Comparison of metabolic outcomes in patients undergoing laparoscopic roux-en-Y gastric bypass versus sleeve gastrectomy - a systematic review and meta-analysis of randomised controlled trials

Bariatric surgery is the most effective treatment for morbid obesity and is known to have beneficial effects on glycaemic control in patients with type 2 diabetes mellitus (T2DM) and in diabetes prevention. The preferred type of surgery and mechanism of action is, however, unclear. We performed a systematic review and meta-analysis of randomised controlled trials (RCTs) comparing the effects of laparoscopic roux-en-Y gastric bypass (RYGB) with those of sleeve gastrectomy (SG) on metabolic outcome, with a special focus on glycaemic control. A literature search of the Medline, Pubmed, Cochrane, Embase and SCOPUS databases was performed in November 2014 for RCTs comparing RYGB with SG in overweight and obese patients with or without T2DM. The primary outcome was improvement in postoperative glycaemic control. Secondary outcomes included weight-related and lipid metabolism parameters. Synthesis of these data followed established statistical procedures for meta-analysis. Sixteen RCTs with a total of 1132 patients with overweight or obesity were included in the analysis. When compared with patients who underwent SG, those who underwent RYGB showed no difference after 12 months in mean fasting blood glucose (mean difference [MD] -6.22 mg/dl, 95% confidence interval [CI] -17.27 to 4.83; p