title: Bone turnover markers in Spanish postmenopausal women: the Camargo cohort study.
abstract: BACKGROUND
  This cross-sectional study was performed to determine the reference ranges for two bone turnover markers--aminoterminal propeptide of type I collagen (P1NP) and C-terminal telopeptide of type I collagen (beta-CrossLaps, beta-CTX)--in normal postmenopausal Spanish women as determined in serum by automated methods.
  
  
  METHODS
  A community-based population of 1080 healthy postmenopausal women was evaluated. Data regarding risk factors for osteoporosis and fractures were collected by means of a structured questionnaire. Fasting serum levels of P1NP, beta-CTX, 25-Hydroxivitamin D (25OHD), and intact parathyroid hormone (iPTH) were measured on the Elecsys 2010 automated analyzer (Roche). BMD at lumbar spine, femoral neck and total hip was determined by DXA.
  
  
  RESULTS
  The mean age of subjects was 63+/-9. Logarithmic transformation of both markers was performed to allow for normal distributions. Mid-95% ranges for P1NP and beta-CTX were 19-100 ng/ml and 0.112-1.018 ng/ml, respectively. Mean values of P1NP (47.7+/-19.9 ng/ml) were similar to those previously determined by the manufacturer of the assays, whereas beta-CTX mean values (0.387+/-0.197 ng/ml) were lower. Both markers were higher among osteoporotic women.
  
  
  CONCLUSIONS
  Values obtained from this well-characterized population study provide reference ranges for serum automated P1NP and beta-CTX in normal Spanish postmenopausal women.
authors.affiliation: Department of Internal Medicine, Hospital Universitario Marqués de Valdecilla, Universidad de Cantabria, RETICEF, Santander, Spain.
authors.forename: Josefina
authors.initials: J
authors.lastname: Martínez
authors.forename: José M
authors.initials: JM
authors.lastname: Olmos
authors.forename: José L
authors.initials: JL
authors.lastname: Hernández
authors.forename: Gabriel
authors.initials: G
authors.lastname: Pinedo
authors.forename: Javier
authors.initials: J
authors.lastname: Llorca
authors.forename: Eduardo
authors.initials: E
authors.lastname: Obregón
authors.forename: Carmen
authors.initials: C
authors.lastname: Valero
authors.forename: Jesús
authors.initials: J
authors.lastname: González-Macías
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D016723:Bone Remodeling; D002112:Calcifediol / Q000097:blood; D015331:Cohort Studies; D024042:Collagen Type I / Q000737:chemistry; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D017698:Postmenopause / Q000097:blood* / Q000502:physiology*; D013030:Spain
chemical_list: D015415:Biomarkers; D024042:Collagen Type I; D010281:Parathyroid Hormone; D010446:Peptide Fragments; D002112:Calcifediol