title: Metabolic acidosis status and mortality in patients on the end stage of renal disease.
abstract: OBJECTIVE
  Uncorrected metabolic acidosis leads to higher death risk in dialysis patients. We observed the relationship between metabolic acidosis status and mortality rate in patients on renal replacement therapy during a median follow up time of 60 months.
  
  
  METHODS
  We studied 76 patients on an on-line hemodiafiltration. The dialysis adequacy was defined by Kt/V for urea. The Framingham risk score (FRS) points were used to determine the 10-year risk for coronary heart disease. We examined the impact of high or low serum bicarbonate concentrations on mortality rate and on 10-year risk for coronary heart disease via the Kaplan-Meier method. Cox's model was used to evaluate a combination of prognostic variables, such as dialysis adequacy defined by Kt/V for urea, age and serum bicarbonate concentrations.
  
  
  RESULTS
  We divided the enrolled patients in three groups according to serum bicarbonate concentrations (< 20 mmol/L, 20-22 mmol/L and > 22 mmol/L). Kaplan-Meier survival curve for the impact of serum bicarbonate concentrations on overall mortality was found significant (log-rank = 7.8,P= 0.02). The prevalence of serum bicarbonate less or more than 20 mmol/L on high FRS (> 20%) by Kaplan-Meier curve was also found significant (log-rank = 4.9,P= 0.02). Cox's model revealed the significant predictive effect of serum bicarbonate on overall mortality (P= 0.006, OR = 1.5, 95% CI = 1.12-1.98) in combination to Kt/V for urea and age.
  
  
  CONCLUSIONS
  Uncorrected severe metabolic acidosis, defined by serum bicarbonate concentrations less than 20 mmol/L, is associated with a 10-year risk for coronary heart disease more than 20% and high overall mortality in patients on renal replacement therapy.
authors.affiliation: The First Department of Medicine, Propaedaetic, National & Kapodistrian University of Athens, School of Medicine, Athens, Greece.
authors.forename: Vaia D
authors.initials: VD
authors.lastname: Raikou
keywords: Framingham risk score; arterial stiffness; dialysis; metabolic acidosis; mortality