Cerebrovascular Dysregulation in Chronic Kidney Disease

Study Overview
=================
Brief Summary
-----------------
The purpose of this study is to test whether or not regular exercise training may improve brain blood flow regulation in patients with chronic kidney disease (CKD).

Detailed Description
-----------------
Prior research has shown that CKD patients have an increased risk of stroke and that impairments in brain blood flow regulation predict stroke in other chronic disease states. This study will test whether exercise training can improve brain blood flow regulation via improved dynamic cerebral autoregulation and cerebrovascular carbon dioxide reactivity in CKD. Participants will undergo exercise training on a stationary bicycle, or stretching exercises, 3 times per week for 12 weeks.

Official Title
-----------------
Cerebrovascular Dysregulation in Chronic Kidney Disease

Conditions
-----------------
Chronic Kidney Diseases

Intervention / Treatment
-----------------
* Behavioral: Exercise
* Behavioral: Stretching


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: • Individuals with chronic kidney disease stages III-IV. Exclusion Criteria: Heart failure Chronic obstructive pulmonary disease Uncontrolled hypertension or hypotension Pregnancy or plans to become pregnant Inability to exercise on a stationary bicycle Current participation in exercise more than 20 minutes twice per week

Ages Eligible for Study
-----------------
Minimum Age: 30 Years
Maximum Age: 75 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Participants will be assigned to one of two conditions:1) aerobic exercise training on a stationary bicycle, or 2) stretching and balance training.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Exercise Training<br>Participants will exercise 3 times a week on a stationary bicycle. Exercise intensity will begin at low levels (50% of maximal heart rate reserve) and increase as tolerated to a maximum of 80% of maximal heart rate reserve. Exercise time will progress from an initial 20 minutes per session to a maximum of 45 minutes per session. | Behavioral: Exercise<br>* Participants randomized to this arm will exercise on a stationary bicycle.<br>|
| Placebo Comparator: Stretching<br>Participants will undergo progressive whole body stretching and balance exercises. This type of low intensity exercise is designed not to increase heart rate but rather to improve joint mobility and the ability to perform activities of daily living. This will serve as the control group to the exercise group. The control group will come in for stretching sessions 3 times per week for 20-45 minutes. | Behavioral: Stretching<br>* Participants randomized to this arm will perform stretching and balance exercise.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in dynamic cerebral autoregulation | Mean arterial pressure and middle cerebral artery blood velocity data will be subjected to transfer function analysis to derive mean arterial pressure-middle cerebral artery blood velocity transfer function phase (radians) and gain (cm/s/mmHg). These indices reflect dynamic cerebral autoregulation. | Mean arterial pressure-middle cerebral artery blood velocity transfer function phase (radians) and gain (cm/s/mmHg) will be compared at baseline (week 0) and after completing the 12-week intervention (week 13). | 
| change in cerebrovascular carbon dioxide reactivity | cerebrovascular carbon dioxide reactivity will be quantified as the change in middle cerebral artery blood velocity for a given change in end-tidal CO2 (cm/s/mmHg). | cerebrovascular carbon dioxide reactivity will be compared at baseline (week 0) and after completing the 12-week intervention (week 13). | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
exercise, brain blood flow