[Bone mineral density in women with rheumatoid arthritis: A link between immune and biochemical markers]

To study the association of bone mineral density (BMD) with serum biochemical and immunological markers in postmenopausal women with rheumatoid arthritis (RA).

The study included 173 women with RA (age 61.0 [56.0; 66.0] years). A survey, dual-energy X-ray absorptiometry to measure the BMD of the lumbar spine (L_I-L_IV), femoral neck (FN) and total hip (TH), routine blood chemistry, measurement of C-reactive protein (CRP), rheumatoid factor, cyclic citrullinated peptide antibodies (CCPA), parathyroid hormone (PTH), vitamin D₃, myostatin, follistatin, interleukin-6 (IL-6), IL-6 receptors, insulin-like growth factor 1, adiponectin, leptin, fibroblast growth factor 23, and tumor necrosis factor SF12 were performed.

PTH (β=-0.22, -0.35 and -0.30 for L_I-L_IV, FN and TH, respectively), CRP (β=-0.18, 0.23 and -0.22 for L_I-L_IV, FN and TH, respectively) and leptin (β=0.35, 0.32 and 0.42 for L_I-L_IV, FN and TH, respectively) were shown a significant association with BMD in all sites of measurement. It was independent of age, body mass index and postmenopause duration. Associations were also found between adiponectin and BMD of L_I-L_IV and TH (β=-0.36 and -0.28, respectively), CCPA and BMD of FN and TH (β=-0.21, -0.24, respectively) and IL-6 and BMD of FN (β=0.37).

The study of biochemical and immunological markers in women with RA demonstrated that CRP, CCPA, PTH, IL-6, adiponectin, and leptin influenced BMD.