Durability of Bariatric Surgery in Maintaining Remission of Diabetes

Study Questions:

Compared to conventional medical treatment, what are 5-year outcomes associated with bariatric surgery for the treatment of type 2 diabetes in obese patients?


This is an analysis of long-term glycemic control 5 years after randomization to medical treatment or bariatric surgery. The authors had previously conducted a three-group, open-label, randomized controlled trial at a single center in Italy. Eligible patients were adults with a body mass index (BMI) of 35 kg/m2 or more and a history of type 2 diabetes lasting at least 5 years. Patients were randomly assigned to receive either medical treatment or surgery by Roux-en-Y gastric bypass or biliopancreatic diversion. In the original trial, the primary endpoint was the rate of diabetes remission at 2 years. In this study of long-term follow-up, the following secondary outcome measures were assessed: durability of diabetes remission and relapse of hyperglycemia, cardiovascular risk factors, medication use, quality of life, and long-term complications.


A total of 60 patients had been randomized to receive either medical treatment (n = 20) or surgery by gastric bypass (n = 20) or biliopancreatic diversion (n = 20). Fifty-three (88%) patients completed 5 years of follow-up. Overall, 19 of the 38 surgical patients maintained diabetes remission at 5 years, compared with none of the 15 medically treated patients (p = 0.0007). Surgery caused more weight loss and greater changes in BMI and waist circumference than did medical treatment; weight changes did not predict diabetes remission. Both surgical procedures were associated with significantly lower plasma lipids and medication use. Surgical patients scored significantly better than medically treated patients for all subdomains of quality of life and for the total score domains.


Roux-en-Y gastric bypass and biliopancreatic diversion were both more effective than standard medical treatment for the long-term control of hyperglycemia. Overall, half of surgically treated patients were able to maintain long-term remission of diabetes in this open-label, randomized controlled trial.


This is an important study that adds evidence to the finding that surgery is more effective than medical treatment for the long-term control of type 2 diabetes in obese patients, although limited by a small sample size (53 patients completed 5 years of follow-up). Of note, weight changes were not associated with either remission or relapse of diabetes. Importantly, and as the authors posit: ‘Gastrointestinal surgery might activate weight-independent mechanisms of diabetes control.’ Bariatric surgery should continue to be an option for the long-term control of obese patients with type 2 diabetes.

Clinical Topics: Diabetes and Cardiometabolic Disease, Dyslipidemia, Prevention, Lipid Metabolism

Keywords: Bariatric Surgery, Biliopancreatic Diversion, Blood Glucose, Body Mass Index, Diabetes Mellitus, Type 2, Gastric Bypass, Hyperglycemia, Lipids, Metabolic Syndrome X, Obesity, Primary Prevention, Quality of Life, Recurrence, Risk Factors, Weight Loss

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