[Treatment of secondary hyperparathyroidism resistant to conventional therapy and tertiary hyperparathyroidism with Cinacalcet: an efficiency strategy].
BACKGROUND
The treatment of secondary hyperparathyroidism (SHPT) in dialysis patients has changed with the introduction of cinacalcet (CC), which represents a medical alternative to surgical parathyroidectomy (PTX). The aim of our study is to prospectively assess the tolerance and efficacy of CC in patients, treated in one centre using long haemodialysis, with SHPT who do not respond to conventional therapy.


METHODS
We prospectively observed all patients treated with CC between September 2004 and 2009. The characteristics of the patients were compared with that recorded for the patients non treated with CC. Biological factors and the efficacy of the treatment in the patients were compared before (T-0) and after (T-End) CC therapy. The haemodialysis (HD) schedule was 3 x 5 to 3 x 8 h per week. The biological criteria for CC prescription were a serum PTH level greater than 300 pg/ml, calcium level greater than 2.45 mmol/l and bone alkaline phosphatase level greater than 20 microg/l or, in cases of tertiary hyperparathyroidism (THPT), a calcium level greater than 2.55 mmol/l.


RESULTS
Eighty-one (14.7%) among the 550 HD patients were treated with CC. As compared to the untreated population, these patients were younger and had higher body mass index (BMI) and higher protein-catabolic rate (nPCR). The treatment failed in 6.1% of the treated patients; 12.3% had severe gastrointestinal side effects and 10% underwent PTX. The treatment was successful in 81.4% patients who were prescribed a mean final CC dosage of 51+/-30 mg/day. Between T-0 and T-End (18+/-15) months), the serum PTH levels decreased by 77%, calcaemia levels decreased by 10% and phosphataemia levels decreased by 14%. Therefore, the percentage of patients with normal biological parameters increased significantly : serum PTH (150-300 pg/ml: 0 to 50%), calcaemia (2.1-2.37 mmol/l: 6 to 77%) and phosphataemia (1.15-1.78 mol/l: 58 to 84%). After 12 months, eight patients (10%) successfully weaned from CC therapy. No episodes of hypocalcaemia (<2.0 mmol/l) occurred. Treatments with alfacalcidol (68 to 40%) and sevelamer (72 to 50%) decreased, treatments with CaCO(3) remained stable (20%), those with native vitamin D increased (55 to 95%).


CONCLUSIONS
The treatment of HD patients having SHPT and THPT with CC and vitamin D derivatives was efficacious and well tolerated in a majority of cases after the failure of conventional therapies. These treatments improved mineral metabolism significantly.
Jean
Guillaume
G
Centre de rein artificiel, 42, avenue du 8-mai-1945, 69160 Tassin-La-Demi-Lune, France. guillaume-jean-crat@wanadoo.fr
Vanel
Thierry
T
Terrat
Jean-Claude
JC
Hurot
Jean-Marc
JM
Lorriaux
Christie
C
Mayor
Brice
B
Deleaval
Patrick
P
Vovan
Cyril
C
Chazot
Charles
C
D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D050071:Bone Density Conservation Agents / Q000627:therapeutic use; D002118:Calcium / Q000097:blood; D002614:Chelating Agents / Q000627:therapeutic use; D000069449:Cinacalcet; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D006887:Hydroxycholecalciferols / Q000627:therapeutic use; D006961:Hyperparathyroidism / Q000188:drug therapy; D006962:Hyperparathyroidism, Secondary / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology; D007676:Kidney Failure, Chronic / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009281:Naphthalenes / Q000009:adverse effects / Q000627:therapeutic use*; D010281:Parathyroid Hormone / Q000097:blood; D011073:Polyamines / Q000627:therapeutic use; D011446:Prospective Studies; D006435:Renal Dialysis / Q000009:adverse effects*; D000069603:Sevelamer; D012720:Severity of Illness Index; D017211:Treatment Failure; D016896:Treatment Outcome; D014807:Vitamin D / Q000627:therapeutic use
D015415:Biomarkers; D050071:Bone Density Conservation Agents; D002614:Chelating Agents; D006887:Hydroxycholecalciferols; D009281:Naphthalenes; D010281:Parathyroid Hormone; D011073:Polyamines; D014807:Vitamin D; D000069603:Sevelamer; D000469:Alkaline Phosphatase; D002118:Calcium; D000069449:Cinacalcet; C008088:alfacalcidol