title: Acute changes in serum osteoprotegerin and receptor activator for nuclear factor-kappaB ligand levels in women with established osteoporosis treated with teriparatide.
abstract: OBJECTIVE
  The mechanisms regulating the anabolic response of the skeleton to intermittent exogenous parathyroid hormone (PTH) administration are not fully elucidated. The aim of this prospective study was to evaluate the acute effect (up to 1 month) of teriparatide (TPTD; human recombinant PTH 1-34) on serum levels of osteoprotegerin (OPG) and receptor activator for nuclear factor-kappaB ligand (RANKL) in women with established osteoporosis.
  
  
  METHODS
  Twenty-three postmenopausal Caucasian women with established osteoporosis (mean age 66.7+/-1.6 years) received daily injections of 20 microg TPTD for 12 months.
  
  
  METHODS
  Serum samples for total calcium (Ca), phosphate, alkaline phosphatase, N-terminal propeptide of type I collagen, intact PTH (iPTH), OPG, and RANKL were obtained at baseline, 1 h, 1 day, and 1 month after initiation of therapy. Lumbar spine bone mineral density (BMD) was measured before and 12 months after TPTD treatment.
  
  
  RESULTS
  Serum total Ca increased and iPTH gradually decreased with TPTD treatment. Serum OPG levels remained unchanged, while RANKL increased gradually during the study (P<0.001). There was no correlation between OPG or RANKL and BMD changes or iPTH levels.
  
  
  CONCLUSIONS
  TPTD therapy in women with postmenopausal osteoporosis results in acute increase in serum RANKL levels but does not affect serum OPG. These changes may reflect an increase in the number of active osteoblasts with therapy and might be responsible for the acceleration of bone turnover rate that characterizes TPTD.
authors.affiliation: Department of Endocrinology, Hippocration General Hospital, 54642 Thessaloniki, Greece. anastath@endo.gr
authors.forename: Athanasios D
authors.initials: AD
authors.lastname: Anastasilakis
authors.forename: Dimirtios G
authors.initials: DG
authors.lastname: Goulis
authors.forename: Stergios A
authors.initials: SA
authors.lastname: Polyzos
authors.forename: Spiridon
authors.initials: S
authors.lastname: Gerou
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Pavlidou
authors.forename: George
authors.initials: G
authors.lastname: Koukoulis
authors.forename: Avraam
authors.initials: A
authors.lastname: Avramidis
mesh_terms: D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D001842:Bone and Bones / Q000187:drug effects / Q000378:metabolism; D002118:Calcium / Q000097:blood; D005260:Female; D006801:Humans; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy* / Q000378:metabolism; D053244:Osteoprotegerin / Q000097:blood*; D010758:Phosphorus / Q000097:blood; D011446:Prospective Studies; D053245:RANK Ligand / Q000097:blood*; D019379:Teriparatide / Q000627:therapeutic use*
chemical_list: D050071:Bone Density Conservation Agents; D053244:Osteoprotegerin; D053245:RANK Ligand; C505688:TNFSF11 protein, human; D019379:Teriparatide; D010758:Phosphorus; D000469:Alkaline Phosphatase; D002118:Calcium