Glucagon-like Peptide 1, Glucose Metabolism and Gastric Bypass

Purpose

The overall goal of this project is to understand the mechanisms by which gastric bypass surgery improves glucose metabolism. The central hypothesis guiding this project is that the reconfiguration of intestinal transit with the Roux-en-Y will increase the release of insulinotropic GI hormones, termed incretins that improve insulin secretion and glucose metabolism. The study is divided into three specific aims. 1. To determine the role of incretin hormones on insulin secretion in patients with gastric bypass surgery using intravenous-oral hyperglycemic clamp. 2. To compare incretin effect and glucose tolerance among patient who suffer from hypoglycemia after RYGB and asymptomatic surgical and non-surgical individuals. 3. To quantify the contribution of GLP-1 to incretin effect enhancement following surgery.

Condition

  • Post-bariatric Surgery

Eligibility

Eligible Ages
Between 18 Years and 65 Years
Eligible Genders
All
Accepts Healthy Volunteers
Yes

Inclusion Criteria

  • age 18-65 - healthy control without diabetes or active organ disease - Individuals with bariatric surgery - recurrent hypoglycemia post gastric bypass

Exclusion Criteria

  • pregnancy - significant anemia - diabetes currently unless pre-op for bariatric surgery procedure - GI obstruction

Study Design

Phase
Early Phase 1
Study Type
Interventional
Allocation
Non-Randomized
Intervention Model
Factorial Assignment
Primary Purpose
Other
Masking
Single (Participant)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
hyperglycemic clamp-Meal tolerance test 		these studies are to evaluate the effect of exendin-9 on insulin secretion before and after meal ingestion in patients after bariatric surgeries compared to non-surgical controls
  • Drug: exendin-(9-39)
    hyperglycemic clamp-meal tolerance test is designed to assess insulin secretion before and after meal ingestion
    Other names:
    • no other name for exendin-(9-39)
Experimental
Labeled meal tolerance test 		The effect of GLP-1 receptor blockade on glucose tolerance and glucose kinetics are evaluated in the group patients with bariatric surgery vs. nonsurgical using exendin-9-39 infusion during one of the the 2-day dual tracer studies of meal tolerance test
  • Drug: exendin -(9-39)
    2-day meal tolerance tests with labeled oral and IV glucose using exendin-(9-39) infusion are designed to evaluate the role of GLP-1 signaling on glucose tolerance and glucose kinetics.
    Other names:
    • no other name for exendin-(9-39)

Recruiting Locations

Texas Diabetes Institute - University Health System
San Antonio, Texas 78207
Contact:
Andrea Hansis-Diarte, MPh
210-567-6691
hansisdiarte@uthscsa.edu

South Texas Veterans Health Care System
San Antonio, Texas 78229
Contact:
Marzieh Salehi, MD MS
210-567-6691
salehi@uthscsa.edu

More Details

Status
Recruiting
Sponsor
The University of Texas Health Science Center at San Antonio

Study Contact

Marzieh Salehi, MD MS
210-567-6691
salehi@uthscsa.edu

Detailed Description

The overall goal of this project is to understand the mechanisms by which gastric bypass surgery improves glucose metabolism. The central hypothesis guiding this project is that the reconfiguration of intestinal transit with the Roux-en-Y will increase the release of insulinotropic GI hormones, termed incretins that improve insulin secretion and glucose metabolism. The study is divided into three specific aims. 1. To determine the role of incretin hormones on insulin secretion in patients with gastric bypass surgery using intravenous-oral hyperglycemic clamp. 2. To compare incretin effect and glucose tolerance among patient who suffer from hypoglycemia after RYGB and asymptomatic surgical and non-surgical individuals. 3. To quantify the contribution of GLP-1 to incretin effect enhancement following surgery.