BONE DEMINERALIZATION FOLLOWING URINARY INTESTINAL DIVERSION ASSESSEDBY 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 a nd 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 sta tus was measured by urinary pyridinium cross-links and dual energy x-r ay absorptiometry. In addition, urinary deoxypyridinoline was measured in 79 patients. Results: Of the 46 patients 7 (15%) with the Kock pou ch (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 aci dosis and bone demineralization among the 3 groups. Additionally, in 7 9 patients urinary deoxypyridinoline reached the highest level immedia tely 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 d iversion did not cause differences in metabolic acidosis and bone reso rption. Bone has a major role in buffering acid overload in the early postoperative period.