RecruitingOBSERVATIONAL

Disentangling the Effect of Brain Insulin Resistance on Brain Health

This study aims to understand why people with diabetes are more likely to develop memory and thinking problems, like dementia. We're particularly interested in two things: how well the brain responds to insulin signals (called 'brain insulin resistance') and the health of blood vessels in the brain. We know diabetes can affect the brain, leading to issues with memory and thinking as people get older, but the exact reasons are still unclear. This research will compare adults aged 50-80 with type 1 diabetes, type 2 diabetes, and those without diabetes. Participants will have brain scans (MRIs), thinking tests, and general health checks to help us find out how these factors are linked to brain health.

At a glance

Status

Recruiting

Sponsor

Henrik Bo Wiberg Larsson

Enrolment target

150

Start

01 Jan 2026

Estimated completion

01 Jan 2032

Diabetes Type 2 Diabetes Type 1

What is this study about?

If you have diabetes, you might have heard that it can sometimes affect memory and thinking skills, and even increase the risk of conditions like Alzheimer's disease. We also know that the brains of people with diabetes can show more natural age-related changes and difficulties with thinking compared to those without diabetes. But why exactly does diabetes affect the brain in this way? That's what this important research project aims to find out.

Two main ideas are being explored. First, some research suggests that in people with diabetes, their brains might not respond properly to insulin, a hormone that helps the body use sugar for energy. This is called 'brain insulin resistance'. Think of it like a key (insulin) that usually opens a lock (brain cells) to let in sugar, but in some people, the lock isn't working as well. We want to see how this brain insulin resistance affects brain function. Second, diabetes is known to cause damage to blood vessels throughout the body, and this can also affect the brain's blood supply. We'll be looking at how healthy the brain's blood vessels are and whether this is linked to thinking abilities.

To do this, we'll be studying people aged 50 to 80 with type 1 diabetes, type 2 diabetes, and a group of healthy volunteers who don't have diabetes. We want to see if there are differences between these groups in their brain's response to insulin, the health of their brain's blood vessels, and their thinking skills. By understanding these links, we hope to learn more about how diabetes affects brain health, which could lead to better ways to help people in the future.

Key takeaways

This study explores how diabetes affects memory and thinking.
It investigates brain insulin resistance and blood vessel health in the brain.
It involves adults aged 50-80 with Type 1 or Type 2 diabetes, and healthy volunteers.
Participation includes health checks, memory tests, and brain MRI scans.
The research aims to improve understanding of diabetes-related brain health.
Your participation is voluntary, and you can withdraw at any time.

Who may be eligible?

To join this study, you need to be between 50 and 80 years old. If you have diabetes, you must have had it for at least 10 years if it's type 1, or at least 5 years if it's type 2. We're also looking for people without diabetes to compare.

There are some reasons why you might not be able to take part. For example, if your diabetes is very difficult to control (HbA1c above 100 mmol/mol) or if you have another type of diabetes. We also can't include people who weigh over 140 kg, have been diagnosed with dementia, or have had a major stroke. Certain other serious medical conditions, recent cancers (within the last year), severe claustrophobia, or metal implants that aren't safe for MRI scans would also mean you couldn't take part.

It's also important that you can understand and take part in thinking tests, so significant problems with vision, hearing (even with aids), or language might prevent your participation. Finally, you must be comfortable with the idea of potentially finding something unexpected on your brain MRI scan and having us inform you about it.

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 50 and 80 years old?
If you have type 1 diabetes, have you had it for at least 10 years? If type 2, at least 5 years?
Do you feel comfortable lying still for an MRI scan and don't have severe claustrophobia?
Do you have any metal implants (like pacemakers or certain screws) in your head or neck that might be unsafe for an MRI scan?
Have you been diagnosed with dementia or had a major stroke?
Are you able to participate in memory and thinking tests without major vision, hearing, or language difficulties?

Answer every question to see your result.

What does participation involve?

If you decide to take part in this study, you will have a thorough health check-up, including blood tests. You will also undergo a series of tests to check your memory, problem-solving, and other thinking skills. A key part of the study involves having MRI (Magnetic Resonance Imaging) scans of your brain. These scans are safe and use powerful magnets and radio waves to create detailed pictures of your brain, but they do require you to lie still inside a scanner. During the study, you might be asked to temporarily pause certain medications for about 12 hours before some tests. We will give you clear instructions about this. This study is designed to be a one-time visit or a few visits over a short period, and there won't be long-term follow-up involved after your assessments are complete.

Potential risks and benefits

Taking part in research like this helps science move forward and can ultimately benefit many people, though there's no direct guarantee of benefit to you individually. You might find it interesting to learn more about your health through the assessments. Potential risks include the minor discomforts of blood tests or lying still for MRI scans. Rarely, an unexpected medical finding might be seen on a scan, which would require follow-up with your own doctor. You are free to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (3)

Rigshospitalet
Verified postcode
Glostrup Municipality, Denmark· Recruiting
Steno Diabetes Center Copenhagen
Verified postcode
Herlev, Denmark· Recruiting
University of Ulm
Verified postcode
Ulm, Germany· Recruiting

Common questions

What is 'brain insulin resistance'?

It's when the brain doesn't respond normally to insulin signals, which are important for how brain cells use energy and work properly.

Will I get results from my brain scans or tests?

You will be informed if any unexpected medical findings are seen on your brain MRI that require follow-up with your doctor. Information from your tests will help the researchers understand brain health in general.

How long does participation last?

The study involves a single visit or a few visits over a short period to complete all the health checks, thinking tests, and brain scans.

Do I need to stop any medications?

You might be asked to temporarily pause certain medications for about 12 hours before some tests. All instructions will be provided clearly by the study team.

Where is this study taking place?

This study is being carried out in different locations, specifically in Denmark and Germany.

How to find out more

Henrik BW Larsson, Professor

henrik.bo.wiberg.larsson@regionh.dk +45 24824294 Official trial record

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