title: Phosphate levels in patients treated with low-flux haemodialysis, pre-dilution haemofiltration and haemodiafiltration: post hoc analysis of a multicentre, randomized and controlled trial.
abstract: BACKGROUND
  Whether convective therapies allow better control of serum phosphate (P) is still undefined, and no data are available concerning on-line haemofiltration (HF). The objectives of the study are to evaluate the effect of convective treatments (CTs) on P levels in comparison with low-flux haemodialysis (HD) and to evaluate the correlates of serum phosphate in a post hoc analysis of a randomized clinical trial.
  
  
  METHODS
  This analysis was performed in the database of a multicentre, open label and randomized controlled study in which 146 chronic HD patients from 27 Italian centres were randomly assigned to HD (70 patients) or CTs: on-line pre-dilution HF (36 patients) or on-line pre-dilution haemodiafiltration (40 patients).
  
  
  RESULTS
  CTs did not affect P (P = 0.526), calcium (Ca) (P = 0.849) and parathyroid hormone levels (P = 0.622). P levels were associated with the use of phosphate binders including aluminium-based phosphate binders (P < 0.001) and sevelamer (P < 0.001), pre-dialysis bicarbonate levels (P < 0.001) and pre-dialysis blood K levels (P < 0.001). On multivariate analysis (generalized linear model), serum P was again largely unassociated with CTs (P = 0.631). Notably, participating centres were by far the strongest independent correlate of serum P, explaining 45.3% of the variance of serum P over the trial and this association was confirmed at multivariate analysis. Bicarbonate (P < 0.001) and, to a weaker extent, serum K (P = 0.032) were independently related to serum P.
  
  
  CONCLUSIONS
  In comparison with low-flux HD, CTs did not significantly affect serum P levels. Participating centres were the main source of P variability during the trial followed by treatment with phosphate binders, serum bicarbonate and, to a weak extent, serum potassium levels (ClinicalTrials.gov Identifier: NCT011583309).
authors.affiliation: Department of Nephrology and Dialysis, Azienda Ospedaliera della Provincia di Lecco, Ospedale Alessandro Manzoni, Lecco, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Locatelli
authors.affiliation: Department of Nephrology and Dialysis, Azienda Ospedaliera G. Brotzu, Cagliari, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Altieri
authors.affiliation: Department of Nephrology and Dialysis, Azienda Ospedaliera della Provincia di Lecco, Ospedale Alessandro Manzoni, Lecco, Italy.
authors.forename: Simeone
authors.initials: S
authors.lastname: Andrulli
authors.affiliation: Department of Nephrology and Dialysis, Azienda Ospedaliera G. Brotzu, Cagliari, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Sau
authors.affiliation: Department of Nephrology and Dialysis, Dipartimento territoriale ASL 8, Cagliari, Italy.
authors.forename: Piergiorgio
authors.initials: P
authors.lastname: Bolasco
authors.affiliation: Department of Nephrology and Dialysis, Ospedale Bolognini, Seriate, Italy.
authors.forename: Luciano A
authors.initials: LA
authors.lastname: Pedrini
authors.affiliation: Department of Nephrology and Dialysis, Ospedale F. Miulli, Acquaviva delle Fonti, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Basile
authors.affiliation: Department of Nephrology and Dialysis, Ospedale Maggiore, Parma, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: David
authors.affiliation: Department of Nephrology and Dialysis,Centro Dialisi della Maddalena, La Maddalena, Italy.
authors.forename: Luanna
authors.initials: L
authors.lastname: Gazzanelli
authors.affiliation: Department of Nephrology and Dialysis, Ospedale di Ravenna, Ravenna, Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Tampieri
authors.affiliation: Department of Nephrology and Dialysis, Ospedale di Ravenna, Ravenna, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Isola
authors.affiliation: Department of Nephrology and Dialysis,Centro Dialisi di Melito e Scilla.
authors.forename: Onofrio
authors.initials: O
authors.lastname: Marzolla
authors.affiliation: Department of Nephrology and Dialysis, Università Federico II, Napoli, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Memoli
authors.affiliation: Department of Nephrology and Dialysis,Centro Dialisi di Ozieri, Ozieri, Italy.
authors.forename: Marino
authors.initials: M
authors.lastname: Ganadu
authors.affiliation: Department of Nephrology and Dialysis, Ospedale di Pinerolo, Italy.
authors.forename: Ernesto
authors.initials: E
authors.lastname: Reina
authors.affiliation: Department of Nephrology and Dialysis, Ospedale Multimedica, Sesto San Giovanni (MI).
authors.forename: Silvio
authors.initials: S
authors.lastname: Bertoli
authors.affiliation: Department of Nephrology and Dialysis, Ospedale SS Trinità ASL 8, Cagliari.
authors.forename: Rocco
authors.initials: R
authors.lastname: Ferrara
authors.affiliation: Department of Nephrology and Dialysis, Ospedale Civile, Alghero, Italy.
authors.forename: Domenica
authors.initials: D
authors.lastname: Casu
authors.affiliation: Department of Nephrology and Dialysis, Ospedale San Camillo, Sorgono, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Logias
authors.affiliation: Department of Nephrology and Dialysis, Azienda Ospedaliera Carlo Poma, Mantua, Italy.
authors.forename: Renzo
authors.initials: R
authors.lastname: Tarchini
authors.affiliation: Department of Nephrology and Dialysis, Ospedale 'S. Francesco', Nuoro, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Mattana
authors.affiliation: Department of Nephrology and Dialysis, ASL 2 of Olbia - P.O. 'P. Dettori', Tempio Pausania, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Passaghe
authors.affiliation: Department of Nephrology and Dialysis, Ospedale S. Giovanni di Dio, Olbia, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Fundoni
authors.affiliation: Department of Nephrology and Dialysis, Fondazione Maugeri IRCCS, Pavia, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Villa
authors.affiliation: Department of Nephrology and Dialysis, Ospedale Agostino Landolfi, Solofra, Italy.
authors.forename: Biagio Raffaele
authors.initials: BR
authors.lastname: Di Iorio
authors.affiliation: Department of Nephrology and Dialysis, Azienda Ospedaliera della Provincia di Lecco, Ospedale Alessandro Manzoni, Lecco, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Pontoriero
authors.affiliation: Department of Nephrology and Dialysis, Azienda Ospedaliera 'Bianchi Melacrino Morelli', Reggio Calabria, Italy.
authors.forename: Carmine
authors.initials: C
authors.lastname: Zoccali
mesh_terms: D000368:Aged; D001639:Bicarbonates / Q000097:blood; D002118:Calcium / Q000097:blood; D005260:Female; D017583:Hemodiafiltration / Q000009:adverse effects; D006440:Hemofiltration; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood*; D006435:Renal Dialysis; D017582:Renal Replacement Therapy
chemical_list: D001639:Bicarbonates; D010281:Parathyroid Hormone; D010710:Phosphates; D002118:Calcium
keywords: convective therapies; haemodialysis; on-line haemodiafiltration; on-line haemofiltration; phosphate