Metabolic AcidosisPhase 4NCT05005793
Effect of Alkali Therapy on Vascular and Graft Function in Kidney Transplant Recipients
A Phase 4 study testing Sodium bicarbonate in people with Metabolic Acidosis and Kidney Transplant; Complications, run by University of Colorado, Denver at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Metabolic Acidosis, Kidney Transplant; Complications, Vascular Diseases
- What is being tested?
- Sodium bicarbonate
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 120 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Dec 2021to 31 Aug 2026
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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).
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- 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).
Who cannot join
- 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)
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- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Colorado
Aurora, Colorado, 80045
Jessica Kendrick, 303-724-4837, jessica.kendrick@cuanschutz.edu
About this study
Official title: Effect of Alkali Therapy on Vascular and Graft Function in Kidney Transplant
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.
- Being tested
- Sodium bicarbonate, Placebo
- Medical subject headings
- Acidosis, Vascular Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Sodium bicarbonateDrug
Oral sodium bicarbonate at 0.5 mEq/kg-lean body weight/day
PlaceboDrug
Placebo at 0.5 mEq/kg-lean body weight/day
| Study group | Role | What they receive |
|---|---|---|
| Sodium bicarbonate | Experimental | Oral sodium bicarbonate at a dose of 0.5 mEq/kg-lean body weight/day Receives: Drug: Sodium bicarbonate |
| Placebo | Placebo comparator | Oral placebo at a dose of 0.5 mEq/kg-lean body weight/day Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Brachial artery flow mediated dilation at 12 months
Brachial artery FMD will be determined using high-resolution ultrasonographyECG-gated end-diastolic ultrasound images and Doppler flow of the brachial artery will be acquired during baseline and FMD conditions. For FMD, reactive hyperemia will be produced by inflating a pediatric BP cuff around the forearm to 250 mmHg for 5 minutes followed by rapid deflation.
Measured: Baseline and 12 months
Secondary outcomes (4)
Change in Large elastic artery stiffness and compliance at 12 months
transcutaneous custom tonometers (Noninvasive hemodynamics Workstation, Cardiovascular Engineering Inc., Norwood, MA) will be positioned at the aorta and femoral artery to measure aortic pulse wave velocity.
Measured: Baseline and 12 months
Change in Tubular atrophy at 12 months
Kidney transplant biopsies will be performed. Morphometric analysis will be performed using trichrome and Sirius Red to determine tubular atrophy. All imaging will be done using an Aperio scanner.
Measured: Baseline and 12 months
Change in participant plasma and urine complement activation fragment levels at 12 months
Complement activation fragments (Ba, C4a, C3a, C5a, sC5b-9) will be measured at the University of Colorado Exsera Biolab located on the Anschutz Medical Campus.
Measured: Baseline and 12 months
Change in interstitial fibrosis at 12 months
Kidney transplant biopsies will be performed. Morphometric analysis will be performed using trichrome and Sirius Red to determine interstitial fibrosis.
Measured: Baseline and 12 months.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Aug 2021
- Study start1 Dec 2021
- Primary completion31 Aug 2026 (estimated)
- Study completion31 Aug 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Metabolic AcidosisStudies of the same condition, open and under way.
- More trials run by University of Colorado, DenverThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 120 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Colorado, Denver
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Jessica Kendrick, MD MPH, Principal investigator, University of Colorado Denver | Anschutz
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05005793
- Sponsor's protocol ID
- 21-3447
- Other IDs
- R01DK130255
- Status last verified
- May 2025
- First submitted
- 14 Jul 2021
- Last updated
- 29 May 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: At the conclusion of the study, data, which has been stripped of all personal identification information and coded with a number, will be made available to qualified individuals within the scientific community who apply for data use. The results and outcomes of this study will be made generally available by publication and journal articles submitted to PubMed Central in compliance with NIH access guidelines.
Study at a glance
From the registry record, last updated by the sponsor on 29 May 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Alkali Therapy on Vascular and Graft Function in Kidney Transplant
- ClinicalTrials.gov ID
- NCT05005793
- Acronym / sponsor ID
- 21-3447
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 120 participants (estimated)
- Lead sponsor
- University of Colorado, DenverUniversity, hospital or other
- Collaborators
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Study start
- 1 Dec 2021 (actual)
- Primary completion
- 31 Aug 2026 (estimated)
- Study completion
- 31 Aug 2026 (estimated)
- First posted
- 16 Aug 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Sodium bicarbonate | Experimental | Drug: Sodium bicarbonateOral sodium bicarbonate at a dose of 0.5 mEq/kg-lean body weight/day |
| Placebo | Placebo comparator | Drug: PlaceboOral placebo at a dose of 0.5 mEq/kg-lean body weight/day |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (11 listed)
- 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
Key exclusion criteria (11 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Sodium bicarbonateOral sodium bicarbonate at 0.5 mEq/kg-lean body weight/day | Drug | Sodium bicarbonate |
| PlaceboPlacebo at 0.5 mEq/kg-lean body weight/day | Drug | Placebo |
Primary outcome
Change in Brachial artery flow mediated dilation at 12 months
Time frame: Baseline and 12 months
Brachial artery FMD will be determined using high-resolution ultrasonographyECG-gated end-diastolic ultrasound images and Doppler flow of the brachial artery will be acquired during baseline and FMD conditions. For FMD, reactive hyperemia will be produced by inflating a pediatric BP cuff around the forearm to 250 mmHg for 5 minutes followed by rapid deflation.
4 secondary outcomes
Change in Large elastic artery stiffness and compliance at 12 months
Time frame: Baseline and 12 months
Change in Tubular atrophy at 12 months
Time frame: Baseline and 12 months
Change in participant plasma and urine complement activation fragment levels at 12 months
Time frame: Baseline and 12 months
Change in interstitial fibrosis at 12 months
Time frame: Baseline and 12 months.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 May 2025.
- Individual participant dataSharing planned: Yes. At the conclusion of the study, data, which has been stripped of all personal identification information and coded with a number, will be made available to qualified individuals within the scientific community who apply for data use. The results and outcomes of this study will be made generally available by publication and journal articles submitted to PubMed Central in compliance with NIH access guidelines.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Jessica Kendrick, MD MPH principal investigator
University of Colorado Denver | Anschutz
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Sodium bicarbonate in people with Metabolic Acidosis and Kidney Transplant; Complications, run by University of Colorado, Denver at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 11 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 29 May 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Jessica Kendrick, MD MPH (3037244837, jessica.kendrick@ucdenver.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Brachial artery flow mediated dilation at 12 months (time frame: Baseline and 12 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 May 2025.