title: Correction of metabolic acidosis with potassium citrate in renal transplant patients and its effect on bone quality.
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.
authors: Renal Division, Stadtspital Waid Zurich, Zurich, Switzerland.
authors: Astrid
authors: A
authors: Starke
authors: Alf
authors: A
authors: Corsenca
authors: Thomas
authors: T
authors: Kohler
authors: Johannes
authors: J
authors: Knubben
authors: Marius
authors: M
authors: Kraenzlin
authors: Daniel
authors: D
authors: Uebelhart
authors: Rudolf P
authors: RP
authors: Wüthrich
authors: Brigitte
authors: B
authors: von Rechenberg
authors: Ralph
authors: R
authors: Müller
authors: Patrice M
authors: PM
authors: Ambühl
mesh_terms: D015502:Absorptiometry, Photon; D000136:Acid-Base Equilibrium / Q000187:drug effects*; D000138:Acidosis / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology; D000328:Adult; D001639:Bicarbonates / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D015519:Bone Density / Q000187:drug effects; D016723:Bone Remodeling / Q000187:drug effects; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005260:Female; D005272:Femur Neck / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007085:Ilium / Q000187:drug effects / Q000378:metabolism; D016030:Kidney Transplantation / Q000009:adverse effects*; D008159:Lumbar Vertebrae / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D019357:Potassium Citrate / Q000627:therapeutic use*; D013557:Switzerland; D013997:Time Factors; D016896:Treatment Outcome; D055114:X-Ray Microtomography
chemical_list: D001639:Bicarbonates; D015415:Biomarkers; D019357:Potassium Citrate