Bone turnover markers in diabetics treated with continuous ambulatory peritoneal dialysis

Low turnover renal osteodystrophy (ROD) is an important problem in patients on CAPD. The aim of the study was to evaluate in CAPD patients the frequency of low turnover ROD with special interest to diabetic nephropathy (DN) as well as estimation the clinical usefulness of some biochemical bone turnover markers in monitoring this complication. The study was performed in group of 54 patients: 28 on CAPD (15 M, 13 F) and 26 on HD (14 M, 12 F). There were 20/28 patients with DN in CAPD group. The observation lasted 12 months. Every 3rd month levels of iPTH, PICP, PINP, ICTP, Ca, P, total AP in serum were determined. Correlation between these biochemical markers of ROD and causes of renal failure, sex, age of patients were analyzed statistically. In CAPD patients significantly lower values of iPTH were found in comparison with HD patients (p < 0.01). In patients with DN levels of iPTH were significantly lower (p < 0.001) than in patients with other causes of renal failure (respectively: iPTH 142 +/- 81 vs 403 +/- 128 pg/ml). In patients with DN treated with CAPD levels of iPTH were significantly lower in men than in women and in younger men with DN (< 50 years). The similar results were found in levels of PINP as a marker of bone formation. Close correlation between PINP and iPTH (r = 0.80) was also found. In summary we showed that low turnover ROD is the predominant bone lesion in CAPD patients. Men with DN < 50 age are specially predisposed to the low turnover ROD. Monitoring of iPTH and PINP levels as sensitive markers of low turnover ROD might be useful in assessment of bone turnover rate in CAPD patients.