Post BariatricsurgeryEarly Phase 1NCT00992901
Role of Neural and Hormonal Regulation Factors on Insulin Secretion After Gastric Bypass Surgery
A Early Phase 1 study testing Exendin-(9-39), Atropine and GLP-1 and GIP in people with Post Bariatricsurgery and Hypoglycemia, run by The University of Texas Health Science Center at San Antonio at 2 sites in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Post Bariatricsurgery, Hypoglycemia
- What is being tested?
- Exendin-(9-39), Atropine and GLP-1 and GIP
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 160 participants
- Where
- 2 sitesUnited States
- Study dates
- Oct 2009to Aug 2027
- Phase
- Early Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
- For administration of atropine, the following exclusions also apply:
- History of glaucoma
- Uncontrolled hypertension (any subjects with BP>140/90 and history of dyslipidemia
Show all 10Show fewer
- 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
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States2 sites, 2 recruiting
- Recruiting
Texas Diabetes Institute - University Health System
San Antonio, Texas, 78207
Jennifer Foster, MSN, 210-450-8696, fosterj6@uthscsa.edu
Marzieh Salehi, MD, MS, 210-567-6691, salehi@uthscsa.edu
- Recruiting
South Texas Veterans Health Care System
San Antonio, Texas, 78229
Marzieh Salehi, 210-567-6691, salehi@uthscsa.edu
Jennifer Foster, MSN, 210-450-8696, fosterj6@uthscsa.edu
About this study
Official title: Hormonal and Neural Control of Insulin Secretion Following Gastric Bypass Surgery
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.
Read the detailed 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
- Being tested
- Exendin-(9-39), Atropine, GLP-1 and GIP
- Keywords
- gastric bypass surgery, glucose tolerance, Insulin response to meal ingestion, Gut hormone and neural response to meal ingestion
- Medical subject headings
- Hypoglycemia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Exendin-(9-39)Drug
Also called No other name for Exendin-(9-39)
A physiological study to evaluate the role of GLP-1 signaling in glucose tolerance and insulin secretion
AtropineDrug
Also called Atropine sulfate
A physiological study to evaluate the effect of neural activation on insulin secretion and glucose metabolism
GLP-1 and GIPDrug
Also called No other names for GLP-1 and GIP.
A physiological study to evaluate the beta-cell sensitivity to different doses of exogenous gut hormones
| Study group | Role | What they receive |
|---|---|---|
| Exendin-(9-39) | Experimental | To evaluate the role of GLP-1 signaling in glucose tolerance and insulin secretion Receives: Drug: Exendin-(9-39) |
| atropine | Experimental | To evaluate the effect of neural activation on insulin secretion and glucose metabolism Receives: Drug: Atropine |
| GLP-1 and GIP | Experimental | to evaluate the beta-cell sensitivity to different doses of exogenous gut hormones Receives: Drug: GLP-1 and GIP |
What is being measured
The primary outcome is the main question the study is designed to answer.
Gut hormones and neural signaling contribution to insulin secretion rate and glucose tolerance
Measured: Each study of the protocol is conducted up to seven hours with data collected at intervals specific to the individual study procedure.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Oct 2009 (estimated)
- Study startOct 2009
- Primary completionAug 2026 (estimated)
- Study completionAug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Post BariatricsurgeryStudies of the same condition, open and under way.
- More trials run by The University of Texas Health Science Center at San AntonioThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 160 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Marzieh Salehi, MD, MS, Principal investigator, Marzieh Salehi
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00992901
- Sponsor's protocol ID
- 18-070H
- Other IDs
- DK083554
- Status last verified
- Sep 2025
- First submitted
- 7 Oct 2009
- Last updated
- 9 Sep 2025
- Results posted
- No
- Data monitoring committee
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Hormonal and Neural Control of Insulin Secretion Following Gastric Bypass Surgery
- ClinicalTrials.gov ID
- NCT00992901
- Acronym / sponsor ID
- 18-070H
- Conditions
- Post Bariatricsurgery, Hypoglycemia
- Keywords
- gastric bypass surgery, glucose tolerance, Insulin response to meal ingestion, Gut hormone and neural response to meal ingestion
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 160 participants (estimated)
- Lead sponsor
- The University of Texas Health Science Center at San AntonioUniversity, hospital or other
- Study start
- Oct 2009
- Primary completion
- Aug 2026 (estimated)
- Study completion
- Aug 2027 (estimated)
- First posted
- 9 Oct 2009 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed 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
Study design
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Exendin-(9-39) | Experimental | Drug: Exendin-(9-39)To evaluate the role of GLP-1 signaling in glucose tolerance and insulin secretion |
| atropine | Experimental | Drug: AtropineTo evaluate the effect of neural activation on insulin secretion and glucose metabolism |
| GLP-1 and GIP | Experimental | Drug: GLP-1 and GIPto evaluate the beta-cell sensitivity to different doses of exogenous gut hormones |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- 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
Key exclusion criteria (10 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Exendin-(9-39)Also: No other name for Exendin-(9-39)A physiological study to evaluate the role of GLP-1 signaling in glucose tolerance and insulin secretion | Drug | Exendin-(9-39) |
| AtropineAlso: Atropine sulfateA physiological study to evaluate the effect of neural activation on insulin secretion and glucose metabolism | Drug | atropine |
| GLP-1 and GIPAlso: No other names for GLP-1 and GIP.A physiological study to evaluate the beta-cell sensitivity to different doses of exogenous gut hormones | Drug | GLP-1 and GIP |
Primary outcome
Gut hormones and neural signaling contribution to insulin secretion rate and glucose tolerance
Time frame: Each study of the protocol is conducted up to seven hours with data collected at intervals specific to the individual study procedure.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Sep 2025.
- Individual participant dataSharing planned: No
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Marzieh Salehi, MD, MS principal investigator
Marzieh Salehi
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Exendin-(9-39), Atropine and GLP-1 and GIP in people with Post Bariatricsurgery and Hypoglycemia, run by The University of Texas Health Science Center at San Antonio at 2 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 9 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Marzieh Salehi, MD MS (210-567-6691, salehi@uthscsa.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Gut hormones and neural signaling contribution to insulin secretion rate and glucose tolerance (time frame: Each study of the protocol is conducted up to seven hours with data collected at intervals specific to the individual study procedure.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Sep 2025.