Role of Pancreatic Triglyceride Content in Beta-cell Function

Study Overview
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Brief Summary
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The study evaluates if fat accumulates in the pancreas in individuals at risk of developing obesity-related diabetes. It also evaluates if the amount of fat in the pancreas can predict the residual functional capacity of the pancreas (insulin secretion).

Official Title
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Role of Pancreatic Triglyceride Content in Beta-cell Function

Conditions
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Obesity, Type 2 Diabetes

Intervention / Treatment
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* Other: No intervention planned.


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: adults without prior history of pancreatic disease (other than diabetes) Exclusion Criteria: use of unapproved medications contraindications to the MRI procedure contraindications to frequent blood draws pregnancy use of more than 2 alcoholic drinks/day

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 99 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Healthy volunteers<br>Normal weight and normal glucose tolerance. | Other: No intervention planned.<br>* This is a cross-sectional observational study, no intervention is planned.<br>|
| Pre-diabetes<br>Impaired fasting glucose of impaired glucose tolerance. | Other: No intervention planned.<br>* This is a cross-sectional observational study, no intervention is planned.<br>|
| Overweight<br>Overweight or obese volunteers, but with normal fasting and postprandial glucose levels. | Other: No intervention planned.<br>* This is a cross-sectional observational study, no intervention is planned.<br>|
| Type 2 diabetes<br>Patients with type 2 diabetes. | Other: No intervention planned.<br>* This is a cross-sectional observational study, no intervention is planned.<br>|
| Type 1 diabetes<br>Patients with type 1 diabetes. | Other: No intervention planned.<br>* This is a cross-sectional observational study, no intervention is planned.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pancreatic and Liver Fat | Pancreatic and liver triglyceride (fat) content measured by the magnetic resonance spectroscopy (MRS) technique in volunteers with a wide range of body mass index (BMI). | Within 1 month after screening visit. | 
| Beta-cell Function; AIRg - Acute Insulin Response to Glucose | Beta-cell function as measured by frequently sampled intravenous glucose tolerance test (FSIVGTT) in volunteers with a wide range of body mass index (BMI). AIRg - acute insulin response to glucose. Blood samples were collected at -5, -1, 2, 3, 4, 5, 6, 8, 10, 14, 19, 22, 25, 30, 40, 50, 70, 100, 140, and 180 minutes, where time 0 is when an i.v. bolus of 50% glucose solution (0.3 g/kg) was injected. | At screening visit. | 
| Insulin Sensitivity (SI) | Sensitivity index measured during frequently sampled intravenous glucose tolerance test (FSIVGTT) in volunteers with a wide range of body mass index (BMI). Blood samples were collected at -5, -1, 2, 3, 4, 5, 6, 8, 10, 14, 19, 22, 25, 30, 40, 50, 70, 100, 140, and 180 minutes, where time 0 is when an i.v. bolus of 50% glucose solution (0.3 g/kg) was injected. Higher numbers indicates better insulin sensitivity Insulin sensitivity was estimated as Matsuda index using formula = 10,000 / (FPG x FPI x Glucosemean0-180 x Insulinmean0-180)0.5, where FPG = fasting plasma glucose and FPI = fasting plasma insulin. | At screening visit. | 
| Disposition Index (DI) | Disposition index measured during frequently sampled intravenous glucose tolerance test (FSIVGTT) in volunteers with a wide range of body mass index (BMI). Blood samples were collected at -5, -1, 2, 3, 4, 5, 6, 8, 10, 14, 19, 22, 25, 30, 40, 50, 70, 100, 140, and 180 minutes, where time 0 is when an i.v. bolus of 50% glucose solution (0.3 g/kg) was injected. Disposition index (DI) was used to characterize the correlation between β-cell sensitivity and insulin sensitivity and was determined using formula DI = AIRg x SI (from outcomes 2 and 3). Higher numbers indicates a better improvement in beta-cell function. | At screening visit. |