Two-hour infusion of vasoactive intestinal polypeptide induces delayed headache and extracranial vasodilation in healthy volunteers

What Was Tested

This randomized controlled trial paper looks at VIP (Vasoactive Intestinal Peptide).

In recent years, vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptides (PACAPs) have gained special interest in headache science.

VIP and PACAPs (two isoforms, PACAP27 and PACAP38) are related in structure and function, as are their receptors, but they show differences in vasodilating- and headache-inducing properties.

Who Took Part

The study group was 12 volunteers.

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

In a double-blinded, placebo-controlled, crossover study in 12 healthy volunteers, diameter changes of cranial arteries, occurrence of headache and the parasympathetic system were examined before, during and after a 2-hour continuous intravenous infusion of VIP and placebo.

How the Study Was Run

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

The volunteers were allocated by chance, so the VIP (Vasoactive Intestinal Peptide) group and the comparison group should start out alike.

Neither the volunteers nor the staff measuring them knew who was on VIP (Vasoactive Intestinal Peptide), so expectations could not easily colour the readings.

The comparison arm used a placebo, so changes seen with VIP (Vasoactive Intestinal Peptide) could be set against what happens without it.

Each person switched between VIP (Vasoactive Intestinal Peptide) and the comparison at some point, usually with a gap in between.

Primary endpoints were the differences in area under the curve for the superficial temporal artery diameter and headache intensity scores, as well as in headache incidence, between VIP and placebo.

What Was Measured

In recent years, vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptides (PACAPs) have gained special interest in headache science.

The subject headings attached to it are Headache, Healthy Volunteers, Temporal Arteries, Vasoactive Intestinal Peptide, Vasodilation and Vasodilator Agents.

Author keywords: Migraine, PACAP27, PACAP38, VIP and parasympathetic system.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of VIP (Vasoactive Intestinal Peptide) in 12 volunteers.

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 5 sentences of the abstract and are left out here on purpose; the source paper is the place to read them.

The publication is from 2020 (Cephalalgia : an international journal of headache), a journal based in England.

More context: the VIP (Vasoactive Intestinal Peptide) compound page, all human trials.