title: Serum osteoprotegerin and its ligand in cirrhotic patients referred for orthotopic liver transplantation: relationship with metabolic bone disease.
abstract: OBJECTIVE
  A prospective study was carried out in 22 cirrhotic patients referred for orthotopic liver transplantation, in order to analyze serum osteoprotegerin (OPG) and RANKL levels and their relationship with metabolic bone disease.
  
  
  METHODS
  Serum levels of OPG and RANKL were measured in all patients as well as bone markers, serum parathyroid hormone and 25-hydroxyvitamin D levels. OPG and RANKL values were compared with those obtained in 29 healthy controls. Bone mineral density (BMD) of the lumbar spine and proximal femur was measured by dual X-ray absorptiometry and spinal X-rays were obtained to assess vertebral fractures.
  
  
  RESULTS
  Serum OPG levels were higher in cirrhotic patients than in controls (6.4+/-2 vs 2.7+/-0.7 pmol/l; P=0.001) and RANKL serum levels were lower in cirrhotic patients (0.215+/-0.6 vs 1.012+/-1.2 pmol/l; P=0.002), with an increased OPG:RANKL ratio when compared with the control group (280.3+/-334.5 vs 113+/-137.6; P=0.04). Ten patients had osteoporosis (45%) and up to 45% skeletal fractures. No differences were found in OPG levels between patients with and without osteoporosis by densitometric criteria or fractures. Negative correlations were found between OPG levels and femoral neck (R-0.46; P=0.03) and total hip BMD (R-0.48; P=0.025). By contrast, OPG values were not related to markers of bone turnover.
  
  
  CONCLUSIONS
  OPG values are elevated in cirrhotic patients before liver transplantation, particularly in those with low bone mass at the proximal femur.
authors.affiliation: Service of Rheumatology Unit, Hospital Clínic, IDIBAPS, University of Barcelona, Barcelona, Spain. 21607amb@comb.es
authors.forename: Ana
authors.initials: A
authors.lastname: Monegal
authors.forename: Miquel
authors.initials: M
authors.lastname: Navasa
authors.forename: Pilar
authors.initials: P
authors.lastname: Peris
authors.forename: Luisa
authors.initials: L
authors.lastname: Alvarez
authors.forename: Francesca
authors.initials: F
authors.lastname: Pons
authors.forename: Joan
authors.initials: J
authors.lastname: Rodés
authors.forename: Nuria
authors.initials: N
authors.lastname: Guañabens
mesh_terms: D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000097:blood / Q000175:diagnosis / Q000209:etiology*; D016022:Case-Control Studies; D050723:Fractures, Bone; D006801:Humans; D008103:Liver Cirrhosis / Q000097:blood / Q000150:complications*; D016031:Liver Transplantation; D010024:Osteoporosis; D053244:Osteoprotegerin / Q000097:blood*; D011446:Prospective Studies; D053245:RANK Ligand / Q000097:blood*
chemical_list: D015415:Biomarkers; D053244:Osteoprotegerin; D053245:RANK Ligand