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.

The Role of Antibiotic Prophylaxis in Anastomotic Leak Prevention during Elective Colorectal Surgery: Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Introduction: Despite several perioperative care advancements and innovations in surgical procedures and technologies, the incidence rate of anastomotic leaks (ALs) after colorectal surgery has not substantially decreased. Gut microbiota can play a critical role in the healing process of anastomotic tissue and alterations in its composition may be largely to blame for anastomotic insufficiency. The use of specific antibiotics for preoperative large bowel decontamination could significantly influence the rate of ALs. The aim of this study was to systematically assess the various antibiotic prophylactic regimen strategies for primary prevention of ALs during colorectal surgery, in view of the available evidence. Methods: A systematic review of the literature was conducted, and randomized clinical trials (RCTs) analyzing prophylactic antibiotic bowel preparation in colorectal surgery were included. PubMed, Embase, the Web of Science Core Collection, and the Cochrane Central Register of Controlled Trials were searched from inception through to 30 November 2022. The methodological quality of the included trials was evaluated. The primary outcome was AL rate; secondary outcomes were superficial/deep surgical site infections (SSIs). The PRISMA guidelines were used to carry out the present systematic review. Results: Thirteen RCTs published between 1977 and 2022, with a total of 4334 patients were included in the meta-analysis. Antibiotic prophylaxis was administered orally in 11/13 studies and intravenously in 2 studies. Patients randomly assigned to antibiotic prophylaxis, regardless of the regimen, had a reduced risk of ALs (p = 0.003) compared to mechanical bowel preparation (MBP) alone. The use of antibiotic prophylaxis was also more effective in significantly reducing SSIs (p < 0.001). Conclusions: The evidence points to an advantage of oral antibiotic prophylaxis in terms of AL rate, a significant contributor to perioperative morbidity, mortality, and rising healthcare expenditures. In light of such results, the use of antibiotic prophylaxis should be strongly encouraged prior to colorectal surgery.

Accurate liquid biopsy for the diagnosis of non-alcoholic steatohepatitis and liver fibrosis.

OBJECTIVE: Clinical diagnosis and approval of new medications for non-alcoholic steatohepatitis (NASH) require invasive liver biopsies. The aim of our study was to identify non-invasive biomarkers of NASH and/or liver fibrosis. DESIGN: This multicentre study includes 250 patients (discovery cohort, n=100 subjects (Bariatric Surgery Versus Non-alcoholic Steato-hepatitis - BRAVES trial); validation cohort, n=150 (Liquid Biopsy for NASH and Liver Fibrosis - LIBRA trial)) with histologically proven non-alcoholic fatty liver (NAFL) or NASH with or without fibrosis. Proteomics was performed in monocytes and hepatic stellate cells (HSCs) with iTRAQ-nano- Liquid Chromatography - Mass Spectrometry/Mass Spectrometry (LC-MS/MS), while flow cytometry measured perilipin-2 (PLIN2) and RAB14 in peripheral blood CD14+CD16- monocytes. Neural network classifiers were used to predict presence/absence of NASH and NASH stages. Logistic bootstrap-based regression was used to measure the accuracy of predicting liver fibrosis. RESULTS: The algorithm for NASH using PLIN2 mean florescence intensity (MFI) combined with waist circumference, triglyceride, alanine aminotransferase (ALT) and presence/absence of diabetes as covariates had an accuracy of 93% in the discovery cohort and of 92% in the validation cohort. Sensitivity and specificity were 95% and 90% in the discovery cohort and 88% and 100% in the validation cohort, respectively.The area under the receiver operating characteristic (AUROC) for NAS level prediction ranged from 83.7% (CI 75.6% to 91.8%) in the discovery cohort to 97.8% (CI 95.8% to 99.8%) in the validation cohort.The algorithm including RAB14 MFI, age, waist circumference, high-density lipoprotein cholesterol, plasma glucose and ALT levels as covariates to predict the presence of liver fibrosis yielded an AUROC of 95.9% (CI 87.9% to 100%) in the discovery cohort and 99.3% (CI 98.1% to 100%) in the validation cohort, respectively. Accuracy was 99.25%, sensitivity 100% and specificity 95.8% in the discovery cohort and 97.6%, 99% and 89.6% in the validation cohort. This novel biomarker was superior to currently used FIB4, non-alcoholic fatty liver disease fibrosis score and aspartate aminotransferase (AST)-to-platelet ratio and was comparable to ultrasound two-dimensional shear wave elastography. CONCLUSIONS: The proposed novel liquid biopsy is accurate, sensitive and specific in diagnosing the presence and severity of NASH or liver fibrosis and is more reliable than currently used biomarkers. CLINICAL TRIALS: Discovery multicentre cohort: Bariatric Surgery versus Non-Alcoholic Steatohepatitis, BRAVES, ClinicalTrials.gov identifier: NCT03524365.Validation multicentre cohort: Liquid Biopsy for NASH and Fibrosis, LIBRA, ClinicalTrials.gov identifier: NCT04677101.

Intracholecystic versus Intravenous Indocyanine Green (ICG) Injection for Biliary Anatomy Evaluation by Fluorescent Cholangiography during Laparoscopic Cholecystectomy: A Case-Control Study.

(1) Background: Fluorescence cholangiography has been proposed as a method for improving the visualization and identification of extrahepatic biliary anatomy in order to possibly reduce injuries and related complications. The most common method of indocyanine green (ICG) administration is the intravenous route, whereas evidence on direct ICG injection into the gallbladder is still quite limited. We aimed to compare the two different methods of ICG administration in terms of the visualization of extrahepatic biliary anatomy during laparoscopic cholecystectomy (LC), analyzing differences in the time of visualization, as well as the efficacy, advantages, and disadvantages of both modalities. (2) Methods: A total of 35 consecutive adult patients affected by acute or chronic gallbladder disease were enrolled in this prospective case−control study. Seventeen patients underwent LC with direct gallbladder ICG injection (IC-ICG) and eighteen subjects received intravenous ICG administration (IV-ICG). (3) Results: The groups were comparable with regard to their demographic and perioperative characteristics. The IV-ICG group had a significantly shorter overall operative time compared to the IC-ICG group (p = 0.017). IV-ICG was better at delineating the duodenum and the common hepatic duct compared to the IC-ICG method (p = 0.009 and p = 0.041, respectively). The cystic duct could be delineated pre-dissection in 76.5% and 66.7% of cases in the IC-ICG and IV-ICG group, respectively, and this increased to 88.2% and 83.3% after dissection. The common bile duct could be highlighted in 76.5% and 77.8% of cases in the IC-ICG and IV-ICG group, respectively. Liver fluorescence was present in one case in the IC-ICG group and in all cases after IV-ICG administration (5.8% versus 100%; p < 0.0001). (4) Conclusions: The present study demonstrates how ICG-fluorescence cholangiography can be helpful in identifying the extrahepatic biliary anatomy during dissection of Calot's triangle in both administration methods. In comparison with intravenous ICG injection, the intracholecystic ICG route could provide a better signal-to-background ratio by avoiding hepatic fluorescence, thus increasing the bile duct-to-liver contrast.

Advice of General Practitioner, of Surgeon, of Endocrinologist, and Self-determination: the Italian Road to Bariatric Surgery.

PURPOSE: Bariatric surgery (BS) is considered the most efficient treatment for severe obesity. International guidelines recommend multidisciplinary approach to BS (general practitioners, endocrinologists, surgeons, psychologists, or psychiatrists), and access to BS should be the final part of a protocol of treatment of obesity. However, there are indications that general practitioners (GPs) are not fully aware of the possible benefits of BS, that specialty physicians are reluctant to refer their patients to surgeons, and that patients with obesity choose self-management of their own obesity, including internet-based choices. There are no data on the pathways chosen by physicians and patients to undergo BS in the real world in Italy. METHODS: An exploratory exam was performed for 6 months in three pilot regions (Lombardy, Lazio, Campania) in twenty-three tertiary centers for the treatment of morbid obesity, to describe the real pathways to BS in Italy. RESULTS: Charts of 2686 patients (788 men and 1895 women, 75.5% in the age range 30-59 years) were evaluated by physicians and surgeons of the participating centers. A chronic condition of obesity was evident for the majority of patients, as indicated by duration of obesity, by presence of several associated medical problems, and by frequency of previous dietary attempts to weight loss. The vast majority (75.8%) patients were self-presenting or referred by bariatric surgeons, 24.2% patients referred by GPs and other specialists. Self-presenting patients were younger, more educated, more professional, and more mobile than patients referred by other physicians. Patients above the age of 40 years or with a duration of obesity greater than 10 years had a higher prevalence of all associated medical problems. CONCLUSIONS: The majority of patients referred to a tertiary center for the treatment of morbid obesity have a valid indication for BS. Most patients self-refer to the centers, with a minority referred by a GP or by specialists. Self-presenting patients are younger, more educated, more professional, and more mobile than patients referred by other physicians. Older patients and with a longer duration of obesity are probably representative of the conservative approach to BS, often regarded as the last resort in an endless story.

Bariatric/Metabolic Surgery.

Bariatric surgery is a gastro-intestinal surgery aimed at obtaining weight loss in obesity. The rapid metabolic effects of this type of operations provided a rational to change its name to metabolic surgery, in fact often the improvement of metabolic diseases is observed before a meaningful weight reduction.In this review, we examine the effects of laparoscopic metabolic surgery on life expectancy, type 2 diabetes, hypertension, cardiovascular disease and cancer.Furthermore, we review the surgical endoscopy approaches to obesity including primary obesity procedures and revision procedures that address weight regain after bariatric surgery.Finally, as a bridge to the specific chapter, we summarize the effects on weight reduction of new anti-obesity medications.

Small intestinal metabolism is central to whole-body insulin resistance.

OBJECTIVE: To assess the role of jejunum in insulin resistance in humans and in experimental animals. DESIGN: Twenty-four subjects undergoing biliopancreatic diversion (BPD) or Roux-en-Y gastric bypass (RYGB) were enrolled. Insulin sensitivity was measured at baseline and at 1 week after surgery using oral glucose minimal model.We excluded the jejunum from intestinal continuity in pigs and created a jejunal loop with its vascular and nerve supply intact accessible from two cutaneous stomas, and reconnected the bowel with an end-to-end anastomosis. Glucose stable isotopes were given in the stomach or in the jejunal loop.In vitro studies using primary porcine and human hepatocytes or myoblasts tested the effects of plasma on gluconeogenesis or glucose uptake and insulin signalling. RESULTS: Whole-body insulin sensitivity (SI∙104: 0.54±0.12 before vs 0.82±0.11 after BPD, p=0.024 and 0.41±0.09 before vs 0.65±0.09/pM/min after RYGB, p=not significant) and Glucose Disposition Index increased only after BPD. In pigs, insulin sensitivity was significantly lower when glucose was administered in the jejunal loop than in the stomach (glucose rate of disappearance (Rd) area under the curve (AUC)/insulin AUC∙10: 1.82±0.31 vs 2.96±0.33 mmol/pM/min, p=0.0017).Metabolomics showed a similar pattern before surgery and during jejunal-loop stimulation, pointing to a higher expression of gluconeogenetic substrates, a metabolic signature of impaired insulin sensitivity.A greater hepatocyte phosphoenolpyruvate-carboxykinase and glucose-6-phosphatase gene expression was elicited with plasma from porcine jejunal loop or before surgery compared with plasma from jejunectomy in pigs or jejunal bypass in humans.Stimulation of myoblasts with plasma from porcine jejunal loop or before surgery reduced glucose uptake, Ser473-Akt phosphorylation and GLUT4 expression compared with plasma obtained during gastric glucose administration after jejunectomy in pigs or after jejunal bypass in humans. CONCLUSION: Proximal gut plays a crucial role in controlling insulin sensitivity through a distinctive metabolic signature involving hepatic gluconeogenesis and muscle insulin resistance. Bypassing the jejunum is beneficial in terms of insulin-mediated glucose disposal in obesity. TRIAL REGISTRATION NUMBER: NCT03111953.

Duodenal-jejunal bypass improves nonalcoholic fatty liver disease independently of weight loss in rodents with diet-induced obesity.

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver-related mortality. NAFLD is associated with obesity, hepatic fat accumulation, and insulin resistance, all of which contribute to its pathophysiology. Weight-loss is the main therapy for NAFLD, and metabolic surgery is the most effective treatment for morbid obesity and its metabolic comorbidities. Although has been reported that Roux-en-Y gastric bypass can reverse NAFLD, it is unclear whether such effects result from reduced weight, from a lower calorie-intake, or from the direct influence of surgery on mechanisms contributing to NAFLD. We aimed to investigate whether gastrointestinal (GI) bypass surgery could induce direct effects on hepatic fat accumulation and insulin resistance, independently of weight reduction. Twenty Wistar rats on a high-fat diet underwent duodenal-jejunal-bypass (DJB) or sham operation and were pair fed (PF) for 15 wk after surgery to obtain a matched weight. Outcome measures include ectopic fat deposition, expression of genes and proteins involved in fat metabolism, insulin-signaling, and gluconeogenesis in liver and muscle. Despite no differences in body weight and calorie intake, DJB showed lower ectopic fat accumulation, improved peripheral and hepatic insulin sensitivity, and enhanced lipid droplet degradation. In both tissues, DJB increased insulin signaling, whereas hepatic key enzymes involved in gluconeogenesis and de novo lipogenesis were decreased. These findings suggest that DJB can reverse, independently of weight loss, ectopic fat deposition and insulin resistance, two features of NAFLD that share a mutual pathway, in which perilipin-2 (PLIN2) seems to be the main player, supporting further investigation into strategies that target the gut to treat metabolic liver diseases.NEW & NOTEWORTHY Our findings suggest that duodenal-jejunal bypass can reverse, independently of weight loss, ectopic fat deposition and insulin resistance, two features of nonalcoholic fatty liver disease that share a mutual pathway, in which perilipin-2 seems to be the main player. Our study supports further investigation into the role of proximal small intestine exclusion in the pathophysiology of nonalcoholic fatty liver disease to uncover less invasive treatments that mimic the effects of metabolic surgery and aims to prevent and treat metabolic liver disease.

Obesity Surgery and Cancer: What Are the Unanswered Questions?

Obesity has become a global epidemic with a soaring economic encumbrance due to its related morbidity and mortality. Amongst obesity-related conditions, cancer is indeed the most redoubtable. Bariatric surgery has been proven to be the most effective treatment for obesity and its associated metabolic and cardiovascular disorders. However, the understanding of whether and how bariatric surgery determines a reduction in cancer risk is limited. Obesity-related malignancies primarily include colorectal and hormone-sensitive (endometrium, breast, prostate) cancers. Additionally, esophago-gastric tumors are growing to be recognized as a new category mainly associated with post-bariatric surgery outcomes. In fact, certain types of surgical procedures have been described to induce the development and subsequent progression of pre-cancerous esophageal and gastric lesions. This emerging category is of great concern and further research is required to possibly prevent such risks. Published data has generated conflicting results. In fact, while overall cancer risk reduction was reported particularly in women, some authors showed no improvement or even increased cancer incidence. Although various studies have reported beneficial effects of surgery on risk of specific cancer development, fundamental insights into the pathogenesis of obesity-related cancer are indispensable to fully elucidate its mechanisms.

The jejunum is the key factor in insulin resistance.

BACKGROUND: Biliopancreatic diversion (BPD) is more effective than Roux-en-Y gastric bypass (RYGB) on both insulin resistance and diabetes. OBJECTIVES: Because the major difference between the 2 procedures resides in the length of jejunal bypass, we investigated the role of the jejunum in insulin resistance. SETTING: University hospital in Italy. METHODS: Insulin sensitivity (IS) and secretion were measured before and 4 weeks after RYGB or BPD in 16 patients. A translational study was also conducted in 6 pigs, by isolating a jejunal loop with its vascular and nerve supply (Thiry-Vella loop [TVL]). TVL was doubly stomatized and bowel continuity restored by a side-to-side jejuno-jejunostomy. At baseline and 4 weeks postoperatively a glucose bolus was injected either in the stomach or in the TVL. Whole-body IS and jejunal heat shock proteins (HSPs) were measured. Primary porcine hepatocyte cultures were incubated with plasma or individual HSPs. RESULTS: Whole-body IS increased from 353.5 ± 26.7 to 442.0 ± 37.4 (P < .05) after RYGB and from 312.4 ± 14.9 to 441.2 ± 15.9 mL/m-2/min-1 (P < .001) after BPD. Hepatic IS was unchanged after RYGB, while it increased from .3 ± .01 to .4 ± .1 (µM/pM) - 1 (P < .01) after BPD. Total insulin secretion rate remained unchanged after RYGB but decreased (from 58.3 ± 23.6 to 33.1 ± 7.8 nmol/m-2, P < .05) after BPD. Jejunectomy in pigs enhanced IS (.3 ± .01 versus .2 ± .01 mM/pM, P < .001), while injection of glucose into TVL reduced it (.1 ± .01 versus .3 ± .01 mM/pM, P < .0001). The jejunum secreted HSPs, Hsp70, and GRP78, which impaired insulin signaling in hepatocyte cultures. CONCLUSIONS: This study shows that jejunal bypass in both humans and pigs improves IS. Injection of glucose into the TVL in pigs determines insulin resistance. In response to glucose, the jejunum secretes HSPs that impair insulin signaling.

Simulation of gastric bypass effects on glucose metabolism and non-alcoholic fatty liver disease with the Sleeveballoon device.

BACKGROUND: Gastric bypass surgery is a very effective treatment of obesity and type 2 diabetes. However, very few eligible patients are offered surgery. Some patients also prefer less invasive approaches. We aimed to study the effects of the Sleeveballoon - a new device combining an intragastric balloon with a connecting sleeve, which covers the duodenal and proximal jejunal mucosa - on insulin sensitivity, glycemic control, body weight and body fat distribution. METHODS: We compared the effects of Sleeveballoon, Roux-en-Y Gastric-Bypass (RYGB) and sham-operation in 30 high-fat diet (HFD) fed Wistar rats. Whole body and hepatic insulin sensitivity and insulin signaling were studied. Transthoracic echocardiography was performed using a Vevo 2100 system (FUJIFILM VisualSonics Inc., Canada). Gastric emptying was measured using gastrografin. FINDINGS: Hepatic (P = .023) and whole-body (P = .011) insulin sensitivity improved in the Sleeveballoon and RYGB groups compared with sham-operated rats. Body weight reduced in both Sleeveballoon and RYGB groups in comparison to the sham-operated group (503.1 ±â€¯8.9 vs. 614.4 ±â€¯20.6 g, P = .006 and 490.0 ±â€¯17.7 vs. 614.4 ±â€¯20.6 g, P = .006, respectively). Ectopic fat deposition was drastically reduced while glycogen content was increased in both liver and skeletal muscle. Gastric emptying (T1/2) was longer (157.7 ±â€¯29.2 min, P = .007) in the Sleeveballoon than in sham-operated rats (97.1 ±â€¯26.3 min), but shorter in RYGB (3.5 ±â€¯1.1 min, P < .0001). Cardiac function was better in Sleeveballoon and RYGB versus sham-operated rats. INTERPRETATION: The Sleeveballoon reduces peripheral and hepatic insulin resistance, glycaemia, body weight and ectopic fat deposition to a similar level as RYGB, although the contribution of gastric emptying to blood glucose reduction is different.

10-year follow-up after laparoscopic sleeve gastrectomy: Outcomes in a monocentric series.

BACKGROUND: Sleeve gastrectomy (SG) has grown into the most popular bariatric operation. Nevertheless, a scarcity of long-term outcomes are available. OBJECTIVES: This study aims at evaluating the long-term percent weight loss (%WL), excess weight loss (%EWL), weight regain (WR), and co-morbidity resolution rates in a single-center cohort undergoing SG as a primary procedure, with a minimum 10-year follow-up. SETTING: University hospital, Italy. METHODS: One hundred eighty-two morbidly obese patients with body mass index (BMI) 46.6 ± 7.3 kg/m2 underwent SG. Obesity-related co-morbidities (type 2 diabetes, hypertension, sleep apnea, gastroesophageal reflux disease) were investigated. Predictors of dichotomous dependent-variable diabetes remission were computed using a binomial logistic regression. RESULTS: Patient retention rate was 77%. Mean %WL was 30.9, %EWL was 52.5%, and WR (≥25% maximum WL) occurred in 10.4%. Baseline BMI significantly (P = .001) and linearly predicted %EWL (10 yr %EWL = 18.951 + initial BMI × .74); the super-obese subgroup generated substantially greater WL compared with those with BMI <50 kg/m2 (%EWL 48.0 ± 18.5 versus 61.5 ± 23.2; P < .001). Type 2 diabetes remission occurred in 64.7%; 42.9% patients developed de novo gastroesophageal reflux disease symptoms postoperatively (P < .0001). CONCLUSIONS: SG generates sustained WL and co-morbidity resolution up to 10 years postoperatively. Although a notable portion of patients experience WR, mean %WL persists to exceed 30%, translating in adequate WL also in the long term. Additionally, WR does not seem to impact negatively on co-morbidity resolution. SG represents a safe and effective bariatric operation, which easily grants the possibility to proceed to revisional bariatric surgery in patients with WR or failure to WL.

Intestinal peptide changes after bariatric and minimally invasive surgery: Relation to diabetes remission.

Bariatric surgery is very effective in achieving and maintaining weight loss but it is also associated with improvement of obesity metabolic complications, primarily type 2 diabetes (T2D). Remission of T2D or at least a net improvement of glycemic control persists for at least 5 years. The bypass of duodenum and of the first portion of the jejunum up to the Treitz ligament as in Roux-en-Y Gastric Bypass (RYGB), or the bypass of the duodenum, the entire jejunum and the first tract of the ileum, such as in Bilio-Pancreatic Diversion (BPD), achieve different results on insulin sensitivity. Insulin resistance is the major driver of T2D manifesting long before insulin secretion failure. In fact, T2D development can be prevented by treatment with insulin sensitizing agents. Interestingly, RYGB improves hepatic insulin sensitivity while BPD ameliorates whole-body insulin sensitivity. Two major theories have been advocated to explain the early remission of T2D following RYGB or BPD before a meaningful weight loss takes place, the foregut and the hindgut hypotheses. The former holds that the bypass of the proximal intestine, i.e. duodenum and jejunum, prevents the secretion of signals - including nervous transmitters and hormones - promoting insulin resistance, the latter instead states that the delivery of nutrients directly into the ileum stimulates the secretion of hormones improving glucose disposal. The most studied candidate is Glucagon Like Peptide 1 (GLP1). However, while there is unambiguous evidence that GLP-1 stimulates insulin secretion, its direct action in lowering insulin resistance, independently of the effect on weight loss secondary to its satiety action, is utterly controversial. In this review we examine the effects on T2D and gastrointestinal peptide secretion produced by different types of metabolic surgery and by minimally invasive endoscopic surgery, whose utilization for the treatment of obesity and T2D is gaining wider interest and acceptance.

Lipidomic Changes in Skeletal Muscle in Patients after Biliopancreatic Diversion.

The mechanisms behind the fast improvements of insulin sensitivity and release of the diabetic metabolic state after bariatric surgery are still not completely understood. To further elucidate the effects on the individual cellular level, we applied mass spectrometry to investigate the changes in the lipidomic profile of skeletal muscle cells before and after biliopancreatic diversion in six patients. We found a decrease in lipid storage species, mainly triacylglycerides (e. g., TAG 52:2 from 19.84 to 13.26 mol%; p=0.028), and an increase in structural and signaling lipids, including phosphatidylcholines [PC 36:2 (18:1/18:1) from 0.12 to 0.65 mol%; p=0.046], phosphatidylinositols (PI 36:2 from 0.008 to 0.039 mol%; p=0.046), and cardiolipins (CL 72:8 from 0.16 to 1.22 mol%; p=0.043). The proportional increase in structural lipids was directly and the decrease in TAGs was inversely correlated to improved post-operative insulin sensitivity, measured by euglycemic hyperinsulinemic clamp. Thus, short-term recovery of insulin sensitivity after biliopancreatic diversion may, beside gut hormonal adaptation, mechanical factors, shifts in the gut microbiome, and changes in bile acid and phospholipid metabolism, additionally be attributed to a metabolic recovery of skeletal muscle cells, reflected by normalization of the cellular lipidomic profile. Further studies are needed to investigate whether improved insulin sensitivity of skeletal muscle might be directly associated with the degradation of ectopic triglycerides, thereby reducing the reservoir of lipotoxic intermediates, which might interfere with insulin signaling and hamper mitochondrial metabolism.

Obesity, Type 2 Diabetes, and the Metabolic Syndrome: Pathophysiologic Relationships and Guidelines for Surgical Intervention.

Several gastrointestinal (GI) operations originally developed for the treatment of severe obesity (bariatric surgery) promote sustained weight loss as well as dramatic, durable improvements of insulin-resistant states, most notably type 2 diabetes mellitus (T2DM). Experimental evidence shows that some rearrangements of GI anatomy can directly affect glucose homeostasis, insulin sensitivity, and inflammation, supporting the idea that the GI tract is a biologically rational target for interventions aimed at correcting pathophysiologic aspects of cardiometabolic disorders. This article reviews the pathophysiology of metabolic disease and the role of bariatric/metabolic surgery in current clinical guidelines for the treatment of obesity and T2DM.

How to Choose the Best Metabolic Procedure?

Bariatric/metabolic surgery has proven to be effective in inducing and maintaining diabetes remission-although with a percentage of patients undergoing hyperglycemia relapse-weight loss, and improvement of the cardiovascular risk. It is, however, associated with mortality, although low, and early and late complications. In particular, metabolic complications are related to vitamin deficiency due to the erratic absorption of the supplemented vitamins and to the unpredictable compliance of patients to vitamin and trace element supplementation. In addition, often, the general practitioners and even the specialists are unaware of the clinical effects of metabolic dysfunction following malabsorptive surgery. The choice of the surgical procedure should be the balance between benefits and risks. Our review addresses this important question trying to give some suggestions.