Arterial pH and Total Body Nitrogen Balances in APD

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00586131
Recruitment Status : Completed
First Posted : January 4, 2008
Last Update Posted : September 5, 2017
Information provided by (Responsible Party):
Los Angeles Biomedical Research Institute

Brief Summary:
This study will test the hypothesis that by slightly lowering the acidity of blood (or increasing the pH), dialysis patients utilize protein and amino acids more efficiently.

Condition or disease Intervention/treatment Phase
End-stage Renal Disease Drug: ammonium chloride or sodium citrate/citric acid Drug: Sodium citrate/citratic acid Phase 4

Detailed Description:

The normal range of pH of the blood (measure of acid-base balance of body) is rather large. It is defined as a range of pH between 7.38 and 7.44. There is evidence to suggest that a high normal arterial pH (7.43-7.45) preserves nutritional status of individuals better than a low normal arterial pH (7.36-7.38). We will test this hypothesis in a small group of stable patients with end-stage renal disease undergoing automated peritoneal dialysis. It needs to be noted that all pH levels to be attained in this study are considered to be normal. The primary outcome measure for the study will be the N-balance. The changes in blood pH will be obtained by medications (ammonium chloride for lower pH and sodium bicarbonate for higher pH).

Study Procedures: A total of eight subjects with end-stage renal disease undergoing automated peritoneal dialysis will be recruited. The initial study procedures will be for purposes of screening individuals for the study. The subjects will perform 24-hour collection of urine and dialysate to assess dialysis dose and a peritoneal equilibration test to evaluate the transport properties of the peritoneum. Only those subjects who receive the minimum dialysis dose and have an average peritoneal transport type will enter the study. During this phase, the subjects will maintain a food diary to evaluate dietary preferences and dietary calorie and protein intake. These data will be used to prepare the diets for the subjects when they are admitted to the GCRC. The next two weeks will be used to evaluate the response of arterial pH to the use of the low alkali solution. If, at the end of two weeks, the arterial pH is not in the desired range, the subjects will require ammonium chloride supplementation to achieve the lower pH. In such subjects, ammonium chloride supplementation will be used for all phases of the study.

Qualifying subjects will be hospitalized in the GCRC for 41 days. The entire period of hospitalization will be divided into two equal phases of 20.5 days each: one will be the low pH phase (low alkali dialysis solution with/without ammonium chloride) and the second will be the high pH phase (high alkali dialysis solution with sodium bicarbonate with/without ammonium chloride). Nitrogen balance will be estimated during the entire period of hospitalization. N-intake is a sum of dietary and medicinal intake, while N-output will be N-losses in dialysate, urine and feces. The N-balance will be the difference between N-intake and N-output. The second outcome measure will be leucine turnover studies. Leucine turnover studies will be performed on days 21 and 41. Leucine turnover studies provide information regarding rates of total body protein synthesis and total body protein degradation as well as rates of leucine oxidation. The study will take 10 hours each - the initial 4 hours will be after an overnight fast and the last six hours will be while being fed. The third outcome measure will be the content of some proteins in a sample of muscle biopsy. Muscle biopsy will be performed on days 21 and 41 after the completion of leucine turnover studies. Finally, nutritional assessment will be performed at the time of patient admission, on day 21 and 41. On days 21 and 41, the nutritional assessment will be performed prior to the start of the leucine turnover studies.

The subjects will be compensated for participation in this study -the amount of compensation will be dependent upon the degree of participation of subjects.

Risk-benefit Assessment: The risks of the study include the risks of performing a muscle biopsy, discomfort associated with the placement of the feeding tube, emotional problems associated with prolonged hospitalization in the GCRC and risks associated with venipuncture. There are no direct benefits to the subjects as a result of their participation in this study. However, if we demonstrate that the higher arterial pH is better at preservation of nutritional status, it may have the potential of decreasing the prevalence and/or severity of protein-energy malnutrition in patients undergoing automated peritoneal dialysis.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 8 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Intervention Model Description: Treatment with sodium citrate/citric acid or ammonium chloride chloride in each phase to achieve the desired arterial pH
Masking: None (Open Label)
Primary Purpose: Other
Official Title: Effect of Arterial pH on N-balances of Patients Undergoing Automated Peritoneal Dialysis
Study Start Date : September 2003
Actual Primary Completion Date : April 2008
Actual Study Completion Date : April 2008

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Active Comparator: Low normal pH (arterial pH 7.36-7.38)
Ammonium chloride or sodium citrate/citrate acid as needed to achieve the target pH
Drug: ammonium chloride or sodium citrate/citric acid
Dose dictated by changes in pH

Active Comparator: High Normal pH (arterial pH 7.44-7.46)
High Normal pH (7.44-7.46) with use of increasing doses of sodium bicarbonate up until the desired pH is achieved
Drug: Sodium citrate/citratic acid
dictated by pH

Primary Outcome Measures :
  1. N-balances [ Time Frame: 20 days ]
    Total body nitrogen balance defined as difference between nitrogen intake and nitrogen appearance in urine, stool, and dialysate

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Men and women from any ethnic/racial group < 65 years.
  2. Treatment with CPD for 6 months and current treatment with APD for at least one month.
  3. Hemoglobin of at least 11.0 g/dl.
  4. Stable dose of erythropoietin treatment for at least the preceding three months.
  5. Subjects with normal nutritional status to mild malnutrition:

    1. Serum albumin > 3.3 g/dl
    2. Relative body weight of 90-120% of the NHANES II median body weight for a given height, age range, gender and frame size.
    3. A normalized protein equivalent of total nitrogen appearance (nPNA) > 0.80 g/kg actual body weight/day at the time of screening.
  6. D/P Cr between 0.48 and 0.81 on the PET performed at the time of the screen.
  7. Total (renal + peritoneal) weekly Kt/V urea > 1.70 and creatinine clearance > 50 L/wk/1.73 m2.
  8. No evidence of primary or secondary (viz., ischemic, neuropathic) myopathy

Exclusion Criteria:

  1. History of active cancer other than basal cell carcinoma.
  2. Symptomatic severe ischemic heart disease, uncontrolled severe dysrhythmias, uncontrolled congestive heart failure, poorly controlled hypertension, severe musculoskeletal disease, arthritis or amputation of the lower extremities.
  3. Insulin requiring diabetes mellitus.
  4. Patients who received L-carnitine or anabolic hormones (other than erythropoietin) within the previous 6 months.
  5. Use of CaCO3 as phosphate binder.
  6. Severe lung or liver disease, uncontrolled asthma, active vasculitis.
  7. Severe chronic infection or any other acute or chronic inflammatory or catabolic illnesses (e.g., active tuberculosis, AIDS, osteomyelitis).
  8. Psychosis, inability to give informed consent, evidence that patient will not comply with study protocol.
  9. Alcohol or other recreational drug abuse.
  10. Pregnancy (rare in CPD patients).
  11. Patients who are physically and/or psychologically incapable of undergoing the protocol.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00586131

United States, California
Los Angeles Biomedical Research Institute
Torrance, California, United States, 90502
Sponsors and Collaborators
Los Angeles Biomedical Research Institute
Principal Investigator: Rajnish Mehrotra, MD Los Angeles Biomedical Research Institute

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Los Angeles Biomedical Research Institute Identifier: NCT00586131     History of Changes
Other Study ID Numbers: 11043
First Posted: January 4, 2008    Key Record Dates
Last Update Posted: September 5, 2017
Last Verified: August 2017

Keywords provided by Los Angeles Biomedical Research Institute:
end-stage renal disease
automated peritoneal dialysis
metabolic acidosis
nitrogen balances

Additional relevant MeSH terms:
Kidney Diseases
Kidney Failure, Chronic
Urologic Diseases
Renal Insufficiency, Chronic
Renal Insufficiency
Citric Acid
Calcium Chelating Agents
Chelating Agents
Sequestering Agents
Molecular Mechanisms of Pharmacological Action