Chronic Kidney Disease
Conditions
Keywords
Kidney Diseases, Renal Insufficiency, Chronic, Dietary nonvolatile acid load, Blood pressure, Urine net acid excretion
Brief summary
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.
Interventions
DRUGSodium bicarbonate
Drug/dietary supplement is used in a crossover design to lower the nonvolatile acid load of the diet compared to the control period.
OTHERControlled diet
Diet without sodium bicarbonate supplementation
Sponsors
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Duke University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
22 Years to No maximum
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in ambulatory blood pressure | Measured at the end of each week of intervention (i.e. one week apart) | Change in mean 24 hour systolic and diastolic blood pressure comparing the end of the controlled feeding plus sodium bicarbonate period to the end of the controlled feeding plus table salt period. |
| Change in urine net acid excretion | Urine net acid excretion will be measured at three timepoints over approximately 3 weeks (i.e. 2 weeks of intervention plus one week baseline data collection/run-in) | Change in urine net acid excretion comparing the end of the controlled feeding plus sodium bicarbonate period to the end of the controlled feeding plus table salt period. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in clinic blood pressure | Clinic blood pressure will be measured at multiple timepoints over approximately 3 weeks (i.e. 2 weeks of intervention plus one week baseline data collection/run-in) | Change in average of three readings of systolic and diastolic blood pressure will be evaluated comparing the end of the controlled feeding plus sodium bicarbonate period to the end of the controlled feeding plus table salt period. |
| Change in plasma nitric oxide metabolites | Measured at the end of each week of intervention (i.e. one week apart) up to 3 weeks | Change in nitric oxide metabolites comparing the end of the controlled feeding plus sodium bicarbonate period to the end of the controlled feeding plus table salt period. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Differences in metabolomic profiles | Measured at the end of each week of intervention (i.e. one week apart) up to 3 weeks | Differences in metabolites will be evaluated comparing the end of the controlled feeding plus sodium bicarbonate period to the end of the controlled feeding plus table salt period. |
Countries
United States
Outcome results
None listed