title: Comparison of peripheral quantitative computed tomography forearm bone density versus DXA in rheumatoid arthritis patients and controls.
abstract: Rheumatoid arthritis (RA) has been associated with osteoporosis. Quantitative computed tomography (QCT) is capable of assessing bone density and composition. We found lower bone density in RA compared to controls. Age and RA duration influenced bone density. QCT may be useful to assess bone metabolism in RA.
  
  
  
  RA is associated with generalized and periarticular osteoporosis. In addition to DXA that determines areal bone mineral density (BMD), peripheral QCT also detects volumetric BMD. QCT differentiates between total, trabecular, and cortical BMD. Here, we compared DXA and QCT in RA patients and healthy controls.
  
  
  
  BMD of 57 female RA patients and 32 age-matched healthy female controls were assessed by DXA. QCT of the forearm ultradistal region was also performed. Densitometry data were correlated with age, disease duration, disease activity, serum CRP, and anti-CCP levels.
  
  
  
  Total bone density (310.4 ± 79.7 versus 354.0 ± 54.1 mg/cm3; p = 0.007) and attenuation (0.37 ± 0.05 versus 0.40 ± 0.03 1/cm; p = 0.001), trabecular density (157.6 ± 57.0 versus 193.8 ± 48.7 mg/cm3; p = 0.005) and attenuation (0.28 ± 0.03 versus 0.32 ± 0.04 1/cm; p < 0.0001), and cortical density (434.3 ± 115.8 versus 492.5 ± 64.0 mg/cm3; p = 0.006) and attenuation (0.44 ± 0.07 versus 0.47 ± 0.04 1/cm; p = 0.004) were significantly lower in RA. Both lumbar and femoral neck BMD, as well as T-scores, were significantly lower in RA versus controls (p < 0.001 in all cases). In RA, total and cortical QCT attenuation and density were associated with age, the presence of RA, and their combination. In contrast, trabecular density and attenuation were only affected by the presence of the disease but not by age. Also in RA, total trabecular and cortical density as determined by QCT significantly correlated with lumbar and/or femoral neck BMD as measured by DXA. Finally, anti-CCP seropositivity was associated with lower trabecular density and attenuation.
  
  
  
  Both DXA and QCT may be suitable to study bone metabolism in RA. Areal BMD determined by DXA may correlate with volumetric bone density measured by QCT. Moreover, trabecular osteoporosis may be associated by the underlying autoimmune-inflammatory disease, while cortical osteoporosis may rather be age-related.
authors.affiliation: Department of Oncology, University of Debrecen Faculty of Medicine, Debrecen, Hungary.
authors.forename: B
authors.initials: B
authors.lastname: Juhász
authors.affiliation: Department of Rheumatology, University of Debrecen Faculty of Medicine, Debrecen, Hungary.
authors.forename: K
authors.initials: K
authors.lastname: Gulyás
authors.affiliation: Department of Rheumatology, University of Debrecen Faculty of Medicine, Debrecen, Hungary.
authors.forename: Á
authors.initials: Á
authors.lastname: Horváth
authors.affiliation: Department of Rheumatology, University of Debrecen Faculty of Medicine, Debrecen, Hungary.
authors.forename: Z
authors.initials: Z
authors.lastname: Pethő
authors.affiliation: Department of Laboratory Medicine, University of Debrecen Faculty of Medicine, Debrecen, Hungary.
authors.forename: H P
authors.initials: HP
authors.lastname: Bhattoa
authors.affiliation: Department of Rheumatology, University of Debrecen Faculty of Medicine, Debrecen, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Váncsa
authors.affiliation: Department of Oncology, University of Debrecen Faculty of Medicine, Debrecen, Hungary.
authors.forename: É
authors.initials: É
authors.lastname: Szekanecz
authors.affiliation: First Department of Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: C
authors.initials: C
authors.lastname: Horváth
authors.affiliation: Department of Oncology, University of Debrecen Faculty of Medicine, Debrecen, Hungary.
authors.forename: J
authors.initials: J
authors.lastname: Kocsis
authors.affiliation: Department of Oncology, University of Debrecen Faculty of Medicine, Debrecen, Hungary.
authors.forename: Z
authors.initials: Z
authors.lastname: Horváth
authors.affiliation: Department of Rheumatology, University of Debrecen Faculty of Medicine, Debrecen, Hungary.
authors.forename: K
authors.initials: K
authors.lastname: Hodosi
authors.affiliation: Department of Rheumatology, University of Debrecen Faculty of Medicine, Debrecen, Hungary.
authors.forename: S
authors.initials: S
authors.lastname: Szántó
authors.affiliation: Department of Rheumatology, University of Debrecen Faculty of Medicine, Debrecen, Hungary.
authors.forename: G
authors.initials: G
authors.lastname: Szűcs
authors.affiliation: Department of Rheumatology, University of Debrecen Faculty of Medicine, Debrecen, Hungary. szekanecz.zoltan@med.unideb.hu.
authors.forename: Z
authors.initials: Z
authors.lastname: Szekanecz
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000328:Adult; D000367:Age Factors; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications* / Q000503:physiopathology; D015519:Bone Density / Q000502:physiology*; D016022:Case-Control Studies; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000503:physiopathology; D005542:Forearm / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000503:physiopathology; D008875:Middle Aged; D010024:Osteoporosis / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult
keywords: Bone densitometry; Bone destruction; Bone mineral density; DXA; Osteoporosis; QCT; Rheumatoid arthritis