title: Effects of bone remodelling on calcium mass transfer during haemodialysis.
abstract: BACKGROUND
  During haemodialysis, calcium balance can affect, or be affected by, mineral metabolism. However, when dialysate calcium concentration (d[Ca]) is chosen or kinetic models are employed to calculate calcium balance, bone remodelling is rarely considered. In this study, we examined whether bone remodelling affects calcium mass transfer during haemodialysis.
  
  
  METHODS
  We dialysed 23 patients using a d[Ca] of 1.0, 1.25, 1.5 or 1.75 mmol/L. Calcium mass transfer was measured and associated with remodelling bone factors.
  
  
  RESULTS
  Calcium balance varied widely depending on the d[Ca]. Calcium removal was -578 +/- 389, -468 +/- 563, +46 +/- 400 and +405 +/- 413 mg when a d[Ca] of 1.0, 1.25, 1.5 or 1.75 mmol/L was used, respectively (1.0 and 1.25 vs 1.5 and 1.75 mmol/L, P < 0.001; 1.5 vs 1.75 mmol/L, P < 0.05). Univariate analysis showed that calcium balance correlated with calcium gradient, parathyroid hormone (PTH), osteocalcin and dialysis vintage. Multivariate analysis revealed that calcium balance was dependent on calcium gradient, PTH and osteocalcin.
  
  
  CONCLUSIONS
  These results suggest that bone remodelling could affect calcium mass transfer during haemodialysis.
authors.affiliation: Nephrology Division, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Cristina
authors.initials: C
authors.lastname: Karohl
authors.forename: Juliana
authors.initials: J
authors.lastname: de Paiva Paschoal
authors.forename: Manuel Carlos Martins
authors.initials: MC
authors.lastname: de Castro
authors.forename: Rosilene Motta
authors.initials: RM
authors.lastname: Elias
authors.forename: Hugo
authors.initials: H
authors.lastname: Abensur
authors.forename: João Egídio
authors.initials: JE
authors.lastname: Romão
authors.forename: Jutta
authors.initials: J
authors.lastname: Passlick-Deetjen
authors.forename: Vanda
authors.initials: V
authors.lastname: Jorgetti
authors.forename: Rosa Maria Affonso
authors.initials: RM
authors.lastname: Moysés
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D016723:Bone Remodeling; D002118:Calcium / Q000378:metabolism*; D015314:Dialysis Solutions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood; D006435:Renal Dialysis; D055815:Young Adult
chemical_list: D015314:Dialysis Solutions; D010281:Parathyroid Hormone; D010710:Phosphates; D015675:Osteocalcin; D002118:Calcium