Active, Not Recruiting

NCT Number: NCT06552130

The Importance of Insulin Action in the Brain for the Immune System During Physical Activity

The goal of this clinical trial is to clarify the interaction of central insulin action and physical activity with the immune system.

Therefore, participants will undergo bicycle spiroergometer tests. This approach will be compared between days with insulin delivery to the brain as nasal spray and days with placebo spray.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Insulin Sensitivity Behavior Glucose Metabolism Disorders Hyperinsulinism Insulin Resistance Metabolic Diseases Motor Activity Nutritional and Metabolic Diseases

Age range

18 year–30 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Universityhospital Ulm

Ulm, 89081, Germany

About this study

This research project aims to investigate if the brain insulin action regulates the immune system via the autonomous nervous system during physical activity.

Therefore, insulin action in the brain will be introduced by application of insulin as nasal spray (on one day) versus carrier solution as placebo nasal spray (on another day) in a randomized, blinded fashion. Spray administration will be performed 30 minutes before a 60 min bicycle spiroergometer test at 70 % VO2max that will introduce a postprandial state. On placebo day, the known spillover of tiny amounts of nasal insulin into the systemic circulation will be mimicked by an appropriate i.v. insulin bolus. Using this approach, brain-derived regulation of the immune system including the stimulation of immune cells via cytokines, physical performance, activity of the autonomous nervous system and gene-expression of leukocytes will be examined.

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

BMI < 24 kg/m2
no known primary diseases
hormonal contraception with a single-phase preparation

Exclusion criteria

Alcohol or drug abuse
Smoking
At screening: Hb < 12 g/dl for women and Hb < 14 g/dl for men
Any (clinical) condition that would endanger participant's safety or question scientific success according to a physician's opinion.

Treatment and study plan

Spiroergometer test with intranasal insulin spray

Other

Participants will undergo a 60 min bicycle spiroergometer test and intranasal insulin spray. Intranasal insulin will be administered 30 minutes prior to the start of the physical activity.

Spiroergometer test with intranasal placebo spray

Other

Participants will undergo a 30 min bicycle spiroergometer test and intranasal placebo spray. To mimic insulin spill-over from nasal spray into systemic circulation, an i.v. insulin bolus of 3 mU × kg-1. will be administered over 15 minutes 30 minutes prior to the start of the physical activity on the placebo spray day. On the insulin spray day a comparable amount of saline will be infused.

Primary outcomes

Immune system activation

Time frame: 120 minutes

Influence of central nervous insulin action on the activation of the immune system activation by exercise, measured by circulating cytokines and cytokines in the supernatant of stimulated peripheral blood mononuclear cells.
Immune system activation

Time frame: 120 minutes

Influence of central nervous insulin action on the activation of the immune system activation by exercise, measured by the composition of immune cells in circulation and cytokine release in the supernatant of stimulated peripheral blood mononuclear cells.

Secondary outcomes

Maximal oxygen consumption (VO2max)

Time frame: 60 minutes

Influence of central nervous insulin action on physical performance measured as VO2 peak during spiroergometry.
Heart rate variability

Time frame: 120 minutes

Influence of central nervous insulin action on the activity of the autonomic nervous system recorded by means of heart rate variability from an electrocardiogram.
Corticotropic pituitary axis modulation

Time frame: 120 minutes

Influence of central nervous insulin action in the activity of the corticotropin pituitary axis during physical activity, measured by cortisol, dehydroepiandrosterone and adrenocorticotropic hormone
Leukocyte gene expression

Time frame: 120 minutes

Influence of central nervous insulin action on the gene expression of leukocytes during physical activity
Individual anaerobic threshold

Time frame: 120 minutes

Influence of central nervous insulin action on physical performance. Individual anaerobic threshold assessed by lactate measurement from venous blood sampling.
Catecholamines

Time frame: 120 minutes

Influence of central nervous insulin action on the activity of the autonomic nervous system recorded by means of measuring catecholamine concentrations from venous blood.
Effects on blood coagulation parameters

Time frame: 120 Minutes

Influence of central nervous insulin action and/or physical activity on blood coagulation parameters assessed through global coagulation tests and single coagulation factors.

Other outcomes

sex differences

Time frame: 120 minutes

Potential differences in the above mentioned outcomes between sexes will be analyzed.

Sponsors and collaborators

Lead sponsor

University of Ulm

Other

Registry information

Important dates

Study start: 2024
Primary completion: 2025
Study completion: 2026
First posted: Aug 13, 2024
Registry last updated: Dec 10, 2025

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.

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