Effects of Antipsychotics on Brain Insulin Action in Females

What Was Tested

The trial (not phased) is built around Insulin Lispro for insulin resistance, prediabetes & type 2 diabetes.

Females treated with antipsychotics have higher rates of comorbid metabolic syndrome than males.

Despite this, females have historically been excluded from many mechanistic studies due to confounding effects of menstrual cycles.

It had two arms (groups): Follicular Phase Visits (experimental) and Luteal Phase Visits (experimental).

The registry classes the interventions as drug.

More on the Plan

BACKGROUND: Antipsychotics (APs) cause serious metabolic adverse effects, including weight gain and type 2 diabetes.

Females are disproportionally more affected by this problem than males.

While the pathophysiology of these effects remain unclear, brain insulin resistance (IR) is posited to be an important determinant.

Currently there are no direct methods to investigate brain IR, but physiological response to intranasal insulin (INI) can be used as a surrogate marker.

Who Took Part

Enrollment: 15 planned participants were the target.

It was open to women only aged from 18 years up to 35 years.

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

Examples of who could join: Age: 18-35 years. Body Mass Index (BMI) between 18.5 - 24.9 kg/m2. Normal menstrual cycle (defined as cycle length ranging from 21 to 35 days over the past 6 months).

The full record lists 3 inclusion and 15 exclusion criteria; among the exclusions: history of psychiatric illness (screened using the mini international neuropsychiatric interview (mini));; evidence of impaired insulin sensitivity, assessed using the homeostatic model assessment for insulin resistance (homa-ir) ≥2.5;; family history of diabetes in a first degree relative (parent or sibling).

How the Study Was Run

It was run as a randomized, crossover and double-blind study.

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

In the crossover set-up each of the insulin resistance, prediabetes & type 2 diabetes participants took both Insulin Lispro and the comparison in turn, acting as their own control.

As a double-blind Insulin Lispro 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 2024-06-03 with completion listed for 2026-12-31.

It ran at 1 site in Canada.

Its stated primary purpose is basic science.

What Was Measured

The main thing measured (primary outcome): Resting State Functional Connectivity (assessed through Functional MRI).

It also tracked 2 secondary outcomes, for example Visuospatial Memory and Processing Speed.

What This Means in Plain Language

Put simply, this is a not phased, randomized trial of Insulin Lispro in 15 people with insulin resistance, prediabetes & type 2 diabetes.

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

Its status is active not recruiting; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Insulin Lispro compound page, Insulin resistance, prediabetes & type 2 diabetes research.