Sympatholysis in Chronic Kidney Disease

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).

DRUG

Placebo

2-4 placebo pills will be given out prior to each exercise or stretching session.

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.

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.

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.

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.

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.

What is a clinical trial?

A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.

Is it safe to participate?

Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.

Will I be compensated?

Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.

Will I receive a placebo instead of treatment?

When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.

Can I leave a trial if I change my mind?

Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.

How long does a clinical trial last?

Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.