ANTIRESORPTIVE OSTEOPOROSIS TREATMENT (ART) IN RHEUMATOID ARTHRITIS (RA) PATIENTS PROTECTS AGAINST GENERALISED BONE LOSS AT HIP AND SPINE BUT NOT AGAINST PERIARTICULAR BONE LOSS IN THE HANDS

Background: The osteoporosis (OPO) in RA is both periarticular (P-OPO) and generalised (G-OPO). Both forms are associated with inflammation and caused by the osteoclast activity. Suppression of inflammation in active RA reduce osteoclast related generalised, but not periarticular hand bone loss. ART with hormone replacement therapy (HRT) or bisphosphonates have in RA patients been shown to protect against G-OPO. Whether periarticular bone loss in RA patients, shown to predict subsequent radiographic progression in early disease, is arrested in ART RA patients is an open question.Objectives: To examine the effect of ART on periarticular bone loss (assessed at the hands) in patients with RA.Methods: In a cohort of 187 RA patients (aged 20 to 70 years) demographic and clinical data were collected and BMD measured (hands, lumbar spine and hip) at baseline and at a mean follow-up of 2.2 years. Hand BMD was measured by digital hand-x-ray radiogrammetry (DXR) (Pronosco X-posure system), a computerised version of the traditional technique of radiogrammetry using conventional hand x-rays. Hip (femoral neck and total hip) and lumbar spine (L2-4) BMD were measured by dual energy X-ray absorptiometry (DXA) (Lunar Expert-XL). Long term in-vitro precision for the DXR was 0.2% and for the DXA 0.8%. Baseline patient characteristics: mean (SD) age 58.2 (9.4) yrs, disease duration 13.1 (9.3) yrs, MHAQ 1.57 (0.43), DAS 4.42 (1.36), ESR 20.2 mm/hr (15.3), females, 83.4%, post-menopausal 77.6%, Waaler positive 45.1%.Results: At follow up 38.4% were current users of ART, 34.1% were current users of calcium and/or vitamin-D and 27.5% were non users of any OPO treatment. 40.0% were current users of CS and 2 year cumulative prednisolone dose was 4.3 (2.6) g. The mean (SD) BMD changes (baseline minus follow-up) given as g/cm2 for no-ART and ART treated RA patients are shown in the table (*P<0.05, **P<0.001). No-ART ART Hands -1.49 (-2.10, -0.89)** -1.38 (-2.01, -0.76)** Femoral neck -1.34 (-2.38, -0.30)* -0.33 (-1.59, +0.94) Total hip -1.11 (-2.21, -0.02)* +0.40 (-0.83, +1.64) Spine L2-4 -1.39 (-2.64, -0.14)* +1.13 (-0.68, +2.94) ]Conclusion: Antiresorptive osteoporosis treatment with bisphosphonates or HRT in RA patients does not protect against hand bone loss as it does in spine and hip. This may reflect different osteoclast-related mechanisms for periarticular- and generalised osteoporosis. Further longitudinal studies are required to confirm these findings.Citation: , volume , supplement , year 2003, page Session: Rheumatoid arthritis – Treatment