LAUSR

Background: To compare bone metabolism in pre- and postmenopausal women with RA Objectives: GCs and inflammation lead to BMD loss through increase the expression of RANK-ligand and decrease the expression of osteoprotegerin in stromal and osteoblastic cells. Determination of indicators relevant for clinical practice for identification a high-risk BMD loss group of RA patients is needed. Methods: The bone turnover markers were analyzed in 58 women with RA: 36 premenopausal (PreM) and 22 postmenopausal (PM). The two groups were significantly different in age (35.9±8.7 PreM vs 57.1±4.1 PM) and BMI (23.8±4.3 PreM vs 28.6±5.0 PM). By disease duration (8.9±5.7 years vs 10.0±6.1 years), disease activity by DAS28, x-ray changes, GC, MTX and biologic therapy both group were comparable. BMD was measured in 3 part of the skeleton: hip, lumbar spine, distal part of forearm. Serum levels of 25 (OH) vitamin D (Vit D), parathormone (PTH), osteoprotegerin (OPG), RANKL were analyzed. Results: Low level of Vit D (25(OH)D<30 ng/ml) was observed in 46.6% of patient and was preferable in PreM women. Vit D deficiency was associated with age (R=-0.31, p<0.05) and positive anti-CCP (R=-0.46, p<0.05). The mean level of PTH was normal in 74.1%. Serum OPG level was significantly higher in more than 50% of patients. It was associated with presence of erosion (R=0.97, p<0.05), decreased cortical index (R=-0.28, p<0.05) in PreM patient and DAS28 (R=-0.44, p<0.05) in all patients. High level of RANKL was preferable in PM women (47.6%), decreased level more often was observed in PreM patient (38.9%). In PM patients increased level of RANKL was correlated with BMI, duration of menopausa and DAS28, in PreM – only with DAS28. In PreM women the changes in serum levels of PTH and vitamin D was negatively correlated with levels of RANKL and C-TP, low level of vitamin D had negative correlation with OPG (R -0.47). According to lineal regression analysis positive correlation between disease duration, Sharp van der Heijde erosion score and PTH (r=0.31; p=0.01, r2=0.11) was observed in all patients, more often in PreM women. Low spine BMD in PreM associated with high PTH (R=0.82, p<0.05), in PM – with high PTH, OPG/RANKL and low level of RANKL. Low hip neck BMD correlated with decreased level of vit D in PM patients. Low levels of vit D, C-TP and high levels of OPG and OPG/RANKL index was significantly associated with forearm low BMD in all patients. In PreM women strong association between low vit D (R=-0.60, p<0.05), high OPG (R=0.89, p<0.05) and BMD in medium part of forearm was observed. Conclusions: In premenopausal women vitamin D deficiency had high predictive value for decrease BMD in the medium part of forearm, high level of PTH – for decrease BMD in the spine. In PreM RA patients low Vit D, low cortical index and high PTH can be considered as an indication for BMD assessment. PM women with high BMI, longstanding postmenopausal period and high disease activity may be candidate for bone markers assessment. References [1] Schett G, Kiechl S, Weger S, et al. High-sensitivity C-reactive protein and risk of non-traumatic fractures in the Bruneck study. Arch Intern Med2006;166:2495–501. [2] Charactcharoenwitthaya N, Khosla S, Atkinson EJ, et al. Effect of blockade of TNF-α and interleukine-1 action on bone resorption in early postmenopausal women. J Bone Miner Res2007;22:724–9. Disclosure of Interest: None declared