title: Thoracic and lumbar vertebral bone mineral density changes in a natural occurring dog model of diffuse idiopathic skeletal hyperostosis.
abstract: Ankylosing spinal disorders can be associated with alterations in vertebral bone mineral density (BMD). There is however controversy about vertebral BMD in patients wuse idiopathic skeletal hyperostosis (DISH). DISH in Boxer dogs has been considered a natural occurring disease model for DISH in people. The purpose of this study was to compare vertebral BMD between Boxers with and without DISH. Fifty-nine Boxers with (n=30) or without (n=29) DISH that underwent computed tomography were included. Vertebral BMD was calculated for each thoracic and lumbar vertebra by using an earlier reported and validated protocol. For each vertebral body, a region of interest was drawn on the axial computed tomographic images at three separate locations: immediately inferior to the superior end plate, in the middle of the vertebral body, and superior to the inferior end plate. Values from the three axial slices were averaged to give a mean Hounsfield Unit value for each vertebral body. Univariate statistical analysis was performed to identify factors to be included in a multivariate model. The multivariate model including all dogs demonstrated that vertebral DISH status (Coefficient 24.63; 95% CI 16.07 to 33.19; p <0.001), lumbar vertebrae (Coefficient -17.25; 95% CI -23.42 to -11.09; p < 0.01), and to a lesser extent higher age (Coefficient -0.56; 95% CI -1.07 to -0.05; p = 0.03) were significant predictors for vertebral BMD. When the multivariate model was repeated using only dogs with DISH, vertebral DISH status (Coefficient 20.67; 95% CI, 10.98 to 30.37; p < 0.001) and lumbar anatomical region (Coefficient -38.24; 95% CI, -47.75 to -28.73; p < 0.001) were again predictors for vertebral BMD but age was not. The results of this study indicate that DISH can be associated with decreased vertebral BMD. Further studies are necessary to evaluate the clinical importance and pathophysiology of this finding.
authors.affiliation: Department of Clinical Science and Services, Royal Veterinary College, University of London, Hawkshead lane, AL9 7TA, Hatfield, United Kingdom.
authors.forename: Steven
authors.initials: S
authors.lastname: De Decker
authors.affiliation: Department of Clinical Science and Services, Royal Veterinary College, University of London, Hawkshead lane, AL9 7TA, Hatfield, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Lam
authors.affiliation: Department of Clinical Science and Services, Royal Veterinary College, University of London, Hawkshead lane, AL9 7TA, Hatfield, United Kingdom.
authors.forename: Rowena M A
authors.initials: RM
authors.lastname: Packer
authors.affiliation: Department of Veterinary Medical Imaging and Small Animal Orthopaedics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
authors.forename: Ingrid M V L
authors.initials: IM
authors.lastname: Gielen
authors.affiliation: Department of Clinical Science and Services, Royal Veterinary College, University of London, Hawkshead lane, AL9 7TA, Hatfield, United Kingdom.
authors.forename: Holger A
authors.initials: HA
authors.lastname: Volk
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D004057:Hyperostosis, Diffuse Idiopathic Skeletal; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D008297:Male; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed