The BASE Study: Bicarbonate Administration to Stabilize Estimated Glomerular Filtration Rate (eGFR) (BASE)

The BASE Study: Bicarbonate Administration to Stabilize eGFR

The two doses of sodium bicarbonate being tested are 0.5 and 0.8 mEq/kg-lean body weight (LBW) per day. Sodium bicarbonate, also known as baking soda, may help prevent kidney failure in people with chronic kidney disease. However, the dose to prescribe in order to test this possibility in a clinical trial is uncertain. The BASE pilot clinical trial will help determine the best dose of sodium bicarbonate to prescribe in a future study that will test the long-term safety and efficacy of sodium bicarbonate as a treatment to preserve kidney function in individuals with chronic kidney disease.

Study Overview

• Status: Completed
• Conditions: Chronic Kidney Disease
• Intervention / Treatment: Drug: Lower Dose Sodium Bicarbonate; Drug: Higher Dose Sodium Bicarbonate; Drug: Placebo

• Study Type: Interventional
• Enrollment (Actual): 194
• Phase: Phase 3

Contacts and Locations

Study Locations

• United States
  • Colorado
    • Denver, Colorado, United States, 80230
      • Denver Nephrology Research
  • District of Columbia
    • Washington, District of Columbia, United States, 20037
      • George Washington University
  • Illinois
    • Chicago, Illinois, United States, 60611
      • Northwestern University
  • Ohio
    • Cleveland, Ohio, United States, 44195-5196
      • Data Coordinating Center; Cleveland Clinic Foundation; Quantitative Health Sciences; 9500 Euclid Avenue
  • Texas
    • Temple, Texas, United States, 76502
      • Baylor/Scott & White
  • Utah
    • Salt Lake City, Utah, United States, 84112
      • University of Utah
    • Salt Lake City, Utah, United States, 84112
      • Utah VA

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Serum bicarbonate 20-28 mEq/L at screening (the average of the two most recent values in Baseline must be 20-28 mEq/L prior to randomization)

2. Moderate to severe chronic kidney disease (CKD) at the time of screening, defined as one of the following:

   • eGFR 20-44 ml/min/1.73m2 or
   • eGFR 45-59 ml/min/1.73m2 plus random urinary albumin:creatinine (ACR) ≥100 mg/gm
3. Blood pressure <160/100 mm Hg at screening (must be <150/100 mm Hg prior to randomization)
4. Lean body weight 38.0-96.0 kg at the time of screening
5. Age allowing legal consent without parental involvement (18-21 years, depending on individual state regulations)
6. Able to provide consent
7. Able to travel to study visits
8. Able to read English
9. In the opinion of the site investigator, willing and able to follow the study treatment regimen and comply with the site investigator's recommendations
10. In the opinion of the site investigator, medically stable

Exclusion Criteria:

1. Use of chronic daily oral alkali (such as sodium bicarbonate, sodium citrate, potassium citrate, etc) with one exception: calcium carbonate ≤1500 mg/day is allowed, as some will take this for the indication of bone health
2. On five or more antihypertensive and/or diuretic agents, regardless of the indication
3. Serum potassium <3.3 or ≥5.5 mEq/L at screening (must be 3.5-5.5 mEq/L prior to randomization)
4. Self-reported vegetarian
5. New York Heart Association Class 3 or 4 heart failure symptoms, known left ventricular ejection fraction ≤30%, or hospital admission for heart failure within the past 3 months
6. Frequent urinary tract infections (≥2 in the past year)
7. Presence of indwelling urinary catheter or urinary conduit (such as neobladder or urostomy)
8. Factors judged to limit adherence to interventions (e.g., alcoholism, history of missing clinic visits, chronic gastrointestinal disorder that makes compliance with the intervention unreliable)
9. Organ transplant recipients (excluding cornea)
10. Active glomerular disease requiring or potentially requiring immunosuppressive treatment
11. Chronic immunosuppressive therapy (for ≥3 months) for any indication. This does not include oral steroids <10 mg per day, inhaled steroids, or topical steroids
12. Anticipated initiation of dialysis or kidney transplantation within 12 months as assessed by the site investigator
13. Current participation in another interventional research study
14. Malignancy requiring therapy within 2 years (basal or squamous cell skin carcinoma and localized prostate cancer are exempted)
15. Pregnancy or planning to become pregnant or currently breast-feeding. Women of childbearing potential (pre-menopausal and not surgically sterilized) will have urine pregnancy test before enrollment.
16. Life expectancy <12 months as determined by the site investigator
17. Institutionalized individuals, including prisoners and nursing home residents
18. Plans to leave the immediate area within the next 12 months
19. Routinely leaves town for multiple weeks each year such that protocol visits would be missed
20. Chronic use of supplemental oxygen
21. Use of both angiotensin-converting-enzyme inhibitor (ACEI) and Angiotensin II Receptor Blockers (ARBs)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Lower Dose Sodium Bicarbonate; Participants will receive oral 0.5 milliequivalents (mEq)/kg-lean body weight (LBW)/day of sodium bicarbonate. Half of the total daily dose is taken in the morning and the other half is taken in the evening. (If the number of capsules is an odd number, the greater number of capsules will be taken in the morning.)	Drug: Lower Dose Sodium Bicarbonate; Lower dose oral Sodium Bicarbonate (0.5 milliequivalents (mEq)/kg-LBW/day)
Experimental: Higher Dose Sodium Bicarbonate; Participants will receive 0.8 mEq/kg-LBW/day of sodium bicarbonate. Half the total daily dose is taken in the morning and the other half is taken in the evening. (If the number of capsules is an odd number, the greater number of capsules will be taken in the morning.)	Drug: Higher Dose Sodium Bicarbonate; Higher dose oral Sodium Bicarbonate (0.8 mEq/kg-LBW/day)
Placebo Comparator: Placebo; Participants will take the same number of placebo capsules as if they were assigned to receive either 0.5 mEq/kg-LBW/day or 0.8 mEq/kg-LBW/day of sodium bicarbonate. Half the total daily dose is taken in the morning and the other half is taken in the evening. (If the number of capsules is an odd number, the greater number of capsules will be taken in the morning.)	Drug: Placebo; Oral placebo equivalent to either 0.5 mEq/kg-LBW/day or 0.8 mEq/kg-LBW/day of Sodium Bicarbonate

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants in Each Dose Arm Prescribed (i) Full Randomized Sodium Bicarbonate Dose at End of 28 Weeks & (ii) at Least 25% of Randomized Sodium Bicarbonate Dose at End of 28 Weeks as a Proportion of the Number Randomized to That Group	The prescribed dose for each participant at the end of 28 weeks will be determined by the safety and tolerability of each dose during the intervention period. The primary assessments will examine the percentage of participants in each dose arm who are prescribed (i) the full randomized sodium bicarbonate dose according to the protocol at the end of 28 weeks and (ii) at least 25% of the randomized sodium bicarbonate dose according to the protocol at the end of 28 weeks. The two doses of sodium bicarbonate being tested are 0.5 and 0.8 mEq/kg-lean body weight per day.	Baseline, 28 weeks

Collaborators and Investigators

• Sponsor: Jennifer Gassman, PhD
• Collaborators: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK); The Cleveland Clinic
• Investigators: Study Director: Michael F. Flessner, MD, PhD, DKUHD, NIDDK, NIH; Study Director: John W. Kusek, PhD, DKUHD, NIDDK, NIH; Study Chair: Linda Fried, MD, MPH, VA Pittsburgh Healthcare System

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2015
• Primary Completion (Actual): January 1, 2018
• Study Completion (Actual): June 1, 2018

Study Registration Dates

• First Submitted: April 27, 2015
• First Submitted That Met QC Criteria: August 7, 2015
• First Posted (Estimate): August 13, 2015

Study Record Updates

• Last Update Posted (Actual): October 20, 2020
• Last Update Submitted That Met QC Criteria: October 19, 2020
• Last Verified: October 1, 2020

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urologic Diseases; Renal Insufficiency; Kidney Diseases; Renal Insufficiency, Chronic
• Other Study ID Numbers: DK099877-B; U01DK099877 (U.S. NIH Grant/Contract)