations; Roux-en-Y Gastric Bypass (RYGB), Laparoscopic Sleeve Gastrectomy (LSG) and Laparoscopic Adjustable Gastric Band (LAGB) are equal in their ability to reverse remodelling. METHODS: Fifty-eight patients underwent CMR to assess left ventricular mass (LVM), LV mass:volume ratio (LVMVR) and LV eccentricity index (LVei) before and after bariatric surgery (26 RYGB, 22 LSG and 10 LAGB), including 46 with short-term (median 251-273 days) and 43 with longer-term (median 983-1027 days) follow-up. Abdominal visceral adipose tissue (VAT) and epicardial adipose tissue (EAT) were also assessed. RESULTS: All three procedures resulted in significant decreases in excess body weight (48-70%). Percentage change in VAT and EAT was significantly greater following RYGB and LSG compared to LAGB at both timepoints (VAT:RYGB -47% and -57%, LSG -47% and -54%, LAGB -31% and -25%; EAT:RYGB -13% and -14%, LSG -16% and -19%, LAGB -5% and -5%). Patients undergoing LAGB, whilst having reduced LVM (-1% and -4%), had a smaller decrease at both short (RYGB: -8%, p < 0.005; LSG: -11%, p < 0.0001) and long (RYGB: -12%, p = 0.009; LSG: -13%, p < 0.0001) term timepoints. There was a significant decrease in LVMVR at the long-term timepoint following both RYGB (-7%, p = 0.006) and LSG (-7%, p = 0.021), but not LAGB (-2%, p = 0.912). LVei appeared to decrease at the long-term timepoint in those undergoing RYGB (-3%, p = 0.063) and LSG (-4%, p = 0.015), but not in those undergoing LAGB (1%, p = 0.857). In all patients, the change in LVM correlated with change in VAT (r = 0.338, p = 0.0134), while the change in LVei correlated with change in EAT (r = 0.437, p = 0.001). CONCLUSIONS: RYGB and LSG appear to result in greater decreases in visceral adiposity, and greater reverse LV remodelling with larger reductions in LVM, concentric remodelling and pericardial restraint than LAGB.

Weight loss in adult male Wistar rats by Roux-en-Y gastric bypass is primarily explained by caloric intake reduction and presurgery body weight.

Diets varying in macronutrient composition, energy density, and/or palatability may cause differences in outcome of bariatric surgery. In the present study, rats feeding a healthy low-fat (LF) diet or an obesogenic high-fat/sucrose diet (HF/S) were either subjected to Roux-en-Y gastric bypass surgery (RYGB) or sham surgery, and weight loss trajectories and various energy balance parameters were assessed. Before RYGB, rats eating an HF/S (n = 14) diet increased body weight relative to rats eating an LF diet (n = 20; P < 0.01). After RYGB, absolute weight loss was larger in HF/S (n = 6) relative to LF feeding (n = 6) rats, and this was associated with reduced cumulative energy intake (EI; P < 0.05) and increased locomotor activity (LA; P < 0.05-0.001), finally leading to similar levels of reduced body fat content in HF/S and LF rats 3 wk after surgery. Regression analysis revealed that variation in RYGB-induced body weight loss was best explained by models including 1) postoperative cumulative EI and preoperative body weight (R2 = 0.87) and 2) postoperative cumulative EI and diet (R2 = 0.79), each without significant contribution of LA. Particularly rats on the LF diet became transiently more hypothermic and circadianally arrhythmic following RYGB (i.e., indicators of surgery-associated malaise) than HF/S feeding rats. Our data suggest that relative to feeding an LF diet, continued feeding an HF/S diet does not negatively impact recovery from RYGB surgery, yet it promotes RYGB-induced weight loss. The RYGB-induced weight loss is primarily explained by reduced cumulative EI and higher preoperative body weight, leading to comparably low levels of body fat content in HF/S and LF feeding rats.NEW & NOTEWORTHY Relative to feeding an LF diet, continued feeding an HF/S diet does not negatively impact recovery from RYGB surgery in rats. Relative to feeding an LF diet, continued feeding an HF/S diet promotes RYGB-induced weight loss. The RYGB-induced weight loss is primarily explained by reduced cumulative EI and higher preoperative body weight, leading to comparably low levels of body fat content in HF/S and LF feeding rats.

Short-term effects of gastric bypass versus sleeve gastrectomy on high LDL cholesterol: The BASALTO randomized clinical trial.

BACKGROUND: There has been a substantial increase in the use of laparoscopic sleeve gastrectomy (SG) to treat morbid obesity despite observational evidence demonstrating the superiority of Roux-en-Y gastric bypass (RYGB) for reducing low-density lipoprotein (LDL) cholesterol. The main aim was to ascertain whether high LDL cholesterol levels should be considered when selecting the most appropriate surgical procedure for each patient (RYGB or SG). METHODS: In this single-center, randomized clinical trial using intention-to-treat analysis, 38 patients with severe obesity and elevated levels of LDL cholesterol were randomly assigned to undergo RYGB or SG. The primary outcome was LDL cholesterol remission at 12 months, defined as LDL cholesterol < 3.36 nmol/l without lipid-lowering medications. Secondary outcomes included changes in weight, other comorbidities, qualitative lipoprotein traits, cholesterol esters, glycoproteins, cholesterol absorption and synthesis metabolites and complications. RESULTS: Intention-to-treat analysis revealed that LDL cholesterol remission occurred in 66.6% of RYGB patients compared to 27.8% of SG patients (p = 0.019). Among patients completing follow-up, RYGB demonstrated superior remission (80.0% vs. 29.4%, p = 0.005). Exclusive benefits of RYGB included a reduction in large, medium, and small LDL particles. Cholesterol absorption markers showed differential behavior after both techniques: campesterol (Δ -15.2 µg/mg, 95% CI -30.2 to -0.1) decreased after RYGB, and sitosterol (Δ 21.1 µg/mg, 95% CI 0.9 to 41.2), cholestanol (Δ 30.6 µg/mg, 95% CI 14.8 to 57.9) and campesterol (Δ 18.4 µg/mg, 95% CI 4.4 to 32.3) increased after SG. No differences in weight loss, cholesterol esters, glycoproteins, cholesterol synthesis metabolites or postoperative complications were observed between techniques. CONCLUSION: In conclusion, RYGB is superior to SG in terms of short-term of high LDL cholesterol remission. Furthermore, RYGB also led to a greater improvement in lipoprotein parameters that confer an atherogenic profile. Therefore, the presence of elevated levels of LDL cholesterol should be considered when determining the optimal bariatric surgery procedure for each patient. TRIAL REGISTRATION: Clinicaltrials.gov number, NCT03975478).

Global benchmarks in primary robotic bariatric surgery redefine quality standards for Roux-en-Y gastric bypass and sleeve gastrectomy.

BACKGROUND: Whether the benefits of the robotic platform in bariatric surgery translate into superior surgical outcomes remains unclear. The aim of this retrospective study was to establish the 'best possible' outcomes for robotic bariatric surgery and compare them with the established laparoscopic benchmarks. METHODS: Benchmark cut-offs were established for consecutive primary robotic bariatric surgery patients of 17 centres across four continents (13 expert centres and 4 learning phase centres) using the 75th percentile of the median outcome values until 90 days after surgery. The benchmark patients had no previous laparotomy, diabetes, sleep apnoea, cardiopathy, renal insufficiency, inflammatory bowel disease, immunosuppression, history of thromboembolic events, BMI greater than 50 kg/m2, or age greater than 65 years. RESULTS: A total of 9097 patients were included, who were mainly female (75.5%) and who had a mean(s.d.) age of 44.7(11.5) years and a mean(s.d.) baseline BMI of 44.6(7.7) kg/m2. In expert centres, 13.74% of the 3020 patients who underwent primary robotic Roux-en-Y gastric bypass and 5.9% of the 4078 patients who underwent primary robotic sleeve gastrectomy presented with greater than or equal to one complication within 90 postoperative days. No patient died and 1.1% of patients had adverse events related to the robotic platform. When compared with laparoscopic benchmarks, robotic Roux-en-Y gastric bypass had lower benchmark cut-offs for hospital stay, postoperative bleeding, and marginal ulceration, but the duration of the operation was 42 min longer. For most surgical outcomes, robotic sleeve gastrectomy outperformed laparoscopic sleeve gastrectomy with a comparable duration of the operation. In robotic learning phase centres, outcomes were within the established benchmarks only for low-risk robotic Roux-en-Y gastric bypass. CONCLUSION: The newly established benchmarks suggest that robotic bariatric surgery may enhance surgical safety compared with laparoscopic bariatric surgery; however, the duration of the operation for robotic Roux-en-Y gastric bypass is longer.

Postbariatric surgery hypoglycemia: Nutritional, pharmacological and surgical perspectives.

Post-bariatric hypoglycaemia (PBH) is a metabolic complication of bariatric surgery (BS), consisting of low post-prandial glucose levels in patients having undergone bariatric procedures. While BS is currently the most effective and relatively safe treatment for obesity and its complications, the development of PBH can significantly impact patients' quality of life and mental health. The diagnosis of PBH is still challenging, considering the lack of definitive and reliable diagnostic tools, and the fact that this condition is frequently asymptomatic. However, PBH's prevalence is alarming, involving up to 88% of the post-bariatric population, depending on the diagnostic tool, and this may be underestimated. Given the prevalence of obesity soaring, and an increasing number of bariatric procedures being performed, it is crucial that physicians are skilled to diagnose PBH and promptly treat patients suffering from it. While the milestone of managing this condition is nutritional therapy, growing evidence suggests that old and new pharmacological approaches may be adopted as adjunct therapies for managing this complex condition.

Canagliflozin or acarbose versus placebo to ameliorate post-bariatric hypoglycaemia - The HypoBar I randomized clinical trial protocol.

INTRODUCTION: Post-bariatric hypoglycaemia (PBH) is a rare yet disabling clinical condition, mostly reported after Roux-en-Y gastric bypass (RYGB) surgery. RYGB is one of the most widely used and effective bariatric procedures. The pathophysiology of PBH remains unclear, and treatment options are limited in effectiveness and/or carry significant side effects. Acarbose slows carbohydrates digestion and absorption and is generally considered first-line pharmacological treatment for PBH but its gastrointestinal side effects limit patient compliance. Canagliflozin inhibits intestinal and renal sodium-dependent glucose absorption and reduces postprandial excursions of glucose, insulin and incretins after RYGB - effects that could be beneficial in ameliorating PBH. AIMS: The trial aims to investigate how blood glucose levels are affected during daily living in subjects with PBH during treatment with canagliflozin or acarbose compared with placebo, and to study the meal-induced entero-endocrine mechanisms implied in the treatment responses. METHODS: In a double-blinded, randomized, crossover clinical trial, HypoBar I will investigate the effectiveness in reducing the risk of PBH, safety, ambulatory glucose profile and entero-endocrine responses when PBH is treated with canagliflozin 300 mg twice daily during a 4-week intervention period, compared with acarbose 50 mg thrice daily or placebo. ETHICS AND DISSEMINATION: HypoBar I is approved by the Local regulatory entities. Results will be published in peer-reviewed journals. CONCLUSION: If effective, well-tolerated and safe, canagliflozin could be a novel treatment for people with PBH. HypoBar I might also unravel new mechanisms underlying PBH, potentially identifying new treatment targets. TRIAL REGISTRATION: EudraCT number 2022-000157-87.

Development of a novel endoscopic suturing simulator: validation and impact on clinical learning curve (with video).

BACKGROUND AND AIMS: Endoscopic suturing is a complex skill with broad applications. The aim of this study was to develop and validate a novel endoscopic suturing simulator and scoring system for the purse-string suture pattern. METHODS: This was a prospective study of an endoscopic suturing simulator that consists of a circular opening representing a dilated gastrojejunal anastomosis of Roux-en-Y gastric bypass with 12 small target holes around its circumference. Purse-string suturing is performed in a counterclockwise fashion. Time allotted is 5 minutes, and each successful bite is awarded 10 points. Participants were divided into the novice, intermediate, and experienced groups. Validity evidence based on content, validity evidence based on other variables, and validity evidence based on consequences of testing were assessed. RESULTS: Seventeen subjects (3 novice, 7 intermediate, and 7 experienced) participated in the study. Validity evidence based on content: The content validity index for realism, relevance, and representativeness was 0.89, 1.00, and 1.00, respectively. Validity evidence based on other variables: The novice, intermediate, and experienced groups scored 30.0 ± 8.2, 57.1 ± 28.1, and 131.2 ± 51.7 (P = .001). Validity evidence based on consequences of testing: The simulator group required 5 ± 5 transoral outlet reduction cases before being able to independently complete an entire purse-string, whereas the non-simulator group required 38 ± 11 clinical cases (P < .0001). CONCLUSIONS: This novel endoscopic suturing simulator seems realistic, relevant, and representative of the clinical suturing experience. In addition, it seems effective at objectively assessing suturing skills and shortening the clinical learning curve.

Fixation of the proximal flange of a lumen-apposing metal stent using a through-the-scope endoscopic suturing system to prevent stent migration in single-session EUS-directed transgastric ERCP: a pilot study.

BACKGROUND AND AIMS: With the global obesity pandemic, clinical scenarios requiring urgent ERCP in patients with gastric bypass surgery are on the rise, and single-session EUS-directed transgastric ERCP (SS-EDGE) can effectively address these technical challenges. The aim of this study was to evaluate and describe the safe and effective use of a through-the-scope endoscopic suturing system for anchoring the lumen-apposing metal stents (LAMSs) during SS-EDGE. METHODS: Six patients with Roux-en-Y gastric bypass (RYGB) underwent SS-EDGE at our center. A through-the-scope endoscopic suturing system was used for anchoring the LAMSs during SS-EDGE. RESULTS: Clinical and technical success was achieved in all 6 patients without any adverse events related to the procedure. No stent migration, pneumoperitoneum, or GI perforation was noted. At the 4-week follow-up, no stent migration was noted, and the through-the-scope suturing system remained anchored. LAMSs along with tacks were removed, and gastric fistulae were successfully closed endoscopically in all patients to prevent weight gain. CONCLUSIONS: Use of through-the-scope endoscopic suturing can be a safe, reliable, and potentially cost-effective novel technique for LAMS fixation to successfully perform SS-EDGE in RYGB patients.

How best to combine liver transplantation and bariatric surgery?-Results from a global, web-based survey.

BACKGROUND AND AIMS: Obesity is a growing healthcare challenge worldwide and a significant risk factor for liver failure as seen with non-alcoholic steatohepatitis (NASH). Combining metabolic-bariatric surgery (MBS) with liver transplantation (LT) appears as attractive strategy to treat both, the underlying liver disease and obesity. However, there is an ongoing debate on best timing and patient selection. This survey was designed to explore the current treatment practice for patients with NASH and obesity worldwide. METHODS: A web-based survey was conducted in 2022 among bariatric and LT surgeons, and hepatologists from Europe, North and South America and Asia. RESULTS: The survey completion rate was 74% (145/196). The average respondents were 41-50 years (38%), male (82.1%) and had >20 years of clinical experience (42.1%). Centres with a high LT-caseload for NASH were mainly located in the USA and United Kingdom. Almost 30% have already performed a combination of LT with MBS and 49% plan to do it. A majority of bariatric surgeons prefer MBS before LT (77.2%), whereas most of LT surgeons (52%) would perform MBS during LT. Most respondents (n = 114; 80%) favour sleeve gastrectomy over other bariatric techniques. One third (n = 42; 29.4%) has an established protocol regarding MBS for LT candidates. CONCLUSION: The most experienced centres doing LT for NASH are in the USA and United Kingdom with growing awareness worldwide. Overall, a combination of MBS and LT has already been performed by a third of respondents. Sleeve gastrectomy is the bariatric technique of choice-preferably performed either before or during LT.

Differential effect of endogenous glucagon-like peptide-1 on prandial glucose counterregulatory response to hypoglycaemia in humans with and without bariatric surgery.

AIM: To determine the effect of endogenous glucagon-like peptide 1 (GLP-1) on prandial counterregulatory response to hypoglycaemia after gastric bypass (GB). MATERIALS AND METHODS: Glucose fluxes, and islet-cell and gut hormone responses before and after mixed-meal ingestion, were compared during a hyperinsulinaemic-hypoglycaemic (~3.2 mmol/L) clamp with and without a GLP-1 receptor (GLP-1R) antagonist exendin-(9-39) infusion in non-diabetic patients who had previously undergone GB compared to matched participants who had previously undergone sleeve gastrectomy (SG) and non-surgical controls. RESULTS: Exendin-(9-39) infusion raised prandial endogenous glucose production (EGP) response to insulin-induced hypoglycaemia in the GB group but had no consistent effect on EGP response among the SG group or non-surgical controls (p < 0.05 for interaction). The rates of systemic appearance of ingested glucose or prandial glucose utilization did not differ among the three groups or between studies with and without exendin-(9-39) infusion. Blockade of GLP-1R had no effect on insulin secretion or insulin action but enhanced prandial glucagon in all three groups. CONCLUSIONS: These results indicate that impaired post-meal glucose counterregulatory response to hypoglycaemia after GB is partly mediated by endogenous GLP-1, highlighting a novel pathogenic mechanism of GLP-1 in developing hypoglycaemia in this population.

A look at duodenal mucosal resurfacing: Rationale for targeting the duodenum in type 2 diabetes.

Affecting 5%-10% of the world population, type 2 diabetes (T2DM) is firmly established as one of the major health burdens of modern society. People with T2DM require long-term therapies to reduce blood glucose, an approach that can mitigate the vascular complications. However, fewer than half of those living with T2DM reach their glycaemic targets despite the availability of multiple oral and injectable medications. Adherence and access to medications are major barriers contributing to suboptimal diabetes treatment. The gastrointestinal tract has recently emerged as a target for treating T2DM and altering the underlying disease course. Preclinical and clinical analyses have elucidated changes in the mucosal layer of the duodenum potentially caused by dietary excess and obesity, which seem to be prevalent among individuals with metabolic disease. Supporting these findings, gastric bypass, a surgical procedure which removes the duodenum from the intestinal nutrient flow, has remarkable effects that improve, and often cause remission of, diabetes. From this perspective, we explore the rationale for targeting the duodenum with duodenal mucosal resurfacing (DMR). We examine the underlying physiology of the duodenum and its emerging role in T2DM pathogenesis, the rationale for targeting the duodenum by DMR as a potential treatment for T2DM, and current data surrounding DMR. Importantly, DMR has been demonstrated to change mucosal abnormalities common in those with obesity and diabetes. Given the multifactorial aetiology of T2DM, understanding proximate contributors to disease pathogenesis opens the door to rethinking therapeutic approaches to T2DM, from symptom management toward disease modification.

The Association of Preoperative Food Insecurity With Early Postoperative Outcomes After Bariatric Surgery.

INTRODUCTION: To assess the rate of food insecurity in patients undergoing bariatric surgery. To compare the rates of 30-d postoperative complications based on food security status. METHODS: Patients undergoing primary Roux-en-Y gastric bypass or sleeve gastrectomy between 7/2020 - 3/2022 were screened for food insecurity via telephone using questions from the Accountable Health Communities Health-Related Social Needs Screening Tool. Screens were matched to patient data and 30-d outcomes from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database. RESULTS: In total, 213 (59%) of the 359 bariatric surgery patients were screened with 81 (38%) screening positive for food insecurity. Evaluation of preoperative variables based on food security status showed comparable age, body mass index, and comorbidity status. Food insecure patients were found to have an increased length of stay following surgery compared to food secure patients (P = 0.003). Food insecurity was not associated with higher rates of Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program reported 30-d postoperative complications including emergency department/urgent care visits (P = 0.34) and hospital readmissions (P = 0.94). CONCLUSIONS: Food insecurity was prevalent at 38% of the bariatric surgical population. Food insecure patients had a statistically longer length of stay after primary bariatric surgery but were not associated with an increased risk of 30-d complications. Future studies are needed to determine the mid-term and long-term effects of food insecurity status on bariatric surgical outcomes and the potential impact of food insecurity on length of stay.