Study of the Renal Perfusion in Healthy Volunteers and Renal Transplant Recipients During an Orthostatic Stress

Study Overview
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Brief Summary
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Autonomic nervous system contributes to the regulation of renal blood flow, affected by upright posture. Kidney transplantation implies sympathetic denervation. The aim of this study is to compare the renal vascular response in volunteers and renal graft recipients to an orthostatic stress induced by a head-up tilt test. Renal peripheral resistances are assessed by echo Doppler. The sympathetic nervous system activity is evaluated by plasma concentrations of catecholamine before and after the head-up tilt test.

Official Title
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Study of the Renal Perfusion in Healthy Volunteers and Renal Transplant Recipients During an Orthostatic Stress

Conditions
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Safe Volunteers, Kidney Transplant Recipients

Intervention / Treatment
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* Other: tilt test


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - Healthy volunteers Male or female, within 18 and 50 year old Caucasian type No cardiovascular risk factor: Body mass index below 25 kg/m2 No smoking No dyslipidemia No diabetes No kidney disease or chronic renal failure No medication Electrocardiogram: normal Arterial blood pressure: normal Plasma creatinine clearance equivalent to 50mL/min or more (Cockroft formula) No proteinuria and no hematuria Able to understand the purpose of the study and sign the informed consent - Renal graft recipients Male or female, within 18 and 50 year old Caucasian type About a year after the first renal allograft Body mass index below 25 kg/m2 No smoking No dylipidemia No diabetes Arterial blood pressure controlled Electrocardiogram: normal Plasma creatinine clearance equivalent to 50mL/min or more (Cockroft formula) Able to understand the purpose of the study and sign the informed consent Exclusion Criteria: Healthy volunteers Creatinine clearance < 50 mL/min (Cockroft formula) More than 2 syncopes a year Pregnancy Renal graft recipients Creatinine clearance < 50 mL/min (Cockroft formula) Second renal allograft or more More than 3 antihypertensive treatments Beta adrenoreceptors blockers Acute rejection More than 2 syncopes a year

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 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 |
| --- | --- |
| Active Comparator: healthy volunteers<br>healthy volunteers | Other: tilt test<br> <br> |
| Active Comparator: renal transplant recipients<br>renal transplant recipients | Other: tilt test<br> <br> |
| Active Comparator: renal transplant recipients grave<br>renal transplant recipients grave | Other: tilt test<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluation of vascular resistance standing in renal transplant subjects compared with healthy subjects. | Evaluation of vascular resistance standing in renal transplant subjects compared with healthy subjects. | three years |