title: Vascular calcification biomarkers and peripheral arterial disease.
abstract: BACKGROUND
  The aim of this study was to evaluate the association of the calcification regulators, osteopontin (OPN) and osteoprotegerin (OPG), which are involved in vascular calcification and atherosclerosis in patients with peripheral arterial disease (PAD).
  
  
  METHODS
  A PubMed search of the English language literature was undertaken to identify articles that examine the role of the vascular calcification markers (OPN and OPG) in patients with PAD. The search retrieved 94 articles. After excluding non-relevant articles, only 11 studies qualified for review.
  
  
  RESULTS
  In 8 studies, OPG levels were correlated with the presence, severity, and progression of PAD, whereas in one article, OPG levels were not significantly elevated. In 2 studies, OPN levels were associated with PAD and vascular stiffness.
  
  
  CONCLUSIONS
  The results from clinical and experimental research regarding the role of vascular calcification markers in PAD are controversial, although most of the studies suggest a positive correlation. Larger studies are needed to determine the exact pathway of vascular calcification, mediated by calcification markers, in patients with PAD.
authors.affiliation: Fifth Department of Surgery, Medical School, Aristotle University of Thessaloniki, Thesslaoniki, Greece - kapten-d@live.com.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Kapetanios
authors.forename: Christos
authors.initials: C
authors.lastname: Karkos
authors.forename: Ioakeim
authors.initials: I
authors.lastname: Giagtzidis
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Papazoglou
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Kiroplastis
authors.forename: Charalampos
authors.initials: C
authors.lastname: Spyridis
mesh_terms: D015415:Biomarkers / Q000097:blood; D006801:Humans; D053495:Osteopontin / Q000097:blood*; D053244:Osteoprotegerin / Q000097:blood*; D058729:Peripheral Arterial Disease / Q000097:blood* / Q000175:diagnosis / Q000503:physiopathology; D011237:Predictive Value of Tests; D011379:Prognosis; D012720:Severity of Illness Index; D061205:Vascular Calcification / Q000097:blood* / Q000175:diagnosis / Q000503:physiopathology; D059289:Vascular Stiffness
chemical_list: D015415:Biomarkers; D053244:Osteoprotegerin; C506895:SPP1 protein, human; C506030:TNFRSF11B protein, human; D053495:Osteopontin