title: The usefulness of high pre-operative levels of serum type I collagen bone markers for the prediction of changes in bone mineral density after parathyroidectomy.
abstract: BACKGROUND
  Amino-terminal procollagen propeptide of type I collagen (P1NP) and cross-linked C-terminal telopeptide of type I collagen (βCTX) are two of the more sensitive bone markers for reflecting and monitoring patients with an increased bone turnover as observed in primary hyperparathyroidism (PHPT) patients.
  
  
  OBJECTIVE
  The present study was performed to evaluate the trend of type I collagen markers one year after parathyroidectomy (PTX) and to examine the relationships between serum P1NP and βCTX levels and bone mineral density (BMD) change after PTX in PHPT Spanish patients.
  
  
  METHODS
  Fifty-three PHPT patients were enroled and were followed for one year by measuring lumbar BMD, lumbar t-score, lumbar z-score, PTH, calcium, phosphorus, P1NP and βCTX.
  
  
  RESULTS
  Pre-surgery concentrations of both markers were elevated (P1NP: 90.71±5.03; βCTX: 1.52±0.44). A significant decrease was observed in mean post-operative βCTX and P1NP concentrations (p<0.0001). Levels of BMD, t-score and z-score at lumbar spine were relatively low (BMD: 0.75±0.16; z-score -0.90±0.23; t-score -2.51±0.32); after PTX a significant increase was observed in the levels of these three parameters. P1NP and βCTX were correlated with lumbar BMD change one year after PTX (P1NP: r=0.79, p=0.016; βCTX: r=0.89, p=0.003).
  
  
  CONCLUSIONS
  Pre-surgery concentrations of both bone markers were elevated and a significant decrease after PTX was found. Serum βCTX and P1NP levels were potently related to lumbar BMD changes over one year after PTX. The measurement of βCTX and P1NP would be useful to predict long-term changes in lumbar BMD after PTX.
authors.affiliation: Division of Endocrine Surgery, Department of General and Digestive Surgery, 12 de Octubre University Hospital, Complutense University of Madrid, Madrid, Spain. y.dum@hotmail.com
authors.forename: S
authors.initials: S
authors.lastname: Alonso
authors.forename: E
authors.initials: E
authors.lastname: Ferrero
authors.forename: M
authors.initials: M
authors.lastname: Donat
authors.forename: G
authors.initials: G
authors.lastname: Martínez
authors.forename: C
authors.initials: C
authors.lastname: Vargas
authors.forename: M
authors.initials: M
authors.lastname: Hidalgo
authors.forename: E
authors.initials: E
authors.lastname: Moreno
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D001862:Bone Resorption / Q000000981:diagnostic imaging / Q000209:etiology*; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000378:metabolism; D024042:Collagen Type I / Q000097:blood*; D004198:Disease Susceptibility; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000097:blood* / Q000601:surgery; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D016105:Parathyroidectomy / Q000009:adverse effects*; D010446:Peptide Fragments / Q000097:blood*; D010455:Peptides / Q000097:blood*; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000209:etiology*; D011237:Predictive Value of Tests; D057234:Preoperative Period; D011347:Procollagen / Q000097:blood*
chemical_list: D015415:Biomarkers; D024042:Collagen Type I; D010446:Peptide Fragments; D010455:Peptides; D011347:Procollagen; C052929:collagen type I trimeric cross-linked peptide; C047202:procollagen Type I N-terminal peptide