title: Increased biochemical markers of bone formation and resorption in primary hyperparathyroidism with special reference to patients with mild disease.
abstract: OBJECTIVE
  To evaluate the impact on bone turnover of primary hyperparathyroidism (pHPT) with special reference to patients with mild pHPT, using biochemical markers of bone formation and resorption.
  
  
  METHODS
  A longitudinal study of patients with pHPT before and one year after surgical treatment.
  
  
  METHODS
  The Departments of Internal Medicine and Surgery, Lund University Hospital.
  
  
  METHODS
  Forty consecutive patients with pHPT. Thirty of these patients had mild pHPT and are reported separately. Data on bone mineral was also compared to a reference population.
  
  
  METHODS
  All patients were operated upon and restudied one year later.
  
  
  METHODS
  Bone resorption and formation was studied by means of the serum concentrations of the telopeptide of the carboxyterminal region of type 1 collagen (ICTP) and of alkaline phosphatase (ALP), osteocalcin and the carboxyterminal propeptide of type 1 procollagen (PICP), respectively. Bone density was measured at the distal radius by single photon absorptiometry (SPA).
  
  
  RESULTS
  Bone formation markers consistently decreased after parathyroid surgery: ALP from 3.51 +/- 0.23 to 2.94 +/- 0.21 microkat L(-1) (P < 0.05), osteocalcin from 6.15 +/- 0.53 to 2.89 +/- 0.23 microg L(-1) (P < 0.001) and PICP from 126.4 +/- 10.9 to 96.0 +/- 6.5 microg L(-1) (P < 0.001). In parallel, the ICTP concentration, reflecting bone resorption, decreased from 5.10 +/- 0.54 to 3.94 +/- 0.34 microg L(-1) (P < 0.001). There was not any significant change in distal radius bone mineral 1 one year after surgery. In the subgroup of patients classified as mild pHPT, a significant decrease was noted for osteocalcin, PICP and for ICTP but not for ALP, without significant changes in variables reflecting distal radius bone mineral content. Glomerular filtration rate was inversely correlated to serum levels of intact PTH, ionized calcium, alkaline phosphatase, osteocalcin and ICTP and directly correlated to the 1.25-dihydroxy-vitamin D concentrations.
  
  
  CONCLUSIONS
  pHPT is associated with substantial changes in circulating levels of biochemical markers of bone formation and resorption. These findings are also present in patients with mild pHPT. Renal function should be considered in the evaluation of the impact of pHPT on bone turnover.
authors.affiliation: Department of Internal Medicine, Lund University Hospital, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Valdemarsson
authors.forename: B
authors.initials: B
authors.lastname: Lindergård
authors.forename: S
authors.initials: S
authors.lastname: Tibblin
authors.forename: A
authors.initials: A
authors.lastname: Bergenfelz
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D016723:Bone Remodeling; D001862:Bone Resorption / Q000097:blood*; D002118:Calcium / Q000097:blood; D003404:Creatinine / Q000097:blood; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000097:blood* / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D007668:Kidney / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood; D011877:Radionuclide Imaging; D011884:Radius / Q000000981:diagnostic imaging / Q000503:physiopathology; D012720:Severity of Illness Index; D014807:Vitamin D / Q000097:blood
chemical_list: D010281:Parathyroid Hormone; D010710:Phosphates; D014807:Vitamin D; D003404:Creatinine; D002118:Calcium