Validation of a 13C Glucose Breath Test Compared With the Euglycaemic Clamp Test

Study Overview
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Brief Summary
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Insulin resistance can be assessed by the euglycaemic clamp technique. To date, this is the golden standard, but it is not suited for clinical practice. A 13C glucose breath test will be tested as a valid alternative. The curve of the exhaled 13C CO2 as a function of glucose metabolism can be correlated to the curve of the glucose disposal rate obtained via the clamp technique.

Detailed Description
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The hyperinsulinemic-euglycemic clamp technique is the golden standard to assess insulin resistance in type 1 diabetes subjects. The plasma insulin concentration is acutely raised and maintained at 100 μU/ml by a continuous infusion of insulin. Meanwhile, the plasma glucose concentration is held constant at basal levels by a variable glucose infusion. When the steady-state is achieved, the glucose infusion rate equals glucose uptake by all the tissues in the body and is therefore a measure of tissue insulin sensitivity. These data will be compared with the results of a 13C glucose breath test. Breath tests using 13C substrates are based on the principle that 13C CO2 in the exhaled breath can be measured as a metabolic tracer. Breath testing has a major advantage over the clamp test in that it can be performed non-invasively and repeatedly without necessary supervision by medical staff.

Official Title
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Validation of a 13C Glucose Breath Test to Quantify Insulin Resistance in Type 1 Diabetes Mellitus Compared With the Euglycaemic Clamp Test

Conditions
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Insulin Resistance, Type 1 Diabetes

Intervention / Treatment
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* Diagnostic Test: euglycaemic clamp test
* Diagnostic Test: 13C glucose breath test


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult type 1 diabetes patients 25/50 subjects with confirmed NAFLD (using ultrasound criteria) Exclusion Criteria: pregnancy gastric bypass surgery cirrhosis secondary cause of liver steatosis present any cause which makes a 4-hour clamp impossible

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| NAFLD+T1DM+<br>Subjects with type 1 diabetes and ultrasound-defined NAFLD | Diagnostic Test: euglycaemic clamp test<br>* clamp test (golden standard) to determine insulin resistance<br>Diagnostic Test: 13C glucose breath test<br>* 13C glucose breath test to compare with the golden standard<br>|
| NAFLD-T1DM+<br>Subjects with type 1 diabetes without ultrasound-defined NAFLD | Diagnostic Test: euglycaemic clamp test<br>* clamp test (golden standard) to determine insulin resistance<br>Diagnostic Test: 13C glucose breath test<br>* 13C glucose breath test to compare with the golden standard<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of the 13C breath test with the golden standard | sensitivity and specificity analysis using linear regression | one day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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insulin resistance, type 1 diabetes, euglycaemic clamp, breath test