Laparoscopic sleeve gastrectomy versus single anastomosis (mini-) gastric bypass for the treatment of type 2 diabetes mellitus: 5-year results of a randomized trial and study of incretin effect.

BACKGROUND: Bariatric surgery may be beneficial in mildly obese patients with poorly controlled diabetes. The optimal procedure to achieve diabetes remission is unknown. In 2011, we published the short-term results of a pilot study designed to evaluate the efficacy of diabetic control and the role of duodenal exclusion in mildly obese diabetic patients undergoing laparoscopic sleeve gastrectomy (SG) vs. a laparoscopic single anastomosis (mini-) gastric bypass (SAGB). This study analyzes the 5-year results and evaluates the incretin effect.

METHODS: A double-blind randomized trial included 60 participants with a hemoglobin A1c (HbA1c) level higher than 7.5%, a body mass index (BMI) between 25 and 35 Kg/m(2), a C-peptide level ≥1.0 ng/mL, and a diagnosis of type 2 diabetes mellitus (T2DM) for at least 6 months. A SAGB with duodenal exclusion or a SG without duodenal exclusion was performed.

RESULTS: The 5-year results of the primary outcome were as an intention-to-treat analysis for HbA1c ≤6.5% without glycemic therapy. Assessments of the incretin effect and β cell function were performed at baseline and between 36 and 60 months. The patients were randomly assigned to SAGB (n = 30) and SG (n = 30). At 60 months, 18 participants (60%; 95% confidence interval (CI), 42 to 78%) in the SAGB group and nine participants (30%; 95% CI, 13 to 47%) in the SG group achieved the primary end points (odds ratio (OR), 0.3; 95% CI, 0.1 to 0.8%). The participants assigned to the SAGB procedure had a similar percentage of weight loss as the SG patients (22.8 ± 5.9 vs. 20.1 ± 5.3%; p > 0.05) but achieved a lower level of HbA1c (6.1 ± 0.7 vs. 7.1 ± 1.2 %; p < 0.05) than the SG patients. There was a significant increase in the incretin effect before and after surgery in both groups, but the SAGB group had a higher incretin effect than the SG group at 5 years.

CONCLUSIONS: In mildly obese patients with T2DM, SG is effective at improving glycemic control at 5 years, but SAGB was more likely to achieve better glycemic control than SG and had a higher incretin effect compared to SG.