Salivary Phosphorus and Level of Kidney Function

This study has been completed.
Sponsor:
Collaborator:
CM&D Pharma Limited
Information provided by:
Denver Nephrologists, P.C.
ClinicalTrials.gov Identifier:
NCT01311973
First received: March 3, 2011
Last updated: July 21, 2011
Last verified: March 2011
  Purpose

The specific purpose of this study is to describe the relationship between salivary phosphorus and kidney function, specifically as it relates to serum phosphorus, FGF23, PTH, vitamin D status and urinary excretion of phosphorus.


Condition
Chronic Kidney Disease

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Assessment of the Relationship Between Salivary Phosphorus and Level of Kidney Function

Resource links provided by NLM:


Further study details as provided by Denver Nephrologists, P.C.:

Primary Outcome Measures:
  • Correlation between fasting salivary phosphorus and estimated glomerular filtration rate [ Time Frame: single value between 7-11 am ] [ Designated as safety issue: No ]
    subjects with various levels of estimated glomerular filtration rate will have a single assessment in the fasted state of salivary phosphorus

  • Correlation between post meal salivary phosphorus and estimated glomerular filtration rate [ Time Frame: single value after meal between 1-4 pm ] [ Designated as safety issue: No ]
    subjects with various levels of estimated glomerular filtration rate will have a single assessment in the fed state (meal between 11 am - 12 noon) of salivary phosphorus measured between 1-4 pm


Secondary Outcome Measures:
  • correlation of fasting salivary phosphorus with plasma fibroblast growth factor 23 levels(FGF-23) [ Time Frame: single AM measurement between 7-11 am ] [ Designated as safety issue: No ]
    subjects will have plasma FGF23 measured in the fasting state between 7-11 am and correlation made with simultaneous assessment of salivary phosphorus

  • Correlation between fasting salivary phosphorus and serum 1,25 vitamin D levels. [ Time Frame: single AM measurement between 7-11 am ] [ Designated as safety issue: No ]
    subjects will have serum 1,25 vitamin D measured in the fasting state between 7-11 am and correlation made with simultaneous assessment of salivary phosphorus

  • Correlation between fasting salivary phosphorus and serum intact parathyroid hormone (iPTH) levels. [ Time Frame: single AM measurement between 7-11 am ] [ Designated as safety issue: No ]
    subjects will have serum intact parathyroid hormone measured in the fasting state between 7-11 am and correlation made with simultaneous assessment of salivary phosphorus


Biospecimen Retention:   Samples Without DNA

Blood, urine, and saliva


Estimated Enrollment: 105
Study Start Date: March 2011
Study Completion Date: July 2011
Primary Completion Date: July 2011 (Final data collection date for primary outcome measure)
Groups/Cohorts
Renal Function Group #1
Creatinine clearance > 90 mL/min
Renal Function Group #2
Creatinine clearance 60-69 mL/min
Renal Function Group #3
Creatinine clearance 50-59 mL/min
Renal Function Group #4
Creatinine clearance 40-49 mL/min
Renal Function Group #5
Creatinine clearance 30-39 mL/min
Renal Function Group #6
Creatinine clearance 20-29 mL/min
Renal Function Group #7
Creatinine clearance < 20 mL/min (not on dialysis)

Detailed Description:

Previous studies have demonstrated that salivary phosphate levels are elevated in patients with chronic kidney disease and that there is a direct and linear correlation between serum phosphorus and salivary phosphorus. However, data regarding the relationship between salivary phosphate levels and stage of kidney disease (estimated glomerular filtration rate (eGFR) is lacking; as such, this study seeks to examine that relationship.

There is a normal circadian rhythm to serum phosphorus with a mid-afternoon peak at approximately 3 PM and a nadir at approximately 7-11 AM. Furthermore it has been demonstrated that a fasting serum phosphorus level at 8 AM is NOT indicative of 24 hour mean serum phosphorus. Thus the relationship between salivary phosphorous and serum phosphorus may vary over the course of the day.

This is a single-center study in which saliva, urine, and serum will be collected at two time points in a minimum of 105 subjects with various degrees of renal function (not on dialysis). Assignment to the renal group will be based upon the Visit 2 estimated glomerular filtration rate value. Enrollment in each group will continue at random until the target of 15 subjects per group is achieved. It is possible that an individual group may exceed the target enrollment number as their assignment will occur retrospectively.

All subjects will be required to have their morning assessment conducted between the hours of 7AM and 11AM. Clinical chemistry, serum phosphorus, intact parathyroid hormone(iPTH), plasma fibroblast growth factor 23 (FGF-23),serum 1,25 di-hydroxyvitamin D, serum 25-OH vitamin D, and a spot urine will be collected. A 24-hour urine sample will also be collected.

Passive and stimulated salivary collection will occur. The salivary collection must occur in a fasting state with nothing to eat or drink for at least 90 minutes prior to the collection.

Subjects will be permitted to leave the facility. They will be instructed to consume a lunch of their choice between the hours of 1100AM and 1200PM. They will be instructed to eat nothing after 1200PM. Subjects will return to the clinic for Visit 3 as directed by the study staff. Visit 3 will be conducted between 1PM and 4PM. Laboratory assessments, salivary collections, and spot urines will be collected at Visit 3. A dietary recall of intake at Visit 2 and 3 will also be completed.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

Normal healthy population an individuals with chronic kidney disease not on dialysis

Criteria

Inclusion Criteria:

  • Men or women greater than 18 years of age.
  • The subject has voluntarily signed and dated the most recent informed consent form approved by an Institutional Review Board (IRB).

Exclusion Criteria:

  • Receiving hemodialysis.
  • Receiving or has received an investigational product (or is currently using an investigational device) within 28 days prior to Visit 2.
  • Evidence of active and clinically significant infection at Visit 2.
  • Dental work within 48 hours prior to Visit 2.
  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: NCT01311973

Locations
United States, Colorado
Denver Nephrologists, PC
Denver, Colorado, United States, 80230
Sponsors and Collaborators
Denver Nephrologists, P.C.
CM&D Pharma Limited
Investigators
Principal Investigator: Geoffrey A Block, MD Denver Nephrologists, PC
  More Information

No publications provided by Denver Nephrologists, P.C.

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Geoffrey A. Block, MD, Principal Investigator, Denver Nephrologists, P.C.
ClinicalTrials.gov Identifier: NCT01311973     History of Changes
Other Study ID Numbers: CMD 003
Study First Received: March 3, 2011
Last Updated: July 21, 2011
Health Authority: United States: Institutional Review Board
United States: Food and Drug Administration

Keywords provided by Denver Nephrologists, P.C.:
Chronic kidney disease, phosphorus, salivary phosphorus

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