title: Biochemical markers of bone metabolism and prediction of fracture in elderly women.
abstract: We studied the ability of various markers of bone turnover to predict fracture in 1040 randomly recruited 75-year-old women. A total of 178 of the women sustained at least one fracture during follow-up (mean, 4.6 years). In elderly women, TRACP5b and urinary fragments of osteocalcin are promising new markers for prediction of fracture, in particular, vertebral fracture.
  
  
  BACKGROUND
  Biochemical markers reflecting bone turnover may improve the prediction of fractures.
  
  
  METHODS
  The ability of 10 markers of bone turnover to predict fracture in 1040 elderly women in the Malmö OPRA study was studied. Serum bone-specific alkaline phosphatase and four different forms of serum osteocalcin (S-OC) were analyzed as markers of bone formation and serum C-terminal cross-linking telopeptides of type I collagen (S-CTX), serum TRACP isoform 5b (S-TRACP5b) and urinary free deoxypyridinoline (U-DPD) as markers of bone resorption. Two novel assays for osteocalcin fragments in urine (U-OC) were analyzed. Areal BMD (aBMD) was measured by DXA in the femoral neck and lumbar spine.
  
  
  RESULTS
  In total, 231 fractures were sustained by 178 of the women during a 3- to 6.5-year (mean, 4.6 years) follow-up period. When women with prospective fractures were compared with women without fractures, S-TRACP5b, S-CTX, one S-OC, and one U-OC were higher in women with a fracture of any type (all p < 0.05), and all bone markers were higher in women with clinical vertebral fracture (all p < 0.05). Markers were not significantly elevated in women with hip fracture. When women within the highest quartile of a bone marker were compared with all others, S-TRACP5b and one U-OC predicted the occurrence of a fracture of any type (odds ratio [OR]), 1.55 and 1.53; p < 0.05). S-TRACP5b, the two U-OCs, and S-CTX predicted vertebral fracture (OR, 2.28, 2.75, 2.71, and 1.94, respectively; all p < 0.05), and the predictive value remained significant for S-TRACP5b and the two U-OCs after adjusting for aBMD (OR, 2.02-2.25; p < 0.05). Bone markers were not able to predict hip fracture.
  
  
  CONCLUSIONS
  These results show that biochemical markers of bone turnover can predict fracture, and in particular, fractures that engage trabecular bone. S-TRACP5b and U-OC are promising new markers for prediction of fracture.
authors.affiliation: Departments of Orthopedics, Malmö University Hospital, Malmö, Sweeden.
authors.forename: Paul
authors.initials: P
authors.lastname: Gerdhem
authors.forename: Kaisa K
authors.initials: KK
authors.lastname: Ivaska
authors.forename: Sari L
authors.initials: SL
authors.lastname: Alatalo
authors.forename: Jussi M
authors.initials: JM
authors.lastname: Halleen
authors.forename: Jukka
authors.initials: J
authors.lastname: Hellman
authors.forename: Anders
authors.initials: A
authors.lastname: Isaksson
authors.forename: Kim
authors.initials: K
authors.lastname: Pettersson
authors.forename: H Kalervo
authors.initials: HK
authors.lastname: Väänänen
authors.forename: Kristina
authors.initials: K
authors.lastname: Akesson
authors.forename: Karl J
authors.initials: KJ
authors.lastname: Obrant
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood / Q000652:urine; D015519:Bone Density; D001842:Bone and Bones / Q000378:metabolism*; D005260:Female; D050723:Fractures, Bone / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D011237:Predictive Value of Tests; D013997:Time Factors
chemical_list: D015415:Biomarkers