Hormonal and Neural Control of Insulin Secretion Following Gastric Bypass Surgery
The University of Texas Health Science Center at San Antonio
Summary
RYGB (roux-en-y gastric bypass) has been reported to reverse type 2 diabetes (T2DM) immediately after surgery before any significant weight loss. In addition, a growing number of patients have been recognized with life-threatening hyperinsulinemic hypoglycemia several years following their surgery. While the mechanisms by which RYGB improves glucose metabolism or alters islet cell function in patients after RYGB are not understood, recent studies suggest that increased secretion of GI hormones, primarily glucagon-like peptide 1 (GLP-1), as well as alteration in neural activity may contribute to enhanced insulin secretion in general, and to a greater extent in patients with hypoglycemia. The proposed research is designed to address the role of RYGB on insulin secretion by evaluating the contribution of stimulatory factors (neural and GI hormone) on islet cell function and the islet cell responsiveness to the physiologic stimulatory factors, in RYGB patients with and without hypoglycemia and non-operated controls.
Description
RYGB (roux-en-y gastric bypass) has been reported to reverse type 2 diabetes (T2DM) immediately after surgery before any significant weight loss. In addition, a growing number of patients have been recognized with life-threatening hyperinsulinemic hypoglycemia several years following their surgery. While the mechanisms by which RYGB improves glucose metabolism or alters islet cell function in patients after RYGB are not understood, recent studies suggest that increased secretion of GI hormones, primarily glucagon-like peptide 1 (GLP-1), as well as alteration in neural activity may contribute t…
Eligibility
- Age range
- 18–65 years
- Sex
- All
- Healthy volunteers
- Yes
Inclusion Criteria: * Hypoglycemic RYGB patients with documented blood glucose level \<50 mg/dl * Asymptomatic individuals with bariatric surgery * Healthy non-surgical patients with no personal history of diabetes * Subjects must physically be able to come to our clinical research center at Cedars-Sinai Medical Center Exclusion Criteria: * Active heart, lung, liver, gastrointestinal or kidney disease; unable to give informed consent; pregnancy; uncontrolled high blood pressure or high cholesterol; significant anemia (hemoglobin \<11g/dL); prisoners or institutionalized individuals; type 2…
Interventions
- DrugExendin-(9-39)
A physiological study to evaluate the role of GLP-1 signaling in glucose tolerance and insulin secretion
- DrugAtropine
A physiological study to evaluate the effect of neural activation on insulin secretion and glucose metabolism
- DrugGLP-1 and GIP
A physiological study to evaluate the beta-cell sensitivity to different doses of exogenous gut hormones
Locations (2)
- Texas Diabetes Institute - University Health SystemSan Antonio, Texas
- South Texas Veterans Health Care SystemSan Antonio, Texas