title: Usefulness of urinary CTX-II and NTX-I in evaluating radiological knee osteoarthritis : the Matsudai knee osteoarthritis survey.
abstract: BACKGROUND
  To assess the usefulness of the urinary crosslinked C-telopeptide of type II collagen (uCTX-II) or crosslinked N-telopeptide of type I collagen (uNTX-I) for evaluating radiological knee osteoarthritis (OA), a cross-sectional study was conducted in the cohorts of the Matsudai knee osteoarthritis survey performed in Niigata, Japan.
  
  
  METHODS
  Urine specimens and standing knee AP X-rays were obtained from 1040 subjects who provided informed consent. The relationship between these markers and gender, age (patients aged 40-59 or 60-79 years), use of bisphosphonates, and OA grades (K-L classification) were analyzed. The diagnostic ability of uCTX-II to detect radiological knee OA was confirmed in the over 60-year-old subjects using a ROC curve.
  
  
  RESULTS
  The over 60-year-old men with OA grade 3,4 group had significantly higher uCTX-II levels than the other OA grade groups. In the over 60-year-old women, the uCTX-II levels significantly increased according to the progression of the knee OA grade. No significant difference was observed between the uNTX-I levels in the different OA grade groups. From the standpoint of biomarkers, the higher quartiles of the uCTX-II and uNTX-I levels gradually included higher numbers of grade ≥2 OA subjects in the over 60 year-old women. The area under the curve (AUC) in ROC analysis of uCTX-II exhibited a significant association with the diagnosis of knee OA in women (AUC 0.63), although the accuracy was evaluated to be low in the single measurement of our health checkup-based analysis.
  
  
  CONCLUSIONS
  This population-based study indicates that the uCTX-II level is strongly correlated with the knee OA grade in women over age 60. A further analysis is needed to clarify its predictive accuracy.
authors: Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan.
authors: Nobuchika
authors: N
authors: Tanishi
authors: Hiroshi
authors: H
authors: Yamagiwa
authors: Tadashi
authors: T
authors: Hayami
authors: Hisashi
authors: H
authors: Mera
authors: Yoshio
authors: Y
authors: Koga
authors: Go
authors: G
authors: Omori
authors: Naoto
authors: N
authors: Endo
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D015415:Biomarkers / Q000652:urine; D050071:Bone Density Conservation Agents / Q000008:administration & dosage; D024042:Collagen Type I / Q000652:urine*; D024043:Collagen Type II / Q000652:urine*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000652:urine*; D010446:Peptide Fragments / Q000652:urine*; D010455:Peptides / Q000652:urine*; D011859:Radiography; D012680:Sensitivity and Specificity; D012737:Sex Factors
chemical_list: D015415:Biomarkers; D050071:Bone Density Conservation Agents; C000590554:C-terminal cross-linking telopeptide of type II collagen, human; D024042:Collagen Type I; D024043:Collagen Type II; D010446:Peptide Fragments; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide