title: Hypocalcemia, morbidity, and mortality in end-stage renal disease.
abstract: BACKGROUND
  Hypocalcemia and hyperphosphatemia with secondary hyper-parathyroidism are characteristic of end-stage renal disease (ESRD). Although calcium levels critically affect almost all cellular processes, the impact of chronic hypocalcemia and other abnormalities of calcium-phosphate homeostasis on the prognosis of ESRD patients is unknown.
  
  
  METHODS
  An inception cohort of 433 patients starting ESRD therapy was followed prospectively for an average of 41 months. Serum calcium and other parameters were measured monthly. The mean calcium levels were 9.4 +/- 0.7 mg/dl. 23% of the patients had mean calcium levels < 8.8 mg/dl. After adjusting for baseline age, diabetes mellitus, ischemic heart disease, smoking and cholesterol levels, as well as serial albumin, hemoglobin, mean arterial blood pressure, phosphate and alkaline phosphatase levels, chronic hypocalcemia was strongly associated with mortality (RR 2.10, p = 0.006 for a mean calcium level < 8.8 mg/dl). The association with mortality was similar in hemodialysis (RR 2.10, p = 0.006) and peritoneal dialysis patients (2.67, p = 0.034). Using similar covariate adjustment, chronic hypocalcemia was associated with de novo ischemic heart disease (RR 5.23, p < 0.001), recurrent ischemic heart disease (RR 2.46, p = 0.006), de novo cardiac failure (RR 2.64, p < 0.001), and recurrent cardiac failure (RR 3.30, p < 0.001). Hypocalcemia retained its independent impact on morbidity and mortality when analyzed as a time-dependent covariate.
  
  
  CONCLUSIONS
  Chronic hypocalcemia, a very common, reversible feature of chronic uremia, is independently associated with morbidity and mortality in ESRD patients.
authors.affiliation: Division of Nephrology, Memorial University, St. John's, Nfld, Canada.
authors.forename: R N
authors.initials: RN
authors.lastname: Foley
authors.forename: P S
authors.initials: PS
authors.lastname: Parfrey
authors.forename: J D
authors.initials: JD
authors.lastname: Harnett
authors.forename: G M
authors.initials: GM
authors.lastname: Kent
authors.forename: L
authors.initials: L
authors.lastname: Hu
authors.forename: R
authors.initials: R
authors.lastname: O'Dea
authors.forename: D C
authors.initials: DC
authors.lastname: Murray
authors.forename: P E
authors.initials: PE
authors.lastname: Barre
mesh_terms: D000469:Alkaline Phosphatase / Q000097:blood; D002118:Calcium / Q000097:blood; D003627:Data Interpretation, Statistical; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006996:Hypocalcemia / Q000097:blood / Q000401:mortality*; D007676:Kidney Failure, Chronic / Q000097:blood / Q000401:mortality* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D010758:Phosphorus / Q000097:blood; D011379:Prognosis; D011446:Prospective Studies; D006435:Renal Dialysis; D015996:Survival Rate
chemical_list: D010758:Phosphorus; D000469:Alkaline Phosphatase; D002118:Calcium