title: Effect of menopause and hormone replacement therapy on urinary excretion of pyridinium cross-links: a longitudinal and cross-sectional study.
abstract: OBJECTIVE
  To study longitudinally the effect of the menopause and hormone replacement therapy on the new markers of bone resorption: urinary excretion of pyridinoline and deoxypyridinoline.
  
  
  METHODS
  Urinary pyridinoline and deoxypyridinoline were measured every 3 months for 2-3 years in 15 healthy women aged 45-54 years. Nine remained premenopausal and six became post-menopausal during the study. Urinary pyridinoline and deoxypyridinoline were also measured before and after 3 months of either placebo or hormone replacement therapy in 65 post-menopausal women, aged 45-54 years, who were participating in a double-blind study.
  
  
  METHODS
  Urinary pyridinoline and deoxypyridinoline were measured in fasting urine samples by spectrofluorometry after high performance liquid chromatography and corrected for creatinine excretion.
  
  
  RESULTS
  Urinary pyridinoline and deoxypyridinoline remained almost constant during the premenopausal period. Both started to increase 6 months after the last menstrual bleeding and the mean post-menopausal values were 30-50% higher than the premenopausal values in the same subjects (values in nmol/mmol creatinine given as mean +/- SEM: urinary pyridinoline (premenopausal) = 29 +/- 2 vs urinary pyridinoline (post-menopausal) = 38 +/- 6, P < 0.05; urinary deoxypyridinoline (premenopausal) = 8 +/- 1 vs urinary deoxypyridinoline (post-menopausal) = 12 +/- 1, P < 0.05). Three months of post-menopausal hormone replacement therapy decreased (P < 0.001) both to premenopausal levels.
  
  
  CONCLUSIONS
  Urinary pyridinoline and deoxypyridinoline, new markers of bone resorption, remain fairly constant in the years before the menopause and start to increase about 6 months after the last menstrual bleeding. This increase is reversed by hormone replacement therapy.
authors.affiliation: Department of Clinical Chemistry, Glostrup Hospital, University of Copenhagen, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Hassager
authors.forename: A
authors.initials: A
authors.lastname: Colwell
authors.forename: A M
authors.initials: AM
authors.lastname: Assiri
authors.forename: R
authors.initials: R
authors.lastname: Eastell
authors.forename: R G
authors.initials: RG
authors.lastname: Russell
authors.forename: C
authors.initials: C
authors.lastname: Christiansen
mesh_terms: D000596:Amino Acids / Q000652:urine*; D001862:Bone Resorption / Q000652:urine*; D003430:Cross-Sectional Studies; D004958:Estradiol / Q000097:blood; D015914:Estrogen Replacement Therapy; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D008137:Longitudinal Studies; D007986:Luteinizing Hormone / Q000097:blood; D008593:Menopause / Q000097:blood / Q000652:urine*; D008875:Middle Aged
chemical_list: D000596:Amino Acids; D004958:Estradiol; C015484:pyridinoline; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; C036020:deoxypyridinoline