Bariatric surgery as a novel treatment for type 2 diabetes mellitus: a systematic review.

Objective: To systematically review the literature pertaining to the reversal of type 2 diabetes mellitus (DM2) after Roux-en-Y gastric bypass and adjustable gastric banding.

Data Sources: We conducted a review of the literature using PubMed and searched the reference lists of published studies to identify additional studies.

Study Selection: We selected all published articles that were relevant with respect to bariatric surgery and its metabolic effects.

Data Extraction: Only 9 original articles reporting on DM2 reversal rates after bariatric surgery were identified: 1 randomized controlled trial and 8 observational studies. Other referenced articles serve as background literature.

Data Synthesis: Roux-en-Y gastric bypass leads to a reversal rate of DM2 of 83%. Adjustable gastric banding confers a reversal rate of 62%, and this effect is achieved later after surgery.

Conclusions: Bariatric surgery leads to marked and long-lasting weight reduction. A large proportion of patients undergoing bariatric surgery have DM2. In fact, the presence of diabetes mellitus is a compelling argument to perform bariatric surgery in those who are eligible according to international criteria. Glycemic control improves in the months after laparoscopic adjustable gastric banding, but it improves more rapidly and completely after laparoscopic Roux-en-Y gastric bypass surgery. Thus, both types of surgery are capable of improving or even curing DM2, but the mechanisms may differ.