P009 Osteoporosis is a frequent complication in enthesitis related arthritis patients

Abstract

Abstract Background Enthesitis related arthritis (ERA) represents a clinical entity of juvenile idiopathic arthritis. This chronic rheumatic disease may lead to early bone mass loss and increase risk fracture. The aims of this study were to evaluate the prevalence of clinical osteoporosis in patients with ERA and to identify what factors are associated with increased occurrence of osteoporosis. Methods We reviewed the medical records of patients with confirmed ERA. We analyzed their demographic data and the clinical characteristics. Dual-energy X-ray absorptiometry (DEXA) was used to determine bone status. Osteoporosis was defined as Z score <-2.5DS. Disease activity was evaluated by: erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Data were analyzed using the SPSS statistical package. A P-value < 0.05 was considered significant. Results Thirty-three patients (27 male and 7 female) with a mean age at of 23.8 ± 7.5 years were enrolled. The mean age at disease onset was 12 ± 2.6 years. Median disease duration was 108 months [12–408]. The median ESR and CRP levels were 35 mm/h [8–90] and 20 mg/l [1–70] respectively. Median BASDAI score was 4.7 [1–9.7]. At bone densitometry, osteoporosis and osteopenia were found in 44.1% and 23.5% cases respectively. None of the patients had a history of osteoporotic fractures. Long term corticosteroid therapy and sedentarily were noted in 18.2% and 47.1% of patients respectively. On statistical analysis, osteoporosis was associated with these parameters: age at ERA onset (P = 0.035), disease duration (P = 0.04), CRP (P = 0.009), BASDAI score (P = 0.05) and sedentarily (P = 0.031). Neither corticosteroid therapy (P = 0.68) nor high ESR level (P = 0.73) were associated with osteoporosis. Conclusion In this study, osteoporosis was a common extra articular feature during ERA. As adult spondyloarthritis, disease activity, duration and sedentarily seem to be associated with the bone loss.