Determining Oral Phosphate Tolerance Across the Spectrum of Glomerular Filtration Rate

NCT02672293 | Completed

• 2 other identifiers: Holden/WhiteQueen's University
• Study Type: interventional
• Target: 78
• Locations: 1 country
• Sites: 1

Brief Summary

Over 20 million people in North America (including 2 million Canadians) have chronic kidney disease. These individuals die from diseases of the heart and blood vessels more often than they need dialysis. This is due to hardening of the arteries caused by calcium deposits inside the blood vessel walls. These deposits damage the vessels, causing them to lose flexibility. This makes them unable to respond to the changing demands of the body, and eventually leads to blockages such as stroke and ultimately death. High levels of phosphate in the blood have been consistently linked to the development of calcium deposits inside blood vessel walls. The kidney is the only organ in the body that can eliminate phosphate that is not required by the body. As kidney function becomes worse, body levels of phosphate increase. However, investigators do not know the time point in the course of kidney disease that problems begin in the way phosphate is eliminated into the urine by the kidneys. Investigators will test the response of the kidneys to a phosphate challenge taken by mouth in subjects who are having accurate measures of kidney function performed by a method called 'inulin clearance'. The investigators believe that the results of this study will provide important information identifying when investigators should be concerned about body levels of phosphate increasing. This information may lead to changes in the way investigators treat patients by reducing the levels of phosphate in the diet at a much earlier time point then is presently recommended.

Conditions

Chronic Kidney Disease

Outcome Measures

Primary Outcomes (1)

• Fractional excretion of phosphate

  Fractional excretion of phosphate will be measured at baseline and at 1 and 2 hours following a standardized oral phosphate challenge

  Change in fractional excretion of phosphate at 1 and 2 hours

Secondary Outcomes (3)

• Fibroblast growth factor-23

  Change in level of fibroblast growth factor 23 at 2 hours

• Vitamin D

  Change in level of vitamin D and vitamin D metabolites at 2 hours

• klotho

  Change in level of circulation kloth at 2 hours

Study Arms (1)

Phosphate

EXPERIMENTAL

500 mg of oral phosphate is administered after an overnight fast.

Drug: Phoslax

Interventions

Phoslax DRUG

Oral sodium phosphate solution (monobasic sodium phosphate 2.4 g and dibasic sodium phosphate 0.9g / 5 mL).

Also known as: Sodium Phosphate

Phosphate

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• stable chronic kidney disease

You may not qualify if:

• unable/unwilling to give informed consent;
• pregnant or breast-feeding;
• known allergy to shellfish, iodine or inulin;
• have evidence of impaired bladder emptying defined as a post-void residual of greater than 20 ml.

Sponsors & Collaborators

• Dr. Rachel Holden: lead

Study Sites (1)

Kingston General Hospital

Kingston, Ontario, K7L 3N6, Canada

Location

MeSH Terms

Conditions

Renal Insufficiency, Chronic

Interventions

sodium phosphate

Condition Hierarchy (Ancestors)

Renal Insufficiency; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Chronic Disease; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Rachel M Holden, MD

  Queen's University

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: OTHER
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: January 16, 2013
• First Posted: February 3, 2016
• Study Start: January 1, 2013
• Primary Completion: April 18, 2018
• Study Completion: April 18, 2018
• Last Updated: July 5, 2022

Record last verified: 2022-06

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)