title: Changes of bone remodeling immediately after parathyroidectomy for secondary hyperparathyroidism.
abstract: BACKGROUND
  Successful parathyroidectomy for secondary hyperparathyroidism alleviates bone pain and is followed by the development of hypophosphatemia and hypocalcemia, as well as an increase in bone mineral density. An increase in osteoblast surface (Ob.S/BS) is not observed several months after surgery. In this study, we investigated early bone changes at 1 week after parathyroidectomy and the mechanism underlying an increase in bone mineral density.
  
  
  METHODS
  Fourteen patients with severe secondary hyperparathyroidism underwent iliac bone biopsy before and 1 week after parathyroidectomy. Changes in histomorphometric parameters, including osteoclast surface (Oc.S/BS), eroded surface (ES/BS), erosion depth (E.De), fibrosis volume (Fb.V/TV), Ob.S/BS, osteoid volume (OV/BV), osteoid surface (OS/BS), and osteoid thickness (O.Th), were investigated. Changes in texture of mineralized bone and osteoid seams were also investigated.
  
  
  RESULTS
  Oc.S/BS (P < 0.001), ES/BS (P < 0.01), and E.De (P < 0.001) decreased, but Fb.V/TV did not change at 1 week postoperatively. In particular, osteoclasts disappeared in almost all patients. Ob.S/BS (P < 0.001) increased, and cuboidal osteoblasts were proliferating on the trabecular surface where osteoclasts had existed before parathyroidectomy. As a result, newly developed osteoblasts coexisted with fibrous tissue after surgery. OV/BV (P < 0.005), OS/BS (P < 0.005), and O.Th (P < 0.005) increased, with lamellar osteoid volume showing a particular increase. Bone mineralization continued despite the low postoperative serum parathyroid hormone level.
  
  
  CONCLUSIONS
  A rapid decrease in serum parathyroid hormone level after parathyroidectomy appears to suppress bone resorption, as well as cause a transient marked increase in bone formation and an increase in normal lamellar osteoid seams.
authors.affiliation: Department of Nephrology, Towa Hospital, Tokyo, Japan. a-and-y@rj8.so-net.ne.jp
authors.forename: Aiji
authors.initials: A
authors.lastname: Yajima
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Ogawa
authors.forename: Hideaki E
authors.initials: HE
authors.lastname: Takahashi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Tominaga
authors.forename: Tsunamasa
authors.initials: T
authors.lastname: Inou
authors.forename: Osamu
authors.initials: O
authors.lastname: Otsubo
mesh_terms: D000328:Adult; D001706:Biopsy; D015519:Bone Density; D016723:Bone Remodeling / Q000502:physiology*; D001862:Bone Resorption; D002118:Calcium / Q000097:blood; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D007085:Ilium / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010006:Osteoblasts / Q000145:classification*; D010010:Osteoclasts / Q000145:classification*; D010012:Osteogenesis / Q000502:physiology*; D010281:Parathyroid Hormone / Q000097:blood; D016105:Parathyroidectomy; D010758:Phosphorus / Q000097:blood
chemical_list: D010281:Parathyroid Hormone; D010758:Phosphorus; D002118:Calcium