Role of Neural and Hormonal Regulation Factors on Insulin Secretion After Gastric Bypass Surgery

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 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.

Conditions

Post Bariatricsurgery, Hypoglycemia

Study Overview

Study Details

Study overview

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.

Hormonal and Neural Control of Insulin Secretion Following Gastric Bypass Surgery

Role of Neural and Hormonal Regulation Factors on Insulin Secretion After Gastric Bypass Surgery

Condition
Post Bariatricsurgery
Intervention / Treatment

-

Contacts and Locations

San Antonio

Texas Diabetes Institute - University Health System, San Antonio, Texas, United States, 78207

San Antonio

South Texas Veterans Health Care System, San Antonio, Texas, United States, 78229

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

For general information about clinical research, read Learn About Studies.

Eligibility 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
  • * 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 diabetes melitis; development of any serious medical or psychiatric illness during recruitment or studies;
  • * RYGB patients will also be disqualified if they have gastric outlet obstruction or severe diarrhea
  • * Healthy non-surgical patients with personal history of diabetes
  • * History of glaucoma
  • * Uncontrolled hypertension (any subjects with BP\>140/90 and history of dyslipidemia
  • * Taking any medication that might interact with atropine and cannot be stopped will be excluded from the study)
  • * Myasthenia gravis
  • * Brain pathology
  • * Enlarged prostate in men

Ages Eligible for Study

18 Years to 65 Years

Sexes Eligible for Study

ALL

Accepts Healthy Volunteers

Yes

Collaborators and Investigators

The University of Texas Health Science Center at San Antonio,

Marzieh Salehi, MD, MS, PRINCIPAL_INVESTIGATOR, Marzieh Salehi

Study Record Dates

2026-08