title: Calcium and phosphate balance with quotidian hemodialysis.
abstract: BACKGROUND
  Conventional hemodialysis (HD) is associated with profound disturbances in calcium and phosphate metabolism and abnormal parathyroid hormone (PTH) levels. Effects of more frequent HD on calcium and phosphate balance have not been fully elucidated.
  
  
  METHODS
  The London Daily/Nocturnal Hemodialysis Study examined effects of quotidian HD, either daily HD (n = 11) or nocturnal HD (n = 12), on calcium and phosphate metabolism, bone alkaline phosphatase levels, and intact PTH (iPTH) levels.
  
  
  RESULTS
  Daily HD patients showed a slight decrease in predialysis serum phosphate levels, no changes in phosphate-binder requirements or serum calcium levels, and slight increases in serum bone alkaline phosphatase and iPTH levels. Nocturnal HD patients showed a trend for decreased predialysis phosphate levels, with significantly lower values than daily HD and matched control patients on conventional HD therapy at several times. Phosphate-binder use by nocturnal HD patients was significantly reduced. Both quotidian HD groups showed decreases in calcium x phosphate product, with significantly lower values for nocturnal HD patients (38.11 mg(2)/dL(2)) compared with daily HD and control patients (53.99 and 52.51 mg(2)/dL(2), respectively) at 18 months. Bone alkaline phosphatase levels increased slightly and attained statistical significance compared with baseline values for both quotidian HD groups. A trend for increases in serum iPTH levels, coupled with increasing levels of bone alkaline phosphatase in nocturnal HD patients, led to the decision to increase the dialysate calcium concentration from 5.0 to 7.0 mg/dL. This 1-time adjustment resulted in a reversal of the trend and a return to baseline values.
  
  
  CONCLUSIONS
  This study shows the superior control of serum phosphate levels in nocturnal HD patients compared with daily HD or conventional HD patients and the benefits of dialysate with a greater calcium concentration in slow nocturnal HD.
authors.affiliation: Optimal Dialysis Research Unit, London Health Sciences Centre, London, Ontario, Canada. robert.lindsay@lhsc.on.ca
authors.forename: Robert M
authors.initials: RM
authors.lastname: Lindsay
authors.forename: Fayez
authors.initials: F
authors.lastname: Alhejaili
authors.forename: Gihad
authors.initials: G
authors.lastname: Nesrallah
authors.forename: Rosemary
authors.initials: R
authors.lastname: Leitch
authors.forename: Laurie
authors.initials: L
authors.lastname: Clement
authors.forename: A Paul
authors.initials: AP
authors.lastname: Heidenheim
authors.forename: Claude
authors.initials: C
authors.lastname: Kortas
mesh_terms: D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood; D001071:Appointments and Schedules; D002118:Calcium / Q000378:metabolism*; D002119:Calcium Carbonate / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D015312:Hemodialysis Solutions; D006437:Hemodialysis, Home / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood / Q000209:etiology; D007527:Isoenzymes / Q000097:blood; D007676:Kidney Failure, Chronic / Q000378:metabolism / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000378:metabolism*; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D015312:Hemodialysis Solutions; D007527:Isoenzymes; D010281:Parathyroid Hormone; D010710:Phosphates; D000469:Alkaline Phosphatase; D002119:Calcium Carbonate; D002118:Calcium