Clinical trial NCT07019519: POTS-FLOW: Interplay Between Gut Hormones and Autonomic Postprandial Blood Flow Regulation in Patients With POTS
Official title: Interplay Between Gut Hormones and Autonomic Postprandial Blood Flow Regulation in Patients With POTS
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Postural Orthostatic Tachycardia Syndrome (POTS)
Healthy
Keywords: Postural Orthostatic Tachycardia Syndrome
POTS
Glucose-dependent insulinotropic polypeptide
GIP
Glucagon-like peptide-1
Glucagon-like peptide-2
GLP-1
GLP-2
CCK-8
Cholecystokinin
Splanchnic Blood Flow
Lead sponsor: University of Copenhagen
Sponsor class: OTHER
Collaborators: name: Rigshospitalet, Denmark
First posted: 2025-06-13
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Single blinded, randomized, crossover trial
Primary purpose: BASIC_SCIENCE

Brief summary: This study will describe the interplay between the gut hormones GIP and CCK and their regulation of blood flow to the large vessels in patients with Postural Orthostatic Tachycardia Syndrome (POTS) and GIP, CCK and GLP-1 in healthy. This is addressed by hormone infusions during MR-scans of the abdomen and intake of oral glucose.

Detailed description: Each participant will attend independent randomized experimental days with MR-scans during and intravenous infusions of hormones or placebo and ingestion of glucose or water. A continuous intravenous infusion of either GIP(3-30)NH2, CCK8- or saline for POTS-group or GIP(3-30)NH2, CCK-8, saline or exendin(9-39)NH2 in healthy is started while the participant lie in the scanner while scans, blood samples and questionnaires are repeated over the time course of 2 hours. At a specific timepoint the participants will ingest 75 g of glucose dissolved in 250 ml water.

Eligibility criteria: Inclusion Criteria POTS patients:

* Previously diagnosed with POTS in tilt test or active stand-test (either newly diagnosed within last 3 months or in new tilt test/active stand test during screenings visit)
* Reproducible orthostatic intolerance with raise in HR on \>30 bpm when standing within 10 minutes of change of supine to standing in age \>19 years or \>40 bpm in age 18-19 years.
* POTS symptoms/orthostatic intolerance
* Age 18-50
* Waist ratio \<180 cm

Exclusion Criteria:

* Chronic illness
* Metallic implants
* Above 10 alcoholic drinks or week or substance abuse
* Other types of sinus tachycardia or heart disease
* Liverenzymes two times above normal values
* Decreased kidney function eGFR \<90 or elevated kreatinkinasis
* Thyroid disease or TSH out of reference
* Uncontrollable low or high blood pressure
* Blood vessels that cannot be visualized on MR
* Any disease that might influence the health of the participant during the study or participants that receives medicine that cannot be paused for 36 hours

Inclusion Criteria:

* Age 18-50
* Waist ratio \<180 cm
* Matched a POTS patient in age, sex and BMI

Exclusion Criteria:

* Chronic illness
* Metallic implants
* Above 10 alcoholic drinks or week or substance abuse
* POTS; other types of sinus tachycardia or heart disease
* Liverenzymes two times above normal values
* Decreased kidney function eGFR \<90 or elevated kreatinkinasis
* Thyroid disease or TSH out of reference
* Uncontrollable low or high blood pressure, Orthostatic hypotension
* Blood vessels that cannot be visualized on MR
* Any disease that might influence the health of the participant during the study or participants that receives medicine that cannot be paused for 36 hours

Primary outcomes:
measure: Redistribution of splanchnic blood flow in the vessel mesenteric superior artery (MR)
timeFrame: Continuously for 80 minutes/during infusions
Secondary outcomes:
measure: Blood flow in portal vein
timeFrame: Continuously for 80 minutes/during infusions
measure: Blood Flow in celiac trunk
timeFrame: Continuously for 80 minutes/during infusions
measure: Blood Flow in the hepatic artery
timeFrame: Continuously for 80 minutes/during infusions
measure: Blood samples for hormones
timeFrame: Every 10-20 minutes before and during and after the infusions and MR scans (120 minutes)
measure: Gastric emptying/Blood sample of paracetamol
timeFrame: Every 10-20 minutes before, during and after the infusions and MRI scans (120 minutes)
measure: Symptomscoring
timeFrame: Continously before and during the infusions (120 minutes)
measure: Blood samples for genes
timeFrame: One measurement at baseline visit
measure: Blood sample for glucose
timeFrame: Every 10-20 minutes before and during and after the infusions and MR scans (120 minutes)
measure: Blood samples for autoantibodies
timeFrame: One measurement at baseline visit
Other outcomes:
Locations:
city: Copenhagen
country: Denmark
facility: Rigshospitalet
Study officials:
affiliation: University of Copenhagen, Rigshospitalet
name: Lærke S Gasbjerg, MD, PhD
role: STUDY_CHAIR
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