Measurement of Endothelial Function With Peripheral Arterial Tonometry in Patients Undergoing Hyperbaric Oxygen Therapy

Study Overview
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Brief Summary
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The purpose of this clinical study is to test whether or not patients treated with HBOT for diabetic foot ulcers will demonstrate measurable changes of the blood vessel function during the course of HBOT treatments. , i.e. an expected increase in the reactive hyperemic index (RHI) measured by the peripheral arterial tonometry (PAT).

Detailed Description
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Measurement and monitoring of endothelial function can be used for prediction of outcome in acute, severe disease. Diabetic patients have a poorer peripheral vascular function measured by peripheral arterial tonometry (PAT) as compared to normals, but the effect of hyperbaric oxygen therapy (HBOT) on endothelial function in these patients is unknown. Measurement of PAT in patients with diabetic foot ulcers undergoing HBOT, may help to improve treatment and changes in the reactive hyperemic index (RHI) might correlate with wound healing in these patients. Peripheral arterial tonometer (PAT) has been shown to be an easy, fast and standardized method for measuring the peripheral arterial endothelial function. The method is also operator-independent and has a high reproducibility. The PAT apparatus (ENDOPAT) measures the post-ischemic response to a five-minute blood flow occlusion of the upper arm, and the relationship between the pre-and post-ischemic pulse amplitude is expressed as a reactive hyperemic index (RHI). The normal RHI in young healthy persons is more than 2, while in critically ill patients and patients with diabetes, hypertension or heart disease it is significantly decreased. The study aims to test whether or not patients treated with HBOT for diabetic foot ulcers will demonstrate an improvement of the endothelial function in the peripheral vessels, i.e. an increase in RHI measured by the PAT. Similarly, essential mediators of angiogenesis and nitric oxide bioavailability will be measured in peripheral blood taken during the PAT measurements which will be performed at the time of inclusion, before HBOT and subsequently for each 10th HBOT session.

Official Title
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Measurements of Endothelial Function by Means of Peripheral Arterial Tonometry in Diabetic Foot Ulcer Patients Undergoing Hyperbaric Oxygen Therapy.

Conditions
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Diabetic Peripheral Vascular Disease

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diabetic patients with foot ulcer None diabetic patients Age > 18 years Patients referred to hyperbaric oxygen therapy. Patients who have given written informed consent to participate in the study Exclusion Criteria: Patients who cannot cooperate to participate in the study Patients who do not understand or speak Danish or English Allergy to the materials used in the experiment. Patients < 18 years

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 |
| --- | --- |
| diabetic patients<br>Diabetic patients given HBOT | |
| None diabetic patients<br>None diabetic patients given HBOT | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peripheral arterial tonometry (PAT) | Changes in PAT measurements upon completion of HBOT sessions. | 6 weeks | 
| Peripheral arterial tonometry (PAT) | Changes in PAT measurements upon completion of HBOT sessions after 12 weeks. | 18 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Nitric oxide and cytokine expression | Measurement of nitric oxide bioavailability and levels of cytokine expression levels in serum after HBOT completion. | 6 weeks | 
| Nitric oxide and cytokine expression | Measurement of nitric oxide bioavailability and levels of cytokine expression levels in serum after HBOT completion following 12 weeks. | 18 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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diabetes, foot, wounds, nitric oxide, endothelium, infection, biological markers, observational study, hyperbaric oxygen, ulcers, cytokines, inflammation