Kidney Transplant; Complications, Metabolic Acidosis
Conditions
Brief summary
Metabolic acidosis is associated with vascular endothelial dysfunction and is a common complication in patients who have received a kidney transplant. Kidney transplant recipients (KTR) with lower serum bicarbonate levels, even within the normal range, have an increased risk of graft loss and mortality. The investigators propose a prospective, double-blind, randomized, placebo-controlled, 18-week crossover pilot study to examine the effects of sodium bicarbonate on vascular endothelial function, graft function, and cognitive function in 20 KTR patients.
Interventions
DRUGSodium Bicarbonate
Participants will take ½ the daily dose of sodium bicarbonate in the morning and the other ½ in the evening.
OTHERPlacebo
Participants will take ½ the daily dose of a placebo in the morning and the other ½ in the evening.
Sponsors
University of Colorado, Denver
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age ≥ 18 years * Kidney transplant received at least 1 year ago * Serum bicarbonate 20-26 mEq/L on 2 separate measurements (at least 1 day apart) * eGFR \>45 ml/min/1.73m2 * Blood pressure \<140/90 mm Hg prior to randomization * BMI \< 40 kg/m2 (FMD measurements can be inaccurate in severely obese patients). * Able to provide consent * Stable kidney transplant medication regimen for at least 1 month 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 · 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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Brachial Artery Flow-Mediated Dilation | Baseline, 8, 10, and 18 weeks | Brachial artery Flow-Mediated Dilation (FMD) will be determined using high-resolution ultrasonography (Toshiba Xario 200) as described originally by Celermajer et al., and more recently by our group. FMD will be measured at the beginning and end of each study period for a total of 4 measurements. ECG-gated end-diastolic ultrasound images and Doppler flow of the brachial artery will be acquired during baseline and FMD conditions. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Transforming Growth Factor Beta 1 (TGF-B1) | Baseline, 8, 10, and 18 weeks | Urinary TGF-B1 will be measured from 24-hour urine collections. It will be measured by a commercially available ELISA (R&D Systems). The within day precision for this assay is 6.7% at 257 pg/ml. All measurements will be performed at the Children's Pediatric CTRC at Children's Hospital Colorado. |
| Change in Cognitive Function | Baseline, 8, 10, and 18 weeks | Cognitive function will be assessed using the National Institutes of Health (NIH) Toolbox computerized tests to evaluate 1) attention, 2) episodic memory, 3) working memory, 4) language, 5) executive function, and 6) processing speed. |
Countries
United States
Outcome results
None listed