Investigations of bone turnover in renal osteopathy

The renal bone disease which develops in chronic renal failure (CRF) is not an uniform disorder. Histomorphometry is accepted to be the best method for characterising the state of disease. The purpose of this study was to evaluate the suitability of pyridinium crosslinks in serum and urine as indicators of bone degradation processes. Patients with CRF had significantly higher Pyridinoline (Pyd) and Deoxypyridinoline (Dpyd) levels in serum and urine compared to normal controls except the urinary excretion in the subgroup of glomerulonephritis. A correlation was found between the serum levels of crosslinks and those of both creatinine and parathormone. The Pyd and Dpyd serum levels in patients under dialysis treatment were significantly higher than those of normal controls. With regard to bone turnover urinary crosslink measurements are of minor importance in CRF. In contrast, serum measurements could be helpful in revealing bone resorption both in patients with CRF and those under dialysis treatment.