Glucose-stimulated Pancreatic Islet and Intestinal Blood Flow in Healthy Subjects and in Type 1 Diabetes

Type 1 diabetes is the major type of diabetes in the young. The pathophysiology still needs clarification in order to reach feasible means of preventing the disease. This study aims in defining the differences in pancreatic and intestinal blood flow between subjects with and without type 1 diabetes and validating the methodology to achieve this. Earlier animal studies have demonstrated changes in pancreatic islet blood flow using microspheres. The aim of this study is to test and validate a method for the assessment of islet perfusion in humans using molecular imaging. The investigators hypothesize that glucose-stimulated pancreatic perfusion is enhanced specifically in islets in healthy subjects and that this increase is mostly suppressed in subjects with type 1 diabetes.

Positron emission tomography (PET) is a non-invasive imaging technique, which can be used to study flow and metabolism of different organs. Using radiowater ([15O]H2O) and PET, cellular perfusion can be measured directly and noninvasively. Recently, diffusion weighted magnetic resonance imaging (DWI) has also been applied as a complimentary method for the assessment to quantitate changes in pancreatic blood flow.

In the study 10 healthy subjects and 10 subjects with type 1 diabetes will be imaged on two separate days. Pancreatic and intestinal perfusion are first measured with [15O]H2O and combined PET/magnetic resonance imaging before and 5 and 15 minutes after intravenous glucose infusion. On the second day, PET imaging is replaced by dynamic DWI conducted in the same time schedule and with intravenous glucose stimulation.

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Key information

Conditions

Type 1 Diabetes Autoimmune Diseases Diabetes Mellitus Diabetes Mellitus, Type 1 Endocrine System Diseases Glucose Metabolism Disorders Immune System Diseases Metabolic Diseases Nutritional and Metabolic Diseases

Age range

18 year–30 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Turku PET Centre

Turku, 20520, Finland

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Criteria for healthy subjects

Inclusion criteria

Healthy as judged by history and examination
Age 18-30 years
Body mass index (BMI) 18 - 27 kg/m2
Normal 2 h oral glucose tolerance test

Exclusion criteria

Any chronic disease
Pregnancy
Blood pressure > 140/90 mmHg
Smoking
Presence of any ferromagnetic objects in the body
Any other condition that could possibly create a hazard to the subject safety, endanger the study procedures or interfere with the interpretation of the study results

Criteria for subjects with type 1 diabetes (T1D)

Inclusion criteria

T1D diagnosed at least 5 years ago
Age 18-30 years
BMI 18 - 30 kg/m2
Good or moderate glycemic control with long-acting insulin analogue combined with injections of rapid-acting insulin
Uncomplicated T1D or with minor microvascular complications

Exclusion criteria

Any other condition or disease possibly affecting circulation, as evaluated by a physician
Pregnancy
Blood pressure > 140/90 mmHg
Smoking
Presence of any ferromagnetic objects in the body
Any other condition that could possibly create a hazard to the subject safety, endanger the study procedures or interfere with the interpretation of the study results

Treatment and study plan

Primary outcomes

Pancreatic islet blood flow acquired with PET and DWI (ml ml-1 min-1)

Time frame: within one study day

healthy subjects and subjects with T1DM are studied once using imaging
Intestinal blood flow acquired with PET and DWI (ml ml-1 min-1)

Time frame: within one study day

healthy subjects and subjects with T1DM are studied once using imaging

Sponsors and collaborators

Lead sponsor

Turku University Hospital

Other Gov

Collaborators

Academy of Finland

Registry information

Official study title

Glucose-stimulated Pancreatic Islet and Intestinal Blood Flow in Healthy Subjects and in Type 1 Diabetes Using Positron Emission Tomography and Diffusion Weighted Imaging

Acronym: ISLET-PET

Important dates

Study start: 2015
Primary completion: 2021
Study completion: 2021
First posted: Sep 11, 2015
Registry last updated: Dec 17, 2021

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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