Unseen woman pricking their finger to test their blood sugar level
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Research from the Mayo Clinic shows that gastric bypass surgery in people with type 2 diabetes results in lasting remission of the disease, even after regaining their weight. The study, published today in the Journal of the American College of Surgeons, shows that gastric bypass patients were more likely to remain in remission five years later even after weight is regained, compared with those who had undergone sleeve gastrectomy, who were five times more likely to see their diabetes return.

Gastric bypass surgery bypasses a part of the small intestine called the duodenum, while sleeve gastrectomy, which is minimally invasive and a more popular surgery, works by making the stomach smaller thereby restricting the amount of food a person can consume.

“We showed that in patients who had bariatric surgery, bypassing the duodenum has a greater benefit for patients with diabetes,” said Omar M. Ghanem, MD, a bariatric and metabolic surgeon at Mayo Clinic and lead author of the study. “We saw that patients who had sleeve gastrectomy and weight recurrence had a much greater chance of having their diabetes return when compared to their gastric bypass counterparts, even after adjusting for all diabetes patient factors.”

Ghanem noted that the duodenum helps regulate what is referred to as the “gut metabolic pathway” and that bypassing it contributes to many physiologic actions or changes in metabolism including the regulation of glycemia.

For this research, the Mayo Clinic team investigated the rates at which diabetes returned in patients who regained their weight after bariatric surgery. It included 224 patients who had undergone gastric bypass surgery and 46 controls who had received a sleeve gastrectomy. Patients had received one or the other surgery between 2008 and 2017 with all patients in this analysis having obesity and a prior type 2 diabetes diagnosis. The patients were followed for five years at which time they were divided into four different weight class categories to see for whom diabetes had returned.

Among the entire group, 75% of gastric bypass patients had their diabetes remain in remission compared with 34.8% of those who received a sleeve gastrectomy. After adjusting for patient weight-related factors the sleeve gastrectomy group was 5.5 times more likely to have their diabetes return compared with those who underwent gastric bypass surgery.

When gastric bypass patients were stratified into four categories of those who first lost weight, then regained defined as regaining 25%, 25% to 50%, 50% to 75%, or more than 75%, over half the patients in all four groups had their diabetes remain in remission. Interestingly, among patients who regained 100% or more their weight after gastric bypass, roughly 60% kept diabetes in remission, while none of the patients in the sleeve gastrectomy group who regained this weight remained in remission.

Factors related to recurrence of diabetes included higher preoperative blood sugar levels (A1c), as well as long preoperative duration of diabetes.

While the findings were limited by the fact that it was a retrospective study, that may not apply to other bariatric programs, the researchers said they will now conduct more in-depth research to better understanding the cellular mechanisms at play that contribute to maintain type 2 diabetes remission. Having this information will be important in making treatment decisions for patients.

“A major determining fact when choosing the most appropriate surgery is if the patient wants to eliminate diabetes or wants to have the least chance of having diabetes come back in the long term,” concluded Ghanem. “While both procedures are great, we know that gastric bypass is a better procedure for patients with diabetes at this point.”

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