Changes in Bone Density in Patients with Ankylosing Spondylitis: A Two-Year Follow-Up Study

Abstract

The objectives of the study were to determine the 2 year rate of bone changes in patients with ankylosing spondylitis (AS) and, whether bone loss is related to physical impairment, systemic inflammation. and therapy. Consecutive outpatients fulfilling the modified New York criteria for AS were included. Baseline assessment included age, disease duration, treatment, clinical, radiologic and laboratory data. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were determined every 6 months. Persistent systemic inflammation was defined as mean ESR > or = 28 mm/h or mean CRP > or = 15 mg/l. Bone mineral density (BMD) at the lumbar spine and femoral neck was measured by dual-energy X-ray absorptiometry, at baseline and year 2. Statistical analysis compared the baseline and 24 month follow-up BMD data, and determined whether baseline data, and persistent systemic inflammation during the 2 years, were related to the 24 month percentage changes in BMD. Fifty-four patients (35 men, 19 women; mean age 37.3 +/- 11.3 years, mean disease duration 12.4 +/- 8.6 years) were included. After 2 years, BMD did not change at the lumbar spine (+0.75% +/- 3.5, p = 0.23), and decreased at the femoral neck (-1.6% +/- 4, p = 0.006). The 24 month percentage change in femoral neck BMD was related to persistent systemic inflammation, defined using ESR (mean percentage change -4.1% +/- 5.7 and -1.2% +/- 3.9 in patients with and without persistent inflammation; respectively; p = 0.007). These results suggest that persistent inflammation might be an etiologic factor of bone loss in AS.

Increase in bone mineral density of patients with spondyloarthropathy treated with anti-tumour necrosis factor alpha

“…BMD (g/cm 2 ) was determined, at baseline and six months later, at the lumbar spine (second to fourth vertebrae, anteroposterior view) and the upper extremity of the left femur, by dual energy x ray absorptiometry (DXA) (QDR 2000, Hologic, Waltham, USA). For the femur the following sites were assessed: trochanter, femoral neck, and the whole femoral extremity (total hip).…”

Bone Mineral Density Changes in Patients with Spondyloarthropathies

“…Several scientists insist that disturbances of mobility function have no influence on lowering BMD in AS patients (Mitra, 1999;Maillefert, 2001). J. Gratacos and colleagues failed to find the correlation between BMD reduction and the results of HAQ-S questionnaire evaluating physical disability of SpA patients.…”

Monitoring DXA Measurement in Clinical Practice

“…Expressed as SDD, a BMD change should exceed 0.02 g/cm 2 at the total hip and 0.04 g/cm 2 at the spine before it can be considered a significant change (El Maghraoui, Do Santos Zounon et al 2005). Indeed, it has become usual to perform repeated DXA measurement: in postmenopausal women to monitor efficacy of treatment and in patients with chronic rheumatic diseases where high prevalence of bone loss has been demonstrated (Maillefert, Aho et al 2001;Johnson, Petkov et al 2005) especially when long term corticosteroid therapy is used. In the reports published, variability is usually expressed as CV and the figures for short term variability are lower than the ones we found [7][8][9].…”