Investigating how brain signals affect organ function in health and disease

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This clinical trial evaluates the role of parasympathetic transmission from the brain to metabolic organs by using atropine to block this transmission during an oral glucose tolerance test. Participants will undergo a randomized infusion of either atropine or saline placebo before the test, allowing researchers to compare healthy individuals with those at high risk for metabolic disorders. The study also aims to explore sex differences in signaling and metabolic control. A double-tracer dilution technique will be employed to measure glucose production and disappearance rates during the test.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* Age: at least 18
* BMI: 20 - 24.9 kg/m2 (for the healthy groups) or more than 28 kg/m2 (for the overweight groups)
* For women: Hormonal contraception with a single-phase preparation (e.g. Nuvaring)
* Understanding and voluntarily signing an informed consent form prior to study-related examinations

Exclusion Criteria:

* Drug and/or alcohol abuse
* smoking
* Taking medication that affects blood sugar or addresses the central and/or autonomic nervous system (e.g. anti-epileptic drugs, beta blockers, dopamine agonists, antidepressants). Taking antihistamines.
* Pre-existing cardiac conditions
* Neurological pre-existing conditions
* Known cardiac arrhythmia
* Known allergies to ingredients, e.g. paracetamol and atropine
* Known narrow-angle glaucoma
* Known hyperthyroidism
* Known diseases of the urinary tract or prostate
* Pregnancy or breastfeeding
* At screening: Hb \< 12 g/dl for women and Hb \< 14 g/dl for men
* No consent to be informed about incidentally discovered pathological findings
* Any (clinical) condition which, in the opinion of the physician, could jeopardize the safety of the
* or would jeopardize the scientific success.
* Liver dysfunction
* Renal insufficiency

Where it's running

• Ulm University Hospital
  Ulm, Germany Recruiting

Study contacts

• Principal investigator: Martin Heni, MD — Ulm University Hopital
• Study coordinator: Martin Heni, MD
• Email: martin.heni@uniklinik-ulm.de
• Phone: +4973150044505

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Isometric Handgrip Training Before and After Heart Surgery to Boost Recovery

  This study tests whether gentle handgrip exercise before and after open-heart surgery helps people recover their physical ability and autonomic function.

  Recruiting Cairo University · Giza · NCT07906873

• Glucose levels during a 6 km loaded march

  We will test how blood sugar changes during a 6 km march carrying 15 kg of equipment in healthy soldiers using continuous glucose monitors.

  Recruiting University of Ulm · Ulm · NCT07543705

• Parental metabolism's imprint on the fetal epigenome in gestational diabetes

  We will see if parents' metabolism during pregnancy is linked to epigenetic changes in the fetus in pregnancies with and without gestational diabetes.

  Recruiting University of Ulm · Ulm, Baden-Wurttemberg · NCT07436195

• How changing thyroid hormone levels affects blood sugar, lipids, and energy use

  This trial will test whether raising or lowering thyroid hormones in people with newly diagnosed Graves' disease or thyroid cancer changes blood sugar, insulin, and lipid metabolism using oral glucose tolerance tests.

  Recruiting University of Ulm · Ulm, Baden-Wurttemberg · NCT07410637

• Once-weekly semaglutide for weight loss in adolescents with monogenic obesity

  This study tests whether once-weekly semaglutide 2.4 mg together with a reduced-calorie diet and increased activity helps adolescents with monogenic obesity lose weight, reduce hunger, and improve quality of life over 68 weeks.

  Recruiting University of Ulm · Paris and 6 other locations · NCT07302802

• Global registry for genetic obesity

  This registry collects health and genetic information from people with genetically confirmed or early-onset severe obesity to see if different genes relate to symptoms, complications, and treatment responses.

  Recruiting University of Ulm · Ulm · NCT07296900

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.