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RYGB and the Gastric Adipose Axis

This study is enrolling participants by invitation only.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Information provided by (Responsible Party):
Naji Abumrad, Vanderbilt University Identifier:
First received: November 15, 2011
Last updated: September 22, 2016
Last verified: September 2016
The purpose of this study is to determine if interruption in gastric-adipose tissue axis signaling contributes to early improvements in oxidative stress, insulin sensitivity, and inflammation, and to determine if interruption of the stomach in RYGB results in reduction of plasma acylated ghrelin (AG) and in an altered acylated ghrelin:unacylated ghrelin (AG:UAG) ratio which may contribute to decreased oxidative stress and improved insulin sensitivity.

Condition Intervention Phase
Drug: human ghrelin
Other: very low calorie diet
Procedure: Hyperinsulinemic/Euglycemic Clamp
Phase 1

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Basic Science
Official Title: RYGB Improves Metabolism by Interrupting the Gastric Adipose Tissue Axis

Further study details as provided by Vanderbilt University:

Primary Outcome Measures:
  • change in glucose disposal rate [ Time Frame: baseline and 1 week ] [ Designated as safety issue: No ]
    Glucose disposal rate is a sensitive laboratory procedure for determining how your body uses sugar (called insulin sensitivity).

Estimated Enrollment: 66
Study Start Date: January 2012
Estimated Study Completion Date: December 2016
Estimated Primary Completion Date: December 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: RYGB
Roux-en-Y gastric bypass surgery (RYGB) subjects to undergo hyperinsulinemic-euglycemic clamp with human ghrelin infusion pre-operatively and post-operatively.
Drug: human ghrelin
0.5-1 pmol/kg.min of human ghrelin administered by IV two times
Procedure: Hyperinsulinemic/Euglycemic Clamp
Insulin and glucose infusions to measure glucose kinetics.
Experimental: VSG
Vertical sleeve gastrectomy (VSG) subjects to undergo hyperinsulinemic-euglycemic clamp pre-operatively and post-operatively.
Procedure: Hyperinsulinemic/Euglycemic Clamp
Insulin and glucose infusions to measure glucose kinetics.
Experimental: Low Calorie Diet
Subjects will receive very low calorie diet prescribed for RYGB patients and undergo hyperinsulinemic-euglycemic before and after diet.
Other: very low calorie diet
standard very low calorie diet that is prescribed for all RYGB patients after their operation
Procedure: Hyperinsulinemic/Euglycemic Clamp
Insulin and glucose infusions to measure glucose kinetics.


Ages Eligible for Study:   18 Years to 65 Years   (Adult)
Genders Eligible for Study:   All
Accepts Healthy Volunteers:   No


Inclusion Criteria:

  • Age 18-65 years
  • BMI ≥ 35 kg/m^2
  • Scheduled for bariatric surgery
  • Considering bariatric surgery
  • Waiting for insurance approval for bariatric surgery
  • Currently not considering bariatric surgery, but otherwise eligible
  • Enrollment in medical weight loss program

Exclusion Criteria:

  • Smoking >7 cigarettes per day
  • Precious malabsorptive or restrictive intestinal surgery
  • Pregnant or breastfeeding
  • Recent history of neoplasia (5<years ago)
  • Malabsorptive syndromes
  • Inflammatory intestinal disease
  • Established organ disfunction
  • Allergy to acetaminophen
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01474785

United States, Tennessee
Vanderbilt University Medical Center
Nashville, Tennessee, United States, 34232
Sponsors and Collaborators
Vanderbilt University
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Principal Investigator: Naji Abumrad, MD Vanderbilt University Medical Center
Study Director: Robyn Tamboli, PhD Vanderbilt University Medical Center
  More Information

Responsible Party: Naji Abumrad, Professor of Surgery, Chairman Department of Surgery, Vanderbilt University Identifier: NCT01474785     History of Changes
Other Study ID Numbers: #111237  R01DK091748 
Study First Received: November 15, 2011
Last Updated: September 22, 2016
Health Authority: United States: Food and Drug Administration

Keywords provided by Vanderbilt University:
Bariatric surgery
Nashville, Tennessee processed this record on January 18, 2017