Razi Journal of Medical Sciences

  Background: Rheumatoid arthritis (RA) is the most common inflammatory arthritis affecting 0.5 to 1% of the general population worldwide. The cause of RA remains unknown. In active RA, bone turnover markers change in serum and urine before the appearance of erosions in radiography. In this study, we compared RA activity index with bone turnover marker levels in serum of RA patients.

  Methods: In this cross-sectional study, RA patients referring to the Rheumatology Clinic of Loghman Hospital were studied. One hundred fourteen established RA patients were included. Bone turnover markers were measured in 75 patients. DAS28 and cumulative dose of steroid were calculated in all patients. RF, Anti-CCP, ESR, CRP, bone turnover markers consisting of osteocalcin, P1NP, βCTX and ALP were measured for all the patients. Cases were divided based on whether steroid and DMARD were used or not. Comparison of DAS28 and bone turnover markers was done with Chi square Pearson test. Also, the relation between bone turnover markers and consumption of DMARDs, steroid and bisphosphonate was evaluated. SPSS V. 16 was also used for data analysis.

  Results: There was significant correlation between DAS28 and serum osteocalcin (p<0.05), but no correlation was found with other markers. There was significant correlation between bisphosphonate consumption and decreased serum osteocalcin (p=0.05) and borderline correlation with decreased P1NP (p=0.06). Significant correlations was found between "erosion and decreased level of osteocalcin" and "erosion and DAS28".

  Conclusion: In active RA patients, decreased bone formation markers especially osteocalcin are suggestive of severe and erosive disease for which early aggressive treatment is recommended. These markers can be applied for differentiating osteoporosis from RA in these patients. Thus increased level of bone formation markers is seen in idiopathic osteoporosis and decreased level in active RA.