Time course of change in calcium x phosphorus product after percutaneous ethanol injection therapy

Abstract

Background. Percutaneous ethanol injection therapy (PEIT) effectively suppresses PTH secretion, but the change in the serum calcium and phosphorus product (Ca x P) after PEIT has not been fully evaluated. Methods. Twenty-seven haemodialysis patients with severe secondary hyperparathyroidism (2HPT) were divided into two groups according to their intact PTH (i-PTH) concentrations 6 months after PEIT: (i) effective (E) group, i-PTH concentration < 360 pg/ml; and (ii) non-effective (N) group i-PTH 360 pg/ml. The changes in serum calcium and phosphorus concentrations and the Ca x P were recorded for the following 2 years under post-PEIT medical treatment with oral calcitriol or intravenous 22-oxacalcitriol (OCT). Result. In the E group, the i-PTH concentrations decreased to < 300 pg/ml 1 year after PEIT (801 ± 302 to 280 ± 134 pg/ml), then increased to 435 ± 201 pg/ml at 2 years. Serum calcium concentration did not show any significant change except for a transient reduction at 1 month after PEIT. The Ca × P decreased for 1 year (from 66.3 ± 15.3 to 56.2 ± 10.3 mg2/dl2; P<0.05), in agreement with the course of phosphorus concentration, and continued to be < 60 mg2/dl2 up to 2 years after PEIT. The Ca x P tended to decrease more with OCT than oral calcitriol. In the N group, calcium and Ca x P increased significantly at 6 months after PEIT and remained at a high value. Conclusion. Treatment with PEIT suppresses serum PTH concentration as well as Ca x P in the long term.