Mechanisms of Muscle Blood Flow Dysregulation and Exercise Intolerance in Chronic Kidney Disease

Not Applicable

Terminated

• Conditions: Chronic Kidney Disease
• Interventions: Behavioral: Forearm exercise training

• Registration Number: NCT02664519
• Lead Sponsor: University of Texas Southwestern Medical Center

Brief Summary

Patients with chronic kidney disease (CKD) experience fatigue and exercise intolerance. Increased oxidative stress in CKD may be a contributing factor. The role of impaired muscle blood flow regulation has not been fully explored. The investigators hypothesize that functional sympatholysis is exaggerated in CKD and this is associated with increased oxidative stress. The investigators also hypothesize that exercise training will improve functional sympatholysis and oxidative stress

Detailed Description

Progressive muscle weakness and premature fatigue are characterize the condition of chronic kidney disease (CKD) which can be very debilitating. Mechanisms underlying exercise intolerance in CKD is not completely understood. Previous studies have demonstrated impaired skeletal muscle vasodilation during exercise in CKD patients, which may contribute to exercise intolerance. Normally, there is blunting of sympathetic mediated vasoconstriction in exercising muscle to allow for steady blood supply to exercising muscles. This phenomenon is called functional sympatholysis. Functional sympatholysis is impaired by increases in reactive oxygen specie and may be impaired in CKD.

Experiments will be performed on 2 groups of subjects 1) Normal kidney function (eGFR\>90) 2) Stage 2-3 CKD (eGFR 30-89). VAsoactive medications will be held for 72 hours before study. All participants will attend a baseline study visit, which will include a physical examination, a medical history review, vital sign measurements, and blood collection. Muscle nerve activity and muscle oxygenation will be measured while the subjects perform hand grip exercise at 30% maximum voluntary contraction with and without lower body negative pressure (- 20 mmHg). Muscle blood flow will be measured before and after hand grip exercises. CKD subjects will then be randomized to exercise training (to squeeze a tennis ball repeatedly for at least 30 min/day) or no exercise training for 28 days. Procedures in baseline visit will be repeated followed by cross over to alternate group for 28 days followed by repeat of baseline procedures. Blood flow, muscle oxygenation and muscle nerve activity will be compared between CKD and normal subjects as well as before and after exercise training for CKD subjects.

Basic Information
|
Recruitment & Eligibility
|
Study & Design
|
Trial Locations

Study Timeline

• Study Start: 2016-01
• Study First Submitted: 2016-01-08
• Study First Submitted QC: 2016-01-26
• Study First Posted: 2016-01-27
• Status Verified: 2021-03
• Primary Completion: 2021-03-18
• Study Completion: 2021-03-18
• Last Update Submitted: 2021-03-19
• Last Update Posted: 2021-03-23

Recruitment & Eligibility

• Status: TERMINATED
• Sex: All
• Target Recruitment: 32

Inclusion Criteria

• Normotensive adults
• CKD 2-3

Read More

Exclusion Criteria

• Blood Pressure ≥140/90
• eGFR >60ml/min/1.73 m2 or eGFR <30ml/min/1.73 m2
• Any evidence of cardiopulmonary disease, left ventricular hypertrophy or systolic dysfunction by echocardiography.
• Diabetes mellitus or other systemic illness
• Pregnancy
• Any history of substance abuse or current cigarette use
• Any history of psychiatric illness
• History of malignancy

Read More

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
No exercise training followed by exercise training	Forearm exercise training	CKD subjects will be randomized to exercise training (to squeeze a tennis ball repeatedly for at least 30 min/day) or no exercise training for 28 days. Procedures in baseline visit will be repeated followed by cross over to alternate group for 28 days followed by repeat of baseline procedures.
Exercise training followed by no exercise training	Forearm exercise training	CKD subjects will be randomized to exercise training (to squeeze a tennis ball repeatedly for at least 30 min/day) or no exercise training for 28 days. Procedures in baseline visit will be repeated followed by cross over to alternate group for 28 days followed by repeat of baseline procedures.

Primary Outcome Measures

Name	Time	Method
Change in muscle oxygenation	After 28 days	Tissue oxygenation will be recorded using Near-infrared spectroscopy (NIRS)

Secondary Outcome Measures

Name	Time	Method
Change in Forearm vascular conductance (FVC)	After 28 days	Doppler ultrasonography to measure blood flow
Change in plasma isoprostanes	After 28 days	Plasma isoprostanes will be used as a measure of oxidative stress
Change in muscle sympathetic nerve activity (MSNA)	After 28 days	MSNA will be measured using tiny tungsten wire inserted into the common peroneal nerve below fibular head.

Trial Locations

Locations (1)

University of Texas Southwestern Medical Center at Dallas; 🇺🇸 Dallas, Texas, United States