Mechanisms of Glycemic Improvement After Gastrointestinal Surgery

This study is ongoing, but not recruiting participants.
Information provided by (Responsible Party):
Skye Steptoe, University of Washington Identifier:
First received: December 2, 2009
Last updated: March 19, 2014
Last verified: March 2014

This study is designed as a prospective clinical trial aimed at investigating the mechanisms behind observed improvements in type 2 diabetes mellitus (T2DM) following bariatric surgery. The majority of patients with T2DM who are undergoing Roux-en-Y gastric bypass (RYGB) surgery, in particular, experience complete remission of T2DM almost immediately post-surgery. This response occurs before significant weight loss is possible. To assess the mechanisms involved with disease resolution, the investigators propose a study to evaluate patients at the UW Medical Center (UWMC) who have T2DM and are undergoing RYGB with G (gastronomy)-tube placement as part of their clinical care. The investigators are interested in this sub-population as the G-tube allows us the unique opportunity to evaluate glycemic control and insulin response following delivery or exclusion of nutrients to the otherwise bypassed portion of the gastrointestinal tract. The investigators hypothesize that nutrient delivery to the proximal GI tract will reverse RYGB-mediated improvements in glucose homeostasis, possibly in association with changes in nutrient-regulated gut peptides involved in glucose control.

Condition Intervention Phase
Diabetes Mellitus, Type II
Other: Metabolic Testing
Phase 3

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Basic Science
Official Title: Mechanisms of Glycemic Improvement After Gastrointestinal Surgery

Further study details as provided by University of Washington:

Primary Outcome Measures:
  • Determine if the improvements in glycemic control occurring early after RYGB can be reversibly inactivated and activated through delivery or exclusion of nutrients in the bypassed proximal small intestine. [ Time Frame: 1/2010 - 6/2014 ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • To evaluate whether improvements in glucose control occurring early after RYGB are related to altered insulin secretion, insulin sensitivity, or both. [ Time Frame: 1/2010-6/2014 ] [ Designated as safety issue: No ]

Estimated Enrollment: 20
Study Start Date: January 2010
Estimated Study Completion Date: June 2015
Estimated Primary Completion Date: June 2015 (Final data collection date for primary outcome measure)
Intervention Details:
    Other: Metabolic Testing
    Four overnight metabolic testing sessions. Each session includes a Meal Tolerance Test and an IV Glucose Tolerance Test with Hyperglycemic/Euglycemic Clamp.
Detailed Description:

Roux-en-Y gastric bypass surgery causes complete, durable remission of type 2 diabetes (T2DM) in 84% of cases, typically within a few days to weeks after surgery. Mounting evidence indicates that this dramatic phenomenon results from effects beyond those related to weight loss and reduced caloric intake alone. The mechanisms mediating the weight-independent anti-diabetes impact of RYGB are unknown, and elucidating them could lead to new diabetes medicines. Human subjects will undergo frequently sampled I.V. glucose tolerance tests (FS-IVGTT) and tracer-enhanced hyperinsulinemic/euglycemic clamps (to measure insulin secretion and sensitivity) before RYBG and 3 times in the first six weeks afterward, during which the proximal small bowel will either be excluded from nutrient contact or exposed to nutrients delivered through an indwelling gastric cannula. We hypothesize that nutrient delivery to the proximal GI tract will reverse RYGB-mediated improvements in glucose homeostasis, possibly in association with changes in nutrient-regulated gut peptides involved in glucose control. Our study will allow us to test the upper intestinal hypothesis rigorously in man, and whether the hypothesis is confirmed or refuted, we will gain valuable new insights into the mechanisms of improved glucose control early after RYGB.


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Age 18 years or greater and planning to undergo RYGB at UWMC
  • Ability to speak English and communicate effectively with research staff
  • Ability to return for follow-up visits at UWMC
  • Adequate IV access
  • A G-tube is planned as part of the bariatric surgical procedure
  • Documented T2DM (fasting plasma glucose >125 mg/dL) that is treated with lifestyle efforts or by taking acceptable oral medications

Exclusion Criteria:

  • Informed consent not obtained
  • Unlikely to comply with the protocol
  • Current HbA1c >8.5% or fasting blood glucose >180 mg/dL
  • Serum creatinine >1.7 mg/dL
  • Use of unacceptable diabetes medications at baseline
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Please refer to this study by its identifier: NCT01025999

United States, Washington
University of Washington Medical Center
Seattle, Washington, United States, 98195
Sponsors and Collaborators
University of Washington
Principal Investigator: David R Flum, MD, MPH University of Washington
Principal Investigator: David E Cummings, MD University of Washington
  More Information

No publications provided

Responsible Party: Skye Steptoe, Project Manager, University of Washington Identifier: NCT01025999     History of Changes
Other Study ID Numbers: 36417-A, 1R01DK084324-01
Study First Received: December 2, 2009
Last Updated: March 19, 2014
Health Authority: United States: Institutional Review Board

Keywords provided by University of Washington:
Gastrostomy tube
Gastric Bypass

Additional relevant MeSH terms:
Diabetes Mellitus, Type 2
Diabetes Mellitus
Endocrine System Diseases
Glucose Metabolism Disorders
Metabolic Diseases processed this record on May 21, 2015