Calcium and Phosphorus Balance and Calcium Kinetics in Patients With Stage 3/4 Chronic Kidney Disease

This study has been completed.
Sponsor:
Collaborators:
Genzyme, a Sanofi Company
Purdue University
Information provided by (Responsible Party):
Munro Peacock, Indiana University
ClinicalTrials.gov Identifier:
NCT01161407
First received: July 12, 2010
Last updated: July 22, 2014
Last verified: July 2014
  Purpose

The purpose of this study is to gain a better understanding of calcium absorption and metabolism in patients with Chronic Kidney Disease (CKD) using calcium balance and kinetic methods.


Condition Intervention
Chronic Kidney Disease
Dietary Supplement: 1500 mg/d elemental calcium as calcium carbonate
Dietary Supplement: Placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Calcium and Phosphorus Balance and Calcium Kinetics in Patients With Stage 3/4 Chronic Kidney Disease

Resource links provided by NLM:


Further study details as provided by Indiana University:

Primary Outcome Measures:
  • Calcium Balance [ Time Frame: 2 weeks ] [ Designated as safety issue: No ]
    Calcium balance is measured by dietary calcium intake (mg/d) minus calcium excretion (mg/d) (from both urine and feces).


Secondary Outcome Measures:
  • Phosphorus Balance [ Time Frame: 2 weeks ] [ Designated as safety issue: No ]
    Phosphorus balance is measured by dietary phosphorus intake (mg/d) minus phosphorus excretion (mg/d) from both urine and feces.

  • "Bone Balance" From Calcium Kinetics [ Time Frame: 2 weeks ] [ Designated as safety issue: No ]
    Calcium kinetics was determined by a calcium radiotracer. Bone balance is the difference between bone formation and bone resorption estimated by calcium kinetic modeling.


Enrollment: 12
Study Start Date: June 2010
Study Completion Date: November 2011
Primary Completion Date: November 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Placebo Comparator: Placebo
Placebo control for calcium carbonate, given in same capsule form as the calcium carbonate, 3 times per day with meals.
Dietary Supplement: Placebo
Placebo for calcium carbonate in same capsule form. Given 3 times per day with meals for 21 days in conjunction with a controlled diet.
Active Comparator: Calcium Carbonate (Phosphate Binder)
500 mg elemental calcium as calcium carbonate given 3 times per day with meals for a total of 1500 mg/d elemental calcium.
Dietary Supplement: 1500 mg/d elemental calcium as calcium carbonate
500 mg elemental calcium as calcium carbonate given 3 times per day with meals for a total of 1500 mg/d elemental calcium. Given for 21 days in conjunction with a controlled diet.

Detailed Description:

The purpose of this study is to gain a better understanding of calcium absorption and metabolism in patients with Chronic Kidney Disease (CKD). It is important that the body get enough calcium to support many important body functions including bone health. CKD changes the calcium balance or how calcium is absorbed and excreted. Because of this, the knowledge of calcium absorption and excretion in patients with normal kidney function cannot be used to assess patients with CKD. In patients with CKD bone heath is often negatively affected due to a combination of poor calcium absorption, increased bone turnover (process where old bone is removed and new bone is formed), increased level of parathyroid hormone (PTH [ a hormone that acts to increase calcium in the blood]) and decrease in vitamin D levels. This negative effect is referred to as Chronic Kidney Disease Mineral Bone Disorder (CKD-MBD).

Treatment to correct CKD-MBD should begin early in the course of CKD. In the normal population calcium supplements are frequently used to help prevent age related bone loss. Calcium supplements can also be used in CKD patients to help bind phosphate. Maintaining correct levels of phosphate in the body is crucial in CKD. However, calcium supplements may have adverse effects by promoting calcium phosphate deposits in soft tissues like the vascular system which could increase the risk of cardiovascular disease.

Therefore this formal balance study is needed to determine if positive calcium balance occurs in patients with advanced CKD who are given calcium with meals as a phosphate binder. This study will also evaluate how the body handles phosphate.

  Eligibility

Ages Eligible for Study:   35 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  1. Patients with a GFR of < 45 ml/min;
  2. Intact serum PTH > 37 pg/ml;
  3. Age > 35 years (both genders and all races);
  4. Able to perform two three-week balance studies;
  5. Not on oral calcium or vitamin D other than multi vitamin, or willing to stop calcium or vitamin D for one month prior to entry in the study (day 1 of first calcium balance period);
  6. Female patients must be post-menopausal (defined as last menstrual period at least 12 months prior to screening visit) or surgically sterile by hysterectomy;
  7. On stable doses of diuretics, bisphosphonates, anti-epileptics (except dilantin) for at least 2 months.

Exclusion Criteria:

  1. Serious underlying systemic disease (including uncontrolled diabetes, lupus, hypertension, amyloid, etc);
  2. Taking drugs that alter calcium and phosphate balance or homeostasis including high dose cholecalciferol or ergocalciferol (1000 U/day or 50,000U/ wk, respectively), active vitamin D metabolites, calcimimetics, PTH analogues in the last 30 days;
  3. Taking drugs that the investigator feels will alter calcium balance;
  4. Plan to initiate dialysis in the next six months;
  5. Hypercalcemia defined as serum calcium > 10.5 mg/dl;
  6. Hyperphosphatemia defined as serum phosphate >5.5mg/ml;
  7. Intestinal disease that alters absorption or normal intestinal function including celiac disease, small bowel resection, bariatric surgery;
  8. Smoking
  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: NCT01161407

Locations
United States, Indiana
Indiana University Hospital - Clinical Research Center
Indianapolis, Indiana, United States, 46202
Sponsors and Collaborators
Indiana University
Genzyme, a Sanofi Company
Purdue University
Investigators
Principal Investigator: Munro Peacock, MD Indiana University
  More Information

Additional Information:
Publications:

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Munro Peacock, Professor, Indiana University
ClinicalTrials.gov Identifier: NCT01161407     History of Changes
Other Study ID Numbers: Genzyme - 0907-07
Study First Received: July 12, 2010
Results First Received: May 30, 2013
Last Updated: July 22, 2014
Health Authority: United States: Institutional Review Board

Additional relevant MeSH terms:
Kidney Diseases
Renal Insufficiency, Chronic
Renal Insufficiency
Urologic Diseases
Calcium Carbonate
Calcium, Dietary
Antacids
Bone Density Conservation Agents
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Physiological Effects of Drugs

ClinicalTrials.gov processed this record on October 23, 2014