title: Comparison of urinary bone resorption markers in women of 40-70 years; day-to-day and long-term variation in individual subjects.
abstract: OBJECTIVE
  Bone resorption can be judged using biochemical markers in urine and blood. Our aim was to study the patterns of markers in the postmenopausal period.
  
  
  METHODS
  The urinary excretion of bone resorption markers was tested using different assays. The study was undertaken to determine the day-to-day and the long-term variation, over 8 years, of these markers in individual women.
  
  
  RESULTS
  Over a period of 2 weeks, the median of the day-to-day variation of the pyridinium crosslink markers varied between 12 and 23%, the median value of the long-term variation over 8 years between 10 and 21%, for the telopeptide markers median day-to-day variation was 18 and 20% and the long-term variation was 17 and 19%. The correlations between the different crosslink markers varied between 0.63 and 0.92, depending on the kind of the crosslink and on the method of determination. The two telopeptide markers showed an excellent correlation with r of 0.95. The excretion of all bone resorption markers varied with postmenopausal age, some differences were found between the crosslink and the telopeptide excretions with age, in women more than 20 years postmenopausal the telopeptides decrease whereas the crosslinks show an increase.
  
  
  CONCLUSIONS
  This study shows that crosslinks and telopeptides give similar information on the rate of bone resorption: an increase during the first 5 years and a slight decrease in the next 5 years after menopause, discrepancies were found after 10 or more postmenopausal years.
authors.affiliation: Department of Clinical Chemistry, University Hospital Utrecht, The Netherlands. M.I.Gerrits@lab.azu.nl
authors.forename: M I
authors.initials: MI
authors.lastname: Gerrits
authors.forename: I M
authors.initials: IM
authors.lastname: Vecht-Hart
authors.forename: A
authors.initials: A
authors.lastname: Oldenhave
authors.forename: J H
authors.initials: JH
authors.lastname: Thijssen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000596:Amino Acids / Q000652:urine; D015415:Biomarkers / Q000652:urine; D001862:Bone Resorption / Q000652:urine*; D003094:Collagen / Q000652:urine; D024042:Collagen Type I; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D006909:Hydroxyproline / Q000652:urine; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000652:urine*; D010455:Peptides / Q000652:urine; D013997:Time Factors
chemical_list: D000596:Amino Acids; D015415:Biomarkers; D024042:Collagen Type I; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; C015484:pyridinoline; C036020:deoxypyridinoline; D003094:Collagen; D006909:Hydroxyproline