Biochemical markers of bone turnover in ankylosing spondylitis : relationship to disease activity

Abstract EN

Objectives: To investigate bone turnover in ankylosing spondylitis (AS) patients using biochemical markers of bone formation and resorption.

Also, to study any relationship between disease activity and markers of bone turnover.

Materials & Methods: Twenty-five AS patients and fifteen healthy controls were included in this study.

They were subjected to thorough clinical examination, radiographic examination of the spine and sacroiliac joints and laboratory investigations namely ESR, C-reactive protein (CRP), rheumatoid factor, serum osteocalcin (OC) and urinary pyridinium crosslinks, pyridinoline and deoxypyridinoline (PYR and DPYR).

Results: Serum concentrations of OC were in the normal range for AS patients and did not differ significantly from those in healthy controls.

Urinary levels of PYR and DPYR were significantly raised in AS patients compared with healthy controls.

Also, there were significant correlations between urinary PYR and DPYR and parameters of disease activity including pain score, tenderness score, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), ESR and CRP.

Conclusion: We demonstrated impairment of bone turnover in AS patients that correlated with disease activity.

AS active disease patients could have a higher risk of bone loss.