Cerebral Responses to Insulin Induced Hypoglycemia

Study Overview
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Brief Summary
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This research study is designed to investigate the effect of hypoglycemia (low blood sugar) on blood flow to and biochemistry in the brain.

Detailed Description
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The purpose of this study is to better understand the effect of low blood sugar (hypoglycemia) on blood flow and biochemistry in the brain. Hypoglycemia is a serious complication of diabetes treatments. It has been previously observed that hypoglycemia causes an increase in blood flow to certain parts of the brain, but it has been difficult to determine which parts of the brain specifically have an increase in blood flow. With new technology, it is now possible to determine the rate of blood flow in very small parts of the brain. The investigator expects that people with type 1 diabetes and hypoglycemia unawareness, poorly controlled diabetes, and normal subjects will have different rates of blood flow to different parts of the brain in response to hypoglycemia. Having a greater understanding of how the brain adapts to hypoglycemia may help us develop better ways to treat diabetes more safely.

Official Title
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Cerebral Responses to Insulin Induced Hypoglycemia

Conditions
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Type 1 Diabetes, Healthy, Hypoglycemia Unawareness

Intervention / Treatment
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* Other: hypoglycemia (low blood sugar) in MRI


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: well controlled type 1 diabetes (hemoglobin A1C <7.5%) healthy controls Exclusion Criteria: History of stroke, seizures, neurosurgical procedures, or arrhythmias Use of drugs that can alter GABA (gamma-aminobutyric acid) metabolism (such as benzodiazepines). Subjects must also meet requirements for a study in the magnet, which includes weight less than 300 lbs and the absence of metallic substances in their body.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: type 1 diabetes<br>type 1 diabetes >5 years duration Well controlled (a1c <7.5%) | Other: hypoglycemia (low blood sugar) in MRI<br>* hypoglycemia (low blood sugar) in MRI<br>|
| Other: healthy controls<br>healthy controls | Other: hypoglycemia (low blood sugar) in MRI<br>* hypoglycemia (low blood sugar) in MRI<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Brain activation during euglycemia (normal blood sugar) using functional MRI | Brain activation during euglycemia (normal blood sugar) using functional MRI | baseline | 
| Brain activation during hypoglycemia (low blood sugar) using functional MRI | Brain activation during hypoglycemia (low blood sugar) using functional MRI | baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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type 1 diabetes, hypoglycemia unawareness, healthy control