AB0742 PREVALENCE AND RISK FACTORS OF OSTEOPOROSIS IN PATIENTS WITH JUVENILE IDIOPATHIC ARTHRITIS

Abstract

Background:Childhood rheumatic diseases are associated with reduced Bone mass and increased risk of fractures (1). Several factors may interact to determine osteoporosis other than direct bone detrimental effects of the disease or its treatment.Objectives:In this work, we aimed to investigate the prevalence of bone loss in patients with JIA and to determine the relative factors associated with osteoporosis during this chronic disease.Methods:A retrospective monocentric study was carried out on JIA patients (ILAR criteria).Dual-energy x-ray absorptiometry (DEXA) was used to determine bone status. Disease activity was evaluated by JADAS10 (Juvenile Arthritis Disease Activity Score) in poly and oligoarticular subtypes and by BASDAI (Bath Ankylosing Spondylitis Disease Activity Index) in arthritis related enthesitis form. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were noted. The data were analyzed using the SPSS statistical package. A p value < 0.05 was considered significant.Results:The sample included 40 JIA (25 male and 15 female) with a mean age at disease onset of 11.3 ± 3.6 years. The median disease duration was 90 months [7-408].The median JIA diagnosis delay was 8 months [1-108]. The JIA subgroups were in decreasing order of frequency: Enthesitis-related Arthritis (n=27), Polyarticular RF- (n=4), Polyarticular RF+ (n=1), Oligoarticular (n=4), Systemic (n=2), Psoriatic Arthritis (n=1) and Undifferentiated (n=1). Median ESR and CRP were 29 mm/hour [2-98] and 14.5 mg/l [0-70] respectively. Median BASDAI score was 4.3 [1-9.7]. Median JADAS10 score was 1[1-21].Overall, 45% of patients had osteoporosis, 27.5% had osteopenia, and 27.5 % had normal bone densitometry. None of the patients had a history of vertebral or peripheral fractures.Thirty per cent of patients (n=12) were on long term corticosteroid therapy with a mean dose of 6.6 ± 2.8 mg/day. Only 12.5% (n=5) of them had a regular physical activity.Osteoporosis was associated with age at JIA onset (p=0.005), disease duration (p=0.001), ESR (p=0.08), CRP (p=0.04), BASDAI score (p=0.017) and sedentarily (p=0.026). Osteopenia was only associated with corticosteroid therapy (p=0.01). Neither osteoporosis (p=0.37) nor Osteopenia (p=0.25) was associated with disease activity score.Conclusion:In our study, osteoporosis was a common feature during JIA. A long term corticosteroid therapy and sedentarily seem to be correlated with more impaired bone abnormalities. Hence, targeted interventions are urgently required to preserve bone health during JIA.