C-peptide does not affect ocular blood flow in patients with type 1 diabetes.

What Was Tested

Researchers studied C-Peptide in this randomized controlled trial publication.

The aim of the present study was to investigate the effect of intravenous C-peptide infusion on ocular blood flow in patients with type 1 diabetes under euglycemic conditions.

To assess retinal blood flow, laser Doppler velocimetry (blood flow velocities) and retinal vessel analyzer (vessels diameters) measurements were performed.

Laser interferometric measurements of fundus pulsation were used to assess pulsatile choroidal blood flow.

Who Took Part

The study group was 10 patients.

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

The study was performed in a randomized, placebo-controlled, double-masked, two-way, crossover design in 10 type 1 diabetic patients.

How the Study Was Run

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

The patients were allocated by chance, so the C-Peptide group and the comparison group should start out alike.

As a double-blind C-Peptide study, the assignments were hidden from both participants and investigators until the end.

A placebo (an inactive look-alike) gave the C-Peptide group a baseline to be compared against.

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

Physiologic saline solution was used as a control for C-peptide on a different study day.

On both study days, euglycemic clamps were performed.

Blood velocities in the ophthalmic artery were measured using color Doppler imaging.

What Was Measured

The subject headings attached to it are Blood Flow Velocity, C-Peptide, Diabetes Mellitus, Type 1, Eye, Laser-Doppler Flowmetry, Ophthalmic Artery and Retinal Vessels.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of C-Peptide in 10 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.

Results are reported in around 7 sentences of the abstract; we leave them to the paper itself rather than summarise them.

The publication is from 2006 (Diabetes care), a journal based in United States.

More context: the C-Peptide compound page, all human trials.