Background: Osteoprotegerin (OPG) is a glycoprotein that inhibits osteoclast differentiation and activity. OPG-deficient mice develop severe osteoporosis and medial arterial calcification. The expression of OPG is detected in early atherosclerotic lesions in non-uraemic patients. We examined whether serum OPG is associated with aortic calcification in haemodialysis patients.
Methods: Serum OPG was measured in 102 patients who were undergoing haemodialysis. The aortic calcification index (ACI) was assessed by computed tomography scans.
Results: Serum OPG level, measured by enzyme-linked immunosorbent assay, was significantly greater in patients with higher ACI than in those with lower ACI. There was a direct relationship between ACI and serum OPG levels and a positive association between OPG and ACI (r = 0.483, P<0.0001). Multiple regression analyses indicated that serum OPG levels were independently associated with the severity of aortic calcification (P<0.0001).
Conclusions: These findings show that serum OPG levels are associated with the extent of vascular calcification, suggesting that OPG may be involved in the development of vascular calcification in haemodialysis patients.