Histological renal osteodystrophy, and 25 hydroxycholecalciferol and aluminum levels in patients on continuous ambulatory peritoneal dialysis

Abstract

Eleven of the 20 paired bone biopsy specimens showed significant improvement in osteitis fibrosa (OF) 4 to 14 months after CAPD (five on 1 αOHCC), and in five patients at 2 years there was no significant deterioration. Six patients without OF at the beginning remained unchanged at 12 months while one patient developed osteomalacia (OM) after parathyroidectomy. These patients, managed on calcium carbonate supplements and in most cases no aluminum-containing phosphate binders (ACPB), maintained normal serum ionized and total calcium levels while mean serum phosphate levels ranged between 1.5 and 1.8 mmoles/liter on a dialysate calcium of 1.75 mmoles/liter. There was a decline in the parathormone level in all but ten patients, six of with whom previous severe OF on hemodialysis required parathyroidectomy. 25-(OH)CC levels declined to subnormal levels related to losses in the PD fluid in the majority of patients. Mean serum aluminum levels were higher than normal health controls; these may have been related to aluminum in the PD fluid. Levels rose further when ACPB was introduced. One patient with aluminum toxicity from prior exposure was treated with desferrioxamine given parenterally with the removal of the chelated aluminum in the PD fluid. CAPD appeared to achieve good control of renal osteodystrophy, but 25-(OH)CC levels were low and cautious amounts of vitamin D replacement therapy may be necessary. Serum aluminum levels were elevated and these may be related to the PD fluid aluminum content.