Raclopride-PET/MRT

Sponsor

University Hospital Tuebingen (Other)

Overall Status

Recruiting

CT.gov ID

NCT03637075

Collaborator

(none)

Enrollment

Location

Arms

70.3

Anticipated Duration (Months)

0.3

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

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.

Condition or Disease	Intervention/Treatment	Phase
Diabetes Mellitus, Type 2	Other: intranasal insulin Other: Placebo	N/A

Study Design

Study Type:

Interventional

Anticipated Enrollment :

24 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Intervention Model Description:

single-blinded, monocentric, prospective crossover studysingle-blinded, monocentric, prospective crossover study

Masking:

Single (Participant)

Primary Purpose:

Other

Official Title:

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

Actual Study Start Date :

Feb 20, 2017

Anticipated Primary Completion Date :

Jun 30, 2022

Anticipated Study Completion Date :

Dec 31, 2022

Arms and Interventions

Arm	Intervention/Treatment
Placebo Comparator: Placebo Intranasal placebo administration	Other: Placebo placebo intranasal administration
Active Comparator: Intranasal insulin Intranasal insulin administration	Other: intranasal insulin intranasal administration of insulin (160 IU)

Arm

Intervention/Treatment

Placebo Comparator: Placebo

Intranasal placebo administration

Other: Placebo

placebo intranasal administration

Active Comparator: Intranasal insulin

Intranasal insulin administration

Other: intranasal insulin

intranasal administration of insulin (160 IU)

Outcome Measures

Primary Outcome Measures

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

Differences between normalweight and overweight subjects regarding insulin sensitivity and availability of dopamine receptors [0 - 60 min]
assessed by fMRI and Raclopride-PET/MRT
Effects of nasal insulin vs. placebo on changes in plasma insulin levels [0 - 60min]
assessed by blood sampling after application.
Effects of nasal insulin vs. placebo on changes in plasma glucose levels [0 - 60min]
assessed by blood sampling after application.
Effects of nasal insulin vs. placebo on changes in FFA levels [0 - 60min]
assessed by blood sampling after application.
Effects of nasal insulin vs. placebo on changes in prolactin levels as a proxy for the dopaminergic tonus [0 - 60min]
assessed by blood sampling after application.
Effects of nasal insulin vs. placebo on changes in autonomic nervous system [-30 - 60 min]
assessed by heart rate variability.

Eligibility Criteria

Criteria

Ages Eligible for Study:

20 Years to 40 Years

Sexes Eligible for Study:

Male

Accepts Healthy Volunteers:

Yes

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