Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. Nov 15, 2018; 9(11): 180-189
Published online Nov 15, 2018. doi: 10.4239/wjd.v9.i11.180
Current and future impact of clinical gastrointestinal research on patient care in diabetes mellitus
Timothy R Koch, Timothy R Shope, Michael Camilleri
Timothy R Koch, Timothy R Shope, Center for Advanced Laparoscopic General and Bariatric Surgery, MedStar Washington Hospital Center and Georgetown University School of Medicine, Washington, DC 20010, United States
Michael Camilleri, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905, United States
Author contributions: All of the authors drafted the manuscript and approved the final version of the article.
Supported by the grant from National Institutes of Health, No. R01-DK67071.
Conflict-of-interest statement: Koch TR and Shope TR have no conflict of interest to report regarding the publication of this paper. Camilleri M received support from Novo Nordisk to conduct research on liraglutide.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Timothy R Koch, MD, Doctor, Professor, Center for Advanced Laparoscopic General and Bariatric Surgery, MedStar Washington Hospital Center and Georgetown University School of Medicine, POB South, Suite 301, 106 Irving Street, NW, Washington, DC 20010, United States. timothy.r.koch@medstar.net
Telephone: +1-202-8777788 Fax: +1-877-6808198
Received: July 23, 2018
Peer-review started: July 23, 2018
First decision: August 3, 2018
Revised: August 12, 2018
Accepted: October 11, 2018
Article in press: October 11, 2018
Published online: November 15, 2018

The worldwide rise in the prevalence of obesity supports the need for an increased interaction between ongoing clinical research in the allied fields of gastrointestinal medicine/surgery and diabetes mellitus. There have been a number of clinically-relevant advances in diabetes, obesity, and metabolic syndrome emanating from gastroenterological research. Gastric emptying is a significant factor in the development of upper gastrointestinal symptoms. However, it is not the only mechanism whereby such symptoms occur in patients with diabetes. Disorders of intrinsic pacing are involved in the control of stomach motility in patients with gastroparesis; on the other hand, there is limited impact of glycemic control on gastric emptying in patients with established diabetic gastroparesis. Upper gastrointestinal functions related to emptying and satiations are significantly associated with weight gain in obesity. Medications used in the treatment of diabetes or metabolic syndrome, particularly those related to pancreatic hormones and incretins affect upper gastrointestinal tract function and reduce hyperglycemia and facilitate weight loss. The degree of gastric emptying delay is significantly correlated with the weight loss in response to liraglutide, a glucagon-like peptide-1 analog. Network meta-analysis shows that liraglutide is one of the two most efficacious medical treatments of obesity, the other being the combination treatment phentermine-topiramate. Interventional therapies for the joint management of obesity and diabetes mellitus include newer endoscopic procedures, which require long-term follow-up and bariatric surgical procedure for which long-term follow up shows advantages for individuals with diabetes. Newer bariatric procedures are presently undergoing clinical evaluation. On the horizon, combination therapies, in part directed at gastrointestinal functions, appear promising for these indications. Ongoing and future gastroenterological research when translated to care of individuals with diabetes mellitus should provide additional options to improve their clinical outcomes.

Keywords: Obesity, Gastric emptying, Diabetes mellitus, Gastric bypass, Bariatric surgery, Weight loss

Core tip: The worldwide prevalence of obesity continues to rise. Delayed gastric emptying and impaired gastric accommodation result in upper gastrointestinal symptoms, through intrinsic nerve and pacemaker dysfunction. Glycemic control has a limited effect on gastric emptying in diabetic gastroparesis. Treatment of diabetes with pancreatic hormones and incretins inhibits gastric emptying, reduces hyperglycemia, and facilitates weight loss. Meta-analysis shows that glucagon-like peptide-1 analog, liraglutide, is one of the two most efficacious treatments of obesity. Bariatric surgery and endoscopic interventions are efficacious in diabetes and obesity, but long term follow-up is required for endoscopic interventions as well as for newer bariatric procedures. On the horizon, combination therapies directed at gastrointestinal function appear promising for these indications.