Review

. 2025 Jul 1;25(1):151.

doi: 10.1186/s12902-025-01961-w.

International expert consensus on surgery for type 2 diabetes mellitus

Mohammad Kermansaravi^#¹, Islam Omar^#^{2

3}, Nicholas Finer⁴, Carel Le Roux⁵, Miguel A Carbajo⁶, David Sarwer⁷, Luca Busetto⁸, Jaime Ponce⁹, Jennifer Logue¹⁰, Helen M Parretti¹¹, Mary O'Kane¹², Shahab Shahabi¹³, Kamlesh Khunti¹⁴, Alexandra I Blakemore¹⁵, Erik Stenberg¹⁶, Sally Abbott¹⁷, Aayed Alqahtani¹⁸, Ali Aminian¹⁹, Bassem Amr²⁰, Jose M Balibrea²¹, Rachel L Batterham²², Estuardo Behrens²³, Deepak L Bhatt²⁴, Paul Chesworth²⁵, Pradeep Chowbey²⁶, Ken Clare²⁷, Manoel Galvao Neto²⁸, Yitka Graham²⁹, Ramen Goel³⁰, Wasim Hanif³¹, Miguel F Herrera³², Kazunori Kasama³³, Radwan Kassir³⁴, Filip K Knop³⁵, Shanu N Kothari³⁶, Jon A Kristinsson³⁷, Barbara McGowan³⁸, Andrew McKechnie³⁹, Karl Miller⁴⁰, Alex D Miras⁴¹, John Morton⁴², Jane Ogden⁴³, Ralph Peterli^{44

45}, Jonathan H Pinkney⁴⁶, Dimitri Pournaras⁴⁷, Sjaak Pouwels⁴⁸, Gerhard Prager⁴⁹, Paulina Salminen^{50

51}, Mireille J Serlie^{52

53}, Asim Shabbir⁵⁴, Rishi Singhal⁵⁵, Shahrad Taheri⁵⁶, Abd A Tahrani⁵⁷, Rudolf Weiner⁵⁸, Scott A Shikora⁵⁹, Kamal Mahawar⁶⁰

Affiliations

¹ Department of Surgery, Minimally Invasive Surgery Research Center, Division of Minimally Invasive and Bariatric Surgery, Hazrat-E Fatemeh Hospital, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. mkermansaravi@yahoo.com.
² Department of Surgery, Chelsea and Westminster Hospital NHS Foundation Trust, London, UK. islamfawzyomar@hotmail.com.
³ Warwick Medical School, University of Warwick, Coventry, UK. islamfawzyomar@hotmail.com.
⁴ Expert Medical Consultant Obesity Medicine, Endocrinology, Cambridge, UK.
⁵ Diabetes Complications Research Center, Conway Institute, School of Medicine, University College Dublin, Dublin, Ireland.
⁶ Center of Excellence for the Study and Treatment of Obesity and Diabetes, Valladolid, Spain.
⁷ Department of Social and Behavioral Sciences, Temple University, Philadelphia, Pennsylvania, USA.
⁸ Center for the Study and the Integrated Treatment of Obesity, Internal Medicine 3, Padua University Hospital, Padua, Italy.
⁹ CHI Memorial Medical Group, Chattanooga, Tennessee, USA.
¹⁰ Lancaster Medical School, Faculty of Health and Medicine, Lancaster University, Lancaster, UK.
¹¹ University of East Anglia, Norwich, UK.
¹² Dietetic Department, Leeds Teaching Hospitals NHS Trust, Leeds, UK.
¹³ Department of Surgery, Minimally Invasive Surgery Research Center, Division of Minimally Invasive and Bariatric Surgery, Hazrat-E Fatemeh Hospital, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
¹⁴ Leicester Diabetes Centre, University of Leicester, Leicester, UK.
¹⁵ College of Health, Medical and Life Sciences, Brunel University London, London, UB8 3PH, UK.
¹⁶ Department of Surgery, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
¹⁷ Research Centre for Healthcare and Communities, Institute of Health and Wellbeing, Coventry University, Coventry, UK.
¹⁸ New You Medical Center, Riyadh, Saudi Arabia.
¹⁹ Bariatric and Metabolic Institute, Department of General Surgery, Cleveland Clinic, Cleveland, Ohio, USA.
²⁰ Taunton and Somerset Foundation Trust, Taunton, UK.
²¹ Gastrointestinal Surgery Department, Hospital Clínic de Barcelona, Barcelona, 08036, Spain.
²² Department of Medicine, University College London, London, UK.
²³ New Life Center, Guatemala, Guatemala.
²⁴ Icahn School of Medicine, Mount Sinai Heart, New York, NY, USA.
²⁵ Patient Representative, Liverpool, UK.
²⁶ Max Institute of Laparoscopic, Endoscopic and Bariatric Surgery, Max Hospital, New Delhi, India.
²⁷ Obesity Institute, School of Health, Leeds Beckett University, Leeds, UK.
²⁸ Division of Gastrointestinal Endoscopy, ABC Medical School, São Paulo, Brazil.
²⁹ Helen McArdle Nursing and Care Research Institute, Faculty of Health Sciences and Wellbeing, University of Sunderland, Sunderland, UK.
³⁰ Wockhardt Hospital, Mumbai, India.
³¹ Department of Diabetes & Endocrinology, University Hospital Birmingham, NHS Trust, Birmingham, UK.
³² Endocrine and Bariatric Surgery, UNAM at INCMNSZ, Mexico City, México.
³³ Weight Loss and Metabolic Surgery Center, Yotsuya Medical Cube, Tokyo, Japan.
³⁴ Digestive and Bariatric Surgery Department, The View Hospital, Doha, Qatar.
³⁵ Clinical Metabolic Physiology Steno Diabetes Center Copenhagen, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark.
³⁶ Department of Surgery, Prisma Health, University of South Carolina, Greenville, South Carolina, USA.
³⁷ Department of Endocrinology, Morbid Obesity and Preventive Medicine, Oslo University Hospital, Oslo, Norway.
³⁸ Guy's and St Thomas' NHS Foundation Trust, London, UK.
³⁹ Lewisham and Greenwich NHS Trust, London, UK.
⁴⁰ Diakonissen Wehrle Private Hospital, Salzburg, Austria.
⁴¹ Department of Metabolism, Reproduction and Digestion, Imperial College London, London, UK.
⁴² Yale School of Medicine, New Haven, Connecticut, USA.
⁴³ School of Psychology, University of Surrey, Guildford, GU2 7XH, UK.
⁴⁴ Department of Surgery, University of Basel, Basel, Switzerland.
⁴⁵ Department of Visceral Surgery, Clarunis, University Centre for Gastrointestinal and Liver Diseases, St Clara Hospital and University Hospital Basel, Basel, Switzerland.
⁴⁶ Faculty of Health, University of Plymouth, Drake Circus, Plymouth, PL4 8 AA, UK.
⁴⁷ Obesity and Bariatric Surgery Service, North Bristol NHS Trust, Bristol, BS10 5 NB, UK.
⁴⁸ Department of Intensive Care Medicine, Elisabeth-Tweesteden Hospital, Tilburg, the Netherlands.
⁴⁹ Department of Surgery, Division of General Surgery, Medical University of Vienna, Vienna, 1090, Austria.
⁵⁰ Department of Digestive Surgery, Division of Digestive Surgery and Urology, Turku University Hospital, Turku, Finland.
⁵¹ Department of Surgery, University of Turku, Turku, Finland.
⁵² Department of Endocrinology and Metabolism, Amsterdam University Medical Center, Amsterdam, Netherlands.
⁵³ Department of Internal Medicine, Yale School of Medicine, New Haven, USA.
⁵⁴ Division of Upper Gastrointestinal Surgery, Department of Surgery, National University Health System, Singapore, Singapore.
⁵⁵ Upper Gastrointestinal and Bariatric Surgery Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
⁵⁶ Department of Medicine, Weill Cornell Medicine-Qatar, PO Box 24144, Doha, Qatar.
⁵⁷ Department of Diabetes and Endocrinology, University Hospitals NHS Foundation Trust, Birmingham, UK.
⁵⁸ Sana-Klinikum Offenbach, Clinic for Surgery of Obesity and Metabolic Disorders, Starkenburgring 66, Offenbach am Main, 63069, Germany.
⁵⁹ Center for Metabolic and Bariatric Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
⁶⁰ South Tyneside and Sunderland NHS Foundation Trust, Sunderland Royal Hospital, Sunderland, UK.

^# Contributed equally.

PMID: 40598146
PMCID: PMC12211331
DOI: 10.1186/s12902-025-01961-w

Review

International expert consensus on surgery for type 2 diabetes mellitus

Mohammad Kermansaravi et al. BMC Endocr Disord. 2025.

. 2025 Jul 1;25(1):151.

doi: 10.1186/s12902-025-01961-w.

Authors

Affiliations

¹ Department of Surgery, Minimally Invasive Surgery Research Center, Division of Minimally Invasive and Bariatric Surgery, Hazrat-E Fatemeh Hospital, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. mkermansaravi@yahoo.com.
² Department of Surgery, Chelsea and Westminster Hospital NHS Foundation Trust, London, UK. islamfawzyomar@hotmail.com.
³ Warwick Medical School, University of Warwick, Coventry, UK. islamfawzyomar@hotmail.com.
⁴ Expert Medical Consultant Obesity Medicine, Endocrinology, Cambridge, UK.
⁵ Diabetes Complications Research Center, Conway Institute, School of Medicine, University College Dublin, Dublin, Ireland.
⁶ Center of Excellence for the Study and Treatment of Obesity and Diabetes, Valladolid, Spain.
⁷ Department of Social and Behavioral Sciences, Temple University, Philadelphia, Pennsylvania, USA.
⁸ Center for the Study and the Integrated Treatment of Obesity, Internal Medicine 3, Padua University Hospital, Padua, Italy.
⁹ CHI Memorial Medical Group, Chattanooga, Tennessee, USA.
¹⁰ Lancaster Medical School, Faculty of Health and Medicine, Lancaster University, Lancaster, UK.
¹¹ University of East Anglia, Norwich, UK.
¹² Dietetic Department, Leeds Teaching Hospitals NHS Trust, Leeds, UK.
¹³ Department of Surgery, Minimally Invasive Surgery Research Center, Division of Minimally Invasive and Bariatric Surgery, Hazrat-E Fatemeh Hospital, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
¹⁴ Leicester Diabetes Centre, University of Leicester, Leicester, UK.
¹⁵ College of Health, Medical and Life Sciences, Brunel University London, London, UB8 3PH, UK.
¹⁶ Department of Surgery, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
¹⁷ Research Centre for Healthcare and Communities, Institute of Health and Wellbeing, Coventry University, Coventry, UK.
¹⁸ New You Medical Center, Riyadh, Saudi Arabia.
¹⁹ Bariatric and Metabolic Institute, Department of General Surgery, Cleveland Clinic, Cleveland, Ohio, USA.
²⁰ Taunton and Somerset Foundation Trust, Taunton, UK.
²¹ Gastrointestinal Surgery Department, Hospital Clínic de Barcelona, Barcelona, 08036, Spain.
²² Department of Medicine, University College London, London, UK.
²³ New Life Center, Guatemala, Guatemala.
²⁴ Icahn School of Medicine, Mount Sinai Heart, New York, NY, USA.
²⁵ Patient Representative, Liverpool, UK.
²⁶ Max Institute of Laparoscopic, Endoscopic and Bariatric Surgery, Max Hospital, New Delhi, India.
²⁷ Obesity Institute, School of Health, Leeds Beckett University, Leeds, UK.
²⁸ Division of Gastrointestinal Endoscopy, ABC Medical School, São Paulo, Brazil.
²⁹ Helen McArdle Nursing and Care Research Institute, Faculty of Health Sciences and Wellbeing, University of Sunderland, Sunderland, UK.
³⁰ Wockhardt Hospital, Mumbai, India.
³¹ Department of Diabetes & Endocrinology, University Hospital Birmingham, NHS Trust, Birmingham, UK.
³² Endocrine and Bariatric Surgery, UNAM at INCMNSZ, Mexico City, México.
³³ Weight Loss and Metabolic Surgery Center, Yotsuya Medical Cube, Tokyo, Japan.
³⁴ Digestive and Bariatric Surgery Department, The View Hospital, Doha, Qatar.
³⁵ Clinical Metabolic Physiology Steno Diabetes Center Copenhagen, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark.
³⁶ Department of Surgery, Prisma Health, University of South Carolina, Greenville, South Carolina, USA.
³⁷ Department of Endocrinology, Morbid Obesity and Preventive Medicine, Oslo University Hospital, Oslo, Norway.
³⁸ Guy's and St Thomas' NHS Foundation Trust, London, UK.
³⁹ Lewisham and Greenwich NHS Trust, London, UK.
⁴⁰ Diakonissen Wehrle Private Hospital, Salzburg, Austria.
⁴¹ Department of Metabolism, Reproduction and Digestion, Imperial College London, London, UK.
⁴² Yale School of Medicine, New Haven, Connecticut, USA.
⁴³ School of Psychology, University of Surrey, Guildford, GU2 7XH, UK.
⁴⁴ Department of Surgery, University of Basel, Basel, Switzerland.
⁴⁵ Department of Visceral Surgery, Clarunis, University Centre for Gastrointestinal and Liver Diseases, St Clara Hospital and University Hospital Basel, Basel, Switzerland.
⁴⁶ Faculty of Health, University of Plymouth, Drake Circus, Plymouth, PL4 8 AA, UK.
⁴⁷ Obesity and Bariatric Surgery Service, North Bristol NHS Trust, Bristol, BS10 5 NB, UK.
⁴⁸ Department of Intensive Care Medicine, Elisabeth-Tweesteden Hospital, Tilburg, the Netherlands.
⁴⁹ Department of Surgery, Division of General Surgery, Medical University of Vienna, Vienna, 1090, Austria.
⁵⁰ Department of Digestive Surgery, Division of Digestive Surgery and Urology, Turku University Hospital, Turku, Finland.
⁵¹ Department of Surgery, University of Turku, Turku, Finland.
⁵² Department of Endocrinology and Metabolism, Amsterdam University Medical Center, Amsterdam, Netherlands.
⁵³ Department of Internal Medicine, Yale School of Medicine, New Haven, USA.
⁵⁴ Division of Upper Gastrointestinal Surgery, Department of Surgery, National University Health System, Singapore, Singapore.
⁵⁵ Upper Gastrointestinal and Bariatric Surgery Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
⁵⁶ Department of Medicine, Weill Cornell Medicine-Qatar, PO Box 24144, Doha, Qatar.
⁵⁷ Department of Diabetes and Endocrinology, University Hospitals NHS Foundation Trust, Birmingham, UK.
⁵⁸ Sana-Klinikum Offenbach, Clinic for Surgery of Obesity and Metabolic Disorders, Starkenburgring 66, Offenbach am Main, 63069, Germany.
⁵⁹ Center for Metabolic and Bariatric Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
⁶⁰ South Tyneside and Sunderland NHS Foundation Trust, Sunderland Royal Hospital, Sunderland, UK.

^# Contributed equally.

PMID: 40598146
PMCID: PMC12211331
DOI: 10.1186/s12902-025-01961-w

Abstract

Introduction: Metabolic and bariatric surgery (MBS) has been an established treatment option for patients with Type 2 diabetes mellitus (T2DM), but there is a relative paucity of evidence-based guidelines on preoperative, operative, and postoperative considerations concerning metabolic surgery for T2DM patients. To address this gap, we initiated a Delphi consensus process with a diverse group of international multidisciplinary experts.

Method: We embarked on a Delphi consensus-building exercise to propose an evidence-based expert consensus covering various aspects of MBS in patients with T2DM. We defined the scope of the exercise and proposed statements and surveyed the literature through electronic databases. The literature summary and voting process were conducted by 52 experts, who evaluated 44 statements. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria.

Results: Consensus, defined as > 80% agreement, was reached for 43 out of 44 statements. The experts reached an agreement on the nature, terminology, and mechanisms of action of MBS. The currently available scores for predicting remission of T2DM after surgery are not robust enough for routine clinical use, and there is a need for further research to enable more personalized treatment. Additionally, they agreed that metabolic surgery for T2DM is cost-effective, and MBS procedures for treating T2DM vary in their safety and efficacy.

Conclusion: This Delphi expert consensus statement guides clinicians on various aspects of metabolic surgery for T2DM and also grades the quality of the available evidence for each of the proposed statements.

Keywords: Bariatric Surgery; Metabolic Surgery; Type 2 diabetes mellitus.

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Conflict of interest statement

Declarations. Ethics approval and consent to participate: This article does not contain any studies with human participants or animals performed by any of the authors. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests.

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References

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International expert consensus on surgery for type 2 diabetes mellitus

Affiliations

International expert consensus on surgery for type 2 diabetes mellitus

Authors

Affiliations

Abstract

Conflict of interest statement

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References

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Medical

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