[Effect of cinacalcet combined with low-dose calcitriol on clinical outcome and bone metabolism in patients with severe secondary hyperparathyroidism].

OBJECTIVE: To observe the clinical outcome and the effect of the combination of cinacalcet hydrochloride with low-dose calcitriol on bone metabolism in maintenance hemodialysis (MHD) patients with severe secondary hyperparathyroidism (SHPT).
 Methods: Thirty SHPT patients were enrolled to receive treatment of cinacalcet combined with low-dose calcitriol, with inclusion criteria as follows: maintenance on MHD>6 months; serum intact parathyroid hormone (iPTH)>600 pg/mL; parathyroid glands with more than 1 nodules by ultrasonography; traditional therapy with no effects. All patients were given cinacalcet 25-75 mg and 0.5 μg calcitriol daily. Serum Ca, P, iPTH, bone metabolic markers and bone density were measured before and after treatment. The clinical symptoms and their changes were recorded.
 Results: The baseline levels of iPTH, Ca and P were (1787.3±1 321.0) pg/mL, (2.54±0.19) mmol/L, and (2.06±0.15) mmol/L, respectively. After 2 weeks of treatment, serum phosphorus decreased by 20%; after 1 and 3 months of treatment, iPTH decreased by 35% and 70%. Ca and P fell to (2.39±0.17) and (1.56±0.50) mmol/L (P<0.05), respectively. The symptoms of the patients relieved. The above indicators remained stable after 12 months. Moreover, after 6 months of treatment, the alkaline phosphatase, osteocalcin and β-cross levels were decreased by 50%, 37% and 49%, respectively. The decline in patients' bone density was inhibited. No severe adverse events were observed.
 Conclusion: Cinacalcet hydrochloride combined with low dose calcitriol can improve high calcium, high phosphorus and high iPTH in MHD patients with severe SHPT, relieve symptoms, and improve bone metabolism. It can be used as a favorable choice for the treatment of SHPT.