Objectives: To evaluate the effects of ileal bladder substitution or colonic Indiana pouch on skeletal bone density and various biochemical parameters related to bone metabolism.
Patients and methods: In 27 patients with urinary diversion and 14 controls with benign urologic disease, bone mineral density (BMD), assessed by dual-photon absorptiometry; serum electrolyte, creatinine, alkaline phosphatase and parathyroid hormone levels were determined, and capillary blood gas analysed. BMD was measured in the lumbar spine and the femur neck. The mean time since surgery was 33.6+/-10.1 months in 17 patients with an ileal bladder substitution and 56+/-9.1 months in 10 patients with a colonic Indiana pouch (p=0.001).
Results: Although BMD did not change in the colonic Indiana pouch group, it was reduced in the patients with ileal bladder substitution compared to control group. The mean pH value was not statistically significant different in the both groups from the control group (p>0.2). The mean base excess value reduced in the substitution group (p<0.01). While alkaline phosphatase levels increased in both groups compared to control group (p<0.05), the mean parathyroid hormone level decreased only in the patients with ileal bladder substitution (p<0.05). The other biochemical parameters were similar in patients and control subjects. There was a statistically significant correlation between the base excess values and BMD values of the patients in both groups.
Conclusion: Although there is decreased BMD in patients with an ileal bladder substitute, there is no change in BMD in the patients with Indiana pouch. Alkaline phosphatase levels increased in both patient groups indicating increased bone turnover.