Recruiting

Alkali Therapy

Sponsor:

University of Colorado, Denver

Code:

NCT05005793

Conditions

Metabolic Acidosis

Kidney Transplant; Complications

Vascular Diseases

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Interventions

Sodium bicarbonate

Placebo

Study Details

Brief summary:

Lower serum bicarbonate levels, even within the normal laboratory range, in kidney transplant recipients (KTRs) are associated with an increased risk of graft loss, cardiovascular events and mortality. Because acid retention is common in KTRs, it is plausible that alkali therapy in KTRs may also result in improved vascular and graft function. The investigators will perform a randomized, double-blinded, placebo-controlled, 12 month study in 120 KTRs to examine the effect of sodium bicarbonate therapy on surrogate markers of CVD and graft function. The overall hypothesis is that treatment with bicarbonate will improve indicators of vascular and graft function in KTRs by decreasing complement activation.

Conditions

Metabolic Acidosis

Kidney Transplant; Complications

Vascular Diseases

Study ID

NCT05005793

Start date

Dec 1, 2021

Status verified date

May, 2025

Completion date

Aug 31, 2026

Anticipated

Primary completion date

Aug 31, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Age 18-80 years
  • Serum bicarbonate 16-24 mEq/L on 2 separate measurements (at least 1 day apart)
  • Kidney transplant received 1 year prior to randomization
  • eGFR ≥ 45 ml/min/1.73m2 by CKD-EPI equation
  • 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
  • Immunosuppression regimen consisting of tacrolimus, mycophenolate mofetil and prednisone (95% of patients at University of Colorado are on this regimen)
  • Stable immunosuppression regimen for at least three months prior to randomization
  • 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:

  • Significant comorbid conditions that lead the investigator to conclude that life expectancy is less than 1 year
  • 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
  • Nephrotic range proteinuria (urine complement activation fragment measurements may not be accurate with severe proteinuria)
  • Factors judged to limit adherence to interventions
  • Current participation in another research study
  • Pregnancy or planning to become pregnant or currently breastfeeding
  • Chronic use of supplemental oxygen
  • Use of anticoagulants

Study Design

Enrollment

120 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Sodium bicarbonate

Oral sodium bicarbonate at a dose of 0.5 mEq/kg-lean body weight/day

placebo comparator: Placebo

Oral placebo at a dose of 0.5 mEq/kg-lean body weight/day

Interventions

Sodium bicarbonate

Oral sodium bicarbonate at 0.5 mEq/kg-lean body weight/day

Placebo

Placebo at 0.5 mEq/kg-lean body weight/day

Primary outcome measure

  • Change in Brachial artery flow mediated dilation at 12 months [ Time Frame: Baseline and 12 months ]

Central Contacts and Locations

Central contacts

Jessica Kendrick, MD MPH

3037244837jessica.kendrick@ucdenver.edu

Locations

University of Colorado

Recruiting

Aurora, Colorado, United States, 80045

Contacts

Jessica Kendrick

303-724-4837jessica.kendrick@cuanschutz.edu

More Information

Sponsor

University of Colorado, Denver

Last update posted

May 29, 2025

Last verified

May, 2025

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by University of Colorado, Denver on 2025-05-29.