Acid-Base Compensation in Chronic Kidney Disease (ABC)

Duke University

Status and phase: Completed; Phase 1

Conditions: Chronic Kidney Disease

Treatments: Other: Controlled diet; Drug: Sodium bicarbonate

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT02427594

K23DK095949 (U.S. NIH Grant/Contract)

Pro00058905

Details and patient eligibility

About

The purpose of this study is to evaluate changes in urine net acid excretion, blood pressure and body chemistry that occur when the dietary acid load is lowered by using a drug/dietary supplement similar to baking soda. This may be important for patients with kidney disease because they may have difficulty removing all of the dietary acid load from the body in the urine. Participants with and without kidney disease will be recruited. Each participant will be fed a controlled diet for one week with sodium bicarbonate and for one week without sodium bicarbonate to evaluate these changes. The investigators will also determine if the effect of dietary acid load reduction is different in patients with kidney disease compared to those without kidney disease.

Enrollment: 14 patients

Sex: All

Ages: 22+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• estimated glomerular filtration rate ≥30 ml/min/1.73m2
• serum bicarbonate 20-28 mEq/L

Exclusion criteria

• diabetes mellitus
• uncontrolled hypertension or recent (<3 weeks) titration of blood pressure medications
• clinically significant volume overload on screening physical examination
• selected medical conditions other than kidney disease and hypertension (active cancer, chronic liver failure, moderate to severe COPD, New York Heart Association class 2 or greater congestive heart failure, obstructive sleep apnea requiring nightly continuous positive airway pressure, solid organ transplant)
• use of alkali supplementation
• body mass index <18.5 or >40 kg/m2
• ideal body weight <45.5 kg
• anemia at screening (hematocrit <29% in participants with kidney disease or <33% in healthy participants)
• pregnancy or breastfeeding
• allergies, intolerance or unwillingness to consume foods or supplement provided in feeding menu
• serum calcium less than 8.6 mg/dl on screening laboratories

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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14 participants in 2 patient groups

Controlled diet first

Experimental group

Description:

In this arm participants will first consume a controlled diet plus added table salt (sodium chloride) for one week. They will then consume an identical controlled diet plus sodium bicarbonate for one week. Sodium bicarbonate will be dosed as 2,600 mg divided three times daily if ideal body weight is \<70 kg or 3,250 mg divided three times daily if ideal body weight is ≥70 kg. Added table salt will match the sodium content of the sodium bicarbonate dose (i.e. 31 or 39 mEq/day).

Treatment:

Drug: Sodium bicarbonate

Other: Controlled diet

Sodium bicarbonate first

Experimental group

Description:

In this arm participants will first consume a controlled diet plus sodium bicarbonate for one week. They will then consume an identical controlled diet plus added table salt (sodium chloride) for one week. Sodium bicarbonate will be dosed as 2,600 mg divided three times daily if ideal body weight is \<70 kg or 3,250 mg divided three times daily if ideal body weight is ≥70 kg. Added table salt will match the sodium content of the sodium bicarbonate dose (i.e. 31 or 39 mEq/day).

Treatment:

Drug: Sodium bicarbonate

Other: Controlled diet