title: Dialysis modality and correction of uremic metabolic acidosis: relationship with all-cause and cause-specific mortality.
abstract: OBJECTIVE
  Uremic metabolic acidosis is only partially corrected in many hemodialysis patients, and low serum bicarbonate predicts higher death risk. This study determined the comparative efficacy of peritoneal dialysis in correcting uremic metabolic acidosis and the association of serum bicarbonate and death risk with the two therapies.
  
  
  METHODS
  Data were obtained from 121,351 prevalent ESRD patients (peritoneal dialysis, 10,400; hemodialysis, 110,951) treated in DaVita facilities between July 1, 2001 and June 30, 2006, with follow-up through June of 2007.
  
  
  RESULTS
  Serum bicarbonate was <22 mEq/L in 25% and 40% of peritoneal dialysis and hemodialysis patients, respectively. Thus, peritoneal dialysis patients were substantially less likely to have lower serum bicarbonate (adjusted odds ratio<20 mEq/L, 0.45 [0.42, 0.49]; <22 mEq/L, 0.41 [0.39, 0.43]). Time-averaged serum bicarbonate<19 mEq/L was associated with an 18% and 25% higher risk for all-cause and cardiovascular mortality, respectively, in prevalent peritoneal dialysis patients (reference group: serum bicarbonate between 24 and <25 mEq/L). In analyses using the entire cohort of peritoneal dialysis and hemodialysis patients, the adjusted risk for all-cause mortality was higher in most subgroups with serum bicarbonate<22 mEq/L, irrespective of dialysis modality.
  
  
  CONCLUSIONS
  The measured bicarbonate is significantly higher in peritoneal dialysis patients, suggesting that the therapy provides a more complete correction of metabolic acidosis than intermittent hemodialysis. Survival data suggest maintaining serum bicarbonate>22 mEq/L for all ESRD patients, irrespective of dialysis modality.
authors.affiliation: Division of Nephrology and Hypertension, Los Angeles Biomedical Research Institute at Harbor-University of California at Los Angeles, Torrance, California, USA.
authors.forename: Tania
authors.initials: T
authors.lastname: Vashistha
authors.forename: Kamyar
authors.initials: K
authors.lastname: Kalantar-Zadeh
authors.forename: Miklos Z
authors.initials: MZ
authors.lastname: Molnar
authors.forename: Klara
authors.initials: K
authors.lastname: Torlén
authors.forename: Rajnish
authors.initials: R
authors.lastname: Mehrotra
mesh_terms: D000138:Acidosis / Q000097:blood / Q000401:mortality* / Q000628:therapy*; D000368:Aged; D001639:Bicarbonates / Q000097:blood; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000401:mortality* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012307:Risk Factors; D014511:Uremia / Q000097:blood / Q000401:mortality* / Q000628:therapy*
chemical_list: D001639:Bicarbonates