title: Plant protein intake is associated with fibroblast growth factor 23 and serum bicarbonate levels in patients with chronic kidney disease: the Chronic Renal Insufficiency Cohort study.
abstract: BACKGROUND
  Protein from plant, as opposed to animal, sources may be preferred in chronic kidney disease (CKD) because of the lower bioavailability of phosphate and lower nonvolatile acid load.
  
  
  METHODS
  Observational cross-sectional study.
  
  
  METHODS
  A total of 2,938 participants with CKD and information on their dietary intake at the baseline visit in the Chronic Renal Insufficiency Cohort Study.
  
  
  METHODS
  Percentage of total protein intake from plant sources (percent plant protein) was determined by scoring individual food items using the National Cancer Institute Diet History Questionnaire (DHQ).
  
  
  RESULTS
  Metabolic parameters, including serum phosphate, bicarbonate (HCO₃), potassium, and albumin, plasma fibroblast growth factor 23 (FGF-23), and parathyroid hormone (PTH), and hemoglobin levels.
  
  
  METHODS
  We modeled the association between percent plant protein and metabolic parameters using linear regression. Models were adjusted for age, sex, race, diabetes status, body mass index, estimated glomerular filtration rate, income, smoking status, total energy intake, total protein intake, 24-hour urinary sodium concentration, use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, and use of diuretics.
  
  
  RESULTS
  Higher percent plant protein was associated with lower FGF-23 (P = .05) and higher HCO₃ (P = .01) levels, but not with serum phosphate or parathyroid hormone concentrations (P = .9 and P = .5, respectively). Higher percent plant protein was not associated with higher serum potassium (P = .2), lower serum albumin (P = .2), or lower hemoglobin (P = .3) levels. The associations of percent plant protein with FGF-23 and HCO₃ levels did not differ by diabetes status, sex, race, CKD stage (2/3 vs. 4/5), or total protein intake (≤0.8 g/kg/day vs. >0.8 g/kg/day; P-interaction >.10 for each).
  
  
  CONCLUSIONS
  This is a cross-sectional study; determination of percent plant protein using the Diet History Questionnaire has not been validated.
  
  
  CONCLUSIONS
  Consumption of a higher percentage of protein from plant sources may lower FGF-23 and raise HCO₃ levels in patients with CKD.
authors.affiliation: Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida 33136, USA. jscialla@med.miami.edu
authors.forename: Julia J
authors.initials: JJ
authors.lastname: Scialla
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Appel
authors.forename: Myles
authors.initials: M
authors.lastname: Wolf
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhang
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Sozio
authors.forename: Edgar R
authors.initials: ER
authors.lastname: Miller
authors.forename: Lydia A
authors.initials: LA
authors.lastname: Bazzano
authors.forename: Magdalena
authors.initials: M
authors.lastname: Cuevas
authors.forename: Melanie J
authors.initials: MJ
authors.lastname: Glenn
authors.forename: Eva
authors.initials: E
authors.lastname: Lustigova
authors.forename: Radhakrishna R
authors.initials: RR
authors.lastname: Kallem
authors.forename: Anna C
authors.initials: AC
authors.lastname: Porter
authors.forename: Raymond R
authors.initials: RR
authors.lastname: Townsend
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Weir
authors.forename: Cheryl A M
authors.initials: CA
authors.lastname: Anderson
mesh_terms: D000328:Adult; D000368:Aged; D001639:Bicarbonates / Q000097:blood*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004032:Diet; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood* / Q000235:genetics; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007676:Kidney Failure, Chronic / Q000188:drug therapy / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010940:Plant Proteins / Q000008:administration & dosage*; D012709:Serum Albumin / Q000032:analysis; D055815:Young Adult
chemical_list: D001639:Bicarbonates; C000717427:FGF23 protein, human; D006454:Hemoglobins; D010281:Parathyroid Hormone; D010940:Plant Proteins; D012709:Serum Albumin; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23