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

NCT ID: NCT02020785

Last Updated: 2019-06-05

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 31 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2014-01-31
• Study Completion Date: 2015-09-30

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).

Conditions

Albuminuria

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: TRIPLE

Study Groups

Higher phosphorus period

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

Group Type: ACTIVE_COMPARATOR

Higher phosphorus period

Intervention Type: 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.

Lower phosphorus period

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

Group Type: PLACEBO_COMPARATOR

Lower phosphorus period

Intervention Type: 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.

Interventions

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.

Intervention Type: 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.

Intervention Type: OTHER

Eligibility Criteria

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

• Minimum Eligible Age: 21 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Johns Hopkins University

OTHER

Sponsor Role: collaborator

Geisinger Clinic

OTHER

Sponsor Role: lead

Responsible Party

Alexander Chang

Clinical Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Alex R Chang, MD, MS

Role: PRINCIPAL_INVESTIGATOR

Geisinger Clinic

Lawrence J Appel, MD, MPH

Role: STUDY_DIRECTOR

Johns Hopkins University

Locations

Prohealth Clinical Research Unit

Baltimore, Maryland, United States

Countries

United States

References

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.

Reference Type: BACKGROUND

PMID: 23810691 (View on PubMed)

Other Identifiers

13CRP16970085

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

Satellite Dialysis

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

NA_00082089

Identifier Type: -

Identifier Source: org_study_id