The Effect of Glucagon on Cerebral Glucose Metabolism in Healthy Humans

What Was Tested

In this not phased trial, researchers set out to test Glucagon.

This is a pilot study in which the investigators will investigate the effect of exogenous glucagon on cerebral glucose metabolism in healthy humans.

Participants will participate in either part C or part D of the study, and each participant will participate in three study days.

During a study day the participant will receive an intravenous infusion of either glucagon, glucose (in an adjustable rate to match to glucose concentrations achieved with the glucagon infusion) or saline.

It had six arms (groups): Acute effect (part C): Glucagon, Saline and Glucose Clamp (experimental), Acute effect (part C): Saline, Glucagon and Glucose Clamp (experimental), Acute effect (part C): Glucagon, Glucose Clamp and Saline (experimental), Later effect (part D): Glucagon, Saline and Glucose Clamp (experimental) and Later effect (part D): Saline, Glucagon and Glucose Clamp (experimental).

The arm includes three study days. Study day sequence: Glucagon, Saline and Glucose clamp. An 18F-FDG PET scan will be performed approximately 15-55 minutes after infusion start.

The arm includes three study days. Study day sequence: Saline, Glucagon and Glucose clamp. An 18F-FDG PET scan will be performed approximately 15-55 minutes after infusion start.

The arm includes three study days. Study day sequence: Glucagon, Glucose clamp and Saline. An 18F-FDG PET scan will be performed approximately 15-55 minutes after infusion start.

The registry classes the interventions as other.

More on the Plan

Participants in this study will participate in four visits; one screening visit and three study days.

Participants will be instructed to avoid strenuous exercise and alcohol intake two days prior to each experimental visit.

Participants will arrive at the Department of Clinical Physiology and Nuclear Medicine after an overnight (\>10 hours) fast (including coffee and medicine).

On all three study days, two peripheral venous catheters will be placed in the antecubital vein of each arm (one for the collection of blood samples and one for infusions).

Who Took Part

12 planned participants were the target.

It was open to people of any sex aged from 55 years up to 70 years.

Healthy volunteers could join, not only people with the condition.

Examples of who could join: Age 55 to 70 years. BMI under or equal to 30 kg/m2. Capable of understanding the participant information and signing the consent form.

The full record lists 3 inclusion and 14 exclusion criteria; among the exclusions: enrolment in other research projects that might interfere with the study; diabetes diagnosis (type 1 and 2); use of medications which, in the opinion of the investigator, may jeopardise participant's safety or compliance with the protocol.

How the Study Was Run

It was run as a randomized, crossover and open-label study.

Because people in this Glucagon study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

In the crossover set-up each of the participants took both Glucagon and the comparison in turn, acting as their own control.

Being open-label, the Glucagon study did not mask who received what.

It started in 2025-03-18 with completion listed for 2026-05.

It ran at 1 site in Denmark.

Its stated primary purpose is basic science.

What Was Measured

Primary outcome: Cerebral metabolic rate of glucose (CMRglc), acute effect (part C) (time frame: 15-55 minutes).

It also tracked 5 secondary outcomes, for example Cerebral metabolic rate of glucose (CMRglc), later effect (part D), Blood-brain glucose transfer capacity (Tmax), acute effect (part C), Blood-brain glucose transfer capacity (Tmax), later effect (part D), FDG net clearance (Ki), acute effect (part C) and FDG net clearance (Ki), later effect (part D).

What This Means in Plain Language

Put simply, this is a not phased, randomized trial of Glucagon in 12 people.

Its size is small, so on its own it can only give an early look.

Its status is active not recruiting; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Glucagon compound page, all human trials.