Not yet recruitingNAINTERVENTIONAL

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

This study is investigating how a hormone called insulin, when it acts in the brain, might affect your body's immune system during exercise. We are particularly interested in people who are overweight. Participants will take part in bicycle exercise tests. On different days, they will receive either an insulin spray or a dummy spray (placebo) into their nose before exercising. Scientists want to see if the brain's insulin action changes how the immune system works during physical activity, and if these effects are different for overweight individuals compared to people of a healthy weight who were studied previously. This helps us understand more about how our brains, exercise, and immune systems are connected.

At a glance

Status

Not yet recruiting

Phase

Sponsor

University of Ulm

Enrolment target

Start

01 Apr 2026

Estimated completion

01 Jun 2027

Insulin Sensitivity

What is this study about?

This research aims to understand how signals from the brain, particularly those involving a hormone called insulin, can influence your body's immune system when you're exercising. Think of insulin as a key that helps unlock cells to use sugar for energy. While we often hear about insulin's role in processing sugar from food, this study focuses on its actions specifically within your brain.

We know that being active is good for our health, and our immune system helps protect us from illness. Scientists want to find out if insulin working in the brain helps to manage this immune response during physical activity. They are also looking at whether people who are overweight react differently compared to people of a healthy weight, as previous research has already looked at healthy-weight individuals. This could help us understand more about how our bodies respond to exercise and manage health, especially in different body types.

By carefully studying these connections, researchers hope to gain a clearer picture of how our brains, physical activity, and immune systems work together. This knowledge could eventually lead to new ways to support health and well-being in the future.

Key takeaways

Researchers are studying the link between insulin in the brain, exercise, and the immune system.
This study focuses on overweight individuals, building on previous research with healthy-weight participants.
Participants will receive either insulin or a dummy spray through their nose before cycling.
The study aims to understand how our brains, exercise, and immunity work together.
Participation involves exercise tests and blood sampling over a few visits.

Who may be eligible?

To join this study, you need to be a man or woman between 18 and 30 years old. Your Body Mass Index (BMI) needs to be above 28, which means you are considered overweight. Women taking a single type of hormonal birth control pill may participate.

You cannot join if you have any serious health conditions that are already known, or if you misuse alcohol or drugs. Also, if a doctor thinks joining the study might put your safety at risk or if you have very low blood iron (anaemia – specifically, haemoglobin less than 12 g/dl for women or 14 g/dl for men), you won't be able to take part.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you between 18 and 30 years old?
Is your BMI above 28 (considered overweight)?
Do you have any known serious medical conditions?
Are you able to participate in moderate exercise on a stationary bike?
Are you male, or a female using a single-type hormonal contraceptive pill?

Answer every question to see your result.

What does participation involve?

If you decide to take part in this study, you will have a few study visits. On two separate days, you'll come to the research centre. On one day, you'll receive a special insulin spray into your nose, and on another day, you'll receive a dummy spray (placebo) into your nose. These sprays are given about 30 minutes before you start exercising.

You will then do an exercise test on a special stationary bicycle, called a spiroergometer, for about 60 minutes. This test helps the researchers measure how your body uses oxygen during exercise. During the study, blood samples will be taken to see how your immune system is reacting, how your body is performing physically, and to look at signals from your nervous system. The whole study will involve these few visits, and there won't be any long-term follow-up beyond the test days.

Potential risks and benefits

Participating in research studies like this can help advance medical knowledge, potentially leading to better understanding of health for everyone in the future. While there's no direct personal benefit promised, you'll be playing an important role in scientific discovery. Potential risks include discomfort from blood draws or the exercise test, and possible temporary side effects from the nasal sprays, though these are generally well-tolerated. Insulin can lower blood sugar, but the medical team will monitor you closely for safety. Remember, you can decide to stop participating at any time without giving a reason, and this will not affect your medical care.

Locations (1)

Ulm University Hospital
Verified postcode
Ulm, Germany

Common questions

What is insulin spray for?

The insulin spray is used to deliver insulin directly to your brain through your nose, so researchers can study its effects there without major effects on your whole body.

What is a placebo spray?

A placebo spray looks and feels exactly like the insulin spray but contains no active medicine. It helps researchers compare the real effects of insulin.

What is a spiroergometer test?

It's an exercise test on a special bike that measures how much oxygen your body uses, helping scientists understand your fitness and how you react to exercise.

Why are you studying overweight people?

Previous research looked at people of a healthy weight. This study wants to see if the brain's insulin use and immune response during exercise are different in overweight individuals.

Will I know if I get the insulin or the dummy spray?

No, you won't know which spray you receive on which day, nor will the study staff who give it to you. This is called 'blinding' and helps make the study results fair.

How to find out more

Martin Heni, MD

martin.heni@uniklinik-ulm.de +4973150044505 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.