SYMPTOMATIC HYPERCALCEMIA IN A DIABETIC PATIENT UNDERGOING CONTINUOUSAMBULATORY PERITONEAL-DIALYSIS - VALUE OF BONE-BIOPSY IN THE DIAGNOSIS AND MANAGEMENT

An elderly man with diabetes mellitus and end-stage renal disease mana ged with continuous ambulatory peritoneal dialysis (CAPD) was hospital ized with peripheral vascular insufficiency; he developed hypercalcemi a and became mentally obtunded, Lowering dialysate Ca from 3.5 mEq/L t o 2.5 mEq/L, stopping calcium acetate, and ultimately hemodialysis wit h calcium-free dialysate did not lead to reversal of the hypercalcemia or improvement of his symptoms, The intact parathyroid hormone PTH le vel was 187 pg/mL, a value rarely associated with significant osteitis fibrosa, A search for other causes of hypercalcemia was unrevealing, and a iliac crest bone biopsy was done, The latter showed osteitis fib rosa, and the patient underwent parathyroidectomy, The hypercalcemia r eversed quickly, and his mental symptoms slowly improved, The discussi on reviews the probable causes of hypercalcemia in diabetic patient un dergoing CAPD with 3.5 mEq/L dialysate calcium and using calcium-conta ining phosphate binders, with hyperparathyroidism certainly not the us ual cause, The reason for the occurrence of significant hyperparathyro idism in the face of only modest elevation of PTH is considered, The v alue of bone biopsy in resolution of this problem is apparent. (C) 199 5 by the National Kidney Foundation, Inc.