Skip to main content
OpenTrials
Completed

NCT Number: NCT03637075

Raclopride-PET/MRT

Cerebral insulin resistance plays an important role in the development of obesity and diabetes mellitus type 2. The aim of this project is to examine the effect of human nasal insulin on the dopaminergic system. Therefore, characteristics of cerebral dopamine receptors before and after administration of nasal insulin vs. placebo shall be analyzed in a randomized way. Moreover, the investigators plan to examine the insulin action on cortical and subcortical activation in humans and the interaction of dopamine metabolism with [11C]-Raclopride-PET/MRI. By performing fMRI measurements, insulin sensitivity of the central nervous system can be investigated simultaneously. Recruiting is planed as a two-step process.First 12 normal-weight (BMI 20-25 kg/m²) men should be examined. If first results show a insulin-dependent effect on the availability of dopamine receptors in the human brain, recruitment of 12 overweight men will get started.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Diabetes Mellitus, Type 2 Diabetes Mellitus Endocrine System Diseases Glucose Metabolism Disorders Metabolic Diseases Nutritional and Metabolic Diseases

Age range

20 year–40 year

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

University of Tuebingen, Department of Internal Medicine IV

Tübingen, 72076, Germany

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Understand and voluntarily sign an informed consent document prior to any study related assessments/procedures.
  • Intake of any medication
  • HbA1C <6%
  • BMI 20-25 kg/m²
  • Clinical routine blood parameters within the normal ranges
  • All participants must agree to get informed of unexpected detected, clinical relevant findings.

Exclusion criteria

  • Acute diseases such as infections (e.g.)
  • Any relevant cardiovascular disease
  • Any surgery within the last three months
  • Any neurologic or psychiatric disease
  • Known allergies
  • Hb < 13 g/dl
  • Presence of any contraindication for the conduct of an MRI investigation, such as cardiac pacemakers, ferromagnetic haemostatic clips in the central nervous system, metallic splinters in the eye, ferromagnetic or electronically operated active devices like automatic cardioverter defibrillators, cochlear implants, insulin pumps and nerve stimulators, prosthetic heart valves etc.
  • Claustrophobia

Treatment and study plan

intranasal insulin

Other

intranasal administration of insulin (160 IU)

Placebo

Other

placebo intranasal administration

Primary outcomes

  1. Effects of nasal insulin vs. placebo on the insulin sensitivity of the human brain as well as effects on regional availability of dopamine receptors.

    Time frame: 0-60 min

    assessed by fMRI (insulin sensitivity of the brain measured as change in regional brain activity and Raclopride-PET/MRT (regional dopamine receptor availability).

Secondary outcomes

  1. Differences between normalweight and overweight subjects regarding insulin sensitivity and availability of dopamine receptors

    Time frame: 0 - 60 min

    assessed by fMRI and Raclopride-PET/MRT

  2. Effects of nasal insulin vs. placebo on changes in plasma insulin levels

    Time frame: 0 - 60min

    assessed by blood sampling after application.

  3. Effects of nasal insulin vs. placebo on changes in plasma glucose levels

    Time frame: 0 - 60min

    assessed by blood sampling after application.

  4. Effects of nasal insulin vs. placebo on changes in FFA levels

    Time frame: 0 - 60min

    assessed by blood sampling after application.

  5. Effects of nasal insulin vs. placebo on changes in prolactin levels as a proxy for the dopaminergic tonus

    Time frame: 0 - 60min

    assessed by blood sampling after application.

  6. Effects of nasal insulin vs. placebo on changes in autonomic nervous system

    Time frame: -30 - 60 min

    assessed by heart rate variability.

Sponsors and collaborators

Lead sponsor

University Hospital Tuebingen

Other

Registry information

Official study title

Characterization of Insulin Action and Dopamine-signaling in the Human Brain of Normal Weight and Obese Subjects by [11C]-Raclopride-PET/MRT

Important dates

Study start
2017
Primary completion
2023
Study completion
2023
First posted
Aug 17, 2018
Registry last updated
May 14, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.