Further Studies

This study explores the effect of acute exercise on brain insulin responsiveness. Can even a single exercise session improve insulin action in the brain?

Condition:

Reduced insulin action in the brain—a possible risk factor for obesity and type 2 diabetes.

Suitable Participants:

Healthy adults between the ages of 20 and 65 who do little exercise (less than 75 minutes per week).

Most Important Exclusion Criteria:

• Manifest diabetes
• Balance or coordination disorders
• Pregnancy
• Medications that affect sugar metabolism
• Metal in the body (MRI must be possible)

Course of the Study:

Three states are compared:

• moderate cycling,
• short intense interval training, and
• resting.

Afterwards, an MRI scan is used to examine how the brain responds to insulin.

Conducting Clinic:

Tübingen

Prof. Dr. Andreas Fritsche
University Hospital Tübingen
Phone: +49 (0)7071–2980687
stoffwechsel@med.uni-tuebingen.de

This study explores whether almonds can improve blood sugar, body weight, and blood lipids, thereby preventing diabetes.

Condition:

Prediabetes.

Suitable participants:

Adults with impaired blood sugar regulation.

Most Important Exclusion Criteria :

• Manifest diabetes (HbA1c ≥6.5%)
• Severe kidney or liver disease
• Nut allergies
• Pregnancy
• Medications that affect glucose metabolism

Course of the Study:

Daily consumption of 60 grams of raw almonds over 16 weeks compared to no additional nut intake.

Conducting Clinic:

Berlin/Potsdam

Prof. Dr. Joachim Spranger
Charité Berlin
Phone: +49 (0)30-450 514 439
diabetes@charite.de
dzd@dife.de

This study explores how gastric surgery affects metabolism, the body's response to insulin, and fatty liver disease.

Condition:

Very severe obesity (BMI 40 or above), often associated with fatty liver disease and early-stage type 2 diabetes.

Suitable Participants:

People who are severely obese and planning to undergo gastric surgery for weight loss (e.g., gastric bypass or sleeve gastrectomy).

Most Important Exclusion Criteria:

• Severe comorbidities that make it unsafe to perform surgery
• Certain weight limits outside the target range

Course of the Study:

Observational study with precise measurements before and after surgery—including blood sugar levels, liver fat, and energy consumption.

Conducting Clinic:

Düsseldorf

Dr. med. Sabine Kahl
German Diabetes Center
Phone: +49 (0)211 3382-698
energiestoffwechsel@ddz.de 

BARIA-DDZ-Studie - Deutsches Diabetes-Zentrum (DDZ) (German only)

This study explores how metabolism and heart function differ after a heart attack in people with and without diabetes, and which factors determine the further course and risk of complications.

Condition:

Severe heart attack with complete occlusion of a coronary artery – in people with and without diabetes.

Suitable Participants:

People between the ages of 18 and 80 who have just suffered a severe heart attack.

Most Important Exclusion Criteria:

• Severe heart failure (LVEF <25%)
• Severe liver or kidney disease
• Active infections
• Tumors undergoing treatment

Course of the Study:

Observational study with detailed examinations of the heart and metabolism – immediately after the heart attack and in the following months. Additional blood tests and imaging examinations.

Conducting Clinic:

Düsseldorf

Prof. Dr. Michael Roden, Prof. Robert Wagner
German Diabetes Center
Phone: +49 (0)211–3382209
studienzentrum@ddz.de

This study explores how exercise changes eating habits and the brain's response to food.

Condition:

Obesity or prediabetes.

Suitable Participants:

Males with increased body weight (BMI between 25 and 34.9).

Most Important Exclusion Criteria:

• Manifest diabetes
• Severe metabolic disorders
• Contraindications for metabolic examinations
• MRI contraindications

Course of the Study:

Research is being conducted into how short, intensive training affects hunger and appetite, as well as the brain's response to images of food.

Conducting Clinic:

Lübeck

Dr. Svenja Meyhöfer
University Hospital Schleswig-Holstein
Phone: +49 (0)451 31017827
dds@uksh.de

This study explores how elevated blood lipids disrupt energy production in cells.

Condition:

Severe insulin-resistant diabetes with lipid metabolism disorder (“functional lipodystrophy”).

Suitable Participants:

Adults with severe insulin resistance (SIRD phenotype).

Most Important Exclusion Criteria:

• Other forms of diabetes than SIRD
• Severe metabolic disorders
• Contraindications for muscle/adipose tissue biopsies

Course of the Study:

Tissue and blood samples are used to investigate how elevated fatty acids in the blood affect muscle and fat cells.

Conducting Clinic:

Heidelberg

Prof. Dr. Julia Szendrödi
Universitäty Hospital Heidelberg
Phone: +49 (0)6221 56-8606
Stoffwechsel.Studien@med.uni-heidelberg.de

This study aims to make early signs of metabolic changes visible in the eye in order to better prevent diabetes.

Condition:

Obesity without diabetes.

Suitable Participants:

Adults of normal weight or overweight without pre-existing conditions.

Most Important Exclusion Criteria:

• Manifest diabetes
• Eye diseases
• High blood pressure
• Chronic diseases

Course of the Study:

Examination of how fluctuations in blood sugar affect subtle changes in the eye – using special imaging techniques.

Conducting Clinic:

Lübeck

Dr. Svenja Meyhöfer
University Hospital Schleswig-Holstein
Phone: +49 (0)451 31017827
dds@uksh.de

This study explores why some people with diabetes develop complications and others do not—in order to better tailor treatments to individuals.

Condition:

Type 1 and type 2 diabetes, prediabetes, and their complications.

Suitable Participants:

Adults with diabetes or prediabetes, as well as healthy control persons.

Most Important Exclusion Criteria:

• Severe comorbidities

Course of the Study:

Observational study using blood, urine, and tissue samples, as well as imaging techniques such as MRI.

Conducting Clinic:

Heidelberg

Prof. Dr. Julia Szendrödi, Dr. Alba Sulaj
Universitäty Hospital Heidelberg
Phone: +49 (0)6221 56-8606
Stoffwechsel.Studien@med.uni-heidelberg.de

This study investigates the effect of genetic variations in ELAPOR1 or ELAPOR2 on insulin secretion and glucose regulation using the hyperglycemic-euglycemic clamp technique and oral glucose tolerance test. How do differences in genetic makeup influence pancreatic function and diabetes risk?

Condition:

Impaired insulin secretion and blood sugar regulation.

Suitable Participants: 

Adults who can undergo blood tests to check insulin secretion and genetic factors.

Most Important Exclusion Criteria:

• Fear of having blood drawn.

Course of the Study:

No medication—instead, blood samples and glucose tests are used to examine how different gene variants influence insulin secretion and blood sugar levels.

Conducting Clinic:

Tübingen

Prof. Dr. Andreas Fritsche
University Hospital Tübingen
Phone: +49 (0)7071–2980687
stoffwechsel@med.uni-tuebingen.de

This study explores whether reduced insulin action in the brain is associated with a higher risk of diabetes and poorer memory performance.

Condition:

Type 2 diabetes, prediabetes, central insulin resistance.

Suitable Participants:

Adults aged 18 years and older with type 2 diabetes, prediabetes, or healthy control persons.

Most Important Exclusion Criteria:

• Severe heart, liver, or kidney disease
• Active infections
• Current tumor therapies
• Pregnancy
• Health problems that make sugar/insulin tests unsafe.

Course of the Study:

4 examination days (approx. 13 hours in total) within 12 weeks; questionnaires, blood/urine samples, fMRI of the brain, whole-body MRI, oral glucose tolerance test if necessary.

Conducting Clinic:

Tübingen

Prof. Dr. Andreas Fritsche
University Hospital Tübingen
Phone: +49 (0)7071–2980687
stoffwechsel@med.uni-tuebingen.de

This study explores how certain neurotransmitters in the brain influence sugar cravings after eating.

Condition:

None or prediabetes.

Suitable Participants:

Healthy adults without metabolic or mental illnesses.

Most Important Exclusion Criteria:

• Manifest diabetes
• Metabolic or mental illnesses
• Use of opioid painkillers
• Metal in the body (MRI must be possible)

Course of the Study:

The effect of a nasal spray containing the active ingredient naloxone on appetite and cravings for sweets after a meal is being tested.

Conducting Clinic:

Cologne

Prof. Dr. Marc Tittgemeyer
University Hospital Cologne
Phone: +49 (0)221-4726-215
tittgemeyerspam prevention@sf.mpg.de

This study explores how depression affects movement and its control in the brain.

Condition:

Depression with slowed movements.

Suitable Participants:

Adults currently experiencing a depressive phase.

Most Important Exclusion Criteria:

• Neurological disorders
• Current addiction
• Metal in the body (MRI must be possible)

Course of the Study:

Changes in brain activity, motor skills, and inflammation levels before and after antidepressant treatment are being investigated.

Conducting Clinic:

Cologne

Prof. Dr. Marc Tittgemeyer
University Hospital Cologne
Phone: +49 (0)221-4726-215
tittgemeyerspam prevention@sf.mpg.de

This study explores how rapid but controlled weight loss changes metabolism in muscle and fat tissue.

Condition:

Overweight/obesity with possible lipid metabolism disorder. 

Suitable Participants:

Adults with increased body weight.

Most Important Exclusion Criteria:

• Manifest diabetes
• Taking medication that affects blood sugar levels
• Multiple pregnancy
• Severe pre-existing heart, liver, kidney, or mental health conditions
• Alcohol or drug abuse

Course of the Study:

A controlled diet program in which fewer calories are consumed than the body expends.

Conducting Clinic:

Tübingen

Prof. Dr. Andreas Fritsche
University Hospital Tübingen
Phone: +49 (0)7071–2980687
stoffwechsel@med.uni-tuebingen.de

This study explores how short-term overeating affects adipose tissue, insulin sensitivity, and risk factors for type 2 diabetes.

Condition:

Reduced insulin action and changes in adipose tissue due to a high-fat diet.

Suitable Participants:

Healthy adults who are willing to change their diet for a few weeks.

Most Important Exclusion Criteria:

• Manifest diabetes
• BMI over 29
• High level of physical activity
• Chronic illnesses
• Unwillingness to adhere to the diet plan

Course of the Study:

Comparison of a normal diet tailored to nutritional requirements vs. a diet with approx. 40% more fat calories than required per day.

Conducting Clinic:

Düsseldorf

Prof. Dr. Michael Roden, Prof. Robert Wagner
German Diabetes Center
Phone: +49 (0)211–3382209
studienzentrum@ddz.de

This study explores which type of diet improves insulin sensitivity in muscles the fastest.

Condition:

Overweight, insulin resistance, or early prediabetes.

Suitable Participants:

Adults who are overweight or have impaired glucose metabolism.

Most Important Exclusion Criteria:

• Type 1 diabetes
• Liver disease
• Alcohol abuse
• Pregnancy
• Metal in the body (MRI must be possible)

Course of the Study:

Various diets compared to the usual everyday diet.

Conducting Clinic:

Dresden

Prof. Dr. Peter Schwarz, Prof. Dr. Nikolaos Perakakis
University Hospital Dresden
Phone: +49 (0)351-25933250
studie-stoffwechsel@uniklinikum-dresden.de

This study explores how gestational diabetes in the mother—even if treated—affects the long-term health of the child.

Condition:

Gestational diabetes—possible long-term consequences for the children.

Suitable Participants:

Children of mothers who had diabetes during pregnancy and participated in the PREG study, as well as children of healthy mothers for comparison.

Most Important Exclusion Criteria:

• None

Course of the Study:

Examinations of the children at ages 2, 6, 10, 14, and 17.

Conducting Clinic:

Tübingen

Prof. Dr. Andreas Fritsche
University Hospital Tübingen
Phone: +49 (0)7071–2980687
stoffwechsel@med.uni-tuebingen.de

This study explores which distribution of nutrients throughout the day is more beneficial for blood sugar and heart health.

Condition:

Prediabetes or type 2 diabetes in overweight individuals.

Suitable Participants:

Overweight adults with impaired blood sugar regulation.

Most Important Exclusion Criteria:

• Type 1 diabetes
• Insulin therapy
• Severe organ diseases
• Pregnancy
• Unwillingness to adhere to the dietary protocol

Course of the Study:

Two different diets: protein-rich breakfast with carbohydrate-rich dinner – or vice versa.

Conducting Clinic:

Berlin/Potsdam

Prof. Dr. Joachim Spranger
Charité Berlin
Phone: +49 (0)30-450 514 439
diabetes@charite.de
dzd@dife.de

This study explores how insulin and sugar control learning and reward processing in the brain.

Condition:

None.

Suitable Participants:

Healthy adults between the ages of 18 and 50.

Most Important Exclusion Criteria:

• Manifest diabetes
• Neurological diseases
• Medications that affect metabolism

Course of the Study:

The effect of insulin nasal spray and sugary drinks on learning processes and brain activity is being investigated.

Conducting Clinic:

Cologne

Prof. Dr. Marc Tittgemeyer
University Hospital Cologne
Phone: +49 (0)221-4726-215
tittgemeyerspam prevention@sf.mpg.de

This study explores how the intestinal hormone GLP-1 influences the central insulin effect in the brain and whether early metabolic disorders can be normalized as a result.

Condition:

Prediabetes or insulin resistance.

Suitable Participants:

Adults with prediabetes or insulin resistance.

Most Important Exclusion Criteria:

• Manifest diabetes
• Chronic diseases
• Neurological disorders
• Current infections
• Pregnancy
• Restrictions on semaglutide/insulin administration
• Metal in the body (MRI must be possible)

Course of the Study:

9 days of testing (approx. 23 hours in total) with MRI scans, oral glucose tolerance test (OGTT), blood samples, and injection of semaglutide or placebo (4 times during the study).

Conducting Clinic:

Tübingen

Prof. Dr. Andreas Fritsche
University Hospital Tübingen
Phone: +49 (0)7071–2980687
stoffwechsel@med.uni-tuebingen.de

This study examines and characterizes individuals with diabetes in order to identify parameters that predict the progression of diabetes and its complications, such as neuropathy, retinopathy, nephropathy, or cardiovascular disease. How can dietary changes reduce liver fat and liver inflammation?

Condition:

Diabetes mellitus (all types), obesity, fatty liver disease (MAFLD).

Suitable Participants:

Adults with diabetes mellitus and healthy control individuals without diabetes.

Most Important Exclusion Criteria:

• None

Course of the Study:

A low-fat diet program; blood/urine tests, vascular ultrasound, eye examinations, body fat measurements, and questionnaires are used to collect data that can predict the progression of diabetes.

Conducting Clinic:

Tübingen

Prof. Dr. Andreas Fritsche
University Hospital Tübingen
Phone: +49 (0)7071–2980687
stoffwechsel@med.uni-tuebingen.de