title: Outcomes associated with serum calcium level in men with non-dialysis-dependent chronic kidney disease.
abstract: OBJECTIVE
  Elevated serum calcium has been associated with increased mortality in dialysis patients, but it is unclear whether the same is true in non-dialysis-dependent (NDD) chronic kidney disease (CKD). Outcomes associated with low serum calcium are also not well-characterized.
  
  
  METHODS
  We examined associations of baseline, time-varying, and time-averaged serum calcium with all-cause mortality in a historic prospective cohort of 1243 men with moderate and advanced NDD CKD by using Cox models.
  
  
  RESULTS
  The association of serum calcium with mortality varied according to the applied statistical models. Higher baseline calcium and time-averaged calcium were associated with higher mortality (multivariable adjusted hazard ratio (95% confidence interval): 1.31 (1.13, 1.53); P < 0.001 for a baseline calcium 1 mg/dl higher). However, in time-varying analyses, lower calcium levels were associated with increased mortality.
  
  
  CONCLUSIONS
  Higher serum calcium is associated with increased long-term mortality (as reflected by the baseline and time-averaged models), and lower serum calcium is associated with increased short-term mortality (as reflected by the time-varying models) in patients with NDD CKD. Clinical trials are warranted to determine whether maintaining normal serum calcium can improve outcomes in these patients.
authors.affiliation: Division of Nephrology, Salem VA Medical Center, 1970 Roanoke Boulevard, Salem, VA 24153, USA. csaba.kovesdy@va.gov
authors.forename: Csaba P
authors.initials: CP
authors.lastname: Kovesdy
authors.forename: Olga
authors.initials: O
authors.lastname: Kuchmak
authors.forename: Jun L
authors.initials: JL
authors.lastname: Lu
authors.forename: Kamyar
authors.initials: K
authors.lastname: Kalantar-Zadeh
mesh_terms: D000368:Aged; D002118:Calcium / Q000097:blood*; D002908:Chronic Disease; D006801:Humans; D006934:Hypercalcemia / Q000097:blood / Q000209:etiology / Q000401:mortality*; D006996:Hypocalcemia / Q000097:blood / Q000209:etiology / Q000401:mortality*; D007674:Kidney Diseases / Q000097:blood / Q000150:complications / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D014728:Veterans
chemical_list: D002118:Calcium