POTS-FLOW: Interplay Between Gut Hormones and Autonomic Postprandial Blood Flow Regulation in Patients With POTS

Not Applicable

Recruiting

• Conditions: Postural Orthostatic Tachycardia Syndrome (POTS); Healthy

• Registration Number: NCT07019519
• Lead Sponsor: University of Copenhagen

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.

Study Timeline

• Study First Submitted: 2025-03-13
• Study Start: 2025-03-15
• Status Verified: 2025-06
• Study First Submitted QC: 2025-06-10
• Last Update Submitted: 2025-06-10
• Study First Posted: 2025-06-13
• Last Update Posted: 2025-06-13
• Primary Completion: 2026-06-30
• Study Completion: 2026-09-30

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 30

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Redistribution of splanchnic blood flow in the vessel mesenteric superior artery (MR)	Continuously for 80 minutes/during infusions	Blood flow in the superior mesenteric artery measured with MR ml/min

Secondary Outcome Measures

Name	Time	Method
Blood flow in portal vein	Continuously for 80 minutes/during infusions	Blood flow in the portal vein measured with MR-scans in ml/min
Blood Flow in celiac trunk	Continuously for 80 minutes/during infusions	Blood flow in the celiac trunk measured with MR-scans in ml/min
Blood Flow in the hepatic artery	Continuously for 80 minutes/during infusions	Blood flow in the hepatic artery measured with MR-scans in ml/min
Blood samples for hormones	Every 10-20 minutes before and during and after the infusions and MR scans (120 minutes)	Blood samples of hormones types: GLP-1(7-36 NH2), GLP-2(1-33), GIP(1-42), Exendin(9-39)NH2, GLP-2(3-33), GIP(3-30)NH2, Glucagon, Insulin/C-peptid, CCK
Symptomscoring	Continously before and during the infusions (120 minutes)	Symptomscoring of autonome dysfunction with VOSS (Vanderbilt Orthostatic Symptom Score) questionnaire: this consists of 10 symptoms: lightheadedness, brain fog, shortness of breath, palpitations, tremor, headache, tightness in chest, blurred vision, nausea and sleepiness rated from 0-10 where 0 is not ocurring and 10 is worts experienced.
Blood samples for genes	One measurement at baseline visit	Genes analyzed from buffycoat: GLP-1R: NM_002062, GLP-2R: NM_004246, GIPR: NM_000164 and NM_001308418, CCKR: NM_000730 and NM_176875,
Blood samples for autoantibodies	One measurement at baseline visit	Autoantibodies: Angiotensin-II-receptor-1 AT1R-ab, Endothelin-receptor-A ETAR-ab, Alpha1 adrenergic-receptor-ab, Alpha2 adrenergic-receptor-ab, Beta1 adrenergic-receptor-ab, Beta2 adrenergic-receptor-ab, Muscarinic cholinergic M1-receptor-ab, Muscarinic cholinergic M2-receptor-ab, Muscarinic cholinergic M3-receptor-ab, Muscarinic cholinergic M4-receptor-ab, Muscarinic cholinergic M5-receptor-ab
Gastric emptying/Blood sample of paracetamol	Every 10-20 minutes before, during and after the infusions and MRI scans (120 minutes)	Uptake/amount of paracetamol in the blood over time as a measure of gastric emptying
Blood sample for glucose	Every 10-20 minutes before and during and after the infusions and MR scans (120 minutes)	Glucose measurements

Trial Locations

Locations (1)

Rigshospitalet; 🇩🇰 Copenhagen, Denmark