Glucagon Decreases IGF-1 Bioactivity in Humans, Independently of Insulin, by Modulating Its Binding Proteins

What Was Tested

The paper reports a study of IGF-1 LR3 and Glucagon, published as a randomized controlled trial.

The present study highlights the glucagon effect on the GH/insulinlike growth factor 1 (IGF-1)/IGF-binding protein (IGFBP) axis in vivo and in vitro, taking into consideration insulin as a confounding factor.

Why It Was Studied

Glucagon-induced growth hormone (GH) release can promote its effect on lipid metabolism, although the underlying mechanisms have not been well-defined.

Who Took Part

According to the abstract, 11 participants were involved.

PubMed indexes the participants as adults, both men and women.

In a double-blind, placebo-controlled study, the researchers investigated changes in GH, IGFBP, and IGF-1 bioactivity after intramuscular glucagon administration in 13 lean controls, 11 obese participants, and 13 patients with type 1 diabetes mellitus (T1DM).

How the Study Was Run

The design is described as randomized, double-blind and placebo-controlled.

Because people in this IGF-1 LR3 study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

As a double-blind IGF-1 LR3 study, the assignments were hidden from both participants and investigators until the end.

A placebo (an inactive look-alike) gave the IGF-1 LR3 group a baseline to be compared against.

The effect of glucagon on the transcription factor forkhead box protein O1 (FOXO1) translocation, the transcription of GH/IGF-1 system members, and phosphorylation of protein kinase B (Akt) was further investigated in vitro.

What Was Measured

Topics PubMed links to this paper include Blotting, Western, Diabetes Mellitus, Type 1, Enzyme-Linked Immunosorbent Assay, Forkhead Box Protein O1, Glucagon, Growth Hormone and Insulin-Like Growth Factor Binding Proteins.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of IGF-1 LR3 and Glucagon in 11 participants.

With fewer than 40 people, it is a small study, so it is better read as an early signal for further research than as a settled answer.

Its findings take up roughly 6 sentences of the abstract and are left out here on purpose; the source paper is the place to read them.

The publication is from 2017 (The Journal of clinical endocrinology and metabolism), a journal based in United States.

More context: the IGF-1 LR3 compound page and the Glucagon compound page, all human trials.