title: Serum osteoprotegerin levels and the extent of vascular calcification in haemodialysis patients.
abstract: 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.
authors.affiliation: Department of Medicine, Kidney Center, Tokyo Women's Medical University, Tokyo, Japan. nitta@kc.twmu.ac.jp
authors.forename: Kosaku
authors.initials: K
authors.lastname: Nitta
authors.forename: Takashi
authors.initials: T
authors.lastname: Akiba
authors.forename: Keiko
authors.initials: K
authors.lastname: Uchida
authors.forename: Shigeru
authors.initials: S
authors.lastname: Otsubo
authors.forename: Takashi
authors.initials: T
authors.lastname: Takei
authors.forename: Wako
authors.initials: W
authors.lastname: Yumura
authors.forename: Takashi
authors.initials: T
authors.lastname: Kabaya
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nihei
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001018:Aortic Diseases / Q000097:blood* / Q000209:etiology; D002114:Calcinosis / Q000097:blood* / Q000209:etiology; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D053244:Osteoprotegerin; D018160:Receptors, Cytoplasmic and Nuclear / Q000097:blood*; D018124:Receptors, Tumor Necrosis Factor; D006435:Renal Dialysis / Q000009:adverse effects*; D012720:Severity of Illness Index
chemical_list: D006023:Glycoproteins; D053244:Osteoprotegerin; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor; C506030:TNFRSF11B protein, human