Does cinacalcet HCl, an oral calcimimetic agent for the treatment of secondary hyperparathyroidism, improve arterial stiffness in patients on continuous ambulatory peritoneal dialysis?

Vascular calcification (VC) and arterial stiffness (AS) are major contributors to cardiovascular disease, and in chronic kidney disease, VC and AS are correlated. Disorders of calcium and phosphate metabolism contribute to the progression of VC and to increases in AS. The efficacy of cinacalcet (CIN) in reducing AS in patients on continuous ambulatory peritoneal dialysis (CAPD) has not been determined. The present study enrolled 19 CAPD patients (12 women, 7 men; mean age: 62.2 +/- 3.6 years) with serum intact parathyroid hormone (iPTH) greater than 500 ng/dL (mean value: 675 +/- 106 ng/dL) in whom daily oral treatment with CIN 25 mg was started. If administration of CIN for 3 months failed to reduce the level of iPTH to less than 300 ng/dL, the dose of CIN was increased to 50 mg daily. Before the start of CIN and at 3 years after the start of CIN, pulse wave velocity (PWV) was determined. In 11 patients, levels of iPTH were reduced to less than 300 ng/dL; levels in the rest of the patients remained high. We observed no significant differences in PWV before CIN and at 3 years after CIN start (1856 +/- 198 cm/s vs. 1726 +/- 187 cm/s). Multivariate regression analysis of PWV demonstrated that both systolic blood pressure and changes in serum levels of phosphate contributed to decreases in PWV In patients receiving CAPD, VC and AS might be the result of higher systolic blood pressure and increased serum levels of phosphate.