RecruitingNAINTERVENTIONAL

Understanding Individual Variability in Neuronal Signal Transmission to Target Organs in Health and Disease

This research explores how the brain communicates with organs responsible for metabolism, particularly focusing on blood sugar control. We're investigating a specific brain signal system (the parasympathetic nervous system) and how it affects different organs. Participants will have a special sugar drink test, sometimes with a medicine called atropine to temporarily block these signals, and sometimes with a dummy medicine (placebo). By comparing healthy individuals with those at higher risk of certain health conditions, and looking at differences between men and women, we hope to understand more about how these brain-body connections work in health and disease. The aim is to uncover how these signals might change in at-risk groups.

At a glance

Status

Recruiting

Phase

Sponsor

University of Ulm

Enrolment target

Start

14 May 2025

Estimated completion

01 May 2027

Autonomic Function

What is this study about?

You're probably aware that your brain is in charge of almost everything your body does, from thinking to walking. But it also controls many things you don't even think about, like how your body handles food and regulates blood sugar. This study is all about understanding these 'background' messages that the brain sends to organs involved in your metabolism – the processes that turn food into energy. We're particularly interested in a specific messaging system called the parasympathetic nervous system, which acts like a quiet conductor, telling your organs what to do.

We want to see how these messages from the brain affect organs, especially after you've eaten. We'll be comparing people who are generally healthy with those who might be at a higher risk of developing certain health issues related to how their body uses sugar. We also know that men and women can sometimes respond differently to things, so we'll be carefully looking at any potential differences between sexes.

By taking part, you'd help us learn more about how these crucial brain-body signals work. This knowledge could eventually help doctors better understand why some people develop metabolic problems and potentially lead to new ways of helping them. We're essentially trying to paint a clearer picture of how your brain helps manage your body's energy use.

Key takeaways

Study explores brain's role in controlling body's sugar use.
Compares healthy people with those at higher risk of metabolic issues.
Examines differences between men and women.
Involves specific sugar drink tests with and without a temporary signal-blocking medicine.
Participation includes two separate study days.

Who may be eligible?

To join this study, you need to be at least 18 years old. For healthy groups, your Body Mass Index (BMI) should be between 20 and 24.9. If you're in the group considered at higher risk, your BMI should be 28 or above. Women participants must be using a specific type of hormone-based contraception, like a continuous pill or patch. You also need to be able to understand the study information and agree to take part by signing a consent form.

There are several reasons why you might not be able to join. These include if you smoke, use certain drugs or alcohol, or are taking medications that affect your blood sugar, brain, or nerve systems (like some epilepsy or depression medicines). You also can't participate if you have heart problems, certain nerve conditions, known allergies to any of the study medicines (like paracetamol or atropine), or conditions like glaucoma, an overactive thyroid, or bladder/prostate problems.

We also can't include you if you're pregnant or breastfeeding, have very low iron levels (anaemia), or if, in the doctor's expert opinion, joining the study might put your safety at risk or prevent us from getting accurate results. Serious liver or kidney problems would also exclude you.

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 18 years old or older?
Is your BMI (body weight in relation to height) within the required range for healthy (20-24.9) or higher-risk (>28) groups?
If you're a woman, are you using specific hormone-based contraception (e.g., Nuvaring or a continuous pill)?
Do you not smoke or have any major heart, nerve, liver, or kidney problems?
Are you able to understand the study details and willing to give your consent?
Are you not pregnant or breastfeeding, and not taking medicines that affect blood sugar or brain/nerve function?

Answer every question to see your result.

What does participation involve?

If you decide to take part, you'll visit the study centre on two separate days. On each day, you'll be given a special sugar drink that contains a small amount of paracetamol (to help us measure how quickly your stomach empties). Alongside this, on one day you'll receive a slow drip (infusion) of a medicine called atropine, which temporarily blocks certain brain signals. On the other day, you'll receive a drip of a dummy medicine called saline (a saltwater solution). These will be given in a random order, and you won't know which one you're getting on which day. The drips will start 20 minutes before you drink the sugar solution and continue until the end of the 2-hour sugar test.

Throughout these visits, we'll be taking blood samples to measure how your body processes the sugar. This sugar drink will also contain special types of sugar that help us track exactly how your body is making and using sugar. We’ll be carefully monitoring you during the entire process. The total duration of your participation, including both study days, will be a short period, with each visit lasting a few hours.

Potential risks and benefits

By taking part in this study, you'll be contributing valuable information that could help us better understand how the brain controls metabolism, potentially leading to better care for people in the future. There are always some potential risks with any medical study. You might experience minor discomfort from blood draws or from the temporary effects of atropine (like a dry mouth or slight blurring of vision, which will be carefully monitored). We will explain all potential risks in detail before you agree to participate. You are free to stop participating at any time, for any reason, without it affecting your medical care.

Locations (1)

Ulm University Hospital
Verified postcode
Ulm, Germany· Recruiting

Common questions

What is the main goal of this study?

The main goal is to understand how signals from your brain influence how your body handles sugar and energy, especially after you've eaten.

What is atropine and why is it used?

Atropine is a medicine that temporarily blocks certain nerve signals from the brain. We use it to see what happens to your body's sugar control when these signals are turned down.

Will I know if I'm getting the real medicine or the placebo?

No, for the best results, you won't know whether you're getting atropine or the dummy medicine (placebo) on each study day.

How long will each study visit take?

Each study visit will likely last several hours on two separate days, mainly due to the 2-hour sugar test and preparation time.

What happens if I change my mind about taking part?

You are completely free to withdraw from the study at any point, without having to give a reason, and it will not affect your usual medical care.

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.