ObesityPhase 1NCT02537314
Role of the Foregut in Nutrient Metabolism in Lean and Obese Humans
A Phase 1 study testing benzocaine in people with Obesity, run by Vanderbilt University Medical Center at 1 site in United States.
Trial summary
The overall hypothesis of this proposal is that nutrient sensing in the foregut regulates metabolic hormone secretion and nutrient metabolism via enteric neural signals, and these mechanisms might be defective in obesity. Read more about this study
- Who is it for?
- Ages 20 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Obesity
- What is being tested?
- benzocaine
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 27 participants
- Where
- 1 siteUnited States
- Study dates
- Sep 2015to 8 Dec 2022
- Phase
- Phase 1
- Are there results?
- None posted in the registry
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 20 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- BMI 19 - 25 kg/m2 or 30 - 50 kg/m2
- Age 20 - 50 years
Who cannot join
- Contraindication to a nasoduodenal feeding tube (e.g., deviated nasal septum, prior upper gastrointestinal bleed, or history of easy bleeding)
- Prior gastric or intestinal surgery or pancreas resection
- Females with a positive pregnancy test
- Known history of intestinal diseases including, but not limited to, inflammatory bowel disease (e.g. ulcerative colitis, Crohn's disease), celiac sprue
- Type 1 or type 2 diabetes
- Recent presence of or treatment for gastroenteritis (diarrhea and/or vomiting), constipation, or upper respiratory infection
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- Anemia
- Abnormal electrocardiogram
- Prior adverse reaction to anesthesia
- Tobacco use
Trial locations and contacts
1 site in 1 country.
United States1 site
Vanderbilt University Medical Center
Nashville, Tennessee, 37232
About this study
The overall hypothesis of this proposal is that nutrient sensing in the foregut regulates metabolic hormone secretion and nutrient metabolism via enteric neural signals, and these mechanisms might be defective in obesity.
Read the detailed description
The study proposes two specific aims Aim 1 will determine if blocking enteric neuronal signaling will alter: a) circulating levels of nutrient substrates and secretion of hormones that regulate nutrient metabolism; and b) glucose and fatty acid absorption, production, and utilization.
Obese (BMI = 30-50 kg/m2) subjects will be studied. The topical anesthetic benzocaine will be infused into the duodenum prior to infusion of glucose and oleic acid into the duodenum. Duodenal infusions with a naso-intestinal feeding tube will circumvent the confounding effects of gastric emptying on the metabolic responses to a meal. Substrates (glucose, free fatty acids), and lipoproteins) and hormones will be measured by standard biochemical and immunological methods. Aim 2 will determine if enteric neural signals regulate appetite. The studies will be carried out in both lean and obese humans and the procedure will be performed as described above. In addition, the subjects will be asked to use a visual analog scale to estimate their level of appetite before, during and after enteral infusions.
- Conditions
- Obesity
- Being tested
- benzocaine, placebo
- Keywords
- Normal Body Weight
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
benzocaineDrug
Also called ethyl 4-aminobenzoate
0.5% benzocaine solution in saline/hydrochloric acid administered by intraduodenal infusion one time (6 ml bolus followed by 75 ml/hour for 105 minutes)
placeboOther
Also called NaCl, sodium chloride
Placebo (saline) solution administered by intraduodenal infusion one time (6 ml bolus followed by 75 ml/hour for 105 minutes)
| Study group | Role | What they receive |
|---|---|---|
| benzocaine | Active comparator | 0.5% benzocaine solution in saline/hydrochloric acid administered by intraduodenal infusion one time (6 ml bolus followed by 75 ml/hour for 105 minutes) Receives: Drug: benzocaine |
| placebo | Placebo comparator | Placebo (saline) solution administered by intraduodenal infusion one time (6 ml bolus followed by 75 ml/hour for 105 minutes) Receives: Other: placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Gastrointestinal Hormones
Plasma levels of Cholecystokinin, gastric inhibitory peptide and glucagon like peptide and Ghrelin
Measured: 5 Hours
Pancreatic Hormones
Plasma levels of Insulin, C-peptide, Glucagon
Measured: 5 Hours
Glucose and Free Fatty Acids
Plasma levels
Measured: 5 Hours
Secondary outcomes (2)
Glucose Metabolism
Glucose tracer kinetics ([3-tritiated] glucose and [U-13C-carbon] oleate)
Measured: 5 Hours
Fat Metabolism
Oleate tracer kinetics ([U-13 C-carbon] oleate)
Measured: 5 Hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Sep 2015 (estimated)
- Study startSep 2015
- Primary completion8 Dec 2022
- Study completion8 Dec 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for ObesityStudies 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
- Interventional
- Phase
- Phase 1
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 27 participants (actual)
Sponsor and investigators
- Lead sponsor
- Vanderbilt University Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Naji Abumrad, Vanderbilt University Medical Center
- Investigators
- Sinju Sundaresan, PhD, Principal investigator, Vanderbilt University Medical CenterNaji N Abumrad, MD, Principal investigator, Vanderbilt University Medical CenterKala Dixon, MS, Study director, Vanderbilt University Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02537314
- Sponsor's protocol ID
- 131032
- Other IDs
- R01DK100431
- Status last verified
- Jun 2026
- First submitted
- 25 Aug 2015
- Last updated
- 11 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
Publications
Sundaresan S, Johnson C, Dixon KB, Dole M, Kilkelly D, Antoun J, Flynn CR, Abumrad NN, Tamboli R. Intraduodenal nutrient infusion differentially alters intestinal nutrient sensing, appetite, and satiety responses in lean and obese subjects. Am J Clin Nutr. 2023 Sep;118(3):646-656. doi: 10.1016/j.ajcnut.2023.06.011. Epub 2023 Aug 8.
PubMed 37661107
Study at a glance
From the registry record, last updated by the sponsor on 11 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Role of the Foregut in Nutrient Metabolism in Lean and Obese Humans
- ClinicalTrials.gov ID
- NCT02537314
- Acronym / sponsor ID
- 131032
- Conditions
- Obesity
- Keywords
- Normal Body Weight
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 27 participants (actual)
- Lead sponsor
- Vanderbilt University Medical CenterUniversity, hospital or other
- Collaborators
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Study start
- Sep 2015
- Primary completion
- 8 Dec 2022 (actual)
- Study completion
- 8 Dec 2022 (actual)
- First posted
- 1 Sep 2015 (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.
The overall hypothesis of this proposal is that nutrient sensing in the foregut regulates metabolic hormone secretion and nutrient metabolism via enteric neural signals, and these mechanisms might be defective in obesity.
Detailed description
The study proposes two specific aims Aim 1 will determine if blocking enteric neuronal signaling will alter: a) circulating levels of nutrient substrates and secretion of hormones that regulate nutrient metabolism; and b) glucose and fatty acid absorption, production, and utilization.
Obese (BMI = 30-50 kg/m2) subjects will be studied. The topical anesthetic benzocaine will be infused into the duodenum prior to infusion of glucose and oleic acid into the duodenum. Duodenal infusions with a naso-intestinal feeding tube will circumvent the confounding effects of gastric emptying on the metabolic responses to a meal. Substrates (glucose, free fatty acids), and lipoproteins) and hormones will be measured by standard biochemical and immunological methods. Aim 2 will determine if enteric neural signals regulate appetite. The studies will be carried out in both lean and obese humans and the procedure will be performed as described above. In addition, the subjects will be asked to use a visual analog scale to estimate their level of appetite before, during and after enteral infusions.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| benzocaine | Active comparator | Drug: benzocaine0.5% benzocaine solution in saline/hydrochloric acid administered by intraduodenal infusion one time (6 ml bolus followed by 75 ml/hour for 105 minutes) |
| placebo | Placebo comparator | Other: placeboPlacebo (saline) solution administered by intraduodenal infusion one time (6 ml bolus followed by 75 ml/hour for 105 minutes) |
Who may qualify
- Ages
- 20 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- BMI 19 - 25 kg/m2 or 30 - 50 kg/m2
- Age 20 - 50 years
Key exclusion criteria (10 listed)
- Contraindication to a nasoduodenal feeding tube (e.g., deviated nasal septum, prior upper gastrointestinal bleed, or history of easy bleeding)
- Prior gastric or intestinal surgery or pancreas resection
- Females with a positive pregnancy test
- Known history of intestinal diseases including, but not limited to, inflammatory bowel disease (e.g. ulcerative colitis, Crohn's disease), celiac sprue
- Type 1 or type 2 diabetes
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 |
|---|---|---|
| benzocaineAlso: ethyl 4-aminobenzoate0.5% benzocaine solution in saline/hydrochloric acid administered by intraduodenal infusion one time (6 ml bolus followed by 75 ml/hour for 105 minutes) | Drug | benzocaine |
| placeboAlso: NaCl, sodium chloridePlacebo (saline) solution administered by intraduodenal infusion one time (6 ml bolus followed by 75 ml/hour for 105 minutes) | Other | placebo |
Primary outcome
Gastrointestinal Hormones
Time frame: 5 Hours
Plasma levels of Cholecystokinin, gastric inhibitory peptide and glucagon like peptide and Ghrelin
Pancreatic Hormones
Time frame: 5 Hours
Plasma levels of Insulin, C-peptide, Glucagon
Glucose and Free Fatty Acids
Time frame: 5 Hours
Plasma levels
2 secondary outcomes
Glucose Metabolism
Time frame: 5 Hours
Fat Metabolism
Time frame: 5 Hours
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Jun 2026.
- Background: PubMed 37661107Sundaresan S, Johnson C, Dixon KB, Dole M, Kilkelly D, Antoun J, Flynn CR, Abumrad NN, Tamboli R. Intraduodenal nutrient infusion differentially alters intestinal nutrient sensing, appetite, and satiety responses in lean and obese subjects. Am J Clin Nutr. 2023 Sep;118(3):646-656. doi: 10.1016/j.ajcnut.2023.06.011. Epub 2023 Aug 8.
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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. This study is not recruiting at the moment.
Sinju Sundaresan, PhD principal investigator
Vanderbilt University Medical Center
Naji N Abumrad, MD principal investigator
Vanderbilt University Medical Center
Kala Dixon, MS study director
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?
A Phase 1 study testing benzocaine in people with Obesity, 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 2 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: finished, as of the sponsor's last update on 11 Jun 2026. 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. Some participants in this study may receive a placebo. 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?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Gastrointestinal Hormones (time frame: 5 Hours). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02537314, which also lists 1 linked publication.
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 11 Jun 2026.