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Enrolling by Invitation

NCT Number: NCT03407833

Physiologic and Functional Adaptations of Insulin Sensitive Tissues

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.

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Key information

Conditions

Diabetes Bariatric Surgery Candidate Body Weight Diabetes Mellitus Digestive System Diseases Endocrine System Diseases Glucose Metabolism Disorders Hyperinsulinism Insulin Resistance Liver Diseases Metabolic Diseases Nutrition Disorders Nutritional and Metabolic Diseases Obesity Overnutrition Overweight Pathological Conditions, Signs and Symptoms Roux-en-y Gastric Bypass Signs and Symptoms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Vanderbilt University Medical Center

Nashville, Tennessee, 37232, United States

About this study

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

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 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

Exclusion criteria

  • 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)
  • 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

Treatment and study plan

Endoscopy biopsy

Other

Tissue samples will be collected from the jejunum, duodenum, and colon during the subject's standard of care procedure.

Surgical biopsy

Other

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 test

Other

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 Sampling

Other

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.

Primary outcomes

  1. Ability to establish organoid cultures

    Time frame: 12 months

    Measure percent success rate of making organoid cultures from tissue biopsies

Sponsors and collaborators

Lead sponsor

Vanderbilt University Medical Center

Other

Registry information

Official study title

Physiologic and Functional Adaptations of Insulin Sensitive Tissues After Bariatric Surgery

Important dates

Study start
2018
Primary completion
2028
Study completion
2028
First posted
Jan 23, 2018
Registry last updated
Dec 18, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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