title: Urinary CTX-II and glucosyl-galactosyl-pyridinoline are associated with the presence and severity of radiographic knee osteoarthritis in men.
abstract: OBJECTIVE
  To investigate the association between biochemical markers of bone, cartilage, and synovial turnover with the presence and severity of knee osteoarthritis (OA) in men.
  
  
  METHODS
  176 men aged 59-70 years from the MRC Hertfordshire Cohort were studied. Weightbearing anteroposterior and lateral semiflexed radiographs were taken of both knees. A lifestyle questionnaire including basic demographic details and a questionnaire detailing knee pain was completed. This random sample was stratified based on the Kellgren and Lawrence (K&L) score, and the following biochemical markers were analysed: serum osteocalcin, serum C-terminal crosslinked telopeptide of type I collagen (CTX-I), urinary C-terminal crosslinked telopeptide of type II collagen (CTX-II), and urinary glucosyl-galactosyl-pyridinoline (Glc-Gal-Pyd).
  
  
  RESULTS
  Age, body mass index (BMI), social class, smoking, and alcohol consumption were similar across K&L grades. Only one subject had a grade 4 K&L score, and was amalgamated with grade 3 subjects. A strong significant association was found between the presence of knee OA and urinary CTX-II and urinary Glc-Gal-Pyd (p=0.0001 and p=0.009), which persisted after adjustment for age and BMI. A significant positive association was also found between urinary CTX-II and urinary Glc-Gal-Pyd and the severity of K&L grade, joint space narrowing, and osteophytes scores, which persisted after adjustment for age and BMI. No associations between the presence and severity of knee OA were found for serum CTX-I or serum osteocalcin.
  
  
  CONCLUSIONS
  Urinary CTX-II and Glc-Gal-Pyd, but not systemic markers of bone turnover, are strongly associated with disease severity and the presence of OA at the tibiofemoral and patellofemoral joints in men.
authors.affiliation: Bone and Joint, MRC Epidemiology Resource Centre, Southampton University, Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK.
authors.forename: K M
authors.initials: KM
authors.lastname: Jordan
authors.forename: H E
authors.initials: HE
authors.lastname: Syddall
authors.forename: P
authors.initials: P
authors.lastname: Garnero
authors.forename: E
authors.initials: E
authors.lastname: Gineyts
authors.forename: E M
authors.initials: EM
authors.lastname: Dennison
authors.forename: A A
authors.initials: AA
authors.lastname: Sayer
authors.forename: P D
authors.initials: PD
authors.lastname: Delmas
authors.forename: C
authors.initials: C
authors.lastname: Cooper
authors.forename: N K
authors.initials: NK
authors.lastname: Arden
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000652:urine; D016723:Bone Remodeling; D002358:Cartilage, Articular / Q000473:pathology; D024042:Collagen Type I / Q000652:urine; D006027:Glycosides / Q000652:urine*; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000652:urine*; D015675:Osteocalcin / Q000652:urine; D010455:Peptides / Q000652:urine; D011859:Radiography; D013585:Synovitis / Q000652:urine
chemical_list: D015415:Biomarkers; D024042:Collagen Type I; D006027:Glycosides; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D015675:Osteocalcin