Association of serum bicarbonate levels with mortality in patients with non-dialysis-dependent CKD

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Csaba P Kovesdy1, John E Anderson, Kamyar Kalantar-Zadeh

  • 1Division of Nephrology, Salem Veterans Affairs Medical Center, 1970 Roanoke Blvd., Salem, VA 24153, USA. csaba.kovesdy@va.gov

Nephrology, Dialysis, Transplantation : Official Publication of the European Dialysis and Transplant Association - European Renal Association
|November 19, 2008
PubMed

Insights

Metabolic acidosis in chronic kidney disease (CKD) is linked to mortality. In non-dialysis-dependent CKD (NDD-CKD), both low and high serum bicarbonate levels increase mortality risk, suggesting a need for optimized bicarbonate levels.

Area of Science:

  • Nephrology
  • Internal Medicine
  • Clinical Research

Background:

  • Metabolic acidosis, indicated by low serum bicarbonate, is common in chronic kidney disease (CKD).
  • While linked to mortality in dialysis patients, its association in non-dialysis-dependent CKD (NDD-CKD) remains unclear.

Purpose of the Study:

  • To investigate the association between serum bicarbonate levels and mortality in patients with moderate to advanced NDD-CKD.
  • To determine if serum bicarbonate levels impact all-cause mortality and progression to end-stage renal disease.

Main Methods:

  • Utilized multivariable-adjusted Cox models.
  • Examined baseline and time-variable serum bicarbonate (total CO2) in 1240 male NDD-CKD patients.
  • Assessed outcomes including all-cause mortality and a composite of pre-dialysis mortality or end-stage renal disease.

Main Results:

  • A significant U-shaped association was found between serum bicarbonate and all-cause mortality.
  • Highest mortality occurred with serum bicarbonate <22 mmol/L (HR 1.33, P=0.02).
  • Lowest mortality was observed with serum bicarbonate levels of 26-29 mmol/L. Associations were more pronounced in patients with better nutritional status and lower inflammation.

Conclusions:

  • Both low and high serum bicarbonate levels are associated with increased all-cause mortality in NDD-CKD patients.
  • Further clinical trials are necessary to explore therapeutic interventions for optimizing serum bicarbonate levels.
  • Optimizing serum bicarbonate may improve outcomes in this patient population.
Abstract

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