Calcium and Phosphorus Balance and Calcium Kinetics in Patients With Stage 3/4 Chronic Kidney Disease
|Chronic Kidney Disease||Dietary Supplement: 1500 mg/d elemental calcium as calcium carbonate Dietary Supplement: Placebo|
|Study Design:||Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||Calcium and Phosphorus Balance and Calcium Kinetics in Patients With Stage 3/4 Chronic Kidney Disease|
- Calcium Balance [ Time Frame: 2 weeks ]Calcium balance is measured by dietary calcium intake (mg/d) minus calcium excretion (mg/d) (from both urine and feces).
- Phosphorus Balance [ Time Frame: 2 weeks ]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 ]Calcium kinetics was determined by a calcium radiotracer. Bone balance is the difference between bone formation and bone resorption estimated by calcium kinetic modeling.
|Study Start Date:||June 2010|
|Study Completion Date:||November 2011|
|Primary Completion Date:||November 2011 (Final data collection date for primary outcome measure)|
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.
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.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01161407
|United States, Indiana|
|Indiana University Hospital - Clinical Research Center|
|Indianapolis, Indiana, United States, 46202|
|Principal Investigator:||Munro Peacock, MD||Indiana University|