title: Decreased serum osteoprotegerin levels in patients with cardiac syndrome X.
abstract: Receptor activator of nuclear factor KB (RANK) and osteoprotegerin (OPG) represent the ligand and decoy receptor, respectively, of a pleiotropic cytokine system that regulates bone metabolism and vascular biology. Several studies supported systemic microvascular abnormalities in patients with cardiac syndrome X (CSX). This study investigates serum OPG levels in healthy obese subjects and healthy lean controls affected by cardiac syndrome X.
  
  
  METHODS
  We compared the OPG levels in 8 patients with cardiac syndrome X [2 males, 6 females; age: 46+/-6 yr; body mass index (BMI): 30+/-5 kg/m2] with 24 obese subjects (8 males, 16 females; age: 38+/-5 yr; BMI: 35+/-5 kg/m2) and 15 healthy lean controls (6 males, 9 females; age: 36+/-5 yr; BMI: 23+/-2 kg/m2; BMI<25kg/m2).
  
  
  RESULTS
  Serum OPG levels in patients with cardiac syndrome X were lower than those in obese subjects and lean controls (11.45+/-8.36 pg/ml, 14.78+/-8.22 pg/ml, 19.24+/-6.96 pg/ml, respectively, cardiac syndrome X vs lean controls, p=0.039).
  
  
  CONCLUSIONS
  Serum OPG levels are lower in patients with CSX. Further studies on the mechanisms of OPG in microangiopathy may help to evaluate the OPG system role as a marker for disease activity, prognosis and response to therapy in cardiovascular diseases.
authors.affiliation: Department of Cardiology, Faculty of Medicine, University of Trakya, Edirne, Turkey. altun@medscape.com
authors.forename: A
authors.initials: A
authors.lastname: Altun
authors.forename: B
authors.initials: B
authors.lastname: Ugur-Altun
authors.forename: E
authors.initials: E
authors.lastname: Tatli
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D008297:Male; D017566:Microvascular Angina / Q000097:blood*; D008875:Middle Aged; D009765:Obesity / Q000097:blood; D053244:Osteoprotegerin; D018160:Receptors, Cytoplasmic and Nuclear / Q000097:blood*; D018124:Receptors, Tumor Necrosis Factor
chemical_list: D006023:Glycoproteins; D053244:Osteoprotegerin; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor; C506030:TNFRSF11B protein, human