Changes in Serum Electrolytes at Different Glucose Concentrations + Impact on a Non-invasive Glucose Monitoring Method

Study Overview
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Brief Summary
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In healthy subjects: Continuous monitoring of the glucose concentration in the skin by means of a non-invasive glucose sensor during a glucose clamp when systematically changing the blood glucose concentration (e.g. to hyperglycemia). Simultaneous frequent determinations of serum electrolytes.

Detailed Description
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Non-invasive continuous glucose monitoring is a promising approach in diabetes therapy. It is known that changes in glucose concentration in the skin can be registered by means of optical, spectroscopic measures in subjects with diabetes. The precision of such measures, however, so far has been unsatisfactory. This study evaluates the changes in skin glucose concentration by means of a non-invasive glucose sensor and compares these to blood glucose concentrations during a glucose clamp. It is also known that with hyperglycemic blood glucose concentrations there is a consecutive hyponatraemia. This study shall evaluate to which extent and how fast serum electrolyte parameters change when establishing a hyperglycaemic blood glucose level. This shall help estimate which impact these changes in electrolytes have on the non-invasive glucose sensor.

Official Title
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A Single Center, Open Study to Evaluate Changes in Serum Electrolytes at Different Glucose Concentrations and Their Impact on a Non-invasive Glucose Monitoring Method

Conditions
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Diabetes Mellitus

Intervention / Treatment
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* Device: Non-invasive CGMS
* Procedure: Hyperglycemic glucose clamp


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Written informed consent Age between 18 and 65 years Exclusion Criteria: Uncontrolled hypertension (diastolic blood pressure > 100 mmHG and/or systolic blood pressure > 180 mmHg) Pregnancy or lactation period for female subjects Serious clinical signs of a liver disease, acute or chronic hepatitis, acute or chronic kidney disease, or ALAT > 2.5 times the upper level of normal values, or serum creatinine > 1.3 mg/dL (women)/1.5 mg/dL (men) Any serious acute illness (at the decision of the investigator), e.g. sepsis, gastric or duodenal ulcer, acute myocardial infarction, acute asthma attack Any other serious chronic illness (at the decision of the investigator), e.g. chronic obstructive pulmonary disease, any kind of cancer

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: Treatment
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Intervention/Treatment |
| --- |
|Device: Non-invasive CGMS|A non-invasive continuous glucose monitoring device measured was applied at the wrist and measured skin glucose as an indirect measure of blood glucose every 10 min.|
|Procedure: Hyperglycemic glucose clamp|The automated glucose clamp technique was used to control glucose levels at baseline glycemia for 1h, hyperglycemia (16.7 mmol/L) for at least 2.5h and euglycemia (5 mmol/L) for another 2.5h. A continuous somatostatin infusion was initiated after 1h to suppress endogenous insulin secretion. A glucose solution was infused to increase the blood glucose towards the hyperglycemic target level. At approximately t=3.5h the somatostatin infusion was stopped and blood glucose was controlled at the euglycemic target level.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| plasma ion concentrations (sodium, potassium, chloride, calcium, magnesium) and osmolarity |  | blood samples every 10 min during baseline, plateau hyperglycemic and final euglycemic phase, every 5 min during increase and decrease of blood glucose | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| blood glucose concentration |  | continuously during glucose clamp | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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diabetes