title: Establishing a reference range for bone turnover markers in young, healthy women.
abstract: BACKGROUND
  Biochemical markers of bone turnover (BTMs) are important in determining fracture risk in postmenopausal women; high levels being associated with increased risk. A proposed goal of anti-resorptive therapy is to reduce BTMs to the lower half of the reference range for healthy young pre-menopausal women. Our aims were a) to establish reference ranges for bone alkaline phosphatase (bone ALP), crosslinked C- and N-telopeptides of type I collagen (betaCTX, NTX), osteocalcin (OC) and procollagen type I N propeptide (PINP) in pre-menopausal women and b) to investigate the determinants of these BTMs.
  
  
  METHODS
  BTMs were measured in peripheral blood and second morning void urine collected from 200 healthy pre-menopausal women ages 30 to 45 years. Each subject completed a short medical and lifestyle questionnaire.
  
  
  RESULTS
  BTMs were higher before the age of 35 years than after it. BTMs were higher in women with low BMI (betaCTX and OC), low alcohol consumption (PINP), current smoking habit (bone ALP and NTX), and around time of ovulation (NTX).
  
  
  CONCLUSIONS
  We recommend that the age range 35 to 45 years should be used when establishing BTM reference ranges in women.
authors.affiliation: Academic Unit of Bone Metabolism, School of Medicine and Biomedical Sciences, University of Sheffield, Medical School, Beech Hill Road, Sheffield, S10 2RX, UK. s.glover@sheffield.ac.uk
authors.forename: S J
authors.initials: SJ
authors.lastname: Glover
authors.forename: P
authors.initials: P
authors.lastname: Garnero
authors.forename: K
authors.initials: K
authors.lastname: Naylor
authors.forename: A
authors.initials: A
authors.lastname: Rogers
authors.forename: R
authors.initials: R
authors.lastname: Eastell
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood* / Q000652:urine*; D001842:Bone and Bones / Q000378:metabolism*; D005260:Female; D006262:Health; D006801:Humans; D008875:Middle Aged; D012016:Reference Values
chemical_list: D015415:Biomarkers