Nutrient Sensing in the Duodenum

Phase 1

Completed

• Conditions: The Effect of LCFA on Nutrient Absorption
• Interventions: Drug: Benzocaine Infusion into Duodenum

• Registration Number: NCT01694004
• Lead Sponsor: Vanderbilt University Medical Center

Brief Summary

Preliminary studies in humans suggest that the presence of lipids in the gut can modify glucose absorption. The overall hypothesis of this proposal is that long chain fatty acid sensing in the duodenum has a significant role in modifying nutrient (glucose and amino acid) absorption from the GI tract through a gut-brain-gut axis.

Detailed Description

The investigator will conduct a study in 20 lean (BMI = 19-27 kg/m2) subjects involving intravenous (IV) and intraduodenal (ID) infusions of glucose tracers or amino acid tracers and measurement of tracer rate of appearance in the plasma. An ID infusion of LCFA will allow the investigators to determine if LCFA can alter nutrient absorption and glucose and amino acid metabolism. Benzocaine will be added to the ID infusion of LCFA to inhibit nerve terminals in the duodenum thereby preventing gut-brain communication. Plasma levels of glucose and amino acid tracers, glucose oxidation (13CO2 breath test), gut hormones (CCK, GIP, PYY, GLP-1, ghrelin), and bioactive lipids (N-acyl phosphatidylethanolamines, NAPEs) will be measured during all infusion periods.

Study Timeline

• Study First Submitted: 2012-09-24
• Study First Submitted QC: 2012-09-24
• Study First Posted: 2012-09-26
• Study Start: 2012-11
• Primary Completion: 2014-10-27
• Study Completion: 2014-10-27
• Status Verified: 2024-04
• Last Update Submitted: 2024-04-09
• Last Update Posted: 2024-04-11

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 16

Inclusion Criteria

• BMI = 19-27 kg/m2
• 30-55 years of age

Exclusion Criteria

• Contraindication for nasal tube placement (e.g. deviated 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, Barrett's esophagus
• Type 1 or type 2 diabetes
• Gastroenteritis (diarrhea and/or vomiting) or constipation within the past week

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Benzocaine Infusion into Duodenum	Benzocaine Infusion into Duodenum	The investigator will conduct a study in 20 lean (BMI = 19-27 kg/m2) subjects involving intravenous (IV) and intraduodenal (ID) infusions of glucose tracers or amino acid traces and measurement of tracer rate of appearance in the plasma. An ID infusion of LCFA will allow the investigators to determine if LCFA can alter nutrient absorption and glucose and amino acid metabolism. Benzocaine will be added to the ID infusion of LCFA to inhibit nerve terminals in the duodenum thereby preventing gut-brain communication. Plasma levels of glucose and amino acid tracers, glucose oxidation (13CO2 breath test), gut hormones (CCK, GIP, PYY, GLP-1, ghrelin), and bioactive lipids (N-acyl phosphatidylethanolamines, NAPEs) will be measured during all infusion periods.

Primary Outcome Measures

Name	Time	Method
Nutrient Absorption	6 hours	Stable isotope tracers (glucose or amino acid) will be administered intravenously (IV) and intraduodenally (ID) and tracer rate of appearance in the plasma will be measured.

Secondary Outcome Measures

Name	Time	Method
Substrate Oxidation	6 hours	Oxidation of intraduodenally administered glucose or amino acid will be determined by the amount of 13C recovered from expired air.
Gut Hormone Levels	6 hours	Plasma levels of gut hormones will be measured by standard RIA or ELISA assays

Trial Locations

Locations (1)

Vanderbilt University Medical Center; 🇺🇸 Nashville, Tennessee, United States