To examine bone mineral density (BMD) in the spines of patients with juvenile idiopathic arthritis (JIA), and to identify the main predictors of spine BMD.
160 patients with JIA (82 female, 78 male; median age, 8.7±3.9 years (range, 2.2-18.2 years)) who fulfilled the International League of Associations for Rheumatology (ILAR) criteria were enrolled. All subjects underwent an initial dual energy x-ray absorptiometry (DXA) scan of the lumbar spine, while 114 and 87 patients underwent a second and third scan, respectively. The data were compared with those obtained for 114 sex- and age-matched healthy controls.
The DXA scans revealed that the JIA patients had a significant spine BMD deficit compared with control subjects (p<0.001). Longitudinal comparison of patients revealed no significant short-term improvement in the spine BMD. Spine BMD correlated with the age (p<0.05), subtype (p<0.05), and disease activity (p<0.01), BMI (p=0.001), glucocorticoid (GC) exposure (p< 0.05), methotrexate (MTX) therapy (p<0.05), and non-steroidal anti-inflammatory agents (NSAIDs) (p<0.05), erythrocyte sedimentation rate (ESR) (p<0.01), and C-reactive protein (CRP) levels (p<0.01).
Patients with JIA have low bone mass, especially those in the polyarticular group >7 years old with higher disease activity.