title: Comparison between calcitriol and calcitriol plus low-dose cinacalcet for the treatment of moderate to severe secondary hyperparathyroidism in chronic dialysis patients.
abstract: OBJECTIVE
  Uremic hyperparathyroidism (UHPT) has been shown to contribute to the development and progression of chronic kidney disease-mineral bone disorder. UHPT is frequently observed in chronic dialysis patients, and patients with UHPT are associated with increased risk of all-cause and cardiovascular mortality. Cinacalcet is a novel agent that increases sensitivity to the calcium-sensing receptor and is approved for control of UHPT. Nevertheless, cinacalcet is costly and information regarding efficacy of low-dose cinacalcet on UHPT is limited.
  
  
  METHODS
  We conducted a retrospective study to evaluate treatment with either low-dose calcitriol combined with low-dose cinacalcet (25 mg) (d-cinacalcet) or calcitriol alone (VitD) in dialysis patients with moderate to severe UHPT. A total of 81 dialysis patients were enrolled (40 subjects in d-cinacalcet group and 41 subjects in VitD group). Demographic data including age, gender, duration on dialysis and biochemical data were reviewed and recorded.
  
  
  RESULTS
  At the end of the study, the intact parathyroid hormone (iPTH) levels of the d-cinacalcet group declined significantly (from 1166.0 ± 469.3 pg/mL to 679.8 ± 421.6 pg/mL, p < 0.0001), while there was no significant change in the VitD group. Significant decrease of serum calcium (Ca: 9.9 ± 0.6 mg/dL vs. 9.6 ± 0.8 mg/dL, p = 0.002), phosphorus (P: 5.9 ± 1.3 mg/dL vs. 4.9 ± 0.9 mg/dL, p < 0.0001) and calcium phosphate product (Ca × P: 58.7 ± 15.0 mg2/dL2 vs. 46.9 ± 8.9 mg2/dL2, p < 0.0001) were observed in the d-cinacalcet group. In addition, the subjects in the d-cinacalcet group had a greater proportion to achieve Kidney Disease Outcomes Quality Initiative (KDOQI)-recommended biochemical targets than the subjects in the VitD group (Ca: 48% vs. 24%; P: 78% vs. 32%; Ca × P: 85% vs. 37%; iPTH: 15% vs. 0%).
  
  
  CONCLUSIONS
  We conclude that combination therapy of low-dose cinacalcet and calcitriol is more effective than calcitriol alone as a treatment for moderate and severe UHPT in chronic dialysis patients. Furthermore, this therapy is associated with improvement in hyperphosphatemia and hypercalcemia.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, 833, Taiwan.
authors.forename: Yueh-Ting
authors.initials: YT
authors.lastname: Lee
authors.forename: Hwee-Yeong
authors.initials: HY
authors.lastname: Ng
authors.forename: Chien-Chun
authors.initials: CC
authors.lastname: Kuo
authors.forename: Te-Chuan
authors.initials: TC
authors.lastname: Chen
authors.forename: Chien-Shing
authors.initials: CS
authors.lastname: Wu
authors.forename: Terry Ting-Yu
authors.initials: TT
authors.lastname: Chiu
authors.forename: Wen-Chin
authors.initials: WC
authors.lastname: Lee
authors.forename: Chien-Te
authors.initials: CT
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D057966:Calcimimetic Agents / Q000008:administration & dosage*; D002117:Calcitriol / Q000627:therapeutic use*; D002118:Calcium / Q000097:blood; D000069449:Cinacalcet; D004359:Drug Therapy, Combination; D005260:Female; D019983:Guideline Adherence; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D009281:Naphthalenes / Q000008:administration & dosage*; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood; D017410:Practice Guidelines as Topic; D006435:Renal Dialysis / Q000009:adverse effects*; D051436:Renal Insufficiency, Chronic / Q000150:complications / Q000628:therapy*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014511:Uremia / Q000209:etiology; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D015415:Biomarkers; D057966:Calcimimetic Agents; D009281:Naphthalenes; C470125:PTH protein, human; D010281:Parathyroid Hormone; D010710:Phosphates; D014815:Vitamins; D002117:Calcitriol; D002118:Calcium; D000069449:Cinacalcet