This article is more than 5 years old. Information may no longer be current.
Lateral projection BMD increased in ankylosing spondylitis
Click Here to Manage Email Alerts
Lateral projection spinal bone mineral density increased over a period of 5 years in multiple locations along the spine, among patients with ankylosing spondylitis, according to findings published in Arthritis Research and Therapy.
The researchers added that their findings suggest that the femoral neck is the best place to test bone loss among patients with ankylosing spondylitis.
“This study is important because ankylosing spondylitis patients have an increased risk for low bone mineral density (BMD), but there is still a lack of knowledge regarding risk factors for developing low BMD and which measuring sites are best for diagnosis of osteoporosis, as well as monitoring changes in BMD,” Anna Deminger, a PhD student at the University of Gothenburg, in Sweden, told Healio Rheumatology. “New bone formation in the spine is common in ankylosing spondylitis and can falsely raise BMD when measured with the conventional anterior-posterior dual-energy x-ray absorptiometry in the spine.”
To analyze changes in BMD over an extended follow-up period among patients with ankylosing spondylitis, and to determine which variables and medications are predictors of such changes, the researchers conducted a longitudinal of 204 Swedish patients recruited at three sites. The researchers measured BMD at the hip, the lumbar spine anterior-posterior and lateral projections, and the total radius, both at baseline and after 5 years.
Of the 204 enrolled patients, 168 were reassessed at the 5-year follow-up. Patients were examined using questionnaires, blood samples and spinal radiographs. Ankylosing spondylitis-related changes in the spine were graded with the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS), and vertebral fractures were assessed with the Genant score. The researchers used multiple linear regression to identify predictors for changes in BMD.
According to the researchers, BMD decreased significantly at the femoral neck and radius, but significantly increased at the lumbar spine, both in the anterior-posterior and lateral projections. In addition, the researchers identified mean C-reactive protein as a predictor for decreases in femoral neck bone mineral density (change in percentage, =–0.15, P =.046). Bisphosphonate use predicted an increase in BMD at all locations except for the total radius. In addition, TNF inhibitor use was a predictor for increased anterior-posterior spinal BMD (=3.15, P=.012).
“In this group of patients with long-standing ankylosing spondylitis, BMD decreased at the femoral neck and increased at the spine, both the anterior-posterior projection, and, interestingly, also at the lateral projection,” Deminger said. “Inflammation was associated with decreases in BMD. ... The clinical significance of these findings is the importance of measuring BMD at the femoral neck in these patients, and to treat inflammation.” – by Jason Laday
Disclosure: Deminger reports no relevant financial disclosures. See the full study for additional authors’ disclosures.
Click Here to Manage Email Alerts