RESUMEN
The response of hyperparathyroidism and skeletal calcium loss in haemodialysis patients to treatment with 1alpha-hydroxyvitamin D3 and a dialysate calcium concentration of 1.375 mmol/l was compared with the response to treatment with a dialysate calcium concentration of 1.375 or 1.75 mmol/l alone over a 6 month period. In patients treated with 1alpha-hydroxyvitamin D3 there was a significant rise in plasma calcium associated with a significant fall in plasma alkaline phosphatase and plasma parathyroid hormone as well as resolution of sub-periosteal erosions. In these patients there was a significant rise in the calcium content of the forearm assessed by neutron activation analysis in comparison to patients treated with a dialysate calcium concentration of 1.75 or 1.375 mmol/l alone. In patients treated with a dialysate calcium concentration of 1.375 or 1.75 mmol/l alone there was no significant change in the plasma calcium, alkaline phosphatase or parathyroid hormone after 6 months and in these patients subperiosteal erosions either did not change or became worse. No significant difference in the response in these two groups was observed. This study indicates that treatment of haemodialysis patients with 1alpha-hydroxyvitamin D3 is significantly more effective than treatment with a dialysate calcium concentration of 1.375 or 1.75 mmol/l alone in preventing progression of hyperparathyroidism and skeletal calcium loss.