title: Mineral metabolism and haemoglobin concentration among haemodialysis patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS).
abstract: BACKGROUND
  Bone and mineral metabolism is abnormal in most chronic haemodialysis patients and is associated with a high mortality risk. Because of possible pathogenic links between anaemia and intact parathyroid hormone (iPTH), the present study evaluated associations of mineral metabolism indicators with haemoglobin (Hb).
  
  
  METHODS
  Data were collected from 317 facilities (12 089 haemodialysis patients) in Australia, Belgium, Canada, France, Germany, Italy, Japan, New Zealand, Spain, Sweden, the United Kingdom and the United States by the Dialysis Outcomes and Practice Patterns Study (DOPPS). The major outcome studied was probability of haemodialysis patients having a target Hb, per guidelines, of >/=11 g/dl at baseline. Major predictor variables were patient characteristics and laboratory markers of mineral metabolism: albumin-corrected serum calcium (calcium(Alb)), serum phosphorus (PO(4)) and iPTH. Analyses were adjusted for demographics, 15 comorbidity classes, baseline laboratory values, body mass index, years on dialysis, erythropoietin dose, vitamin D and catheter use, cause of end-stage renal disease and country.
  
  
  RESULTS
  The adjusted odds ratio (AOR) of having Hb >/=11 g/dl was significantly higher (P<0.0001) in patients with higher calcium(Alb) (AOR = 1.32 per 1 mg/dl), higher PO(4) (AOR = 1.08 per 1 mg/dl) and lower iPTH (AOR = 0.96 per 100 pg/ml). Furthermore, 4 month intrapatient changes in Hb concentration were significantly (P<0.0001) related to 4 month changes in calcium(Alb) (0.17 g/dl Hb rise per 1 mg/dl higher calcium(Alb)) and PO(4) (0.11 g/dl Hb rise per 1 mg/dl higher PO(4)). Mean weekly recombinant human erythropoietin (rHuEpo) doses were higher for patients with high PO(4) or iPTH levels, but lower for patients with calcium(Alb) >9.5 mg/dl, after patient mix and Hb concentration adjustments.
  
  
  CONCLUSIONS
  The results of this study indicate that higher serum calcium(Alb) and PO(4) levels are each independently associated with better anaemia control. This relationship is independent of vitamin D use, PTH levels and prescribed rHuEpo dose. Despite this benefit of better anaemia control at higher serum calcium(Alb) and PO(4) concentrations, lower calcium and PO(4) levels, as recommended by the K/DOQI guidelines, should still serve as the long-term goal for HD patients in order to minimize tissue calcification and mortality risk.
authors.affiliation: Division of Blood Purification, Kidney Center, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kimata
authors.forename: Takashi
authors.initials: T
authors.lastname: Akiba
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Pisoni
authors.forename: Justin M
authors.initials: JM
authors.lastname: Albert
authors.forename: Sudtida
authors.initials: S
authors.lastname: Satayathum
authors.forename: José M
authors.initials: JM
authors.lastname: Cruz
authors.forename: Tadao
authors.initials: T
authors.lastname: Akizawa
authors.forename: Vittorio E
authors.initials: VE
authors.lastname: Andreucci
authors.forename: Eric W
authors.initials: EW
authors.lastname: Young
authors.forename: Friedrich K
authors.initials: FK
authors.lastname: Port
mesh_terms: D000328:Adult; D000368:Aged; D000740:Anemia / Q000188:drug therapy; D002118:Calcium / Q000378:metabolism*; D002454:Cell Differentiation; D049109:Cell Proliferation; D041905:Erythroid Cells / Q000166:cytology; D004921:Erythropoietin / Q000627:therapeutic use; D005260:Female; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000378:metabolism*; D011994:Recombinant Proteins; D006435:Renal Dialysis
chemical_list: D006454:Hemoglobins; D010281:Parathyroid Hormone; D011994:Recombinant Proteins; D004921:Erythropoietin; D010758:Phosphorus; D002118:Calcium