Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
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RECRUITING
PHASE4
60 participants
INTERVENTIONAL
2023-01-25
2024-12-31
Brief Summary
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Detailed Description
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All participants will first undergo a screening visit starting with signing an informed consent form. Then they will undergo a physical examination, are interviewed about their medical history. Finally, some routine laboratory tests are collected, and a 75 g oral glucose tolerance test is performed. The participants who are eligibile for the study will continue to the PET studies.
The dose escalation study will be completed first. In this 8 participants will be studied once with Siemens Biovision Quadra PET/CT scanner. They will receive eight doses of oxygen-15 labelledradiowater (H2\[15O\]O) ranging from 25 to 700 MBq, with each dose repeated twice to evaluate repeatability of each dose. These participants will not undergo any further studies.
For the other subjects, there will be two more PET study visits.
On the first visit, the effects of emotions, evoked by short movie clips or cold exposure of one leg, on whole-body blood flow will studied with oxygen-15 labelled radiowater. Each participant will be studied 8 times in one session, with repeated H2\[15O\]O boluses of 400 MBq followed by 7.5 min dynamic PET scans with Siemens Biovision Quadra PET/CT scanner and a 5 min recovery and wash-out period.
On the other visit the effects of insulin on circulation will be studied by performing a hyperinsulinemic, euglycemic clamp during the PET scan. During the clamp, fast-acting insulin (NovoRapid, NovoNordisk) is administered intravenously at a fixed rate (40 mU/m2 body surface area/min). Plasma glucose is monitored every 5-10 minutes, and 20 % glucose is administered at a varying rate to maintain euglycemia (5.0 mmol/L).
At the scanner a fasting H2\[15O\]O PET/CT scan (400 MBq) will be performed first. After this, the hyperinsulinemic, euglycemic clamp is started, and the radiowater scans are repeated 10 minutes and 50 minutes into the insulin infusion. 60 minutes after the start of clamp, 100 MBq of glucose analogue tracer \[18F\]fluorodeoxyglucose is administered and a 50 min dynamic PET scan is started. After the scan, insulin infusion is discontinued and participants are monitored until plasma glucose levels are adequate for safe discharge.
For a subgroup of participants, skeletal muscle microvascular bloodflow will also be assessed with contrast-enhanced ultrasound performed during fasting and 30 minutes after the start of clamp. The participants will be administered intravenous contrast agent, and after steady plasma concentration is reached (2.5 min), the contrast agent micro bubbles are destroyed with a high-intensity ultrasound signal, and the rate at which small arterioles are refilled is measured.
Data will be analysed using in-house developed programs. Regions of interest will be drawn manually for peripheral tissues (skeletal muscle, visceral, brown and subcutaneous adipose tissue, liver, kidney, intestines) and using automated segmentation tools for the brain.
Conditions
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Keywords
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Study Design
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NON_RANDOMIZED
PARALLEL
BASIC_SCIENCE
SINGLE
Study Groups
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TOTAL dose test
The aim of the studies performed in this arm (8 subjects) is to test the lowest dose of H2\[15O\]O (radiowater) for the Siemens Quadra PET/CT scanner. Each participant will be studied once with the scanner with 4 different doses (25-700 MBq) of H2\[15O\]O, each repeated 2 times
H2[15O]O PET/CT
H2\[15O\]O PET/CT, with a dose of 25-700 MB/bolus repeated 2-8 times per scan.
TOTAL
The participants in this arm will undergo two PET visits. On one visit the effects of visual stimuli or cold on whole body perfusion will be studied with H2\[15O\]O PET/CT. On the second visit whole-body insulin sensitivity is studied with \[18F\]fluorodeoxyglucose PET/CT, and the acute and delayed effects of intravenous insulin on blood flow will be studied with H2\[15O\]O PET/CT.
Movies
Participants will watch eight short movie clips, and the changes different emotions evoked by the clips will be studied using H2\[15O\]O PET/CT.
Cold
Participants will be studied with H2\[15O\]O PET/CT while one of their legs will be exposed to cold to study the effects of cold stimulus on whole-body blood flow.
Hyperinsulinemic euglycemic clamp
Participants will be administered intravenous fast acting insulin (NovoRapid, Novo Nordisk, 1 mU/m2 body surface area/min) together with 20 % glucose to maintain normal glucose values (5.0 mmol/L) to study the effects of insulin on whole body blood flow with H2\[15O\]O PET/CT, and to assess tissue insulin-stimulated glucose uptake with \[18F\]FDG PET/CT.
H2[15O]O PET/CT
H2\[15O\]O PET/CT, with a dose of 25-700 MB/bolus repeated 2-8 times per scan.
[18F]FDG PET/CT
Whole-body \[18F\]FDG PET/CT scan to study tissue glucose uptake, dose 100 MBq
CEUS or Contrast enhanced Ultrasound
Contrast-enhanced ultrasound of left forearm muscles is performed during fasting and after 30-40 minutes of hyperinsulinemia
Interventions
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Movies
Participants will watch eight short movie clips, and the changes different emotions evoked by the clips will be studied using H2\[15O\]O PET/CT.
Cold
Participants will be studied with H2\[15O\]O PET/CT while one of their legs will be exposed to cold to study the effects of cold stimulus on whole-body blood flow.
Hyperinsulinemic euglycemic clamp
Participants will be administered intravenous fast acting insulin (NovoRapid, Novo Nordisk, 1 mU/m2 body surface area/min) together with 20 % glucose to maintain normal glucose values (5.0 mmol/L) to study the effects of insulin on whole body blood flow with H2\[15O\]O PET/CT, and to assess tissue insulin-stimulated glucose uptake with \[18F\]FDG PET/CT.
H2[15O]O PET/CT
H2\[15O\]O PET/CT, with a dose of 25-700 MB/bolus repeated 2-8 times per scan.
[18F]FDG PET/CT
Whole-body \[18F\]FDG PET/CT scan to study tissue glucose uptake, dose 100 MBq
CEUS or Contrast enhanced Ultrasound
Contrast-enhanced ultrasound of left forearm muscles is performed during fasting and after 30-40 minutes of hyperinsulinemia
Eligibility Criteria
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Inclusion Criteria
2. BMI either 18.5-25 kg/m2 or above 30 kg/m2
3. Use of hormonal contraception for women in child bearing age
Exclusion Criteria
2. In the group with obesity: current or previous use of GLP-1-agonists or insulin
3. History of eating disorders
4. Smoking, use of narcotics, excessive use of alcohol
5. Previous participation in PET studies
6. Previous significant exposure to radiation
7. Claustrophobia
8. Active plans for concieving (both sexes)
9. Any other condition that in the opinion of the investigator could create a hazard to the subject safety, endanger the study procedures or interfere with the interpretation of study results
20 Years
60 Years
ALL
Yes
Sponsors
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Turku University Hospital
OTHER_GOV
Responsible Party
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Pirjo Nuutila
professor
Principal Investigators
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Lauri Nummenmaa, Professor
Role: PRINCIPAL_INVESTIGATOR
University of Turku
Pirjo Nuutila, professor
Role: PRINCIPAL_INVESTIGATOR
University of Turku, Turku University Hospital
Locations
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Turku PET Centre
Turku, , Finland
Countries
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Central Contacts
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Facility Contacts
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Pirjo Nuutila, Professor
Role: primary
Sanna Himanen, RN
Role: backup
Provided Documents
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Document Type: Study Protocol and Statistical Analysis Plan
Other Identifiers
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T335/2022
Identifier Type: -
Identifier Source: org_study_id