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Study of Dietary Additive Phosphorus on Proteinuria and Fibroblast Growth Factor-23 (SODA-POP)

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ClinicalTrials.gov Identifier: NCT02020785
Recruitment Status : Completed
First Posted : December 25, 2013
Results First Posted : June 5, 2019
Last Update Posted : June 5, 2019
Sponsor:
Collaborator:
Johns Hopkins University
Information provided by (Responsible Party):
Alexander Chang, Geisinger Clinic

Tracking Information
First Submitted Date  ICMJE December 19, 2013
First Posted Date  ICMJE December 25, 2013
Results First Submitted Date  ICMJE November 17, 2017
Results First Posted Date  ICMJE June 5, 2019
Last Update Posted Date June 5, 2019
Study Start Date  ICMJE January 2014
Actual Primary Completion Date September 2015   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: September 16, 2015)
  • 24-hour Urine Albumin Excretion [ Time Frame: 3 weeks ]
    Two 24-hour urine collections will be collected during the 3rd week of each period
  • Fibroblast Growth Factor-23 (FGF-23) [ Time Frame: 3 weeks ]
    Plasma FGF-23 will be measured at the end of each 3 week period in the morning after an overnight fast. As this is a small pilot study, we will not adjust for multiple comparisons. A p value<0.05 will be considered statistically significant for both outcomes
Original Primary Outcome Measures  ICMJE
 (submitted: December 19, 2013)
  • 24-hour Urine Albumin Excretion [ Time Frame: 3 weeks ]
    Two 24-hour urine collections will be collected during the 3rd week of each period
  • Fibroblast Growth Factor-23 (FGF-23) [ Time Frame: 3 weeks ]
    Intact FGF-23 will be collected at the end of each 3 week periods in the morning after an overnight fast
Change History
Current Secondary Outcome Measures  ICMJE
 (submitted: February 26, 2019)
  • Systolic Blood Pressure [ Time Frame: 2-3 weeks ]
    Blood pressure was measured at the end of weeks 1, 2, and 3. At each visit, 3 readings were obtained in the seated position by trained and certified observers after 5 minutes of rest with an Omron HEM-907 device (Omron Healthcare Inc, Bannockburn, Ill) using a standardized protocol. We used the average of all blood pressure measurements at the end of weeks 1, 2, and 3 for each period.
  • Diastolic Blood Pressure [ Time Frame: 2-3 weeks ]
    Blood pressure measured at the end of weeks 1, 2, and 3. At each visit, 3 readings were obtained in the seated position by trained and certified observers after 5 minutes of rest with an Omron HEM-907 device (Omron Healthcare Inc, Bannockburn, Ill) using a standardized protocol. We used the average of all these readings taken during end of weeks 1, 2, and 3 for each period.
Original Secondary Outcome Measures  ICMJE Not Provided
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
 
Descriptive Information
Brief Title  ICMJE Study of Dietary Additive Phosphorus on Proteinuria and Fibroblast Growth Factor-23
Official Title  ICMJE Randomized Cross-over Study Examining the Effects of Phosphorus Additives on Urinary Albumin Excretion and Fibroblast Growth Factor-23
Brief Summary

Phosphorus-based food additives are commonly used by food manufacturers for many applications, such as enhancing flavor, in ready-to-eat foods and beverages. While these additives can significantly increase an individual's daily phosphorus intake, little is known about the effect of dietary phosphorus on kidney health. In this study, the investigators will first lower baseline phosphorus intake to about 1000mg/d by educating participants to avoid foods with phosphorus additives. Then, participants will be randomized to a higher phosphorus period (~2gm/d) and a lower phosphorus period (~1gm/d) by providing unaltered, commercially-available food/beverage products with and without phosphorus additives.

The investigators hypothesize that participants will have higher urine albumin excretion and fibroblast growth factor-23 (FGF-23) during the higher phosphorus period compared to the lower phosphorus period.

Detailed Description The Study of Dietary Additive Phosphorus on Proteinuria and FGF-23 (SODA-POP) was a single-center, randomized, double-blind, two-period cross-over study that examined the effect of higher vs. lower phosphorus intake for 3 week periods, achieved by addition of commercially available diet beverages and breakfast bars to diet on albuminuria and fibroblast growth factor 23, in adults with presumed early chronic kidney disease (estimated glomerular filtration rate >= 45 ml/min/1.73m2; and urine albumin/creatinine ratio >=17 mg/g for men or >=25 mg/g for women).
Study Type  ICMJE Interventional
Study Phase  ICMJE Not Applicable
Study Design  ICMJE Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Condition  ICMJE Albuminuria
Intervention  ICMJE
  • Other: Higher phosphorus period

    Commercially-available unaltered food/beverage products containing phosphorus additives (~1gm/d of phosphorus) will be given for 3 weeks.

    All participants at the beginning of the study will receive dietary education to reduce their baseline consumption of phosphorus to a goal of ~1gm/d by receiving education on avoiding phosphorus-based additives.

  • Other: Lower phosphorus period

    Commercially-available unaltered food/beverage products without phosphorus additives (<10mg/d of phosphorus) will be given for 3 weeks.

    All participants at the beginning of the study will receive dietary education to reduce their baseline consumption of phosphorus to a goal of ~1gm/d by receiving education on avoiding phosphorus-based additives.

Study Arms  ICMJE
  • Active Comparator: Higher phosphorus period
    Commercially-available unaltered food/beverage products containing phosphorus additives (~1gm/d of phosphorus) will be given for 3 weeks
    Intervention: Other: Higher phosphorus period
  • Placebo Comparator: Lower phosphorus period
    Commercially-available unaltered food/beverage products without phosphorus additives (<10mg/d of phosphorus) will be given for 3 weeks
    Intervention: Other: Lower phosphorus period
Publications * Chang A, Batch BC, McGuire HL, Vollmer WM, Svetkey LP, Tyson CC, Sanguankeo A, Anderson C, Houston J, Appel LJ. Association of a reduction in central obesity and phosphorus intake with changes in urinary albumin excretion: the PREMIER study. Am J Kidney Dis. 2013 Nov;62(5):900-7. doi: 10.1053/j.ajkd.2013.04.022. Epub 2013 Jun 28.

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Recruitment Information
Recruitment Status  ICMJE Completed
Actual Enrollment  ICMJE
 (submitted: October 8, 2015)
31
Original Estimated Enrollment  ICMJE
 (submitted: December 19, 2013)
30
Actual Study Completion Date  ICMJE September 2015
Actual Primary Completion Date September 2015   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

Inclusion Criteria:

Adults at least 21 years of age with at least microalbuminuria

Exclusion Criteria:

Estimated glomerular filtration rate <45ml/min/1.73m2, poorly controlled diabetes or hypertension, nephrotic syndrome, hyperparathyroidism, Paget's Disease, multiple myeloma, uncontrolled thyroid disease, chronic antacid use, use of phosphorus binders, phosphorus supplements, or high-dose vitamin D, inability to complete feeding study, investigator discretion

Sex/Gender  ICMJE
Sexes Eligible for Study: All
Ages  ICMJE 21 Years and older   (Adult, Older Adult)
Accepts Healthy Volunteers  ICMJE No
Contacts  ICMJE Contact information is only displayed when the study is recruiting subjects
Listed Location Countries  ICMJE United States
Removed Location Countries  
 
Administrative Information
NCT Number  ICMJE NCT02020785
Other Study ID Numbers  ICMJE NA_00082089
13CRP16970085 ( Other Grant/Funding Number: American Heart Association )
Satellite Dialysis ( Other Grant/Funding Number: National Kidney Foundation )
Has Data Monitoring Committee No
U.S. FDA-regulated Product Not Provided
IPD Sharing Statement  ICMJE Not Provided
Responsible Party Alexander Chang, Geisinger Clinic
Study Sponsor  ICMJE Geisinger Clinic
Collaborators  ICMJE Johns Hopkins University
Investigators  ICMJE
Principal Investigator: Alex R Chang, MD, MS Geisinger Clinic
Study Director: Lawrence J Appel, MD, MPH Johns Hopkins University
PRS Account Geisinger Clinic
Verification Date February 2019

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP