Bone demineralization following urinary intestinal diversion assessed by urinary pyridinium cross-links and dual energy x-ray absorptiometry

Purpose: We investigated the acid-base balance and bone mineral status in patients with 3 types of urinary intestinal diversion. Materials and Methods: Of 46 men with urinary intestinal diversions 20 had a Kock pouch, 15 had an Indiana pouch and 11 had an ileal conduit. Acid-base balance was assessed by arterial blood gas analysis. Bone mineral status was measured by urinary pyridinium cross-links and dual energy x-ray absorptiometry. In addition, urinary deoxypyridinoline was measured in 79 patients. Results: Of the 46 patients 7 (15%) with the Kock pouch (1), Indiana pouch (5) and ileal conduit (1) had metabolic acidosis associated with significantly lower bone mineral densities (p <0.05) and higher urinary pyridinium cross-links (p <0.005) than did those with normal acid-base status. No difference was found in metabolic acidosis and bone demineralization among the 3 groups. Additionally, in 79 patients urinary deoxypyridinoline reached the highest level immediately postoperatively and then gradually decreased to the stable level within 1 or 2 years. Conclusions: Metabolic acidosis following urinary intestinal diversion results in bone demineralization. The types of diversion did not cause differences in metabolic acidosis and bone resorption. Bone has a major role in buffering acid overload in the early postoperative period.