Factors affecting bone mineral density in children and adolescents with systemic lupus erythematosus

Abstract

Purpose Patients with juvenile-onset systemic lupus erythematosus (JSLE) are at a high risk of entering adulthood with disease-related morbidities like reduced bone mass and osteoporosis. This study aimed to evaluate the clinical characteristics of JSLE and to analyze the factors associated with low bone mineral density (BMD) in these patients. Methods Children and adolescents diagnosed with JSLE at a single institution in Korea were included. Demographic, clinical, and laboratory data as well as details about the use of glucocorticoids (GCs) and disease-modifying antirheumatic drugs were collected. The lumbar spine (LS) BMD z-score was measured using dual energy x-ray absorptiometry, and lateral thoracolumbar spine radiographs were collected. Results A total of 29 patients with JSLE were included in this study. Of these patients, 7 had a BMD z-score of -2.0 or lower and were designated as the low BMD group. The differences in the clinical parameters and treatment variables between the low BMD and non-low BMD groups were compared. Higher cumulative GC dose, longer GC exposure, and higher cumulative hydroxychloroquine (HCQ) dose were all associated with low BMD; among them, the main factor was the duration of GC exposure. There was no significant correlation between BMD and clinical profile, disease activity, or bone-metabolism markers. Conclusions The duration of GC exposure, cumulative GC dose, and cumulative HCQ dose were risk factors for low BMD in patients with JSLE, with the main factor being the duration of GC exposure. Thus, patients with JSLE should be routinely monitored for low BMD and potential fracture risks, and GC-sparing treatment regimens should be considered.

Keywords

• bone density
• metabolic bone diseases
• glucocorticoids
• juvenile osteoporosis
• systemic lupus erythematosus