DiabetesNCT03407833
Physiologic and Functional Adaptations of Insulin Sensitive Tissues
An observational study of Diabetes and Insulin Resistance, run by Vanderbilt University Medical Center at 1 site in United States.
Trial summary
The long-term goal is to understand the mechanisms of intestinal nutrient sensing and signal relays to insulin sensitive tissues (adipose, skeletal muscle, liver) in humans. The investigators hypothesize that human tissue biopsies (from obese surgery and non-surgery subjects as well as lean controls) can be used to… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Diabetes, Insulin Resistance, Obesity
- What is being tested?
- Endoscopy biopsy, Surgical biopsy and Mixed-meal tolerance test
- Type of treatment
- Injection or infusion
- How many people
- 500 participants
- Where
- 1 siteUnited States
- Study dates
- 13 Feb 2018to Feb 2028
- Phase
- Observational
- 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Obese or lean subjects seen in the Vanderbilt Endoscopy Clinic, obese subjects planning surgery at the Center for Surgical Weight Loss, or obese or lean subjects planning liver transplantation surgery will be approached by research staff to participate in the study.
Who may be able to join
- Scheduled for upper endoscopy, colonoscopy or metabolic and bariatric surgery, or liver transplantation at Vanderbilt University Medical Center.
- Additional inclusion criteria for individuals scheduled for metabolic and bariatric surgery: Obese, ≥ 40 kg/m2 or ≥ 35 kg/m2 + one comorbidity (type 2 diabetes [fasting blood glucose ≥ 120 mg/dL; HbA1C ≥ 6.5%]; fatty liver disease, hypertension, cardiovascular disease, hyperlipidemia)
- Additional inclusion criteria for individuals scheduled for liver transplantation: diagnosis of nonalcoholic liver disease or nonalcoholic steatohepatitis
Who cannot join
- Known history of intestinal diseases including, but not limited to, inflammatory bowel disease (e.g. ulcerative colitis, Crohn's disease) and celiac sprue.
- Smoking >7 cigarettes per day
- Malabsorptive syndromes
- Pregnant or breastfeeding
- Additional exclusion criteria for patients undergoing endoscopy/colonoscopy:
- Recent history of malignancy (<5 years ago)
Show all 15Show fewer
- Previous lap band surgery
- Established renal disease
- Additional exclusion criteria for patients undergoing bariatric surgery:
- Previous lap band, sleeve gastrectomy, or gastric bypass surgery
- Recent history of malignancy (< 5 years ago)
- Established organ dysfunction
- Additional exclusion criteria for patients undergoing liver transplantation:
- Previous lap band, sleeve gastrectomy, or gastric bypass surgery
- Alpha 1 anti-trypsin disease, Wilson's disease, viral hepatitis, alcoholic liver disease
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
Vanderbilt University Medical Center
Nashville, Tennessee, 37232
About this study
Official title: Physiologic and Functional Adaptations of Insulin Sensitive Tissues After Bariatric Surgery
The long-term goal is to understand the mechanisms of intestinal nutrient sensing and signal relays to insulin sensitive tissues (adipose, skeletal muscle, liver) in humans. The investigators hypothesize that human tissue biopsies (from obese surgery and non-surgery subjects as well as lean controls) can be used to understand the molecular mechanisms underlying intestinal nutrient sensing and signal relay in humans. The investigator will obtain tissue specimens from patients during scheduled upper endoscopies, colonoscopies and scheduled metabolic and bariatric surgeries or liver transplantation. A blood sample (4mL) will be obtained concurrent with these procedures. From metabolic and bariatric surgery subjects blood and tissues (liver, adipose, small intestine, omentum, skeletal muscle) can be collected at the time of surgery. From liver transplantation patients, excised liver tissue will be collected. Stool can be obtained preoperatively and at various time points after surgery. Some bariatric surgery subjects will participate in a mixed-meal tolerance test at their pre-operative visit and several post-operative visits to compare the whole-body metabolic alterations following bariatric procedures.
Read the detailed description
Upper endoscopy (subset)
- Intestinal biopsies will be obtained during scheduled upper endoscopy from the mid-duodenum and/or proximal jejunum. In the case that a patient requires an upper endoscopy after metabolic and bariatric surgery, biopsies will be obtained from the mid-jejunum.
- Blood will be collected from an IV placed in the arm used for administering anesthesia required for the indicated procedure.
Colonoscopy (subset)
- Biopsies of the colon will be obtained during scheduled colonoscopy.
- Blood will be collected from an IV placed in the arm used for administering anesthesia required for the indicated procedure.
Metabolic and bariatric surgery (subset)
- During the metabolic and bariatric surgical procedures, biopsy of the jejunum, liver and omentum (visceral adipose) may be obtained. Biopsies of skeletal muscle and subcutaneous adipose will be taken at the sites of trocar placement for laparotomy.
- Blood will be collected from an IV placed in the arm used for administering anesthesia required for the indicated procedure.
- Feces will be self-collected by the patient using a provided culture swab specimen container or FOB card.
Liver transplantation (subset)
- Tissue will be collected from excised disease liver
- Conditions
- Diabetes, Insulin Resistance, Obesity, Bariatric Surgery Candidate, Roux-en-y Gastric Bypass, Liver Diseases
- Being tested
- Endoscopy biopsy, Surgical biopsy, Mixed-meal tolerance test, Excised Liver Tissue Sampling
- Medical subject headings
- Diabetes Mellitus, Insulin Resistance, Obesity, Liver Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Endoscopy biopsyOther
Tissue samples will be collected from the jejunum, duodenum, and colon during the subject's standard of care procedure.
Surgical biopsyOther
Biopsy of the liver is standard of care for diagnosing NAFLD. Biopsy of omentum, skeletal muscle and subcutaneous adipose (the latter two tissues taken at the site of trocar placement) will be collected intraoperatively at the time of Roux-en-Y gastric bypass (RYGB) or vertical sleeve gastrectomy (VSG).
Mixed-meal tolerance testOther
The mixed meal tolerance test (MMTT) shows how much insulin your body is making after drinking a liquid meal beverage that contains fats, protein and carbohydrates (sugar). Glucose, C-peptide, free fatty acids, triglycerides, incretins, pancreatic polypertide, bile aceis, and fatty acid amides can also be measured. A total of 9 tablespoons of blood is taken over a 255 minute period.
Excised Liver Tissue SamplingOther
Tissue will be collected from the excised liver for research after the diseased liver has been removed as part of the standard of care procedure.
| Study group | Role | What they receive |
|---|---|---|
| Obese, surgery | Obese subjects recruited from the Center for Surgical Weight loss who are undergoing weight loss surgery as part of their standard of care. Tissue biopsies, blood, and fecal swabs will be collected at surgical visits. Receives: Other: Surgical biopsy; Other: Mixed-meal tolerance test | |
| Obese, nonsurgery | Obese subjects recruited from the Vanderbilt Endoscopy Clinic who are undergoing upper endoscopy or colonoscopy as part of their standard of care. Tissue biopsies, blood, and fecal swabs will be collected at day of procedure. Receives: Other: Endoscopy biopsy | |
| Lean control | Lean control subjects recruited from the Vanderbilt Endoscopy Clinic who are undergoing upper endoscopy or colonoscopy as part of their standard of care. Tissue biopsies, blood, and fecal swabs will be collected at day of procedure. Receives: Other: Endoscopy biopsy | |
| Liver transplant | Lean or obese subjects who are undergoing liver transplantation as part of their standard of care. Excised liver tissue will be collected the day of procedure. Receives: Other: Excised Liver Tissue Sampling |
What is being measured
The primary outcome is the main question the study is designed to answer.
Ability to establish organoid cultures
Measure percent success rate of making organoid cultures from tissue biopsies
Measured: 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jan 2018
- Study start13 Feb 2018
- Primary completionFeb 2028 (estimated)
- Study completionFeb 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for DiabetesStudies of the same condition, open and under way.
- More trials run by Vanderbilt University Medical CenterThe 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
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 500 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Vanderbilt University Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Charles R. Flynn, Vanderbilt University Medical Center
- Investigators
- Charles Flynn, Ph.D., Principal investigator, Vanderbilt University Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03407833
- Sponsor's protocol ID
- 171845
- Status last verified
- Dec 2025
- First submitted
- 4 Jan 2018
- Last updated
- 18 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 18 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Physiologic and Functional Adaptations of Insulin Sensitive Tissues After Bariatric Surgery
- ClinicalTrials.gov ID
- NCT03407833
- Acronym / sponsor ID
- 171845
- Conditions
- Diabetes, Insulin Resistance, Obesity, Bariatric Surgery Candidate, Roux-en-y Gastric Bypass, Liver Diseases
- Study type
- Observational
- Recruitment status
- Enrolling by invitation
- Enrolment
- 500 participants (estimated)
- Lead sponsor
- Vanderbilt University Medical CenterUniversity, hospital or other
- Study start
- 13 Feb 2018 (actual)
- Primary completion
- Feb 2028 (estimated)
- Study completion
- Feb 2028 (estimated)
- First posted
- 23 Jan 2018 (actual)
- 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.
The long-term goal is to understand the mechanisms of intestinal nutrient sensing and signal relays to insulin sensitive tissues (adipose, skeletal muscle, liver) in humans. The investigators hypothesize that human tissue biopsies (from obese surgery and non-surgery subjects as well as lean controls) can be used to understand the molecular mechanisms underlying intestinal nutrient sensing and signal relay in humans. The investigator will obtain tissue specimens from patients during scheduled upper endoscopies, colonoscopies and scheduled metabolic and bariatric surgeries or liver transplantation. A blood sample (4mL) will be obtained concurrent with these procedures. From metabolic and bariatric surgery subjects blood and tissues (liver, adipose, small intestine, omentum, skeletal muscle) can be collected at the time of surgery. From liver transplantation patients, excised liver tissue will be collected. Stool can be obtained preoperatively and at various time points after surgery. Some bariatric surgery subjects will participate in a mixed-meal tolerance test at their pre-operative visit and several post-operative visits to compare the whole-body metabolic alterations following bariatric procedures.
Detailed description
Upper endoscopy (subset)
- Intestinal biopsies will be obtained during scheduled upper endoscopy from the mid-duodenum and/or proximal jejunum. In the case that a patient requires an upper endoscopy after metabolic and bariatric surgery, biopsies will be obtained from the mid-jejunum.
- Blood will be collected from an IV placed in the arm used for administering anesthesia required for the indicated procedure.
Colonoscopy (subset)
- Biopsies of the colon will be obtained during scheduled colonoscopy.
- Blood will be collected from an IV placed in the arm used for administering anesthesia required for the indicated procedure.
Metabolic and bariatric surgery (subset)
- During the metabolic and bariatric surgical procedures, biopsy of the jejunum, liver and omentum (visceral adipose) may be obtained. Biopsies of skeletal muscle and subcutaneous adipose will be taken at the sites of trocar placement for laparotomy.
- Blood will be collected from an IV placed in the arm used for administering anesthesia required for the indicated procedure.
- Feces will be self-collected by the patient using a provided culture swab specimen container or FOB card.
Liver transplantation (subset)
- Tissue will be collected from excised disease liver
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Obese, surgery | – | Other: Surgical biopsy, Other: Mixed-meal tolerance testObese subjects recruited from the Center for Surgical Weight loss who are undergoing weight loss surgery as part of their standard of care. Tissue biopsies, blood, and fecal swabs will be collected at surgical visits. |
| Obese, nonsurgery | – | Other: Endoscopy biopsyObese subjects recruited from the Vanderbilt Endoscopy Clinic who are undergoing upper endoscopy or colonoscopy as part of their standard of care. Tissue biopsies, blood, and fecal swabs will be collected at day of procedure. |
| Lean control | – | Other: Endoscopy biopsyLean control subjects recruited from the Vanderbilt Endoscopy Clinic who are undergoing upper endoscopy or colonoscopy as part of their standard of care. Tissue biopsies, blood, and fecal swabs will be collected at day of procedure. |
| Liver transplant | – | Other: Excised Liver Tissue SamplingLean or obese subjects who are undergoing liver transplantation as part of their standard of care. Excised liver tissue will be collected the day of procedure. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Obese or lean subjects seen in the Vanderbilt Endoscopy Clinic, obese subjects planning surgery at the Center for Surgical Weight Loss, or obese or lean subjects planning liver transplantation surgery will be approached by research staff to participate in the study.
Key inclusion criteria (3 listed)
- Scheduled for upper endoscopy, colonoscopy or metabolic and bariatric surgery, or liver transplantation at Vanderbilt University Medical Center.
- Additional inclusion criteria for individuals scheduled for metabolic and bariatric surgery: Obese, ≥ 40 kg/m2 or ≥ 35 kg/m2 + one comorbidity (type 2 diabetes [fasting blood glucose ≥ 120 mg/dL; HbA1C ≥ 6.5%]; fatty liver disease, hypertension, cardiovascular disease, hyperlipidemia)
- Additional inclusion criteria for individuals scheduled for liver transplantation: diagnosis of nonalcoholic liver disease or nonalcoholic steatohepatitis
Key exclusion criteria (15 listed)
- Known history of intestinal diseases including, but not limited to, inflammatory bowel disease (e.g. ulcerative colitis, Crohn's disease) and celiac sprue.
- Smoking >7 cigarettes per day
- Malabsorptive syndromes
- Pregnant or breastfeeding
- Recent history of malignancy (<5 years ago)
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 |
|---|---|---|
| Endoscopy biopsyTissue samples will be collected from the jejunum, duodenum, and colon during the subject's standard of care procedure. | Other | Lean control, Obese, nonsurgery |
| Surgical biopsyBiopsy of the liver is standard of care for diagnosing NAFLD. Biopsy of omentum, skeletal muscle and subcutaneous adipose (the latter two tissues taken at the site of trocar placement) will be collected intraoperatively at the time of Roux-en-Y gastric bypass (RYGB) or vertical sleeve gastrectomy (VSG). | Other | Obese, surgery |
| Mixed-meal tolerance testThe mixed meal tolerance test (MMTT) shows how much insulin your body is making after drinking a liquid meal beverage that contains fats, protein and carbohydrates (sugar). Glucose, C-peptide, free fatty acids, triglycerides, incretins, pancreatic polypertide, bile aceis, and fatty acid amides can also be measured. A total of 9 tablespoons of blood is taken over a 255 minute period. | Other | Obese, surgery |
| Excised Liver Tissue SamplingTissue will be collected from the excised liver for research after the diseased liver has been removed as part of the standard of care procedure. | Other | Liver transplant |
Primary outcome
Ability to establish organoid cultures
Time frame: 12 months
Measure percent success rate of making organoid cultures from tissue biopsies
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 18 Dec 2025.
- Individual participant dataSharing planned: No
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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.
Charles Flynn, Ph.D. principal investigator
Vanderbilt University Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Diabetes and Insulin Resistance, run by Vanderbilt University Medical Center at 1 site 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 3 inclusion and 15 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: enrolling by invitation, as of the sponsor's last update on 18 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site 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.
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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Ability to establish organoid cultures (time frame: 12 months). 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 18 Dec 2025.