Bicarbonate Administration in CKD

University of Colorado Denver (CU Denver)

Status: Completed

Conditions: Chronic Kidney Disease; Metabolic Acidosis

Treatments: Drug: Placebo; Drug: Sodium bicarbonate

Study type: Interventional

Funder types: Other

Identifiers

NCT02915601

16-1572

Details and patient eligibility

About

Low serum bicarbonate levels, even within the normal laboratory range, are strongly associated with increased risks of hypertension, endothelial dysfunction, cardiovascular disease and death. The current proposal will investigate whether bicarbonate administration in patients with chronic kidney disease (CKD) will improve the health and function of arteries and reduce the size of the left ventricle of the heart. Overall, the proposed research will provide important new scientific evidence upon which physicians can base recommendations to patients with CKD to decrease the risk of developing cardiovascular diseases.

Enrollment: 109 patients

Sex: All

Ages: 21 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Age ≥ 21 years
• Serum bicarbonate 22-25 mEq/L on 2 separate measurements (at least 1 day apart)
• CKD stage 3B or 4 at time of screening (eGFR 15-44 ml/min/1.73m2)
• Blood pressure <130/80 mm Hg prior to randomization
• BMI < 40 kg/m2 (FMD measurements can be inaccurate in severely obese patients).
• Able to provide consent
• Stable anti-hypertensive regimen for at least one month prior to randomization
• Not taking medications that interact with agents administered during experimental sessions (e.g. sildenafil interacts with nitroglycerin).

Exclusion criteria

• Use of chronic daily oral alkali within the last 3 months (including sodium bicarbonate, calcium carbonate or baking soda)
• Uncontrolled hypertension
• Serum potassium < 3.3 or ≥ 5.5 mEq/L at screening
• New York Heart Association Class 3 or 4 heart failure symptoms, known EF ≤30%, or hospital admission for heart failure within the past 3 months
• Factors judged to limit adherence to interventions
• Anticipated initiation of dialysis or kidney transplantation within 12 months
• Current participation in another research study
• Pregnancy or planning to become pregnant or currently breastfeeding
• Chronic use of supplemental oxygen
• Use of immunosuppression in past 3 months
• Metal implant or implanted electrical device (patient will be unable to get MRI)

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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109 participants in 2 patient groups, including a placebo group

Sodium Bicarbonate

Experimental group

Description:

Participants assigned to oral sodium bicarbonate will receive 0.5 mEq/kg-lean body weight (LBW)/day for the entire 12 months. Participants will take ½ the daily dose in the morning and the other ½ in the evening. The number of capsules will be rounded to the nearest whole capsule. To reduce pill burden and increase compliance the maximum number of pills per day will be six.

Treatment:

Drug: Sodium bicarbonate

Placebo

Placebo Comparator group

Description:

Subjects randomly assigned to placebo will take the same number of capsules as if they were assigned to receive 0.5 mEq/kg-LBW/day of sodium bicarbonate. Participants will take ½ the daily dose in the morning and the other ½ in the evening. The number of capsules will be rounded to the nearest whole capsule. To reduce pill burden and increase compliance the maximum number of pills per day will be six.

Treatment:

Drug: Placebo