Effect of Exercise on Endothelial Function and Vascular Compliance in Chronic Kidney Disease

Study Overview
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Brief Summary
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The study hypothesis is that 6 weeks of repetitive handgrip exercise will improve endothelial function and venous compliance in pre-dialysis patients with an estimated glomerular filtration rate of less than or equal to 20 ml/min. If proven correct then arm exercise might be useful to improve the success rate for a surgically created arteriovenous fistula in the forearm to become usable as a vascular access for hemodialysis.

Detailed Description
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An arteriovenous fistula (AVF) is the optimal vascular access for chronic hemodialysis. However, AVFs frequently fail to mature. Better strategies are needed to promote AVF maturation. Successful AVF maturation involves arterial and venous dilation. Arterial dilation depends on endothelial release of nitric oxide which can be measured by brachial artery flow-mediated dilation (FMD) and has been reported to predict successful AVF maturation. Venous dilation depends on venous compliance which can be measured by venous plethysmography and is also predictive of successful AVF maturation. Endothelial function is impaired in patients with chronic kidney disease (CKD). Aerobic exercise has been reported to improve endothelial function and venous compliance but it has not been studied in the pre-dialysis patient. To address this question we will determine whether 6 weeks of repetitive handgrip exercise with upper arm venous compression can improve brachial artery endothelial function or venous compliance in pre-dialysis patients with an estimated glomerular filtration rate of less than or equal to 20 ml/min.

Official Title
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Effect of Forearm Exercise on Flow Mediated Vasodilation Prior to Arteriovenous Fistula Placement for Hemodialysis

Conditions
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Kidney Failure, Chronic

Intervention / Treatment
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* Other: Repetitive arm exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age exceeding the age of majority (18 years of age). Chronic renal failure with a calculated GFR (MDRD equation) less than or equal to 20 ml/min Eligible for creation of an arteriovenous fistula for the purpose of hemodialysis. The subject is expected to stay within driving distance of study site for at least 4 months. The subject's physician(s) will allow the patient to participate. Ability to give informed consent. Exclusion Criteria: Unstable angina. Uncontrolled hypertension (resting blood pressure >170 systolic or >100 diastolic). Musculoskeletal or neurologic problem that prevents arm exercise. Currently functioning arteriovenous access in the same arm as the planned new fistula. Subjects who are eligible to participate in the ongoing DAC fistula trial. Planned new access surgery in less than 6 weeks Anticipated non-compliance with medical care based on physician judgment. Patient refusal.

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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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Repetitive handgrip exercise<br>After baseline testing and randomization, subjects in this group are instructed to perform the intervention: daily repetitive handgrip exercise with upper arm compression band. Brachial artery endothelial function and venous compliance are tested at baseline and 6 weeks. | Other: Repetitive arm exercise<br>* After baseline testing and randomization, subjects in this group are instructed to perform repetitive handgrip exercise with an upper arm compression band until arm fatigue occurs. After resting 1 minute this exercise is repeated 9 times daily for 6 weeks.<br>|
| No Intervention: No arm exercise<br>Time control. Subjects do usual activities without any exercise intervention. Brachial artery endothelial function and venous compliance are tested at baseline and 6 weeks. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Brachial artery flow-mediated dilatation |  | 6 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Forearm venous compliance by plethysmography |  | 6 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Endothelium, Vasodilatation, Vein, Compliance, Arteriovenous shunt, surgical