Correction of metabolic acidosis with potassium citrate in renal transplant patients and its effect on bone quality

Clin J Am Soc Nephrol. 2012 Sep;7(9):1461-72. doi: 10.2215/CJN.01100112. Epub 2012 Jul 5.

Abstract

Background: Acidosis and transplantation are associated with increased risk of bone disturbances. This study aimed to assess bone morphology and metabolism in acidotic patients with a renal graft, and to ameliorate bone characteristics by restoration of acid/base homeostasis with potassium citrate.

Methods: This was a 12-month controlled, randomized, interventional trial that included 30 renal transplant patients with metabolic acidosis (S-[HCO(3)(-)] <24 mmol/L) undergoing treatment with either potassium citrate to maintain S-[HCO(3)(-)] >24 mmol/L, or potassium chloride (control group). Iliac crest bone biopsies and dual-energy X-ray absorptiometry were performed at baseline and after 12 months of treatment. Bone biopsies were analyzed by in vitro micro-computed tomography and histomorphometry, including tetracycline double labeling. Serum biomarkers of bone turnover were measured at baseline and study end. Twenty-three healthy participants with normal kidney function comprised the reference group.

Results: Administration of potassium citrate resulted in persisting normalization of S-[HCO(3)(-)] versus potassium chloride. At 12 months, bone surface, connectivity density, cortical thickness, and cortical porosity were better preserved with potassium citrate than with potassium chloride, respectively. Serological biomarkers and bone tetracycline labeling indicate higher bone turnover with potassium citrate versus potassium chloride. In contrast, no relevant changes in bone mineral density were detected by dual-energy X-ray absorptiometry.

Conclusions: Treatment with potassium citrate in renal transplant patients is efficient and well tolerated for correction of metabolic acidosis and may be associated with improvement in bone quality. This study is limited by the heterogeneity of the investigated population with regard to age, sex, and transplant vintage.

Trial registration: ClinicalTrials.gov NCT00913796.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorptiometry, Photon
  • Acid-Base Equilibrium / drug effects*
  • Acidosis / blood
  • Acidosis / diagnosis
  • Acidosis / drug therapy*
  • Acidosis / etiology
  • Adult
  • Bicarbonates / blood
  • Biomarkers / blood
  • Biopsy
  • Bone Density / drug effects
  • Bone Remodeling / drug effects
  • Bone and Bones / diagnostic imaging
  • Bone and Bones / drug effects*
  • Bone and Bones / metabolism
  • Bone and Bones / pathology
  • Female
  • Femur Neck / drug effects
  • Femur Neck / metabolism
  • Humans
  • Ilium / drug effects
  • Ilium / metabolism
  • Kidney Transplantation / adverse effects*
  • Lumbar Vertebrae / drug effects
  • Lumbar Vertebrae / metabolism
  • Male
  • Middle Aged
  • Potassium Citrate / therapeutic use*
  • Switzerland
  • Time Factors
  • Treatment Outcome
  • X-Ray Microtomography

Substances

  • Bicarbonates
  • Biomarkers
  • Potassium Citrate

Associated data

  • ClinicalTrials.gov/NCT00913796