ESPE Abstracts

Background: Children and adolescents with chronic disease are at risk of developing bone fragility. In particular, low bone mineral density (BMD) is increasingly recognized in pediatric patients with glucocorticoid treated rheumatic disease. The purpose of this study was to evaluate the clinical characteristics of children and adolescents with systemic lupus erythematosus (SLE), and to analyze the factors associated with a lower BMD in these patients.

Methods: Children and adolescents diagnosed with SLE who had received GC treatment were included. Clinical and laboratory data including anthropometry, GC exposure, other anti-rheumatic drug treatment, biochemical markers related to bone metabolism, serologic markers of disease activity in SLE, lateral thoracolumbar(D-L) spine radiography, and BMD were collected. Lumbar spine bone mineral density (LSBMD) was measured by Dual-energy x-ray absorptiometry (DXA). The correlation between BMD and anthropometry, steroid and anti-rheumatic treatment, biochemical variables was investigated.

Results: A total of 30 patients with median age of 17.5 years (range 12 -25years) were included. Of the 29 patients who had DXA done, 7 patients had LSBMD z score lower than -2.0, and diagnosed as osteoporosis. SLE patients with osteoporosis were compared with those with a z score higher than -2.0. These patients had longer GC exposure, higher cumulative GC dose, longer hydroxychloroquine exposure. The main factor correlated with a low BMD was duration of GC exposure. BMD was positively correlated with height and weight at diagnosis. Bone metabolic markers and serologic markers of disease activity in SLE had no significant correlation with BMD.

Conclusion: Children and adolescent SLE patients with OP had longer GC exposure, higher cumulative GC dose compared with those with LSBMD z score higher than -2.0. The main factor correlated with a low BMD was duration of GC exposure. Therefore, efforts should be made to reduce the duration of GC exposure and reduce medication to the lower possible maintenance dose. Since longer treatment duration affects BMD, close monitoring during the treatment period is recommended to prevent further loss of bone mass in pediatric SLE patients.