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.