Adding Phosphorus to Osteoporosis Drug Treatment

July 5, 2016 updated by: Creighton University

Bone Sparing by Calcium Salts With and Without Extra Phosphorus

Osteoporosis causes bones to weaken and break more easily. Calcium and phosphorus are two minerals that are essential for normal bone formation. Unfortunately, calcium salts commonly prescribed in anti-osteoporosis treatment bind phosphorus from food and restrict phosphorus available for bone building. Teriparatide is a drug that reduces the risk of fractures by increasing bone thickness and strength. Vitamin D is also necessary for strong bones and teeth. The purpose of this study is to evaluate the bone-building effectiveness of two calcium supplements, one with a source of phosphorus and one without, in combination with teriparatide and vitamin D in women with osteoporosis.

Study Overview

Status

Completed

Detailed Description

Osteoporosis is the most common type of bone disease. Calcium supplements normally used in anti-osteoporosis treatment are calcium salts of carbonate or citrate; however, these salts bind phosphorus from food in the intestine and restrict phosphorus available for bone building. This study will evaluate the efficacy of adding calcium phosphate to a regimen of teriparatide and vitamin D in increasing bone mineral density in women with osteoporosis. It is hypothesized that the group taking the phosphate-containing calcium supplement will have greater gains in bone mineral density (BMD) during the course of the study than the group not receiving phosphate.

All participants will receive teriparatide and vitamin D during the course of the 12-month study. Participants will be randomly assigned to one of two groups. One group will receive calcium phosphate and the other will receive calcium carbonate. BMD will be measured at spine and hip at baseline and at 3, 6, and 12 months of treatment.

Study Type

Interventional

Enrollment (Actual)

241

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Nebraska
      • Omaha, Nebraska, United States, 68131
        • Creighton University Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

58 years to 83 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • Bone mineral density (BMD) T-score less than -1.0
  • One or more vertebral fractures
  • Serum creatinine less than 1.3 mg/dL
  • Serum phosphorus less than 3.6 mg/dL
  • Daily phosphorus intake below NHANES-III median
  • Body mass index (BMI) less than 30 kg/m2

Exclusion Criteria:

  • Paget's disease or history of osteosarcoma
  • Systemic corticosteroid therapy
  • Hyperparathyroidism
  • Recent history of kidney stone
  • Anticonvulsant therapy known to alter vitamin D metabolism
  • Radiation therapy to bone

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Calcium Phosphate Treatment Group
Participants will receive teriparatide and vitamin D during the course of the 12-month study. They will also receive calcium phosphate.
Participants will receive teriparatide and vitamin D during the course of the 12-month study. They will also receive calcium phosphate.
Active Comparator: Calcium Carbonate Treatment Group
Participants will receive teriparatide and vitamin D during the course of the 12-month study. They will also receive calcium carbonate.
Participants will receive teriparatide and vitamin D during the course of the 12-month study. They will also receive calcium carbonate.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Lumbar Spine and Hip BMD, Measured as Grams Per Square Centimeter.
Time Frame: Measured at Baseline
Bone mineral density (BMD, measured by dual X-ray absorptiometry - DEXA) measured at several intervals during the study. BMD measured as grams per square centimeter (g/cm2).
Measured at Baseline
Bone Mineral Density (BMD) Under Treatment With an Anabolic Agent (Teriparatide).
Time Frame: 12 months
The principle outcome measure was change in bone mineral density (BMD) under treatment with an anabolic agent (teriparatide).
12 months

Secondary Outcome Measures

Outcome Measure
Time Frame
Change From Baseline in Serum Phosphorus, Serum Creatinine, Serum Calcium at 12 Months
Time Frame: Measured at baseline and 12 months
Measured at baseline and 12 months
Change From Baseline in Urinary Calcium to Creatinine Ratio, Urinary Phosphorus to Creatinine Ratio at 12 Months
Time Frame: Measured at baseline and 12 months
Measured at baseline and 12 months
Change From Baseline in Urinary N-telopeptide at 12 Months
Time Frame: Measured at baseline and 12 months
Measured at baseline and 12 months
Change From Baseline in Urinary Hydroxyproline to Creatinine Ratio at 12 Months
Time Frame: Measured at baseline and 12 months
Measured at baseline and 12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Robert P. Heaney, MD, Creighton University Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

August 1, 2004

Primary Completion (Actual)

June 1, 2008

Study Completion (Actual)

June 1, 2008

Study Registration Dates

First Submitted

December 19, 2003

First Submitted That Met QC Criteria

December 19, 2003

First Posted (Estimate)

December 22, 2003

Study Record Updates

Last Update Posted (Estimate)

July 6, 2016

Last Update Submitted That Met QC Criteria

July 5, 2016

Last Verified

July 1, 2016

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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