A Study to Examine Changes in GIP Plasma Levels Following Gastric Bypass Surgery in Obese Patients

This study has suspended participant recruitment.
Information provided by:
Boston Medical Center
ClinicalTrials.gov Identifier:
First received: September 13, 2005
Last updated: November 15, 2005
Last verified: August 2005
Obesity is a multinational epidemic. There is evidence that despite educational measures and increased public awareness, the number of obese individuals continues to increase. Of the numerous obesity-related comorbidities, type 2 diabetes remains one of the most significant in terms of mortality and health care costs. Gastric Bypass Surgery (GBS) not only offers an effective form of therapy for morbid obesity, but also amelioration of type 2 diabetes mellitus. The normalization of glucose levels in GBS patients occurs within days after surgery and has been shown in surgical literature to be independent of the weight loss after surgery. The proximal gut, the site of release of certain incretins, may play a role in glucose homeostasis in obese individuals with type 2 diabetes mellitus. One such incretin is GIP, which when released into the circulation during the immediate postprandial period, accentuates the insulin response to a glucose meal. It is hypothesized that overactivity of this enteroinsular axis in obese individuals produces cell resistance to insulin and subsequent type 2 diabetes mellitus. A previous study reported elevated fasting GIP levels, as well as an exaggerated GIP response to a glucose meal, in obese subjects, which was significantly reduced months after GBS following weight loss. This pilot study of obese patients scheduled for GBS will compare the serum levels of certain peptides, including GIP, following a glucose meal before and after GBS, before weight loss has occured. In order to reproduce the preoperative state, and therefore to demonstrate the physiologic change, a small group of subjects who undergo open surgery will undergo the same measurements after surgery, but using a model in which the meal traverses the stomach, duodenum and jejunum with the aid of a gastrostomy tube.

Condition Intervention
Type 2 Diabetes Mellitus
Insulin Resistance
Procedure: Oral glucose tolerance test
Procedure: G tube glucose tolerance test

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Diagnostic
Official Title: A Pilot Study to Examine the Relationship Between Changes in Plasma GIP Levels and Other Gastrointestinal Peptides Following Gastric Bypass Surgery in Obese Patients

Further study details as provided by Boston Medical Center:

Primary Outcome Measures:
  • GIP area under the curve after OGTT

Secondary Outcome Measures:
  • Other GI peptides and hormones after OGTT

Estimated Enrollment: 30
Study Start Date: March 2004
Estimated Study Completion Date: March 2005
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Ages Eligible for Study:   21 Years to 64 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Patients 21-64 years of age
  • Obese (defined as a body mass index, BMI, > or = 30)
  • Type 2 diabetes or impaired glucose tolerance
  • Have been selected and scheduled for gastric bypass surgery.

Exclusion Criteria:

  • Substance abuse
  • Consumption of more than two alcoholic drinks per day
  • Use of more than 20 units of insulin (any brand or type) per day
  • Fasting blood glucose >180mg/dl on screening bloodwork.
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00207389

United States, Massachusetts
Boston University Medical Center
Boston, Massachusetts, United States, 02118
Sponsors and Collaborators
Boston Medical Center
Principal Investigator: Caroline Apovian, MD Boston University Medical Cneter
Principal Investigator: Michael Wolfe, MD Boston University
Study Chair: Marie Mcdonnell, MD Boston University
Study Chair: Harmony Allison, MD Boston University
  More Information

Bayliss WM, Starling EH. Croonian lecture. The chemical regulation of the secretory process. Proc R Soc Lond 1904(73):310-332.
Kosaka T, Lim RKS. Demonstration of the humoral agent in fat inhibited gastric secretion. Proc Soc Exp Biol Med 1930;27:890-891.
Arnold R, Ebert R, Creutzfeldt W, H.D. B, Börger H. Inhibition of gastric acid secretion by gastric inhibitory polypeptide (GIP) in man. Scand J Gastroenterol 1978;13(Suppl 48):11.

ClinicalTrials.gov Identifier: NCT00207389     History of Changes
Other Study ID Numbers: H-22610 
Study First Received: September 13, 2005
Last Updated: November 15, 2005
Health Authority: United States: Institutional Review Board

Keywords provided by Boston Medical Center:
Incretins:GIP , GLP-1
Gastric bypass surgery
Laparascopic gastric bypass surgery
Postprandial expression of GIP

Additional relevant MeSH terms:
Diabetes Mellitus, Type 2
Insulin Resistance
Diabetes Mellitus
Endocrine System Diseases
Glucose Metabolism Disorders
Metabolic Diseases

ClinicalTrials.gov processed this record on April 27, 2016