Development and Evaluation of a Glucagon Sensitivity Test in Individuals With and Without Hepatic Steatosis

NCT ID: NCT04907721

Last Updated: 2023-10-24

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 65 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2021-05-27
• Study Completion Date: 2023-10-21

Brief Summary

Glucagon is secreted from pancreatic alpha-cells in response to protein-rich meals and during hypoglycemia. A physiological feedback system exists between the liver and the pancreatic alpha cells termed the liver-alpha cell axis and signifies the role between amino acid-stimulated glucagon secretion and glucagon-stimulated amino acid metabolism.

Individuals with non-alcoholic fatty liver disease have increased levels of glucagon (hyperglucagonemia) and amino acids (hyperaminoacidemia), which suggests that hepatic steatosis may uncouple glucagon's effect on amino acid metabolism (i.e. reduced glucagon sensitivity). Since hyperglucagonemia contributes to diabetes progression - due to its potentiating effects on hepatic glucose production - hepatic steatosis may create a diabetogenic circle. This study aims to develop and evaluate a test for measuring glucagon sensitivity in humans.

The investigators (Associate Prof. Nicolai J Wewer Albrechtsen and Prof. Jørgen Rungby) will investigate whether amino acid metabolism is attenuated in individuals with hepatic steatosis (assessed by magnetic resonance imaging) due to impaired hepatic glucagon sensitivity and if glucagon's effect on hepatic glucose production is intact compared to individuals without hepatic steatosis suggestive of biased signaling.

Detailed Description

Amino acids administered orally or intravenously stimulate glucagon secretion from the pancreas and in turn, glucagon is a powerful stimulus for hepatic amino acid turnover through transcriptional (long-term) and non- transcriptional (acute) mechanisms. Several groups including the investigators have linked glucagon secretion to hepatic amino acid metabolism suggesting a mutual feedback cycle, termed the liver-alpha cell axis. A disruption of this axis, which has been shown both pharmacologically using glucagon receptor antagonists and genetically in glucagon receptor knockout mouse models, leads to increased glucagon (hyperglucagonemia) and amino acid (hyperaminoacidemia) concentrations. This phenotype is also evident in subjects with biopsy-verified metabolic dysfunction-associated steatotic liver disease (MASLD) independent of type 2 diabetes suggesting reduced hepatic glucagon sensitivity in the presence of hepatic steatosis. Glucagon increases amino acid catabolism by potentiating ureagenesis, a pathway exclusive to the liver, and hepatic accumulation of triglycerides may reduce glucagon's ability to augment amino acid turnover. Some amino acids are more potent in stimulating glucagon secretion (glucagonotropic amino acids), including alanine, and the glucagon-alanine index is currently used as a surrogate marker for the hepatic actions of glucagon on ureagenesis. The fate of amino acid turnover depends on both glucagon and insulin dynamics by stimulating amino acid catabolism and synthesis, respectively. Studying the effects of glucagon in individuals with type 1 diabetes will allow one to differentiate between the combined effects of glucagon and insulin compared to the effects of glucagon alone.

This study aims to explore hepatic glucagon sensitivity towards amino acid metabolism in individuals with and without hepatic steatosis (based on magnetic resonance imaging (MRI)).

The investigators hypothesize that the effect of endogenous and exogenous glucagon on plasma amino acid levels are impaired in individuals with MASLD (based on hepatic steatosis measured by MRI) compared to controls.

The nomenclature for MASLD has recently been updated from non-alcoholic fatty liver disease (NAFLD) (https://pubmed.ncbi.nlm.nih.gov/37363821/).

Conditions

Non-Alcoholic Fatty Liver Disease; Glucagon Resistance; Type 1 Diabetes; Obesity

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Measuring glucagon sensitivity in humans

Participants will be subjected to two experimental days.

Group Type: EXPERIMENTAL

Glucagon Sensitivity test consisting of an amino acid tolerance test and a bolus infusion of glucagon

Intervention Type: DIAGNOSTIC_TEST

The test consists of two experimental study days:

Day 1: intravenous bolus-injection of glucagon (0.2 mg at time 0 minutes) evaluating the effect of exogenous glucagon on amino acid disappearance. Blood samples will be obtained from time -10 to 120 minutes.

Day 2: 45-minute intravenous infusion of mixed amino acids (331 mg/min/kg body weight from time 0-45 minutes) to evaluate the effect of endogenous glucagon on amino acid metabolism. Blood samples will be obtained from time -10 to 180 minutes.

All participants will be subjected to a magnetic resonance imaging scan to assess whole-liver steatosis, and a bioelectrical impedance analysis to assess body composition.

Following study inclusion and the magnetic resonance imaging scan, participants will be stratified into groups based on hepatic steatosis. Individuals with <5.6 % hepatic steatosis will be classified as controls and individuals with ≥5.6 % hepatic steatosis will be classified as MASLD.

Interventions

Glucagon Sensitivity test consisting of an amino acid tolerance test and a bolus infusion of glucagon

The test consists of two experimental study days:

Day 1: intravenous bolus-injection of glucagon (0.2 mg at time 0 minutes) evaluating the effect of exogenous glucagon on amino acid disappearance. Blood samples will be obtained from time -10 to 120 minutes.

Day 2: 45-minute intravenous infusion of mixed amino acids (331 mg/min/kg body weight from time 0-45 minutes) to evaluate the effect of endogenous glucagon on amino acid metabolism. Blood samples will be obtained from time -10 to 180 minutes.

All participants will be subjected to a magnetic resonance imaging scan to assess whole-liver steatosis, and a bioelectrical impedance analysis to assess body composition.

Following study inclusion and the magnetic resonance imaging scan, participants will be stratified into groups based on hepatic steatosis. Individuals with <5.6 % hepatic steatosis will be classified as controls and individuals with ≥5.6 % hepatic steatosis will be classified as MASLD.

Intervention Type: DIAGNOSTIC_TEST

Eligibility Criteria

Inclusion Criteria

• BMI = 18.6-25 kg/m2
• Male or female
• 25-65 years of age

• BMI = 25-40 kg/m2
• Male or female
• 25-65 years of age

• BMI = 18.6-40 kg/m2
• Male or female
• C-peptide negative
• Insulin pump user
• 25-65 years of age

Exclusion Criteria

• Diabetes (ADA criteria)
• Significant alcohol/drug abuse as per investigators judgement
• Amino acid-related diseases such as phenylketonuria
• Kidney disease
• Cardiac problems
• Cancer within the past 1 year
• Severe claustrophobia
• Pacemaker or other non-MR-compatible devices
• Pregnancy or breastfeeding.
• Fib4 score > 3.25.
• Any medicine, acute illness (within the last two weeks) or other circumstances that in the opinion of the investigator might endanger the participants' safety or compliance with the protocol

Group 2 (overweight and obese individuals)

• Diabetes (ADA criteria)
• Significant alcohol/drug abuse as per investigators judgement
• Amino acid-related diseases such as phenylketonuria
• Kidney disease
• Cardiac problems
• Cancer within the past 1 year
• Severe claustrophobia
• Pacemaker or other non-MR-compatible devices
• Pregnancy or breastfeeding
• Abdominal diameter >70 cm
• Fib4 score > 3.25.
• Any medicine, acute illness (within the last two weeks) or other circumstances that in the opinion of the investigator might endanger the participants' safety or compliance with the protocol

Group 3 (individuals with type 1 diabetes)

• Type 2 diabetes
• Closed loop user
• Microalbuminuria (30-300 mg/g)
• Significant alcohol/drug abuse as per investigators judgement
• Amino acid-related diseases such as phenylketonuria
• Kidney disease
• Cardiac problems
• Cancer within the past 1 year
• Severe claustrophobia
• Pacemaker or other non-MR-compatible devices
• Pregnancy or breastfeeding
• Abdominal diameter >70 cm
• Fib4 score > 3.25.
• Any medicine, acute illness (within the last two weeks) or other circumstances that in the opinion of the investigator might endanger the participants' safety or compliance with the protocol

Following inclusion and study completion, our two groups of lean individuals (n=20) and overweight and obese individuals (n=30) will be stratified into two groups based on liver fat content assessed by the magnetic resonance imaging scan. Individuals with <5.6% hepatic steatosis will be allocated to the control group and individuals with ≥5.6% hepatic steatosis to the MASLD group.

• Minimum Eligible Age: 25 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Bispebjerg Hospital

OTHER

Sponsor Role: collaborator

Rigshospitalet, Denmark

OTHER

Sponsor Role: collaborator

University of Copenhagen

OTHER

Sponsor Role: lead

Responsible Party

Nicolai Jacob Wewer Albrechtsen

Associate Professor, MD, PhD

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Bispebjerg University Hospital

Copenhagen, , Denmark

Countries

Denmark

Provided Documents

Document Type: Statistical Analysis Plan

View Document

Other Identifiers

GLUSENTIC

Identifier Type: -

Identifier Source: org_study_id