Measuring Amino Acid and Glucose Metabolism in Healthy Volunteers and NAFLD Patients Using Total-body PET

NCT07366710 | Active Not Recruiting

• 1 other identifier: 565_23
• Study Type: interventional
• Target: 36
• Locations: 1 country
• Sites: 1

Brief Summary

This observational study aims to quantify whole-body amino acid and glucose metabolism in healthy adults and in patients with non-alcoholic fatty liver disease (NAFLD) using total-body PET/CT. The study investigates how orally and intravenously administered PET tracers (18F-FDG and 18F-FET) are absorbed in the gastrointestinal tract, distributed across major organs, and metabolized in different physiological and pathological states. A further objective is to examine how glucagon, during a pancreatic clamp using somatostatin, influences amino acid metabolism in healthy individuals and whether this response is altered in patients with NAFLD. Participants will be healthy volunteers or patients with NAFLD, aged 18-70 years. Depending on study group, participants will undergo one or more total-body PET/CT scans following oral or intravenous tracer administration, and in some cases receive glucagon or placebo infusion. Blood samples will be collected during scanning to assess hormone levels and metabolic responses. Data from these imaging sessions will be used to characterize nutrient metabolism, compare oral and intravenous tracer kinetics, and explore glucagon-induced metabolic changes across study groups.

Conditions

Glucose Metabolism; NAFLD (Nonalcoholic Fatty Liver Disease)

Outcome Measures

Primary Outcomes (1)

• Whole-body tracer uptake (SUVmean) assessed using total-body PET/CT

  0-180 minutes after tracer administration

Study Arms (4)

Healthy Controls: FDG (oral & IV)

EXPERIMENTAL

Healthy volunteers receive 18F-FDG by oral administration and intravenous administration on separate study days, including an oral glucose tolerance test visit. Total-body PET/CT imaging is performed after each tracer administration.

Drug: 18F-FDG (oral); Drug: 18F-FDG (intravenous); Other: Oral Glucose Tolerance Test

Healthy Controls: FET (oral & IV)

EXPERIMENTAL

Healthy volunteers receive 18F-FET by oral administration and intravenous administration on separate study days. Dynamic and static total-body PET/CT imaging is performed.

Drug: 18F-FET (oral); Drug: 18F-FET (intravenous)

Healthy Controls: Oral FET + Glucagon/Somatostatin Clamp (Crossover)

EXPERIMENTAL

Healthy participants undergo two study days with oral \^18F-FET administration combined with either glucagon infusion during a pancreatic clamp (somatostatin infusion) or placebo. Total-body PET/CT imaging is performed using a crossover design.

Drug: 18F-FET (oral); Drug: Glucagon; Drug: Somatostatin; Drug: Sodium chloride (placebo)

NAFLD Patients: Oral FET + Glucagon/Somatostatin Clamp (Crossover)

EXPERIMENTAL

Participants with NAFLD undergo two study days with oral \^18F-FET administration combined with either glucagon infusion during a pancreatic clamp (somatostatin infusion) or placebo. Total-body PET/CT imaging is performed using a crossover design.

Drug: 18F-FET (oral); Drug: Glucagon; Drug: Somatostatin; Drug: Sodium chloride (placebo)

Interventions

18F-FDG (oral) DRUG

Oral administration of 18F-fluorodeoxyglucose (\^18F-FDG) for total-body PET/CT to assess gastrointestinal absorption, systemic biodistribution, and whole-body glucose metabolism.

Healthy Controls: FDG (oral & IV)

18F-FDG (intravenous) DRUG

Intravenous bolus administration of 18F-fluorodeoxyglucose (18F-FDG) for total-body PET/CT to measure systemic biodistribution and whole-body glucose metabolism.

Healthy Controls: FDG (oral & IV)

18F-FET (oral) DRUG

Oral administration of O-(2-\[18F\]fluoroethyl)-L-tyrosine (18F-FET) for total-body PET/CT to assess gastrointestinal amino acid absorption and whole-body amino acid metabolism.

Healthy Controls: FET (oral & IV); Healthy Controls: Oral FET + Glucagon/Somatostatin Clamp (Crossover); NAFLD Patients: Oral FET + Glucagon/Somatostatin Clamp (Crossover)

18F-FET (intravenous) DRUG

Intravenous bolus administration of O-(2-\[18F\]fluoroethyl)-L-tyrosine (18F-FET) for total-body PET/CT to measure systemic amino acid biodistribution and dynamic metabolic kinetics.

Healthy Controls: FET (oral & IV)

Glucagon DRUG

Continuous intravenous glucagon infusion to stimulate hepatic amino acid metabolism during a pancreatic clamp.

Healthy Controls: Oral FET + Glucagon/Somatostatin Clamp (Crossover); NAFLD Patients: Oral FET + Glucagon/Somatostatin Clamp (Crossover)

Somatostatin DRUG

Continuous intravenous somatostatin infusion to suppress endogenous pancreatic hormone secretion during the pancreatic clamp.

Healthy Controls: Oral FET + Glucagon/Somatostatin Clamp (Crossover); NAFLD Patients: Oral FET + Glucagon/Somatostatin Clamp (Crossover)

Sodium chloride (placebo) DRUG

Intravenous infusion of isotonic sodium chloride solution used as placebo during crossover comparison with glucagon infusion.

Healthy Controls: Oral FET + Glucagon/Somatostatin Clamp (Crossover); NAFLD Patients: Oral FET + Glucagon/Somatostatin Clamp (Crossover)

Oral Glucose Tolerance Test OTHER

Standard oral glucose load (75 g in 250 mL water) to assess glucose-stimulated metabolic responses during PET/CT.

Healthy Controls: FDG (oral & IV)

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 18-70 years
• Body mass index (BMI) 20-27 kg/m2

You may not qualify if:

• Pregnancy
• Claustrophobia
• Inability to give consent due to psychological or other causes
• Inability to speak/read Danish
• Diabetes, cancer (active or treated within the last five years) or inflammatory diseases.
• Low albumin
• Chronic disorders that require medical treatment

Sponsors & Collaborators

• Rigshospitalet, Denmark: lead

Study Sites (1)

Copenhagen University Hospital - Rigshospitalet

Copenhagen, 2100, Denmark

Location

MeSH Terms

Conditions

Non-alcoholic Fatty Liver Disease

Interventions

Fluorodeoxyglucose F18; (18F)fluoroethyltyrosine; Glucagon; Somatostatin; Sodium Chloride; Glucose Tolerance Test

Condition Hierarchy (Ancestors)

Fatty Liver; Liver Diseases; Digestive System Diseases

Intervention Hierarchy (Ancestors)

Deoxyglucose; Deoxy Sugars; Carbohydrates; Proglucagon; Pancreatic Hormones; Peptide Hormones; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Peptides; Amino Acids, Peptides, and Proteins; Pituitary Hormone Release Inhibiting Hormones; Hypothalamic Hormones; Neuropeptides; Nerve Tissue Proteins; Proteins; Chlorides; Hydrochloric Acid; Chlorine Compounds; Inorganic Chemicals; Sodium Compounds; Blood Chemical Analysis; Clinical Chemistry Tests; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Diagnostic Techniques, Endocrine; Investigative Techniques

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Physician

Study Record Dates

• First Submitted: January 16, 2026
• First Posted: January 26, 2026
• Study Start: November 5, 2024
• Primary Completion (Estimated): October 1, 2027
• Study Completion (Estimated): October 1, 2027
• Last Updated: February 2, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

DK (1)