title: A randomized, double-blind, placebo-controlled trial of calcium acetate on serum phosphorus concentrations in patients with advanced non-dialysis-dependent chronic kidney disease.
abstract: BACKGROUND
  Hyperphosphatemia in patients with chronic kidney disease (CKD) contributes to secondary hyperparathyroidism, soft tissue calcification, and increased mortality risk. This trial was conducted to examine the efficacy and safety of calcium acetate in controlling serum phosphorus in pre-dialysis patients with CKD.
  
  
  METHODS
  In this randomized, double-blind, placebo-controlled trial, 110 nondialyzed patients from 34 sites with estimated GFR < 30 mL/min/1.73 m² and serum phosphorus > 4.5 mg/dL were randomized to calcium acetate or placebo for 12 weeks. The dose of study drugs was titrated to achieve target serum phosphorus of 2.7-4.5 mg/dL. Serum phosphorus, calcium, iPTH, bicarbonate and serum albumin were measured at baseline and every 2 weeks for the 12 week study period. The primary efficacy endpoint was serum phosphorus at 12 weeks. Secondary endpoints were to measure serum calcium and intact parathyroid hormone (iPTH) levels.
  
  
  RESULTS
  At 12 weeks, serum phosphorus concentration was significantly lower in the calcium acetate group compared to the placebo group (4.4 ± 1.2 mg/dL vs. 5.1 ± 1.4 mg/dL; p = 0.04). The albumin-adjusted serum calcium concentration was significantly higher (9.5 ± 0.8 vs. 8.8 ± 0.8; p < 0.001) and iPTH was significantly lower in the calcium acetate group compared to placebo (150 ± 157 vs. 351 ± 292 pg/mL respectively; p < 0.001). At 12 weeks, the proportions of subjects who had hypocalcemia were 5.4% and 19.5% for the calcium acetate and the placebo groups, respectively, while the proportions of those with hypercalcemia were 13.5% and 0%, respectively. Adverse events did not differ between the treatment groups.
  
  
  CONCLUSIONS
  In CKD patients not yet on dialysis, calcium acetate was effective in reducing serum phosphorus and iPTH over a 12 week period.
  
  
  BACKGROUND
  www.clinicaltrials.gov NCT00211978.
authors.affiliation: Department of Medicine, University of Texas Health Sciences Center, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA. QUNIBI@UTHSCSA.EDU
authors.forename: Wajeh
authors.initials: W
authors.lastname: Qunibi
authors.forename: Wolfgang C
authors.initials: WC
authors.lastname: Winkelmayer
authors.forename: Richard
authors.initials: R
authors.lastname: Solomon
authors.forename: Moustafa
authors.initials: M
authors.lastname: Moustafa
authors.forename: Paul
authors.initials: P
authors.lastname: Kessler
authors.forename: Chiang-Hong
authors.initials: CH
authors.lastname: Ho
authors.forename: Jonathan
authors.initials: J
authors.lastname: Greenberg
authors.forename: Jose A
authors.initials: JA
authors.lastname: Diaz-Buxo
mesh_terms: D000085:Acetates / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use*; D002118:Calcium / Q000097:blood*; D017610:Calcium Compounds / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use; D002614:Chelating Agents / Q000009:adverse effects / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D057194:Intention to Treat Analysis; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*; D010758:Phosphorus / Q000097:blood*; D011446:Prospective Studies; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000188:drug therapy*
chemical_list: D000085:Acetates; D017610:Calcium Compounds; D002614:Chelating Agents; D010281:Parathyroid Hormone; D010758:Phosphorus; D002118:Calcium; C120662:calcium acetate