title: Metabolic Acidosis of CKD: An Update.
abstract: The kidney has the principal role in the maintenance of acid-base balance. Therefore, a decrease in renal ammonium excretion and a positive acid balance often leading to a reduction in serum bicarbonate concentration are observed in the course of chronic kidney disease (CKD). The decrease in serum bicarbonate concentration is usually absent until glomerular filtration rate decreases to <20 to 25mL/min/1.73 m(2), although it can develop with lesser degrees of decreased kidney function. Non-anion gap acidosis, high-anion gap acidosis, or both can be found at all stages of CKD. The acidosis can be associated with muscle wasting, bone disease, hypoalbuminemia, inflammation, progression of CKD, and increased mortality. Administration of base may decrease muscle wasting, improve bone disease, and slow the progression of CKD. Base is suggested when serum bicarbonate concentration is <22 mEq/L, but the target serum bicarbonate concentration is unclear. Evidence that increments in serum bicarbonate concentration > 24 mEq/L might be associated with worsening of cardiovascular disease adds complexity to treatment decisions. Further study of the mechanisms through which metabolic acidosis contributes to the progression of CKD, as well as the pathways involved in mediating the benefits and complications of base therapy, is warranted.
authors.affiliation: Medical and Research Services, VHAGLA Healthcare System, UCLA Membrane Biology Laboratory, Los Angeles, CA; Division of Nephrology, VHAGLA Healthcare System and David Geffen School of Medicine, Los Angeles, CA. Electronic address: jkraut@ucla.edu.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Kraut
authors.affiliation: Department of Medicine, Division of Nephrology, St. Elizabeth's Medical Center, Boston, MA; Department of Medicine, Tufts University School of Medicine, Boston, MA. Electronic address: nicolaos.madias@steward.org.
authors.forename: Nicolaos E
authors.initials: NE
authors.lastname: Madias
mesh_terms: D000136:Acid-Base Equilibrium / Q000502:physiology; D000138:Acidosis / Q000175:diagnosis* / Q000453:epidemiology* / Q000378:metabolism; D000818:Animals; D001639:Bicarbonates / Q000378:metabolism; D018450:Disease Progression; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007668:Kidney / Q000378:metabolism / Q000473:pathology; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis* / Q000453:epidemiology* / Q000378:metabolism
chemical_list: D001639:Bicarbonates
keywords: Metabolic acidosis; acid-base balance; base therapy; chronic kidney disease (CKD); hypobicarbonatemia; positive acid balance; renal disease progression; review; serum bicarbonate