New findings on long-term remission of type-2 diabetes after bariatric surgery

A retrospective observational study from the USA compared whether there are differences between a Roux-Y gastric bypass and the application of sleeve gastrectomy for remission in type-2 diabetes.

The chances of remission seem greater with gastric bypass than with a sleeve gastrectomy

Bariatric surgery can sometimes change the course of obese patients with type 2 diabetes and lead to a complete remission of the metabolic disease. However, the risk of recurrence is relatively high. A retrospective observational study from the USA compared whether there are differences between a Roux-Y gastric bypass and the application of sleeve gastrectomy.

Numerous studies have now shown that bariatric surgery for obesity can lead to a remission of type-2 diabetes and thus reduce the risk of micro- and macrovascular complications. However, the results vary depending on the type of surgery and the subpopulation studied. In addition, in the long term, between a quarter to half of the patients experience a recurrence of diabetes despite initial remission.

Retrospective long-term comparison

Little is known about the influence of the type of bariatric intervention on the course of type-2 diabetes. Kathleen M. McTigue, from the University of Pittsburgh’s Department of Medicine and her colleagues, have therefore compared the long-term course of Roux-Y gastric bypass (RYGB) and sleeve gastrectomy surgery as the two most common bariatric surgeries in the Patient-Centered Clinical Research Network (PCORNet) Bariatric Study.

The data were evaluated from 9,710 adult patients with type-2 diabetes and obesity (72.6% women) who underwent one of the two surgeries at 34 US centers between January 2005 and September 2015. In 35.8% of patients, sleeve gastrectomy was chosen, and in 64.2% a Roux-Y gastric bypass was performed. At the time of the operation, the patients were on average 49.8 years old (20 to 80 years) and their body mass index (BMI) was on average 49.0 kg/m2.  There were no significant differences between the two groups in terms of age, gender, or initial BMI. The mean follow-up period was 2.7 years.

Mean preoperative HbA1c was 7.2% and patients took 1.66 diabetes drugs on average. Most patients had obesity-associated comorbidities, with some concomitant diseases such as sleep apnea syndrome (57.9% vs. 50%), non-alcoholic fatty liver disease (30.7 vs. 21%), and gastroesophageal reflux disease (41.9 vs. 36.4%) showing a slightly higher prevalence in the RYGB group.

Greater weight loss with gastric bypass

The greatest weight loss in both groups occurred in the first postoperative year (sleeve gastrectomy: -22.8%, RYGB: -29.1%), after which most patients gained weight again. After five years, patients treated with RYGB had lost significantly more weight than patients with sleeve gastrectomy (-6.2 vs. 7.0% compared to the initial weight) - this corresponded to a difference of 8.1% and 10.2 kg.

Fewer recurrences of diabetes in patients with gastric bypass

Within five years, 86.1% of the patients with RYGB and 83.5% of the patients with sleeve gastrectomy had a diabetes remission defined as HBA1c value > 6.5% without diabetes medication for at least six months. In the patients with initial remission after five years, 33.1% of the patients with RYGB and 41.6% of the patients with sleeve gastrectomy had a recurrence of diabetes. Thus, patients on gastric bypass had a 25% lower risk of developing a recurrence of diabetes. Good long-term glycaemic control (defined as HbA1c constant < 6.5%) was also more frequently observed with RYGB.


This study has thus also confirmed that obese type-2 diabetics have a very good chance of diabetes remission through bariatric surgery such as sleeve gastrectomy and gastric bypass. In terms of the risk of recurrence and long-term glycemic control, however, gastric bypass seems somewhat superior to sleeve gastrectomy. The authors write that this should be taken into account when choosing the bariatric procedure, along with other factors such as the personal life situation of the patient, and the side effect profile of the respective surgeries, and should also be included in preoperative patient education.

Source: Kathleen M. McTigue et al; Comparing the 5-Year Diabetes Outcomes of Sleeve Gastrectomy and Gastric BypassThe National Patient-Centered Clinical Research Network (PCORNet) Bariatric Study; JAMA Surg (2020); DOI:10.1001/jamasurg.2020.0087