title: Association between cartilage and bone biomarkers and incidence of radiographic knee osteoarthritis (RKOA) in UK females: a prospective study.
abstract: OBJECTIVE
  There is a need to find biochemical markers that would identify people with increased risk of developing radiographic knee osteoarthritis (RKOA). The aim of this study was to evaluate the ability of cartilage and bone biomarkers (cartilage oligomeric matrix protein (COMP), aggrecan, cellular inhibitor of apoptosis protein (cIAP), N-telopeptide-to-helix (NTx)) to predict RKOA incidence in a 10-year follow-up of UK females from the Chingford community study.
  
  
  METHODS
  Joint space narrowing (JSN), osteophytes (OSP) and Kellgren-Lawrence (K/L) grades were scored from radiographs of both knees at study baseline and 10 years later in 1,003 women aged 45-64. Circulating levels of biomarkers and demographic variables were measured at baseline. Statistical association analysis was conducted between the potential predictor factors measured at baseline and documentation of RKOA at 10-year follow-up.
  
  
  RESULTS
  Age and body mass index (BMI), were significant predictors of incidence of RKOA as assessed by K/L and OSP. Considering biomarkers, independent significant association was found between COMP circulating levels and K/L scores (Odd Ratio (OR) = 2.87, 95% Confidence Interval (CI) = 1.19-6.89, P = 0.018). Significant negative association was detected between aggrecan plasma concentrations and JSN, with OR = 0.37 (95% CI 0.15-0.89), P = 0.026.
  
  
  CONCLUSIONS
  Aggrecan and COMP circulating levels contribute to identification of phenotype-specific RKOA incidence. These data suggest potentially protective role of aggrecan in cartilage loss, as measured by JSN. High COMP levels are risk factors for development of RKOA, as assessed by K/L scores.
authors.affiliation: Human Population Biology Research Unit, Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: O
authors.initials: O
authors.lastname: Blumenfeld
authors.forename: F M K
authors.initials: FM
authors.lastname: Williams
authors.forename: D J
authors.initials: DJ
authors.lastname: Hart
authors.forename: T D
authors.initials: TD
authors.lastname: Spector
authors.forename: N
authors.initials: N
authors.lastname: Arden
authors.forename: G
authors.initials: G
authors.lastname: Livshits
mesh_terms: D000367:Age Factors; D053674:Aggrecans / Q000097:blood*; D015992:Body Mass Index; D064236:Cartilage Oligomeric Matrix Protein / Q000097:blood*; D024042:Collagen Type I / Q000652:urine*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D051034:Inhibitor of Apoptosis Proteins / Q000097:blood*; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000473:pathology; D008131:London / Q000453:epidemiology; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000378:metabolism*; D054850:Osteophyte / Q000000981:diagnostic imaging / Q000473:pathology; D010455:Peptides / Q000652:urine*; D011446:Prospective Studies; D011859:Radiography; D012307:Risk Factors
chemical_list: D053674:Aggrecans; D064236:Cartilage Oligomeric Matrix Protein; D024042:Collagen Type I; D051034:Inhibitor of Apoptosis Proteins; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide