Restoration of the insulinotropic effect of glucose-dependent insulinotropic polypeptide contributes to the antidiabetic effect of dipeptidyl peptidase-4 inhibitors

What Was Tested

The paper reports a study of GIP (Gastric Inhibitory Polypeptide), published as a randomized controlled trial.

To examine whether 12 weeks of treatment with a dipeptidyl peptidase-4 (DPP-4) inhibitor, sitagliptin, influences the insulin secretion induced by glucose, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) during a hyperglycaemic clamp in patients with type 2 diabetes (T2DM).

Who Took Part

The abstract describes 25 patients taking part.

By PubMed's age tags, the people studied were middle-aged adults, both men and women.

In weeks 1 and 12, the patients underwent three 2-h 15-mM hyperglycaemic clamp experiments with infusion of either saline, GLP-1 or GIP. β-cell function was evaluated according to first-phase, second-phase, incremental and total insulin and C-peptide responses.

How the Study Was Run

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

Because people in this GIP (Gastric Inhibitory Polypeptide) 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 GIP (Gastric Inhibitory Polypeptide) study, the assignments were hidden from both participants and investigators until the end.

The comparison arm used a placebo, so changes seen with GIP (Gastric Inhibitory Polypeptide) could be set against what happens without it.

What Was Measured

The subject headings attached to it are C-Peptide, Diabetes Mellitus, Type 2, Dipeptidyl-Peptidase IV Inhibitors, Gastric Inhibitory Polypeptide, Glucagon-Like Peptide 1, Glucose Clamp Technique and Glycated Hemoglobin.

Author keywords: DPP-IV inhibitor, GIP, GLP-1, insulin secretion, metformin and randomised trial.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of GIP (Gastric Inhibitory Polypeptide) in 25 patients.

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 2015 (Diabetes, obesity & metabolism), a journal based in England.

More context: the GIP (Gastric Inhibitory Polypeptide) compound page, all human trials.