Study of Dietary Additive Phosphorus on Proteinuria and Fibroblast Growth Factor-23

NCT02020785 | Completed Results

• 3 other identifiers: NA_0008208913CRP16970085Satellite Dialysis
• Study Type: interventional
• Target: 31
• Locations: 1 country
• Sites: 1

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.

Conditions

Albuminuria

Keywords

proteinuria

Outcome Measures

Primary Outcomes (2)

• 24-hour Urine Albumin Excretion

  Two 24-hour urine collections will be collected during the 3rd week of each period

  3 weeks

• Fibroblast Growth Factor-23 (FGF-23)

  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

  3 weeks

Secondary Outcomes (2)

• Systolic Blood Pressure

  2-3 weeks

• Diastolic Blood Pressure

  2-3 weeks

Study Arms (2)

Higher phosphorus period

ACTIVE COMPARATOR

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

Other: Higher phosphorus period

Lower phosphorus period

PLACEBO COMPARATOR

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

Other: Lower phosphorus period

Interventions

Higher phosphorus period OTHER

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.

Higher phosphorus period

Lower phosphorus period OTHER

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.

Lower phosphorus period

Eligibility Criteria

• Age: 21 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults at least 21 years of age with at least microalbuminuria

You may not qualify if:

• 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

Sponsors & Collaborators

• Geisinger Clinic: lead
• Johns Hopkins University: collaborator

Study Sites (1)

Prohealth Clinical Research Unit

Baltimore, Maryland, 21207, United States

Location

Related Publications (1)

• 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.

  PMID: 23810691 BACKGROUND

MeSH Terms

Conditions

Albuminuria; Proteinuria

Condition Hierarchy (Ancestors)

Urination Disorders; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Urological Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Limitations and Caveats

Small sample size, short duration of intervention, changes in background diet during the intervention.

Results Point of Contact

• Title: Alex Chang, MD
• Organization: Geisinger

achang@geisinger.edu

570-271-8026

Study Officials

• Alex R Chang, MD, MS

  Geisinger Clinic

  PRINCIPAL INVESTIGATOR

• Lawrence J Appel, MD, MPH

  Johns Hopkins University

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Clinical Investigator

Study Record Dates

• First Submitted: December 19, 2013
• First Posted: December 25, 2013
• Study Start: January 1, 2014
• Primary Completion: September 1, 2015
• Study Completion: September 1, 2015
• Last Updated: June 5, 2019
• Results First Posted: June 5, 2019

Record last verified: 2019-02

Locations

US (1)