Background: Atherosclerosis and diseases derived from vascular calcification are one of the important causes of mortality in the patients with rheumatoid arthritis (RA). Although several studies have assessed in this case, however, there are no many results on relationship between those factors and bone biomarkers and their correlation with vascular calcification. The aim of this study was designed to investigate the comparison of serum levels of matrix Gla protein (MGP) and osteoprotegrin (OPG) and their relationship with the severity of disease activity (DAS28) in women with rheumatoid arthritis.

Materials and methods: 45 female patients with rheumatoid arthritis and 45 matched healthy women as control group were selected. Serum levels of matrix Gla protein (MGP) and osteoprotegrin (OPG) by ELISA, and serum high sensitivity CRP (hs-CRP) by torbidometery method were measured.

Results: Results indicated a significant increase in serum OPG (p= 0.001) and hs-CRP (p= 0.001) in the patient group were compared to control group. No significant differences were found in the level of serum MGP (p=o.302) between patient and control groups. Significant positive correlations were found between hs-CRP and erythrocyte sedimentation rates (ESR) (p=0.001, r=0.487), between hs-CRP levels and the degree of disease activity of 28 (DAS28) (p=0.001, r=0.570) and between ESR and values of (DAS28) (p=0.007, r=0.448) in patient group.

Conclusion: The present study confirms that increasing OPG level could possibly decrease inflammatory responses by reduction of cytokines level in women with rheumatoid arthritis and may reduce the bone destruction. Also, reduction in MGP could result in vascular calcification and vessel wall damage in RA patients.

Keywords: Rheumatoid arthritis (RA), osteoprotegrin (OPG), matrix Gla protein (MGP), high sensitivity CRP (hs-CRP).