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

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.

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