Abstract
The conventional therapy for secondary hyperparathyroidism (SHPT) consists of serum phosphate reduction using a phosphate binder and suppressing parathyroid hormone (PTH) with vitamin D sterols. Excess vitamin D may promote intestinal calcium absorption, which leads to hypercalcemia and increased risk of cardiac and vascular calcifications. We prospectively endeavored to reduce the amount of vitamin D during therapy with cinacalcet for SHPT. Adult patients undergoing hemodialysis who had difficulty achieving the target of biomarkers recommended by the National Kidney Foundation Kidney Disease Outcome Quality Initiative (NKF-K/DOQI) with conventional therapy for SHPT were enrolled. The patients received combined therapy, i.e. a calcimimetic and a low dose of vitamin D, and the primary assessments included plasma wPTH, serum ionized calcium, calcium, phosphorus and calcium-phosphorus products every 2 weeks for 28 weeks. In total, 30 patients were enrolled in the study and 27 completed the 28-week course. The primary endpoint was defined as a mean plasma wPTH concentration≤160pg/mL and was achieved in 67% of patients. Moreover, 96% had a Ca×P≤55mg2/dL2 (At baseline, the proportions were 11% and 26%, respectively). At the end of the study, 85% of patients received vitamin D and the mean±SD dose was 0.42±0.22μg/day. Our findings suggest that combination therapy with a low dose of vitamin D and cinacalcet is effective for the treatment of SHPT in patients on chronic hemodialysis.
