抄録
Objective: A low bone quality is a risk factor for fractures independent of the bone mineral density (BMD). Pentosidine and homocysteine are the main bone quality markers used in clinical practice, and the levels of these markers are reported to be high in patients with rheumatoid arthritis (RA) compared to normal controls. It has been shown that biologic agents and methotrexate reduce the serum pentosidine level. However, there have so far been no reports that have compared the homocysteine level, bone metabolic markers and bone mineral density after treatment with biologic agents. The aim of this study was to assess the plasma concentrations of bone quality markers and bone metabolic markers, BMD and disease activity in patients with RA who were receiving biologic agents, and to compare the values to control subjects using other agents.
Methods: Sixty-two patients with RA (9 male, 53 female; median age: 66.5 years) without diabetes mellitus or renal dysfunction were included in this study. Thirty-two of 62 patients received biologic agents. The plasma concentrations of pentosidine, homocysteine, intact P1NP, TRACP-5b, CRP, ESR, and MMP-3 levels, the DAS28-ESR, DAS28-CRP, CDAI, and SDAI scores, and the BMD of the lumbar spine and proximal femur were assessed. We compared these parameters between patients being treated with biologic agents (B group) and those being treated with other agents (N group). The relationships between disease activity and bone quality markers were examined.
Results: The CDAI, SDAI, CRP, and MMP-3 were significantly lower in the B group than the N group (p < 0.05). The BMD, intact P1NP and TRACP-5b levels showed no significant differences between the two groups. However, the levels of pentosidine were significantly lower in the B group than the N group (p < 0.05). The pentosidine level was significantly correlated with ESR, DAS28-ESR, CDAI, and SDAI, and the homocysteine level was significantly correlated with DAS28-CRP, respectively.
Conclusion: In this study, the BMD and bone metabolic markers showed no significant differences between the patients with RA being treated with biologic agents and those who were being treated with other agents. However, the levels of bone quality markers were significantly lower in the group treated with biologic agents. These results suggest that biologic therapy can improve not only disease activity, but also the bone quality in patients with RA.
