Worldwide clinical experience with auranofin

Comparison of PA spine, lateral spine, and femoral BMD measurements to determine bone loss in ankylosing spondylitis

To evaluate bone loss in the early- and late-stage ankylosing spondylitis (AS) patients using posteroanterior (PA) and lateral lumbar and femoral bone mineral density (BMD) measurement methods. Eighty-six AS patients and 50 control subjects were enrolled. PA spine, lateral spine, and femur BMD values of patients and controls were measured. The presence of any syndesmophytes or compression fractures was determined. Patients were divided as early (<10 years) and late stage (≥10 years) according to the onset of the inflammatory pain. Mean PA spinal BMD was similar in patients and controls (p = 0.460). Femoral and lateral spine BMD values were significantly lower in patients (p = 0.012 and p = 0.001). When comparing early- and late-stage AS groups, mean PA spinal BMD was found to be lower in the early group (p = 0.005), while femoral and lateral spinal values were lower (although statistically not significant) in the late group. At least one compression fracture was present in 28 % of patients. Although not statistically significant, mean PA spinal BMD was higher in those with fractures. Femoral and lateral spinal BMD values were significantly lower in the fracture group (p = 0.034 and p = 0.004). Lateral spinal BMD values were significantly lower in patients with syndesmophytes (p = 0.004). Bone loss is increased in AS compared with control subjects. The BMD measurement at the lateral lumbar spine reflects bone loss and fracture risk better than PA spine and femoral measurements.

Bone mineral density in ankylosing spondylitis

Vertebral osteoporosis is a well-recognized feature of ankylosing spondylitis (AS) and also the vertebral compression fractures due to osteoporosis are a common but frequently unrecognized complication of AS. Both may contribute to the pathogenesis of spinal deformity and back pain. The aim of this study was to measure vertebral and femoral neck bone mass in patients with AS by dual photon absorptiometry, to determine the prevalence of compression fractures and to examine the relationship between bone density and disease severity. We found that the bone mass was diminished in the lumbar spine in moderate AS versus mild forms but the patients with advanced disease had the highest BMD values. Examination of spinal radiographs revealed compression and biconcave fractures in 9 (40.9%) cases. Neither the duration of the disease and the degree of sacroiliitis, nor the disease activity assessed by laboratory and clinical parameters was found to significantly affect the results.

Appendicular and vertebral bone mass in ankylosing spondylitis. A comparison of plain radiographs with single- and dual-photon absorptiometry and with quantitative computed tomography

OBJECTIVE

We assessed the prevalence, severity, and anatomic distribution of ankylosing spondylitis (AS)-related osteopenia (OP).

METHODS

We studied 70 patients (60 males, 10 premenopausal females) with AS (according to the New York criteria) to determine the frequency of OP. Bone mass was measured by plain radiographs of the spine, by single-photon absorptiometry (SPA) of the distal and midshaft of the radius on the nondominant side, by dual-photon absorptiometry (DPA) of the lumbar spine (L2-L4), and by quantitative computed tomography (QCT) of the lumbar spine.

RESULTS

SPA values for the radius mass were normal in males and in females, both at the distal and midshaft sites. In contrast, spine radiographs showed diminished density of the vertebral bodies in 69% of the males and 50% of the premenopausal females. Two male patients had had a vertebral compression fracture, and one female patient had had two. DPA values for the spine mass were significantly diminished in the male patients compared with the controls, but not in the female patients. Males with less severe AS also had the largest reduction in lumbar bone mineral content. In patients with more severe disease, lumbar bone mineral content was not statistically different from that in controls. QCT of the lumbar spine performed in 10 patients disclosed low density of the trabecular bone of the vertebral bodies, more so in those with more severe AS and syndesmophyte formation and/or apophyseal joint fusion, which contrasts with the normal values on DPA in these patients.

CONCLUSION

Male patients with AS have axial osteopenia. In those who have very severe AS with new bone formation, DPA demonstrates normal values as a result of two opposite trends: central osteopenia (as assessed from QCT) and peripheral new-bone formation, which transforms vertebral bodies into long bones. This could modify the mechanical resistance of the spine and account for the propensity for anteroposterior transvertebral and transdiscal fractures after trauma in AS.