Low Phosphate Diets in Patients With Early Stages of Chronic Kidney Disease

This study has been completed.
Sponsor:
Collaborator:
Shire
Information provided by (Responsible Party):
Myles S. Wolf, Massachusetts General Hospital
ClinicalTrials.gov Identifier:
NCT00438932
First received: February 20, 2007
Last updated: September 23, 2011
Last verified: September 2011
  Purpose

The purpose of this study is to learn more about how the kidneys control the blood levels of phosphorus in patients with early chronic kidney disease. The ultimate goal is to use this information to design improved treatment strategies for phosphorus-related problems for the millions of patients with chronic kidney disease.


Condition Intervention
Chronic Kidney Disease
Drug: Lanthanum Carbonate
Dietary Supplement: Low Phosphorus Diet
Dietary Supplement: Unrestricted Phosphorus Diet
Drug: Placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Factorial Assignment
Masking: Single Blind (Subject)
Primary Purpose: Prevention
Official Title: Reduced Phosphate Intake in "Normo-Phosphatemic" Chronic Kidney Disease Patients

Resource links provided by NLM:


Further study details as provided by Massachusetts General Hospital:

Primary Outcome Measures:
  • Fibroblast Growth Factor 23 (FGF-23) [ Time Frame: 2 weeks ] [ Designated as safety issue: No ]
    Plasma FGF-23 was measured using c-terminal FGF23 assay.


Secondary Outcome Measures:
  • 24-hour Urinary Phosphate [ Time Frame: 2 weeks ] [ Designated as safety issue: No ]
    from 24-hr urine collections


Enrollment: 16
Study Start Date: January 2007
Study Completion Date: January 2010
Primary Completion Date: January 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Lanthanum Carbonate and Low Phosphorus Diet
25% of subjects will receive binders plus a phosphate restricted diet.
Drug: Lanthanum Carbonate
Lanthanum carbonate 1000mg 3x/day
Dietary Supplement: Low Phosphorus Diet
Low phosphorus diet will consist of 800 mg of phosphorus per day.
Active Comparator: Lanthanum Carbonate and Unrestricted Phosphorus Diet
25% binders + unrestricted phosphate diet.
Drug: Lanthanum Carbonate
Lanthanum carbonate 1000mg 3x/day
Dietary Supplement: Unrestricted Phosphorus Diet
Unrestricted diet will contain 1550 mg of phosphorus per day - 800 mg of which is dietary and 750mg of Neutraphos (3 packets/day); each packet is 250mg.
Other Name: Neutraphos
Active Comparator: Placebo and Low Phosphorus Diet
25% placebo + phosphate restricted diet.
Dietary Supplement: Low Phosphorus Diet
Low phosphorus diet will consist of 800 mg of phosphorus per day.
Drug: Placebo
Lanthanum Carbonate placebo given three times a day with meals.
Active Comparator: Placebo and Unrestricted Phosphorus Diet
25% placebo + unrestricted phosphate diet.
Dietary Supplement: Unrestricted Phosphorus Diet
Unrestricted diet will contain 1550 mg of phosphorus per day - 800 mg of which is dietary and 750mg of Neutraphos (3 packets/day); each packet is 250mg.
Other Name: Neutraphos
Drug: Placebo
Lanthanum Carbonate placebo given three times a day with meals.

Detailed Description:

Phosphorus is a mineral found in dairy products, nuts, and meat that is essential for bone health and many other important functions inside the body's cells. The kidneys are responsible for keeping the blood levels of phosphorus normal. Healthy kidneys do this by spilling excess phosphorus into the urine. In patients with chronic kidney disease, the kidneys are unable to spill an adequate amount of phosphorus so that excess phosphorus can accumulate in the walls of blood vessels leading to heart disease, their leading cause of death. A recently discovered hormone called FGF-23 helps control the blood levels of phosphorus by "telling" the kidney how much phosphorus to spill in the urine. The purpose of this study is to learn more about how FGF-23 helps the kidneys control the blood levels of phosphorus. The ultimate goal is to use this information to design improved treatment strategies for phosphorus-related problems for the millions of patients with chronic kidney disease.

  Eligibility

Ages Eligible for Study:   18 Years to 80 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • subjects with stage 3a, 3b and 4 CKD
  • subjects have to be aged 18 years or older
  • subjects have to have normal serum phosphate levels (< 4.6 mg/dl)
  • subjects have to have sufficient 25-OH Vit0amin D levels (≥ 20 ng/ml)

Exclusion Criteria:

  • subjects with rapidly advancing renal failure who thus might develop hyperphosphatemia or end stage renal disease requiring initiation of dialysis during the study period
  • subjects expected to require dialysis initiation within the follow up period
  • subjects with hyperphosphatemia > 4.6 mg/dL
  • subjects with any previous or current treatment with phosphate binders or active vitamin D (doxercalciferol or calcitriol)
  • subjects with malnutrition, defined as a serum albumin < 3.0 mg/dl, in order to avoid worsening protein-malnutrition status during the restricted study period since phosphate restricted diets are also low in protein
  • subjects with chronic gastrointestinal diseases that could impede their absorptive ability such as Crohn's disease, ulcerative colitis and sprue
  • subjects with liver disease (ALT or AST > 100 U/L) or cholestasis (direct bilirubin > 1.0 mg/dl) because this can limit their ability to absorb fat soluble vitamins such as vitamin D
  • subjects with anemia, defined as a hematocrit <27% at the screening visit
  • subjects wht have been hospitalization within the previous 4 weeks
  • subjects who are pregnant
  • subjects who are breastfeeding mothers
  • subjects with primary hypoparathyroidism
  • subjects with primary hyperparathyroidism
  • subjects with previous subtotal parathyroidectomy
  • subjects with previous outpatient counseling by a renal nutritionist
  • subjects who are unable to independently provide written informed consent - prisoners, mentally incompetent, minors
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00438932

Locations
United States, Massachusetts
Massachusetts General Hospital
Boston, Massachusetts, United States, 02114
Sponsors and Collaborators
Massachusetts General Hospital
Shire
Investigators
Principal Investigator: Myles Wolf, MD, MMSc Univesity of Miami Miller School of Medicine
Principal Investigator: Harald Jueppner, MD Massachusetts General Hospital
  More Information

Publications:
Responsible Party: Myles S. Wolf, Associate Professor, Massachusetts General Hospital
ClinicalTrials.gov Identifier: NCT00438932     History of Changes
Other Study ID Numbers: 2005P000486
Study First Received: February 20, 2007
Results First Received: July 25, 2011
Last Updated: September 23, 2011
Health Authority: United States: Food and Drug Administration

Keywords provided by Massachusetts General Hospital:
phosphate, phosphorus, FGF-23, PTH, 1,25D

Additional relevant MeSH terms:
Kidney Diseases
Renal Insufficiency, Chronic
Kidney Failure, Chronic
Urologic Diseases
Renal Insufficiency

ClinicalTrials.gov processed this record on July 28, 2014