title: Phosphorus Additives and Albuminuria in Early Stages of CKD: A Randomized Controlled Trial.
abstract: BACKGROUND
  Little is known about the effects of phosphorus additives on patients with kidney disease.
  
  
  METHODS
  Randomized, double-blind, crossover trial.
  
  
  METHODS
  31 adults with early stages of presumed chronic kidney disease (estimated glomerular filtration rate ≥ 45mL/min/1.73m2; urine albumin-creatinine ratio sex-specific cutoff points: men ≥ 17mg/g, women ≥ 25mg/g).
  
  
  METHODS
  Higher versus lower phosphorus intake for 3 weeks. Higher phosphorus intake was achieved by the addition of commercially available diet beverages and breakfast bars to diet.
  
  
  RESULTS
  Change in 24-hour urine albumin excretion and plasma fibroblast growth factor 23 level.
  
  
  METHODS
  Two 24-hour urine collections and a single fasting blood draw at the end of each period.
  
  
  RESULTS
  Mean baseline values for phosphorus intake, 24-hour urine phosphorus excretion, and estimated glomerular filtration rate were 1,113±549 (SD) mg/d, 688±300mg/d, and 74.6±22.0mL/min/1.73m2. Median urine albumin excretion of 82.7 (IQR, 39.6-174.1) mg/d. Although phosphorus intake from study products increased by 993mg/d (P<0.001) during the higher compared to lower phosphorus additive period, background phosphorus intake decreased by 151mg/d (P=0.004). Higher phosphorus additive consumption increased 24-hour urine phosphorus excretion by 505 (95% CI, 381 to 629) mg/d (P<0.001), but did not significantly increase albuminuria (higher vs lower: 14.3%; 95% CI, -2.5% to 34.0%; P=0.1) or fibroblast growth factor 23 level (higher vs lower: 3.4%; 95% CI, -5.9% to 13.6%; P=0.4).
  
  
  CONCLUSIONS
  Small sample size, short duration of intervention, changes in background diet during the intervention.
  
  
  CONCLUSIONS
  A 3-week consumption of higher phosphorus food additives did not significantly increase albuminuria. Further studies are needed to confirm these results.
authors.affiliation: Geisinger Health System, Division of Nephrology, Danville, PA. Electronic address: achang@geisinger.edu.
authors.forename: Alex R
authors.initials: AR
authors.lastname: Chang
authors.affiliation: Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins University, Baltimore, MD; Division of General Internal Medicine, Johns Hopkins University, Baltimore, MD.
authors.forename: Edgar R
authors.initials: ER
authors.lastname: Miller
authors.affiliation: Department of Family and Preventive Medicine, University of California, San Diego, CA.
authors.forename: Cheryl A
authors.initials: CA
authors.lastname: Anderson
authors.affiliation: Division of General Internal Medicine, Johns Hopkins University, Baltimore, MD.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Juraschek
authors.affiliation: Institute for Clinical and Translational Research, Johns Hopkins University, Baltimore, MD.
authors.forename: Melissa
authors.initials: M
authors.lastname: Moser
authors.affiliation: Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins University, Baltimore, MD.
authors.forename: Karen
authors.initials: K
authors.lastname: White
authors.affiliation: Institute for Clinical and Translational Research, Johns Hopkins University, Baltimore, MD.
authors.forename: Bobbie
authors.initials: B
authors.lastname: Henry
authors.affiliation: Institute for Clinical and Translational Research, Johns Hopkins University, Baltimore, MD.
authors.forename: Caitlin
authors.initials: C
authors.lastname: Krekel
authors.affiliation: Institute for Clinical and Translational Research, Johns Hopkins University, Baltimore, MD.
authors.forename: Susan
authors.initials: S
authors.lastname: Oh
authors.affiliation: Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins University, Baltimore, MD; Division of General Internal Medicine, Johns Hopkins University, Baltimore, MD.
authors.forename: Jeanne
authors.initials: J
authors.lastname: Charleston
authors.affiliation: Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins University, Baltimore, MD; Division of General Internal Medicine, Johns Hopkins University, Baltimore, MD.
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Appel
mesh_terms: D000368:Aged; D000419:Albuminuria / Q000097:blood / Q000209:etiology*; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D016226:Phosphorus, Dietary / Q000008:administration & dosage*; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000150:complications* / Q000178:diet therapy*; D012720:Severity of Illness Index
chemical_list: C000717427:FGF23 protein, human; D016226:Phosphorus, Dietary; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23
keywords: Phosphorus intake; albuminuria; chronic kidney disease (CKD); diet; fibroblast growth factor 23 (FGF-23); modifiable risk factor; nutrition; parathyroid hormone (PTH); phosphate; proteinuria; randomized controlled trial; urine albumin excretion