Avaliação da densidade mineral ossea na espondilite anquilosante
AUTOR(ES)
Maria Cristina Ferraz de Mello
DATA DE PUBLICAÇÃO
1998
RESUMO
Bone mineral density (BMD) of lumbar spine and femoral neck was measured in 42 male patients with Ankylosing Spondylitis (AS) by dual-energy X-ray absoptiometry (DEXA). Patient?s mean age was 36 years, mean age at onset was 23,4 years and mean disease duration was 12,6 years. HLA-B27 was positive in 76,2% of patients. All patients underwent clinical and radiological investigation in purpose to determine: lumbar mobility by Schober test, functional index, pattern of articular involvement, grades of sacroiliitis and radiographic changes in spine, as well as presence of radiological hip disease. The influence of these variables on B:MD was evaluated. Lumbar osteopenia occurred in 40,5% of patients and osteoporosis in 26,2%. At femoral neck, the values obtained was 45% and 22,5%, respectively. HLA-B27 positivity was related to a reduced RMD in lumbar spine, whereas the presence of radiological hip involvement related to an augmented lumbar BMD. Age at onset and presence of peripheral articular disease exerced no influence on BMD. Sacroiliitis progression was accompanied by a significant increase in lumbar BMD, but by a BMD reduction in femoral neck. Clinical and radiological markers of disease chronicity (longer disease duration, worse functional index and lumbar. mobility, advanced sacroiliitis and radiographic changes in spine) correlated to a significant and progressive bone loss in femoral neck. In conclusion, AS can be considered an independent risk factor for bone loss and femoral neck seems to be .the most suitable site for serial BMD assessment by DEXA in AS, since it is sensitive to clinical and radiological changes of disease course and avoids interpretation errors caused by new bone formation, as occurs at axial skeleton
