Sympatholysis in Chronic Kidney Disease (Sym-CKD)

May 14, 2026 updated by: Jeanie Park, Emory University

Functional Sympatholysis and Exercise Intolerance in Chronic Kidney Disease

The purpose of this study is to find out why patients with chronic kidney disease (CKD) have poor exercise capacity and what causes an increase in blood pressure during exercise (i.e. increased adrenaline levels, or decreased ability of blood vessels to dilate).

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Patients with chronic kidney disease (CKD) suffer from exercise intolerance and poor physical capacity which contributes to increased cardiovascular risk in this patient population. Prior studies have shown that CKD patients have an exaggerated increase in blood pressure (BP) during both static and rhythmic exercise. Such abnormal hemodynamic responses to exercise can contribute to poor physical capacity and abnormal muscle blood flow during exercise in these patients. The goals of this project are to investigate the mechanisms and potential therapies targeting the abnormal hemodynamic response during exercise in CKD by examining the roles of impaired vasodilation, and exaggerated vasoconstriction.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
110

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Jeanie Park, MD
  • Phone Number: 207070 404-321-6111

Study Contact Backup

Study Locations

  • United States
    • Georgia
      • Decatur, Georgia, United States, 30033
        • Recruiting
        • Atlanta VA Medical Center
        • Principal Investigator:
          • Jeanie Park, MD
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Veterans with Stages III and IV Chronic Kidney Disease (CKD)
  • Kidney transplant recipients with varying degrees of kidney function
  • Veterans 18-75 years old, without kidney disease, as study controls
  • Exercise less than 20 minutes twice per week
  • Willing and able to cooperate with the protocol

Exclusion Criteria:

  • Severe CKD (estimated glomerular filtration rate (eGFR) < 15 cc/minute)
  • Metabolic alkalosis (serum bicarbonate > 28 meq/L)
  • Ongoing drug or alcohol abuse
  • Diabetic neuropathy
  • Any serious systemic disease that might influence survival
  • Severe anemia with hemoglobin (Hbg) level < 10 g/dL
  • Clinical evidence of congestive heart failure or ejection fraction below 35%
  • Symptomatic heart disease determined by prior electrocardiogram, stress test, and/or history
  • Treatment with central alpha agonists (clonidine)
  • Uncontrolled hypertension with blood pressure (BP) greater than 170/100 mmHg
  • Low blood pressure with BP less than 100/50 mmHg
  • Pregnancy or plans to become pregnant
  • Current treatment with monoamine oxidase inhibitors (MAOIs)
  • Inability to exercise on a stationary bicycle

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Exercise Training plus Sodium Bicarbonate
Subjects with CKD will undergo exercise training on a stationary bicycle for 20-45 minutes, 3 times per week, for 6-12 weeks. Additionally, subjects will take 1300-2600 mg (2-4 pills) of sodium bicarbonate prior to each exercise session three times a week.
Drug: Sodium Bicarbonate
Sodium bicarbonate tablet is 650 mg for one tablet. Oral sodium bicarbonate will be given out as 1300mg-2600mg (2-4 pills) prior to each exercise or stretching session. Serum bicarbonate measurements will be monitored throughout the study (at 2 weeks, then every 2-4 weeks thereafter), and bicarbonate dosages will be adjusted to avoid metabolic alkalosis (serum bicarbonate > 30).
Behavioral: Exercise Training
Exercise training consists of riding a stationary bicycle for 20-45 minutes, 3 times per week, supervised by trained exercise specialists, for 6-12 weeks. The exercise program will follow the guidelines provided by the American College of Sports Medicine (ACSM) for optimizing cardiovascular fitness. Exercise intensity will begin at low levels (50 percent of resting heart rate) and increase to no greater than 80 percent of resting heart rate. Exercise time will progress, depending on subject's progress, from 20 minutes per session at first, to a maximum of 45 minutes. Trained staff members will give instructions throughout each exercise session. Before beginning each exercise session, subjects will be instructed on a warm-up focusing on preparing the legs for activity.
Active Comparator: Exercise Training plus Placebo
Subjects with CKD will undergo exercise training on a stationary bicycle,for 20-45 minutes, 3 times per week, for 6-12 weeks. Additionally, subjects will take 2-4 placebo tablets prior to each exercise session three times a week.
Behavioral: Exercise Training
Exercise training consists of riding a stationary bicycle for 20-45 minutes, 3 times per week, supervised by trained exercise specialists, for 6-12 weeks. The exercise program will follow the guidelines provided by the American College of Sports Medicine (ACSM) for optimizing cardiovascular fitness. Exercise intensity will begin at low levels (50 percent of resting heart rate) and increase to no greater than 80 percent of resting heart rate. Exercise time will progress, depending on subject's progress, from 20 minutes per session at first, to a maximum of 45 minutes. Trained staff members will give instructions throughout each exercise session. Before beginning each exercise session, subjects will be instructed on a warm-up focusing on preparing the legs for activity.
Drug: Placebo
2-4 placebo pills will be given out prior to each exercise or stretching session.
Active Comparator: Control to Exercise (Stretching) plus Sodium Bicarbonate
Subjects with CKD will undergo progressive whole body stretching and toning exercises 3 times a week for 20-45 minutes for 6-12 weeks. Additionally, subjects will take 1300-2600 mg (2-4 pills) of sodium bicarbonate prior to each stretching session three times a week.
Drug: Sodium Bicarbonate
Sodium bicarbonate tablet is 650 mg for one tablet. Oral sodium bicarbonate will be given out as 1300mg-2600mg (2-4 pills) prior to each exercise or stretching session. Serum bicarbonate measurements will be monitored throughout the study (at 2 weeks, then every 2-4 weeks thereafter), and bicarbonate dosages will be adjusted to avoid metabolic alkalosis (serum bicarbonate > 30).
Behavioral: Control to Exercise (Stretching)
Stretching exercise will consist of muscle stretching and toning for 20-45 minutes, 3 times per week, supervised by trained exercise specialists, for 6-12 weeks. Trained staff members will guide subjects with the stretching exercises, and activities are designed to increase flexibility and range of motion. Before beginning each stretching exercise session, subjects will be instructed to warm-up.
Placebo Comparator: Control to Exercise (Stretching) plus Placebo
Subjects with CKD will undergo progressive whole body stretching and toning exercises 3 times a week for 20-45 minutes for 6-12 weeks. Additionally, subjects will take 2-4 placebo tablets prior to each exercise session three times a week.
Drug: Placebo
2-4 placebo pills will be given out prior to each exercise or stretching session.
Behavioral: Control to Exercise (Stretching)
Stretching exercise will consist of muscle stretching and toning for 20-45 minutes, 3 times per week, supervised by trained exercise specialists, for 6-12 weeks. Trained staff members will guide subjects with the stretching exercises, and activities are designed to increase flexibility and range of motion. Before beginning each stretching exercise session, subjects will be instructed to warm-up.
No Intervention: Healthy Control
Healthy subjects without CKD will not receive any interventions.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in muscle oxygenation after exercise/stretching training
Time Frame: Baseline, Week 12
Near-infrared spectroscopy (NIRS) will measure and record tissue oxyhemoglobin, deoxyhemoglobin, and total hemoglobin.
Baseline, Week 12
Change in muscle interstitial pH after exercise/stretching training
Time Frame: Baseline, Week 12
Near-infrared spectroscopy (NIRS) will give an estimation of the pH levels within the muscle interstitial space. Muscle interstitial pH markedly decreases during exercise, and is often lower than blood pH with a larger intracellular to interstitial pH gradient. CKD patients may have less ability to buffer pH changes in the interstitial space during exercise. Bicarbonate supplementation may improve muscle interstitial buffering capacity during exercise, and prevent exaggerated reductions in muscle interstitial pH during exercise.
Baseline, Week 12
Change in venoconstriction after exercise/stretching training
Time Frame: Baseline, Week 12
Dorsal hand vein model will be used to assess vascular alpha-1 adrenergic responsiveness by measuring the degree of venous constriction in response to varying dosages of local phenylephrine (PE) infusion.
Baseline, Week 12

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in Functional Sympatholysis
Time Frame: Baseline, 30 minutes
Functional sympatholysis is determined by measuring the change in forearm oxygenation via near infrared spectroscopy (NIRS), and forearm blood flow and conductance using ultrasound, during sympathetic activation induced by lower body negative pressure (LBNP), at rest and during handgrip exercise. NIRS measures and records tissue oxyhemoglobin, deoxyhemoglobin, and total hemoglobin.
Baseline, 30 minutes
Change in muscle interstitial pH after handgrip exercise
Time Frame: Baseline, 30 minutes
Near-infrared spectroscopy (NIRS) will give an estimation of the pH levels within the muscle interstitial space. Muscle interstitial pH markedly decreases during exercise, and is often lower than blood pH with a larger intracellular to interstitial pH gradient. CKD patients may have less ability to buffer pH changes in the interstitial space during exercise. Bicarbonate supplementation may improve muscle interstitial buffering capacity during exercise, and prevent exaggerated reductions in muscle interstitial pH during exercise.
Baseline, 30 minutes
Change in Venoconstriction after Phenylephrine
Time Frame: Baseline, 30 minutes
Vascular function is measured as venoconstriction after administration of phenylephrine. Dorsal hand vein model will be used to assess vascular alpha-1 adrenergic responsiveness by measuring the degree of venous constriction in response to varying dosages of local phenylephrine (PE) infusion.
Baseline, 30 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Emory University

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Heart, Lung, and Blood Institute (NHLBI)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Jeanie Park, MD, Emory University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 11, 2015

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 3, 2015

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 7, 2015

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 8, 2015

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 18, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 14, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB00078214
  • 2025P011323 (Other Identifier: Emory IRB)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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