title: Which low-protein diet for which CKD patient? An observational, personalized approach.
abstract: OBJECTIVE
  Low protein diets (LPDs) are milestones in chronic kidney disease (CKD). Concerns over compliance and safety limit their use. The aim of this study was to test the feasibility and main results of a multiple-choice approach to LPDs, adapted to patient preferences.
  
  
  METHODS
  From December 2007 to January 2013, all CKD patients (stages 4/5; progressive stage 3) without contraindications (malnutrition, short life expectancy), were offered two main LPDs (proteins 0.6 g/kg daily): Vegan supplemented (LPD-KA) or with "aproteic" commercial food (LPD-ACF). LPDs followed a qualitative approach based on forbidden and allowed food; one to three free meals per week, and flexible control policy (1-3 mo). Start of dialysis, death, and combined outcome (death-dialysis) were analyzed by Kaplan-Meier curves and Cox model. Comparison with dialysis in patients with glomerular filtration rate (GRF) <15 mL/min, (corresponding to "early" dialysis start) employed standardized mortality rates, with respect to the Italian and the United States Dialysis Registry.
  
  
  RESULTS
  One hundred eighty-five patients (222 patient-years) started at least a trial of LPD-KA, 122 (177 patients-years) LPD-ACF; only 3 patients with GFR <30 mL/min denied an LPD trial. Patients who chose LPD-KA were younger than those on LPD-ACF (63 versus 74 y), had less comorbidity (82% versus 93%), higher proteinuria (1.4 versus 0.7 g/d) and lower GFR (17 versus 23 mL/min) (P < 0.001). Median daily protein intake was 0.7 g/kg on both diets (Maroni-Mitch formula). The combined outcome (death or dialysis) was not influenced by the diet chosen (Cox analysis). Relative risk for death on the diet (patients with GFR <15 mL/min) was 0.5 with respect to the Italian Registry and 0.3 to the United States Dialysis Registry. The diets had comparable costs (1 y on dialysis: 50 patient-years on LPD).
  
  
  CONCLUSIONS
  The choice of diet is strictly linked to patient characteristics, thus supporting a multiple-choice offer. Once corrected for baseline data, both LPDs led to similar results, suggesting at least survival equivalence with dialysis, at lesser cost.
authors.affiliation: SS Nephrology, Department of Clinical and Biological Sciences ASOU San Luigi, University of Turin, Orbassano, Turin, Italy. Electronic address: Giorgina.piccoli@unito.it.
authors.forename: Giorgina B
authors.initials: GB
authors.lastname: Piccoli
authors.affiliation: SS Nephrology, Department of Clinical and Biological Sciences ASOU San Luigi, University of Turin, Orbassano, Turin, Italy.
authors.forename: Maria Chiara
authors.initials: MC
authors.lastname: Deagostini
authors.affiliation: SS Nephrology, Department of Clinical and Biological Sciences ASOU San Luigi, University of Turin, Orbassano, Turin, Italy.
authors.forename: Federica Neve
authors.initials: FN
authors.lastname: Vigotti
authors.affiliation: SS Nephrology, Department of Clinical and Biological Sciences ASOU San Luigi, University of Turin, Orbassano, Turin, Italy.
authors.forename: Martina
authors.initials: M
authors.lastname: Ferraresi
authors.affiliation: SS Nephrology, Department of Clinical and Biological Sciences ASOU San Luigi, University of Turin, Orbassano, Turin, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Moro
authors.affiliation: SS Nephrology, Department of Clinical and Biological Sciences ASOU San Luigi, University of Turin, Orbassano, Turin, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Consiglio
authors.affiliation: SS Nephrology, Department of Clinical and Biological Sciences ASOU San Luigi, University of Turin, Orbassano, Turin, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Scognamiglio
authors.affiliation: SS Nephrology, Department of Clinical and Biological Sciences ASOU San Luigi, University of Turin, Orbassano, Turin, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Mongilardi
authors.affiliation: SS Nephrology, Department of Clinical and Biological Sciences ASOU San Luigi, University of Turin, Orbassano, Turin, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Clari
authors.affiliation: General Laboratory, Department of Clinical and Biological Sciences, ASOU San Luigi, University of Turin, Orbassano, Turin, Italy.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Aroasio
authors.affiliation: Epidemiology, Department of Clinical and Biological Sciences, ASOU San Luigi, University of Turin, Orbassano, Turin, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Versino
authors.affiliation: Urology Department of Oncology, ASOU San Luigi, University of Turin, Orbassano, Turin, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Porpiglia
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D015897:Comorbidity; D018753:Diet, Protein-Restricted; D014676:Diet, Vegetarian; D004044:Dietary Proteins / Q000008:administration & dosage*; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D011507:Proteinuria / Q000453:epidemiology; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000178:diet therapy*
chemical_list: D004044:Dietary Proteins
keywords: CKD; Individualised therapies; Low-protein diets; Observational study; Patient survival; Renal survival