Abstract: objective To observe the effect of low calcium dialysate combined with active vitamin D and sevelamer hydrochloride on secondary hyperparathyroidism in chronic renal failure patients with maintenance hemodialysis (MHD). Methods We recruited 30 cases of chronic renal failure patients with MHD treated in the Nephrology Department of Qinghai Province People's Hospital using low calcium dialysate (1.25 mmol/ L) combined with pulse treatment of active vitamin D and oral administration of sevelamer hydrochloride. Changes of serum calcium, phosphorus, calcium-phosphorus product, and intact parathyroid hormone (iPTH) were recorded after the treatment for 6 months. Results In the 30 cases before the treatment, after the treatment for 3 months and for 6 months, serum calcium was 2.34 ± 0.17 mmol/L, 2.36 ± 0.21 mmol/L and 2.37 ± 0.20 mmol/L, respectively, all within the normal serum range; serum phosphate was 2.27 ± 0.39 mmol/L,17 5 ± 0.41 mmol/L and 1.41 ± 0.35 mmol/L, respectively; calcium- phosphorus product was 63.21 ± 10.13 mg2/dl2, 53.27 ± 9.57 mg2/dl2 and 48.51 ± 9.74 mg2/dl2, respectively; serum iPTH was 650.80 ± 119.40 pg/ml, 376.10 ± 117.40 pg/ml and 211.90±109.40 pg/ml, respectively. As compared with those before the treatment, serum phosphate, calcium- phosphorus product and iPTH decreased after the treatment for 3 months (F=1.10, P= 4.97×10-6 for serum phosphate; F=0.89, P=0.0002 for calcium-phosphorus product; F=0.97, P=1.40×10-12 for iPTH), and decreased further after the treatment for 6 months (F=0.81, P=1.38×10- 12 for serum phosphate; F=0.92, P=3.79×10-7 for calcium-phosphorus product; F=0.84, P=2.06×10-21 for iPTH). Four patients were found to have adverse gastrointestinal reactions that disappeared after appropriate treatment. Conclu-sion Dialysis with low calcium dialysate combined with sevelamer hydrochloride and pulse doses of active vitamin D can significantly decrease serum phosphorus and calcium-phosphorus product for secondary hyperparathyroidism in chronic renal failure patients on MHD. This combination therapy prevents the patients from hypercalcemia and metastatic calcification, and is effective to renal osteopathy of high transport type.

Key words: Low calcium dialysate, Active vitamin D, Sevelamer hydrochloride, Secondary hyperparathyroidism