New Study Finds Diabetes under Control without Insulin Seven Years after Bariatric Surgery

Seven years after bariatric surgery, 44 percent of patients with severe obesity had their diabetes under control and were able to stop taking insulin, and 15 percent achieved diabetes remission, according to researchers from the Cleveland Clinic in Ohio who presented their findings today at ObesityWeek 2017, the largest international event focused on the basic science, clinical application and prevention and treatment of obesity. The annual conference is hosted by the American Society for Metabolic and Bariatric Surgery (ASMBS) and The Obesity Society (TOS).

Cleveland Clinic researchers reviewed the outcomes of 252 patients who had either Roux-en-Y gastric bypass (194 patients) or sleeve gastrectomy (58 patients) between January 2004 and June 2012. Prior to surgery, patients had type 2 diabetes for an average of 11 years, were taking insulin, and had an average body mass index (BMI) of nearly 46 kg/m2. The average age of the patients was 52.

“This study shows bariatric surgery can induce a significant and sustainable improvement in metabolic profile of patients with obesity and insulin-treated type 2 diabetes, typically a much more difficult group to achieve glycemic control or remission,” says Ali Aminian, MD, study co-author and associate professor of surgery at the Cleveland Clinic. “Anytime a patient can come off insulin and still have their diabetes be under control, it’s a big deal, in terms of quality of life, decreased healthcare costs and preventing weight gain.”

While scientists have been conducting research on bariatric and metabolic surgery for years, the Cleveland Clinic study is the largest study of insulin-treated diabetes patients with the longest follow-up.

After seven years, patients on average had reduced their BMI by 11 points, which was associated with a significant reduction in blood sugar, as measured by Hemoglobin A1C (HbA1c) and fasting blood glucose. Before surgery and when on insulin, only 18 percent of patients met the American Diabetes Association blood sugar target of HbA1c of less than 7 percent for people with diabetes. Seven years later, 59 percent met the target. The longer a patient had diabetes before surgery, the less improvement they were likely to experience. Previous studies have shown remission is more likely when a patient with diabetes had not begun insulin.

Gastric bypass patients lost more body weight and used fewer diabetes medications than sleeve gastrectomy patients. A significant improvement in blood pressure and cholesterol was observed in both surgical groups.

Gastric bypass surgery involves cutting and stapling the stomach and rearranging or rerouting the small bowel. Sleeve gastrectomy, the most popular method of bariatric surgery, is performed by removing approximately 80 percent of the stomach and leaving a narrow gastric tube or “sleeve.” In both procedures, because the stomach is made smaller, patients feel satisfied with less food.

“Certainly, we’d like to see patients sooner, but this study demonstrates bariatric and metabolic surgery can still have a significant impact, even after a person has had diabetes for years and years,” says Samer Mattar, MD, president-elect, ASMBS and a bariatric surgeon at Swedish Weight Loss Services in Seattle Washington, who was not involved in the study.