Gastric Bypass Puts Type 2 Diabetes Into Remission

February 28, 2013

Bariatric surgery provides durable glycemic control out to 2 years compared with intensive medical therapy in moderately obese patients with type 2 diabetes, an extension of the Surgical Treatment and Medications Potentially Eradicate Diabetes Efficiently (STAMPEDE) study demonstrates.

"We can put diabetes into remission, and even if this is only for a few years, it will delay the development of complications," lead author Sangeeta R. Kashyap, MD, from the Endocrinology and Metabolism Institute, Cleveland Clinic, Ohio, told Medscape Medical News. Dr. Kashyap and colleagues report their findings online February 25 in Diabetes Care.

She explained that "bariatric surgery allows the pancreas to make insulin again and normalizes blood sugar with fewer or no medications." The results of this study are particularly pertinent because the participants were only moderately obese (body mass index [BMI] range of 27 to 43 kg/m2), in contrast with most studies of weight-loss surgery, which have examined morbidly obese subjects, she noted.

The findings also point to Roux-en-Y gastric bypass (RYGB) being a markedly better option for these patients than sleeve gastrectomy, she said. Although the 2 surgical procedures resulted in the same amount of weight loss, gastric bypass "was most impressive in metabolic terms, having a unique and powerful effect on belly fat and increasing the function of the pancreas 5-fold," Dr. Kashyap noted.

She added that the message for doctors is: "Think about bariatric surgery as a viable therapeutic option for your obese diabetic patients, especially those with a BMI of more than 35 and those who are not responding to lifestyle changes and medications." She acknowledged, however, that the durability of the results will be key, as will demonstrating a beneficial effect of bariatric surgery on complications of diabetes, such as retinopathy, neuropathy, and nephropathy. She and her team plan to follow their cohort out to 5 years to specifically look at this issue.

"The doors have opened for bariatric surgery for type 2 diabetes, and the long-term goal is to see if these procedures have an impact on complications," she observed.

Gastric Bypass Reverses Core Defects in Diabetes

The doors have opened for bariatric surgery for type 2 diabetes, and the long-term goal is to see whether these procedures have an impact on complications. Dr. Sangeeta R. Kashyap

Results from STAMPEDE were first reported a year ago at the American College of Cardiology meeting. The study is a randomized controlled trial that enrolled 150 moderately obese patients (mean BMI, 36) with uncontrolled type 2 diabetes and randomly assigned them to intensive medical therapy (IMT), RYGB, or sleeve gastrectomy. The mean age was 49 years, and mean glycated hemoglobin (HbA1c) was 9.2%.

The main study outcome of HbA1c of less than 6.0% after 12 months of treatment was met by 12% of the medical-therapy group, 42% of the RYGB group (p=0.002 vs medical therapy), and 37% of the sleeve-gastrectomy group (p=0.008 vs medical therapy). The researchers concluded that the surgical patients had better glycemic control, "which was achieved on much lower regimens of both diabetic and [cardiovascular] medications."

Now, Dr. Kashyap and colleagues have followed 54 of these original 150 patients out to 2 years. At this time point, mean HbA1c was 6.7% for gastric bypass, 7.1% for sleeve gastrectomy, and 8.4% for IMT (P < .05 for each surgical group vs IMT).

Reduction in body fat was similar for both surgery groups, with greater absolute reduction in truncal fat in gastric bypass vs sleeve gastrectomy (-16% vs -10%; P = .04). Insulin sensitivity increased significantly from baseline in gastric bypass (2.7-fold; P = .004) but did not change in sleeve gastrectomy or IMT.

Pancreatic ß-cell function increased 5.8-fold in gastric bypass from baseline and was markedly greater than IMT (P = .001) but was not different between sleeve gastrectomy and IMT (P = .30). At 24 months, ß-cell function inversely correlated with truncal fat and prandial free-fatty-acid levels.

"Despite producing a similar weight loss to sleeve gastrectomy, gastric bypass uniquely restores pancreatic ß-cell function and reduces truncal fat, thus reversing the core defects in diabetes," the researchers write.

I would say the gold standard surgical technique is Roux-en-Y gastric bypass. I truly consider it metabolic surgery for people with diabetes.   Dr. Sangeeta R. Kashyap

"I would say the gold standard surgical technique is Roux-en-Y gastric bypass. I truly consider it metabolic surgery for people with diabetes," she told Medscape Medical News.

Dr. Kashyap said those who underwent sleeve gastrectomy experienced relapse. After 1 year, a quarter of them had come off all medications, but by 2 years this figure was down to 10%. "People [who had had sleeve gastrectomy] fell out of remission even though they were able to sustain the weight loss," she remarked.

She added, however, that sleeve gastrectomy "is not terrible. It's often used as a transitional procedure for the very sick, but the better option is bypass."

The STAMPEDE trial was supported by funding from Ethicon Endo-Surgery, a clinical translational award from the American Diabetes Association, and a grant from the National Institutes of Health. Dr. Kashyap reports no conflict of interest. Disclosures for the coauthors are listed in the article.

Diabetes Care. Published online February 25, 2013. Abstract