Markers associated with the development of osteoporosis in children with juvenile idiopathic arthritis

Abstract

Background. The purpose of the study was to investigate the association between bone mineralization le­vel in children with juvenile idiopathic arthritis (JIA) and various exogenous and endogenous factors. Materials and ­me­thods. The study group consisted of 162 children diagnosed with JIA. Medical history, clinical features, and treatment of JIA were studied. Disease activity was evaluated using the Juvenile Arthritis Disease Activity Score (JADAS-27), health status — with the Childhood Health Assessment Questionnaire (CHAQ). Complete blood count with erythrocyte sedimentation rate, biochemical analysis (C-reactive protein, total and ionized calcium) were performed, and instrumental methods (ultrasound densitometry, X-ray and ultrasound examination of joints) were used. Serum levels of osteocalcin, 25-hydroxyvitamin D (25(OH)D), and parathyroid hormone were evaluated using an enzyme-linked immunosorbent assay on an ER500 analyzer (Sinnowa, China). Results. According to our study, osteoporosis was observed in 19 patients (11 girls and 8 boys) out of 162 children with JIA, accounting for 11.7 %. It was significantly more frequent in patients with polyarthritis (73.7 %) compared to those with oligoarthritis (26.3 %) (p < 0.05). Conclusions. Osteoporosis can develop in children with JIA who do not receive systemic glucocorticoid therapy. The main markers associated with osteoporosis in children with JIA include non-infectious disease onset trigger, cervical joint involvement at disease onset, involvement of more than 3 joint groups at onset, gait disturbances, high JADAS-27 and CHAQ scores, signs of systemic inflammatory process, including elevated erythrocyte sedimentation rate.