Background: Juvenile idiopathic arthritis (JIA) is one of the most common rheumatic diseases in children. In all subtypes of JIA, a low bone mass has been detected in a high percentage of children due to failure to develop adequate bone mineralization.
Objective: To determine the extent of osteoporosis among children with JIA.
Patients and Methods: A cross sectional study on thirty patients diagnosed with JIA. In addition, age and sex matched thirty healthy children worked as control. Bone mineral density (BMD) and Z score of lumbar spine, neck of the femur and distal radius were analysed and adjusted for age and sex among patients and controls. Lunar DPX-NT 2013 made in USA by General Electric did dual energy X-ray absorptiometry (DEXA) scan.
Results: 60% of patients were males with a male to female ratio of 3:2. Our patients' age ranged between 6-15 years. The disease duration ranged between 6 months and 10 years. We found that 24 patients (80%) had osteoporosis (age- matched Z score was below normal), while among the control group only 4 children (13.3%) had osteoporosis. There was a significant difference between patients and controls regarding DEXA scan findings. Patients with longer duration of JIA at diagnosis had more osteopenia and osteoporosis than those with short duration of disease. The mean ± SD of disease duration in patients with JIA who were suffering from osteoporosis was 5.1 ± 2.76 years. In oligoarticular type, majority of the cases had osteoporosis 40% (12 patients). In systemic onset JIA 8 cases (26.7%), six of them were osteoporotic. The psoriatic type was diagnosed in four patients (13.3%), all of them were osteoporotic. The polyarticular RF +ve type was diagnosed in four patients (13.3%), half of them were osteoporotic and the polyarticular RF -ve type was diagnosed only in 2 patients (6.7%), all of them were within normal bone density.
Conclusion: Results obtained from this study suggest that osteoporosis was a frequent complication of JIA. JIA patients are likely to have low BMD. Children with JIA who have oligoarticular and systemic onset of JIA patients were more susceptible to low BMD.