Skip to main content
OpenTrials
Not Yet Recruiting

NCT Number: NCT07466173

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

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. In another trial (NCT06552130) lean participants already have been tested. Significant effects on circulating cytokines could be identified. In this amendment, overweight persons in which brain insulin resistance is expected will be tested.

Not Yet Recruiting

Trial opening soon.

Get Notified

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

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 and investigate whether participants with overweight respond different compared to lean persons. The lean persons were already studied in another trial (NCT06552130) and this trial serves as an amendment.

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 > 28 kg/m2
  • no known primary disease
  • hormonal contraception with a single-phase preparation

Exclusion criteria

  • alcohol or drug abuse
  • 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

  1. 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.

Secondary outcomes

  1. Maximal oxygen consumption (VO2max)

    Time frame: 60 minutes

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

  2. Heat 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.

  3. Corticotropic pituitary axis modulation

    Time frame: 120 minutes

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

  4. Leukocyte gene expression

    Time frame: 120 minutes

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

  5. 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.

  6. 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.

  7. 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

  1. Sex differences

    Time frame: 120 minutes

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

  2. Differences between lean and overweight persons

    Time frame: 120 minutes

    Potential differences in the above mentioned outcomes between lean individuals studied in (NCT06552130) and overweight individuals studied in this trial.

Study contacts

Contact information is provided by the study sponsor or research team.

Martin Heni, MD

CONTACT

[email protected]

+4973150044505

Sabrina Wangler

CONTACT

[email protected]

+4973150044782

Sponsors and collaborators

Lead sponsor

University of Ulm

Other

Registry information

Important dates

Study start
2026
Primary completion
2026
Study completion
2027
First posted
Mar 12, 2026
Registry last updated
Mar 16, 2026

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.