An assessment of dialysis-associated osteodystrophy in long-term peritoneal dialysis

To assess the development of dialysis-associated osteodystrophy during intermittent peritoneal dialysis, a study was made of 50 patients with end-stage renal failure. The duration of dialysis therapy ranged from 6 to 37 months, during which the peritoneal dialysis index for creatinine fell from 5.7 to 2.9 ml/min. Serum calcium normalized from predialytic values below normal range. During the period of observation there were no significant changes in serum albumin, phosphate, magnesium, ionized calcium or parathyroid hormone levels. Osteodensitometry, performed on 26 patients, revealed no significant changes. Determination of serum total alkaline phosphatases (TALP) and fractioned alkaline phosphatases showed raised TALP values in 30% of the patients; in only 10% of these patients the increase was due to elevated liver isoenzymes. 6 patients had normal TALP but relatively raised bone isoenzyme values. There was a significant correlation between the bone fraction and TALP, and between the liver fraction and TALP, but none between the bone and liver fraction. Patients on intermittent peritoneal dialysis using a dialysis fluid with a relatively high calcium concentration (2.25 mmol/l) seem less prone to develop dialysis-associated osteodystrophy.