Development of the International Federation for Surgery of Obesity and Metabolic Disorders-European Chapter (IFSO-EC) Grade-Based Guidelines on the Surgical Treatment of Obesity Using Multimodal Strategies: Design and Methodological Aspects.

Background: The prevalence of obesity is already a worldwide health concern. The development of straightforward guidelines regarding the whole available armamentarium (i.e., medical, endoscopic, and surgical interventions in conjunction with a guidance program) is paramount to offering the best multimodal approach to patients with obesity. Methods: The International Federation for Surgery of Obesity and Metabolic Disorders-European Chapter (IFSO-EC) identified a panel of experts to develop the present guidelines. The panel formulated a series of clinical questions (based on the patient, intervention, comparison, and outcome conceptual framework), which have been voted on and approved. A GRADE methodology will be applied to assess the quality of evidence and formulate recommendations employed to minimize selection and information biases. This approach aims to enhance the reliability and validity of recommendations, promoting greater adherence to the best available evidence. Results: These guidelines are intended for adult patients with a body mass index (BMI) ≥ 30 kg/m2 who are candidates for metabolic bariatric surgery (MBS). The expert panel responsible for developing these guidelines comprised 25 panelists (92% were bariatric surgeons) and 3 evidence reviewers, with an average age of 50.1 ± 10.2 years. The panel focused on 3 key questions regarding the combined use of structured lifestyle interventions, approved obesity management medications, and endoscopic weight loss procedures with MBS. Conclusions: The complexity of obesity as a chronic disease requires a comprehensive knowledge of all the available and feasible therapeutic options. The IFSO-EC society felt the urgent need to develop methodologically valid guidelines to give a full picture and awareness of the possible surgical and non-surgical therapeutic strategies employed with a multimodal approach.

Single Anastomosis Duodeno-Ileostomy with Sleeve Gastrectomy/Single Anastomosis Duodenal Switch (SADI-S/SADS) IFSO Position Statement-Update 2023.

The single anastomosis duodeno-ileostomy with sleeve gastrectomy/single anastomosis duodenal switch (SADI-S/SADS) has gained attention as an alternative to the traditional biliopancreatic diversion with duodenal switch (BPD-DS). In 2021, IFSO endorsed SADI-S/SADS as a safe and effective procedure, underscoring the necessity for long-term multidisciplinary care and randomized controlled trials (RCTs). A task force was established to conduct a systematic review of current evidence on SADI-S/SADS to guide clinical practice. A systematic review was conducted across three databases, focusing on studies examining SADI-S/SADS and its outcomes. A total of 93 studies were analyzed. SADI-S/SADS demonstrated efficacy in weight loss and medium-to-long-term control of type 2 diabetes mellitus (T2DM), along with positive outcomes regarding hypertension and hyperlipidemia. However, its impact on other comorbidities remains inconclusive. Frequent nutritional deficiencies were identified, particularly in fat-soluble vitamins, anemia, and hypoalbuminemia. Despite significant efforts, high-quality evidence on SADI-S/SADS remains scarce, prompting IFSO to advocate for increased registry participation, publication of long-term studies, and more RCTs. Lifelong supplementation and monitoring for nutritional deficiencies are recommended. The current position statement will be reviewed in 2 years.

Rapid improvement of hepatic steatosis and liver stiffness after metabolic/bariatric surgery: a prospective study.

Metabolic dysfunction-associated steatotic liver disease (MASLD) and related steatohepatitis (MASH) are common among obese patients and may improve after metabolic/bariatric surgery (MBS). 93 Patients undergoing MBS in 2021-2022 were prospectively enrolled. Liver stiffness measurement (LSM; via vibration-controlled transient elastography [VCTE], point [pSWE] and 2D [2DSWE] shear wave elastography) and non-invasive steatosis assessment (via controlled attenuation parameter [CAP]) were performed before (baseline [BL]) and three months (M3) after surgery. 93 patients (median age 40.9 years, 68.8% female, median BL-BMI: 46.0 kg/m2) were included. BL-liver biopsy showed MASLD in 82.8% and MASH in 34.4% of patients. At M3 the median relative total weight loss (%TWL) was 20.1% and the median BMI was 36.1 kg/m2. LSM assessed by VCTE and 2DSWE, as well as median CAP all decreased significantly from BL to M3 both in the overall cohort and among patients with MASH. There was a decrease from BL to M3 in median levels of ALT (34.0 U/L to 31 U/L; p = 0.025), gamma glutamyl transferase (BL: 30.0 to 21.0 U/L; p < 0.001) and MASLD fibrosis score (BL: - 0.97 to - 1.74; p < 0.001). Decreasing LSM and CAP, as well as liver injury markers suggest an improvement of MASLD/MASH as early as 3 months after MBS.

Revision/Conversion Surgeries After One Anastomosis Gastric Bypass-An Experts' Modified Delphi Consensus.

PURPOSE: There is a lack of evidence for treatment of some conditions including complication management, suboptimal initial weight loss, recurrent weight gain, or worsening of a significant obesity complication after one anastomosis gastric bypass (OAGB). This study was designed to respond to the existing lack of agreement and to provide a valuable resource for clinicians by employing an expert-modified Delphi consensus method. METHODS: Forty-eight recognized bariatric surgeons from 28 countries participated in the modified Delphi consensus to vote on 64 statements in two rounds. An agreement/disagreement among ≥ 70.0% of the experts was regarded to indicate a consensus. RESULTS: A consensus was achieved for 46 statements. For recurrent weight gain or worsening of a significant obesity complication after OAGB, more than 85% of experts reached a consensus that elongation of the biliopancreatic limb (BPL) is an acceptable option and the total bowel length measurement is mandatory during BPL elongation to preserve at least 300-400 cm of common channel limb length to avoid nutritional deficiencies. Also, more than 85% of experts reached a consensus on conversion to Roux-en-Y gastric bypass (RYGB) with or without pouch downsizing as an acceptable option for the treatment of persistent bile reflux after OAGB and recommend detecting and repairing any size of hiatal hernia during conversion to RYGB. CONCLUSION: While the experts reached a consensus on several aspects regarding revision/conversion surgeries after OAGB, there are still lingering areas of disagreement. This highlights the importance of conducting further studies in the future to address these unresolved issues.

The deep abdominal ultrasound transducer (DAX) increases the success rate and diagnostic accuracy of shear wave elastography for liver fibrosis assessment in patients with obesity-A prospective biopsy-controlled study.

BACKGROUND: Obesity impacts the diagnostic accuracy of shear wave elastography (SWE). A deep abdominal ultrasound transducer (DAX) capable of point (pSWE) and two-dimensional (2D)-SWE has recently been introduced to address this issue. METHODS: We performed a prospective study in a cohort of mostly patients with obesity undergoing liver biopsy with a high prevalence of metabolic dysfunction-associate steatotic liver disease (MASLD). Liver stiffness measurement (LSM) was measured using vibration-controlled transient elastography (VCTE), as well as pSWE and 2D SWE on the standard (5C1) and the DAX transducers. RESULTS: We included 129 patients with paired LSM and liver biopsy: median age 44.0 years, 82 (63.6%) women, median BMI: 43.2 kg/m2. Histologic fibrosis stages: F0: N = 55 (42.6%), F1: N = 14 (10.9%), F2: N = 50 (38.8%), F3: N = 2 (1.6%), F4: N = 8 (6.2%). VCTE-LSM failed (N = 13) or were unreliable (IQR/median ≤30% in ≥7.1 kPa, N = 14) in 20.9% of patients. The Pearson correlation of reliable VCTE-LSM with both pSWE and 2D SWE was strong (all >0.78). The diagnostic accuracy for all LSM techniques was poor for significant fibrosis (≥F2, AUC: 0.54-0.63); however, it was good to excellent for advanced fibrosis (≥F3, AUC: 0.87-0.99) and cirrhosis (F4, AUC: 0.86-1.00). In intention-to-diagnose analysis, pSWE on DAX was significantly superior to VCTE-LSM. CONCLUSIONS: pSWE- and 2D-SWE enable the non-invasive identification of advanced fibrosis and cirrhosis in patients with obese MASLD. The use of the DAX transducer for acoustic radiation force imaging (ARFI)-LSM avoids technical failures in an obese population and subsequently offers advantages over VCTE-LSM for the evaluation of fibrosis in an obese MASLD population at risk for fibrosis.

Metabolic Bariatric Surgery Across the IFSO Chapters: Key Insights on the Baseline Patient Demographics, Procedure Types, and Mortality from the Eighth IFSO Global Registry Report.

INTRODUCTION: The International Federation for Surgery for Obesity and Metabolic Disorders (IFSO) Global Registry aims to provide descriptive data about the caseload and penetrance of surgery for metabolic disease and obesity in member countries. The data presented in this report represent the key findings of the eighth report of the IFSO Global Registry. METHODS: All existing Metabolic and Bariatric Surgery (MBS) registries known to IFSO were invited to contribute to the eighth report. Aggregated data was provided by each MBS registry to the team at the Australia and New Zealand Bariatric Surgery Registry (ANZBSR) and was securely stored on a Redcap™ database housed at Monash University, Melbourne, Australia. Data was checked for completeness and analyzed by the IFSO Global Registry Committee. Prior to the finalization of the report, all graphs were circulated to contributors and to the global registry committee of IFSO to ensure data accuracy. RESULTS: Data was received from 24 national and 2 regional registries, providing information on 502,150 procedures. The most performed primary MBS procedure was sleeve gastrectomy, whereas the most performed revisional MBS procedure was Roux-en-Y gastric bypass. Asian countries reported people with lower BMI undergoing MBS along with higher rates of diabetes. Mortality was a rare event. CONCLUSION: Registries enable meaningful comparisons between countries on the demographics, characteristics, operation types and approaches, and trends in MBS procedures. Reported outcomes can be seen as flags of potential issues or relationships that could be studied in more detail in specific research studies.

IFSO Worldwide Survey 2020-2021: Current Trends for Bariatric and Metabolic Procedures.

PURPOSE: This IFSO survey aims to describe the current trends of metabolic and bariatric surgery (MBS) reporting on the number and types of surgical and endoluminal procedures performed in 2020 and 2021, in the world and within each IFSO chapter. METHODS: All national societies belonging to IFSO were asked to complete the survey form. The number and types of procedures performed (surgical and endoluminal interventions) from 2020 to 2021 were documented. A special section focused on the impact of COVID-19, the existence of national protocols for MBS, the use of telemedicine, and any mortality related to MBS. A trend analysis of the data, both worldwide and within each IFSO chapter, was also performed for the period between 2018 and 2021. RESULTS: Fifty-seven of the 74 (77%) IFSO national societies submitted the survey. Twenty-four of the 57 (42.1%) reported data from their national registries. The total number of surgical and endoluminal procedures performed in 2020 was 507,806 and in 2021 was 598,834. Sleeve gastrectomy (SG) remained the most performed bariatric procedure. Thirty national societies (52%) had regional protocols for MBS during COVID-19, 61.4% supported the use of telemedicine, and only 47.3% collected data on mortality after MBS in 2020. These percentages did not significantly change in 2021 (p > 0.05). CONCLUSIONS: The number of MBS markedly decreased worldwide during 2020. Although there was a positive trend in 2021, it did not reach the values obtained before the COVID-19 pandemic. SG continued to be the most performed operation. Adjustable gastric banding (AGB) continues to decrease worldwide.

Current recommendations for procedure selection in class I and II obesity developed by an expert modified Delphi consensus.

Metabolic and bariatric surgery (MBS) is widely considered the most effective option for treating obesity, a chronic, relapsing, and progressive disease. Recently, the American Society of Metabolic and Bariatric Surgery (ASMBS) and the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) issued new guidelines on the indications for MBS, which have superseded the previous 1991 National Institutes of Health guidelines. The aim of this study is to establish the first set of consensus guidelines for selecting procedures in Class I and II obesity, using an Expert Modified Delphi Method. In this study, 78 experienced bariatric surgeons from 32 countries participated in a two-round Modified Delphi consensus voting process. The threshold for consensus was set at an agreement or disagreement of ≥ 70.0% among the experts. The experts reached a consensus on 54 statements. The committee of experts reached a consensus that MBS is a cost-effective treatment option for Class II obesity and for patients with Class I obesity who have not achieved significant weight loss through non-surgical methods. MBS was also considered suitable for patients with Type 2 diabetes mellitus (T2DM) and a body mass index (BMI) of 30 kg/m2 or higher. The committee identified intra-gastric balloon (IGB) as a treatment option for patients with class I obesity and endoscopic sleeve gastroplasty (ESG) as an option for patients with class I and II obesity, as well as for patients with T2DM and a BMI of ≥ 30 kg/m2. Sleeve gastrectomy (1) and Roux-en-Y gastric bypass (RYGB) were also recognized as viable treatment options for these patient groups. The committee also agreed that one anastomosis gastric bypass (OAGB) is a suitable option for patients with Class II obesity and T2DM, regardless of the presence or severity of obesity-related medical problems. The recommendations for selecting procedures in Class I and II obesity, developed through an Expert Modified Delphi Consensus, suggest that the use of standard primary bariatric endoscopic (IGB, ESG) and surgical procedures (SG, RYGB, OAGB) are acceptable in these patient groups, as consensus was reached regarding these procedures. However, randomized controlled trials are still needed in Class I and II Obesity to identify the best treatment approach for these patients in the future.

The Management of Biliary Disease in Patients with Severe Obesity Undergoing Metabolic and Bariatric Surgery-An International Expert Survey.

OBJECTIVE: This study aimed to survey international experts in metabolic and bariatric surgery (MBS) to improve and consolidate the management of biliary disease in patients with severe obesity undergoing MBS. BACKGROUND: Obesity and rapid weight loss after MBS are risk factors for the development of gallstones. Complications, such as cholecystitis, acute cholangitis, and biliary pancreatitis, are potentially life-threatening, and no guidelines for the proper management of gallstone disease exist. METHODS: An international scientific team designed an online confidential questionnaire with 26 multiple-choice questions. The survey was answered by 86 invited experts (from 38 different countries), who participated from August 1, 2023, to September 9, 2023. RESULTS: Two-thirds of experts (67.4%) perform concomitant cholecystectomy in symptomatic gallstones during MBS. Half of experts (50%) would wait 6-12 weeks between both surgeries with an interval approach. Approximately 57% of the experts prescribe ursodeoxycholic acid (UDCA) prophylactically after MBS, and most recommend a 6-month course. More than the half of the experts (59.3%/53.5%) preferred laparoscopic assisted transgastric ERCP as the approach for treating CBD stones in patients who previously had RYGB/OAGB. CONCLUSION: Concomitant cholecystectomy is preferred by the experts, although evidence in the literature reports an increased complication rate. Prophylactic UDCA should be recommended to every MBS patient, even though the current survey demonstrated that not all experts are recommending it. The preferred approach for treating common bile duct stones is a laparoscopic assisted transgastric ERCP after gastric bypass. The conflicting responses will need more scientific work and clarity in the future.

Metabolic and Bariatric Surgery in Patients with Obesity Class V (BMI > 60 kg/m2): a Modified Delphi Study.

BACKGROUND: Metabolic and bariatric surgery (MBS) is the preferred method to achieve significant weight loss in patients with Obesity Class V (BMI > 60 kg/m2). However, there is no consensus regarding the best procedure(s) for this population. Additionally, these patients will likely have a higher risk of complications and mortality. The aim of this study was to achieve a consensus among a global panel of expert bariatric surgeons using a modified Delphi methodology. METHODS: A total of 36 recognized opinion-makers and highly experienced metabolic and bariatric surgeons participated in the present Delphi consensus. 81 statements on preoperative management, selection of the procedure, perioperative management, weight loss parameters, follow-up, and metabolic outcomes were voted on in two rounds. A consensus was considered reached when an agreement of ≥ 70% of experts' votes was achieved. RESULTS: A total of 54 out of 81 statements reached consensus. Remarkably, more than 90% of the experts agreed that patients should be notified of the greater risk of complications, the possibility of modifications to the surgical procedure, and the early start of chemical thromboprophylaxis. Regarding the choice of the procedure, SADI-S, RYGB, and OAGB were the top 3 preferred operations. However, no consensus was reached on the limb length in these operations. CONCLUSION: This study represents the first attempt to reach consensus on the choice of procedures as well as perioperative management in patients with obesity class V. Although overall consensus was reached in different areas, more research is needed to better serve this high-risk population.

IFSO Consensus on Definitions and Clinical Practice Guidelines for Obesity Management-an International Delphi Study.

INTRODUCTION: This survey of international experts in obesity management was conducted to achieve consensus on standardized definitions and to identify areas of consensus and non-consensus in metabolic bariatric surgery (MBS) to assist in an algorithm of clinical practice guidelines for the management of obesity. METHODS: A three-round Delphi survey with 136 statements was conducted by 43 experts in obesity management comprising 26 bariatric surgeons, 4 endoscopists, 8 endocrinologists, 2 nutritionists, 2 counsellors, an internist, and a pediatrician spanning six continents over a 2-day meeting in Hamburg, Germany. To reduce bias, voting was unanimous, and the statements were neither favorable nor unfavorable to the issue voted or evenly balanced between favorable and unfavorable. Consensus was defined as ≥ 70% inter-voter agreement. RESULTS: Consensus was reached on all 15 essential definitional and reporting statements, including initial suboptimal clinical response, baseline weight, recurrent weight gain, conversion, and revision surgery. Consensus was reached on 95/121 statements on the type of surgical procedures favoring Roux-en-Y gastric bypass, sleeve gastrectomy, and endoscopic sleeve gastroplasty. Moderate consensus was reached for sleeve gastrectomy single-anastomosis duodenoileostomy and none on the role of intra-gastric balloons. Consensus was reached for MBS in patients > 65 and < 18 years old, with a BMI > 50 kg/m2, and with various obesity-related complications such as type 2 diabetes, liver, and kidney disease. CONCLUSIONS: In this survey of 43 multi-disciplinary experts, consensus was reached on standardized definitions and reporting standards applicable to the whole medical community. An algorithm for treating patients with obesity was explored utilizing a thoughtful multimodal approach.

[Overweight and obesity in adults: general principles of treatment and conservative management]. / Übergewicht und Adipositas bei Erwachsenen: allgemeine Behandlungsgrundsätze und konservatives Management.

The prevalence of overweight and obesity is steadily increasing in Austria as well as internationally. Obesity in particular is associated with multiple health risks, comorbidities, functional disability, and social stigma. Obesity is an independent, complex, chronic disease and should be treated as such by a multidisciplinary team of appropriately qualified personnel. In addition to recent international guidelines, this consensus paper outlines the overall principles of the management of overweight and obesity and provides guidance for the diagnosis and conservative treatment, focusing on lifestyle modifications and pharmacotherapy. Using the "5A" framework of behavioral health intervention, guidelines for a structured, pragmatic, and patient-centered medical care of adults with overweight or obesity are presented.

[Indications and preoperative planning for bariatric surgery]. / Indikation und präoperative Planung zur bariatrischen Operation.

These clinical practice guidelines represent the consensus opinion of a group of Austrian specialist physicians associated with the treatment of obesity. The recommendations incorporate the current literature and guidelines and aim to balance both procedural feasibility and patient acceptance and adherence. Special emphasis was placed on simplification of the preoperative clarification and maximum patient safety. Therefore, this article makes no claim to be complete in all fields.

Outcome of Gastric Bypass Surgery on Patients with Polycystic Ovary Syndrome: A Review.

Polycystic ovary syndrome (PCOS), the most common endocrine disorder in women of reproductive age, is associated with obesity. The most effective method to achieve and maintain long-term weight loss is by the Roux-en-Y gastric bypass (RYGB). In this review, an overview about metabolic and PCOS-specific outcomes after RYGB in obese PCOS women is provided. The RYGB leads to an adequate excess weight loss and reduction in BMI in this patient population. Testosterone levels decline significantly at 6- and 12-months follow-up, as does the incidence of hirsutism and cycle irregularities. Data about fertility are scarce in this patient population. In conclusion, RYGB surgery seems to be an efficient treatment option for obese PCOS patients and leads to weight loss and improvements in metabolic parameters as well as in an improvement of PCOS-specific characteristics. However, larger prospective studies are warranted, which include all PCOS-specific outcome data in one patient population at the same time.

The Performance of Opioid-Free Anesthesia for Bariatric Surgery in Clinical Practice.

PURPOSE: Opioid-free anesthesia (OFA) is an alternative to conventional opioid-based anesthesia (OBA) in patients undergoing bariatric surgery. Several small studies and a meta-analysis have suggested advantages of OFA for bariatric surgery, but current evidence is still contradictory, and a universally accepted concept has not yet been established. The purpose of this study was to determine whether patients undergoing bariatric surgery experience less postoperative pain and better postoperative recovery when anesthetized with an OFA regimen than with an OBA regimen. MATERIALS AND METHODS: This prospective observational cohort study, conducted between October 2020 and July 2021, compared patients receiving OFA with patients receiving OBA. Patients were visited 24 and 48 h after the surgical procedure and asked about their postoperative pain using the visual analogue scale (VAS). Additionally, the quality of recovery-40 questionnaire (QoR-40) and the postoperative opioid requirements were recorded. RESULTS: Ninety-nine patients were included and analyzed in this study (OFA: N = 50; OBA: N = 49). The OFA cohort exhibited less postoperative pain than the OBA cohort within 24 h (VAS median [interquartile range (IQR)]: 2.2 [1-4.4] vs. 4.1 [2-6.5]; P ≤ 0.001) and 48 h (VAS median [IQR]: 1.9 [0.4-4.1] vs. 3.1 [1.4-5.8]; P ≤ 0.001) postoperatively. Additionally, the OFA cohort had higher QoR-40 scores and required less opioid therapy postoperatively. CONCLUSION: Based on our results the use of OFA for bariatric surgery results in less pain, reduced opioid requirements, and improved postoperative recovery-adding additional evidence regarding the use of OFA in everyday clinical practice.

Impact of Bariatric Surgery on the Stability of the Genetic Material, Oxidation, and Repair of DNA and Telomere Lengths.

Obesity causes genetic instability, which plays a key-role in the etiology of cancer and aging. We investigated the impact of bariatric surgery (BS) on DNA repair, oxidative DNA damage, telomere lengths, alterations of antioxidant enzymes and, selected proteins which reflect inflammation. The study was realized with BS patients (n = 35). DNA damage, base oxidation, BER, and NER were measured before and 1 month and 6 months after surgery with the single-cell gel electrophoresis technique. SOD and GPx were quantified spectrophotometrically, malondealdehyde (MDA) was quantified by HPLC. Telomere lengths were determined with qPCR, and plasma proteome profiling was performed with high-resolution mass spectrophotometry. Six months after the operations, reduction of body weight by 27.5% was observed. DNA damage decreased after this period, this effect was paralleled by reduced formation of oxidized DNA bases, a decline in the MDA levels and of BER and NER, and an increase in the telomere lengths. The activities of antioxidant enzymes were not altered. Clear downregulation of certain proteins (CRP, SAA1) which reflect inflammation and cancer risks was observed. Our findings show that BS causes reduced oxidative damage of DNA bases, possibly as a consequence of reduction of inflammation and lipid peroxidation, and indicate that the surgery has beneficial long-term health effects.

The male patient with obesity undergoing metabolic and bariatric surgery: changes in testosterone levels correlate with weight loss after one-anastomosis gastric bypass and Roux-en-Y gastric bypass.

BACKGROUND: Male obesity secondary hypogonadism (MOSH) is a common disease among men with obesity and can be associated with metabolic syndrome and a variety of metabolic problems ultimately leading to androgen deficiency. Metabolic and bariatric surgery is a well-established treatment option associated with significant weight loss and reduction in metabolic co-morbidities. OBJECTIVES: To evaluate the impact of surgery on plasma levels of sexual hormones and their effect on weight loss comparing 2 surgical methods (one-anastomosis gastric bypass [OAGB] and Roux-en-Y gastric bypass [RYGB]) in male patients with obesity. SETTING: University hospital, Austria. METHODS: Patients undergoing OAGB and RYGB between 2012 and 2017 were analyzed retrospectively. Follow-up in this study was up to 24 months. Systemic levels of sexual hormones (luteinizing hormone [LH]), follicle stimulating hormone [FSH], total testosterone [TT], sexual hormone binding globin [SHBG], 17 beta-estradiol [17bE], androstenedione [AS]) were retrieved at each visit. A linear mixed model was used to assess the correlation between changes in testosterone levels and percent excess weight loss (%EWL). RESULTS: In 30.8% of all patients, MOSH was present preoperatively. A significant increase of TT was observed postoperatively that led to a complete resolution of hypogonadism within the period observed. Bioavailable testosterone (bTT) and FSH levels significantly increased each month of follow-up after surgery (all P < .01). Levels of 17bE did not change significantly after surgery. The overall change of TT, comparing preoperative and 1-year postoperative TT levels (ΔTT), significantly correlated with %EWL. Changes in TT levels were not affected by the choice of surgical method. CONCLUSIONS: Serum plasma testosterone levels rise significantly after metabolic and bariatric surgery in male patients. The change of testosterone levels seems to play a role in continued weight loss after surgery. This is true irrespective of the surgical method used.