Abstract
Background: Osteoprotegerin (OPG) is a recently identified cytokine that acts as a decoy receptor for the receptor activator of nuclear factor-κB ligand (RANKL). OPG and RANKL have been shown to be important regulators of osteoclastogenesis. The aim of this study was to investigate the relationship between the OPG-RANKL system and bone mineral metabolism in patients with chronic renal failure (CRF).
Methods: Serum OPG, RANKL, osteocalcin, cross-linked c-telopeptide of type I collagen (ICTP), intact parathyroid hormone (PTH), bone alkaline phosphatase and cystatin C levels were measured in 40 chronic hemodialysis male patients and 32 age- and sex-matched healthy controls. Their lumbar spine bone mineral density (LS-BMD) was measured by dual energy X-ray absorptiometry.
Results: Serum OPG, RANKL, PTH, bone alkaline phosphatase and cystatin C levels were significantly increased in patients with CRF. Serum OPG was positively correlated to serum RANKL and cystatin C. Positive correlations were found between serum RANKL and cystatin C and ICTP. LS-BMD was significantly lower in patients with CRF than in controls. In patients with CRF, LS-BMD was inversely correlated to serum RANKL and cystatin C, whereas it was positively correlated to serum OPG.
Conclusions: The OPG-RANKL system is involved in the pathogenesis and regulation of bone turnover in CRF. Circulating levels of OPG and RANKL may be useful markers to assess turnover renal osteopathies.
Clin Chem Lab Med 2007;45:1498–503.
©2007 by Walter de Gruyter Berlin New York
