title: Effect of rheumatoid arthritis on volumetric bone mineral density and bone geometry, assessed by peripheral quantitative computed tomography in postmenopausal women treated with bisphosphonates.
abstract: OBJECTIVE
  To investigate the effect of rheumatoid arthritis (RA) on volumetric bone mineral density (vBMD) and bone geometry in postmenopausal women treated with bisphosphonates.
  
  
  METHODS
  Fifty-three postmenopausal women with RA and 87 control subjects, comparable in terms of age, body mass index, and years since menopause, underwent peripheral quantitative computed tomography (pQCT) of the nondominant tibia.
  
  
  RESULTS
  At 4% (trabecular site), trabecular bone mineral content (BMC) and vBMD (p < 0.001) were lower in the RA group, while trabecular area was comparable. At 38% (cortical site), cortical BMC (p < 0.01), area (p < 0.05), and thickness (p < 0.001) were lower in the RA group, whereas vBMD was comparable. Endosteal circumference was higher (p < 0.05), whereas periosteal circumference was comparable, indicating cancellization of cortical bone. In the RA group, muscle area was lower (p < 0.001), while at 14% polar stress strength index was significantly lower (p < 0.01) in patients with RA, indicating impairment of bone mechanical properties.
  
  
  CONCLUSIONS
  RA is associated with negative effects on both cortical and cancellous bone in postmenopausal women treated with bisphosphonates. Cortical geometric properties are also adversely affected mainly by increased endosteal circumference, whereas trabecular geometric properties are generally preserved.
authors.affiliation: Laboratory of Research of the Musculoskeletal System Th. Garofalidis, University of Athens, KAT Hospital, Athens, Greece. stournis@med.uoa.gr
authors.forename: Symeon
authors.initials: S
authors.lastname: Tournis
authors.forename: Vasilios
authors.initials: V
authors.lastname: Samdanis
authors.forename: Savas
authors.initials: S
authors.lastname: Psarelis
authors.forename: Chrysa
authors.initials: C
authors.lastname: Liakou
authors.forename: Julia
authors.initials: J
authors.lastname: Antoniou
authors.forename: Thomas
authors.initials: T
authors.lastname: Georgoulas
authors.forename: Ismini
authors.initials: I
authors.lastname: Dontas
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Papaioannou
authors.forename: Susan
authors.initials: S
authors.lastname: Gazi
authors.forename: George P
authors.initials: GP
authors.lastname: Lyritis
mesh_terms: D000368:Aged; D001172:Arthritis, Rheumatoid / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D015519:Bone Density; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D004164:Diphosphonates / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause / Q000378:metabolism*; D013977:Tibia / Q000000981:diagnostic imaging / Q000473:pathology*; D014057:Tomography, X-Ray Computed
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D005938:Glucocorticoids