Residual renal function plays an important role in regulating parathyroid hormone in patients on continuous ambulatory peritoneal dialysis.

: In the past, hyperparathyroidism was not generally a major problem in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). However, in conjunction with disturbances in serum phosphate, Ca, and CaxP product, hyperparathyroidism has become a serious problem in the cardiovascular diseases of patients with end-stage renal disease-even patients undergoing CAPD. We retrospectively evaluated the first 5 years on CAPD for 17 patients who started and continued dialysis between April 1995 and September 2003. Of these 17 patients, 3 underwent parathyroidectomy. During their clinical course, all of the patients experienced a decline in residual renal function (RRF) that was significantly negatively correlated with their levels of serum Ca and intact parathyroid hormone. Based on these findings, we suggest that RRF is an important factor for the regulation of Ca-P metabolism in patients on CAPD.