title: Calcaneal ultrasound but not bone turnover predicts fractures in vitamin D deficient frail elderly at high risk of falls.
abstract: BACKGROUND
  Biochemical markers of bone turnover have been reported to predict fracture risk independent of bone mass in postmenopausal women. We investigated their use in predicting fractures in the frail elderly.
  
  
  METHODS
  Cases were 151 low trauma fractures. For each case, a control was selected marched for sex, age, institution type and follow-up period. We measured two bone resorption markers (serum ICTP and serum CTX-I) and two bone formation markers (serum PINP and serum BAP). Quantitative Ultrasound (QUS) was measured in the calcaneus. Fractures were ascertained by x-ray reports.
  
  
  RESULTS
  The mean age of subjects was 86.8 years (+/- 5.8 SD) and 86% were female. 76% had hypovitaminosis D (a serum 25 hydroxy vitamin D (25OHD) level < 39 nmol/L) and 81% had BUA < 67.4 dB/MHz (corresponding to a BMD T-score < -2.5). No significant differences in bone turnover markers were detected between fracture cases and their matched controls. In contrast, there was a significant difference between cases and controls for both broadband ultrasound attenuation (BUA) and velocity of sound (VOS) (both P < 0.05). These results remained the same after adjusting for weight, lower leg length and walking aids as well as the higher falls incidence in cases than controls (average 2.7 vs 0.9 falls respectively; P < 0.001) during the follow-up period.
  
  
  CONCLUSIONS
  In the frail elderly with vitamin D deficiency and high falls risk, calcaneal ultrasound but not markers of bone turnover were associated with fractures.
authors.affiliation: Institute of Bone & Joint Research, University of Sydney, Royal North Shore Hospital, St Leonards, Sydney, NSW 2065, Australia.
authors.forename: J S
authors.initials: JS
authors.lastname: Chen
authors.forename: M J
authors.initials: MJ
authors.lastname: Seibel
authors.forename: J
authors.initials: J
authors.lastname: Zochling
authors.forename: L
authors.initials: L
authors.lastname: March
authors.forename: I D
authors.initials: ID
authors.lastname: Cameron
authors.forename: R G
authors.initials: RG
authors.lastname: Cumming
authors.forename: J
authors.initials: J
authors.lastname: Schwarz
authors.forename: J M
authors.initials: JM
authors.lastname: Simpson
authors.forename: P N
authors.initials: PN
authors.lastname: Sambrook
mesh_terms: D000058:Accidental Falls; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D001862:Bone Resorption / Q000097:blood; D002111:Calcaneus / Q000000981:diagnostic imaging* / Q000378:metabolism; D016022:Case-Control Studies; D024042:Collagen Type I / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D050723:Fractures, Bone / Q000097:blood* / Q000175:diagnosis / Q000209:etiology / Q000378:metabolism; D016330:Frail Elderly; D006801:Humans; D008297:Male; D010446:Peptide Fragments / Q000097:blood; D010455:Peptides / Q000097:blood; D011347:Procollagen / Q000097:blood; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014465:Ultrasonics; D014463:Ultrasonography; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000000981:diagnostic imaging
chemical_list: D015415:Biomarkers; D024042:Collagen Type I; D010446:Peptide Fragments; D010455:Peptides; D011347:Procollagen; C052929:collagen type I trimeric cross-linked peptide; D014807:Vitamin D