Gastric Bypass - A Quick Cure for Diabetes?

Monday, June 13, 2005

2:15-4:15 PM

Chair:
David E. Cummings, MD

Faculty:
Lori R. Roust, MD
Philip R. Schauer, MD
Francesco Rubino, MD
Randy Seeley, PhD

Report by Kimberly McFarland, PhD

Dr Roust used 2 case studies to demonstrate the dramatic effects of Roux-en-Y gastric bypass surgery (RYGB) on type 2 diabetes. In each case, the patient’s diabetes resolved or significantly improved; their A1C levels dropped to 6.7%, and they were either able to discontinue all medical management or were able to utilize oral agents alone.

Dr Schauer generalized on Dr Roust’s talk by presenting a series of publications that documented the benefit of gastric bypass surgery (GBS) in type 2 diabetes (Ann Surg. 1995;222:339-350; J Gastrointest Surg. 1997;1:213-220; Ann Surg. 2003;237:751-756; JAMA. 2004;292:1724-1737[meta-analysis]). In these studies, diabetes resolved in greater than 80% of patients, as assessed by a decreased need for medical management and normalized metabolic indicators. Predictors of diabetes remission following GBS included greater weight loss, shorter time with a diagnosis of diabetes, and shorter duration of insulin use.

Talks by Dr Rubino and Dr Seelye addressed potential mechanisms behind GBS efficacy in resolving diabetes. Dr Rubino presented data from work in the Goto-Kakizaki (GK) rat, an experimental model that develops diabetes without weight gain. He utilized duodenal-jejunal bypass (DJB) to demonstrate that surgery improved the rats’ metabolic profile in the absence of significant weight change. Implications of these results are 2-fold: 1) surgical intervention may benefit patients with BMI<35, and 2) the bowel may play a role in diabetes pathogenesis. In Dr Seelye’s lab, ileal-jejunal transpositions resulted in modest weight loss, improved insulin sensitivity, and changes in gut hormone secretion following food intake. As observed by Dr Seelye, information from clinical procedures is driving further understanding of the role of gut hormones in diabetes.