Among obese patients who underwent bariatric surgery 40% achieved at least partial remission of type 2 diabetes mellitus, compared with no patients who underwent a nonsurgical lifestyle intervention program, investigators reported online July 1 in JAMA Surgery.
The randomized clinical trial of 61 patients offers “further important evidence that at longer-term follow-up of 3 years, surgical treatments, including Roux-en-Y gastric bypass and laparoscopic adjustable gastric banding, are superior to lifestyle intervention alone for the remission of type 2 diabetes mellitus in obese individuals, including those with a body mass index (BMI) between 30 and 35 [kg/m2],” said Dr. Anita Courcoulas at the University of Pittsburgh Medical Center and her associates. But further studies will be needed to explore exactly how bariatric surgery affects diabetes and the effect of these procedures on the microvascular and macrovascular complications of diabetes, the investigators added (JAMA Surg. 2015 July 1 [doi:10.1001/jamasurg.2015.1534]).
Dr. Anita Courcoulas
Several studies have reported major improvements in type 2 diabetes mellitus (T2DM) after bariatric surgery, but did not assess long-term efficacy or safety compared with lifestyle and medical management, the researchers noted. To fill that gap, they randomized obese middle-aged adults with T2DM to either an intensive lifestyle weight loss program for 1 year followed by a 2-year low-level lifestyle intervention program, or to Roux-en-Y gastric bypass (RYGB) or laparoscopic adjustable gastric banding (LAGB) followed by the low-level lifestyle intervention program during years 2 and 3.
After 3 years, 40% of RYGB patients and 29% of LAGB patients were fully or partially remitted, compared with none of the control group (P = .004), the investigators reported. The bariatric surgery groups did not significantly differ in terms of complete remission, but 65% of RYGB patients and 33% of LAGB patients were able to stop all insulin and oral diabetes medications, compared with none of the control group (P < .001). Also, RYGB patients lost an average of 25% of their baseline body weight, compared with 15% for LAGB (P = .0002) and only 5.7% for the lifestyle-only control group (P < .0001).
At baseline, patients averaged 100.5 kg (standard deviation, 13.7 kg) in body weight, mean hemoglobin A1c level was 7.8% (standard deviation, 1.9%), average fasting plasma glucose level was 171.3 (72.5) mg per dL, the investigators said. “One important aspect of this study was that more than 40% of the sample were individuals with class I obesity (BMI ≥ 30), for whom data in the literature are largely lacking,” they added. Adverse events were uncommon after the first year, but RYGB was linked to significant drops in lean muscle and bone mass that will need further study, they noted.
The National Institutes of Health and the University of Pittsburgh Medical Center funded the study. Dr. Courcoulas reported research support from Nutrisystem, J&J Ethicon, and Covidien, and consulting relationships with Ethicon and Apollo Endosurgery. Two coauthors reported relationships with the Obesity Society/Nutrisystem, Jawbone/BodyMedia, and Weight Watchers. The other investigators declared no conflicts of interest.