Résumé
Bone mineral density [BMD] that is commonly used as a parameter of bone strength was measured in 25 post menopausal female patients with RA, and its correlation with markers of bone turnover, disease activity and functional capacity were studied. Another 10 healthy female matched for age were chosen as a control group. All the patients were subjected to clinical assessment and laboratory investigations. Bone mineral density was measured by single photon absorptiometry, Bone resorption was assessed by measurement of urinary Deoxy pyridenoline [D-Pyd] cross links with an ELISA. While Bone formation was assessed by measurement of serum osteocalcin by radioimmunassay technique. Results showed a significant decrease in BMD, a significant decrease in serum osteocalcin level and a significant increase in urinary Deoxy pyridenoline in RA patients as compared to healthy controls. The decreased BMD showed a significant correlations with the impairment of functional activity and with increased disease activity. Also the decreased BMD showed a significant correlation with the decreased serum osteocalcin and with the increased urinary Deoxy pyridenoline level. From the previous results we can conclude that, the impairment of functional activity and increased disease activity are the major determinants of BMD. So every effort should be used to keep patients with RA mobile which can counteract the adverse effect on Bone. Also the serum oesteocalin as a marker of bone formation was decreased and urinary Deoxy pyridenoline as a useful measure of bone resorption was increased. So, we suggest that the pathogenesis of osteoporosis in RA may be due to uncoupling of Bone turnover