title: Association of higher levels of serum cartilage oligomeric matrix protein and N-telopeptide crosslinks with the development of radiographic hip osteoarthritis in elderly women.
abstract: OBJECTIVE
  To examine the association of baseline concentrations of serum cartilage oligomeric matrix protein (COMP) and serum N-telopeptide crosslinks (NTX) with the development and progression of radiographic hip osteoarthritis (RHOA) in elderly women.
  
  
  METHODS
  Pelvic radiographs were obtained a mean of 8.3 years apart from white women > or =65 years of age enrolled in the Study of Osteoporotic Fractures. Random sampling from a cohort of 5,928 subjects was performed, with subjects ( approximately 200 per group) assigned to nested case-control studies, one focusing on RHOA incidence and the other on RHOA progression. Baseline serum levels of COMP and NTX were measured by enzyme-linked immunosorbent assay in duplicate. Odds ratios (ORs) and 95% confidence intervals (95% CIs), indicating the likelihood of baseline serum COMP and NTX levels to be predictive of the development or progression of RHOA, were calculated using logistic regression analysis, with adjustment for potential covariates.
  
  
  RESULTS
  At baseline, incident cases of RHOA were associated with higher serum levels of COMP and NTX (P < 0.05 for each) compared with the no RHOA control group. Higher baseline serum COMP and NTX levels were associated with an increased risk of incident RHOA compared with the no RHOA group, with an adjusted OR of 1.31 per SD increase in COMP (95% CI 1.02-1.68) and adjusted OR of 1.38 per SD increase in NTX (95% CI 1.07-1.79). In this community-based cohort, progression of RHOA was modest. However, there was a trend toward increased risk of RHOA progression with higher baseline COMP and NTX levels.
  
  
  CONCLUSIONS
  These data suggest that serum levels of COMP and NTX are modest risk markers for the development of RHOA in a community-based cohort of elderly white women.
authors.affiliation: Stanford University Medical Center, Stanford, California, USA.
authors.forename: A
authors.initials: A
authors.lastname: Kelman
authors.forename: L
authors.initials: L
authors.lastname: Lui
authors.forename: W
authors.initials: W
authors.lastname: Yao
authors.forename: A
authors.initials: A
authors.lastname: Krumme
authors.forename: M
authors.initials: M
authors.lastname: Nevitt
authors.forename: N E
authors.initials: NE
authors.lastname: Lane
mesh_terms: D000368:Aged; D064236:Cartilage Oligomeric Matrix Protein; D016022:Case-Control Studies; D003094:Collagen / Q000097:blood*; D024042:Collagen Type I; D016326:Extracellular Matrix Proteins / Q000097:blood*; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D064235:Matrilin Proteins; D015207:Osteoarthritis, Hip / Q000097:blood* / Q000000981:diagnostic imaging* / Q000209:etiology; D010455:Peptides / Q000097:blood*; D011859:Radiography
chemical_list: D064236:Cartilage Oligomeric Matrix Protein; D024042:Collagen Type I; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D064235:Matrilin Proteins; D010455:Peptides; C577553:TSP5 protein, human; C052929:collagen type I trimeric cross-linked peptide; D003094:Collagen