Effects of Intranasal Insulin Administration on Tissue Specific Insulin Sensitivity

What Was Tested

In this not phased trial, researchers set out to test Insulin (regular human) and Insulin Aspart for insulin resistance, prediabetes & type 2 diabetes.

It is still not known what mechanism causes these changes or what tissues are involved in this.

In this study, the changes in tissue-specific insulin sensitivity and glucose uptake will be investigated by using glucose-analogue radiotracer (\[18F\]-fluorodeoxyglucose) with positron emission tomography (PET) imaging during insulin stimulation.

It had two arms (groups): Insulin nasal spray (active comparator) and Placebo nasal spray (placebo comparator).

The registry classes the interventions as drug and radiation.

More on the Plan

The objective of this study is to investigate the effects of intranasally administered insulin versus placebo on tissue specific glucose uptake of the key metabolic organs as well as on endogenous glucose production.

SAMPLE SIZE: A total of ten (n=10) healthy males are planned to be included, and the study is conducted with a cross-over design with each subject being investigated twice, once using intranasal insulin and once using intranasal placebo in single-blinded randomized order.

SCREENING VISIT/ELIGIBILITY: Main inclusion and exclusion criteria will be evaluated at a screening visit.

PET STUDY VISITS: On the PET study days two cannulas will be inserted, one in a radial or an antecubital vein for tracer injection and infusion of glucose and insulin, another in the opposite radial or antecubital vein for blood sampling.

Who Took Part

Enrollment: 10 actual participants took part.

It was open to men only aged from 20 years up to 35 years.

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

Examples of who could join: BMI 18,5-25 kg/m2. Normal 2-hour oral glucose tolerance test (OGTT).

The full record lists 3 inclusion and 5 exclusion criteria; among the exclusions: any chronic disease or medication that could affect glucose metabolism; history of anorexia nervosa or bulimia; smoking of tobacco, taking of snuffs, or use of narcotics.

How the Study Was Run

Design: randomized, crossover and double-blind.

Random assignment meant chance, not the researchers, decided who got Insulin (regular human) and who got the comparison, which limits bias.

Each person switched between Insulin (regular human) and the comparison at some point, usually with a gap in between.

As a double-blind Insulin (regular human) study, the assignments were hidden from both participants and investigators until the end.

Those kept unaware of assignments: participant and outcomes assessor.

It started in 2016-04 with completion listed for 2016-12.

It ran at 1 site in Finland.

Its stated primary purpose is basic science.

What Was Measured

The main thing measured (primary outcome): Skeletal muscle glucose uptake (time frame: Data is collected during 100 min PET scan started 40 min after spray administration).

It also tracked 2 secondary outcomes, for example Endogenous glucose production and Liver glucose uptake.

What This Means in Plain Language

Put simply, this is a not phased, randomized trial of Insulin (regular human) and Insulin Aspart in 10 people with insulin resistance, prediabetes & type 2 diabetes.

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

The trial is marked completed; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Insulin (regular human) compound page and the Insulin Aspart compound page, Insulin resistance, prediabetes & type 2 diabetes research.