Endocrine Abstracts

JOINT2047

Background: Glucocorticoid-induced osteoporosis (GIO) is a common consequence in children and adolescents with systemic lupus erythematosus (SLE). Vertebral fractures (VFs), which are typically asymptomatic, occur in 4-28 percent of these patients, emphasising the importance of close monitoring. While bone mineral density (BMD), assessed by dual-energy X-ray absorptiometry (DXA), is the gold standard for evaluating bone health. its limitations are evident as many children with VFs show normal BMD Z-scores. Trabecular bone score (TBS) offers insight into bone quality and has been linked to fracture risk. Despite its potential, limit studies have explored TBS’s role in identifying prevalent VFs among SLE children treated with glucocorticoids therapy.

Purpose: To evaluate the TBS in glucocorticoid-treated SLE children and adolescents with and without VF and the correlation between the TBS and BMD data.

Methods: The retrospective cohort study included 48 patients with SLE who had been treated with systemic glucocorticoids (GCs) for over three months. Both TBS and BMD were assessed between January 1, 2017 and December 31, 2024, at the Pediatric Department of Phramongkutklao hospital. TBS was analyzed using iNsight software (version 3. 0. 2. 0) and TBS Z-scores as well as BMD Z-scores were calculated using established reference values for children and adolescents. Patients were classified into two groups: VF and non-VF according to the Genant semi-quantitative method. A comparison of TBS Z-scores between the VF and non-VF groups was done.

Results: At baseline, the mean age (11 years [10. 5-14]), BMI (21. 49 kg/m² [18. 2-25. 99]), cumulative GCs dose (8, 083. 75 mg [5, 105-12, 800]) showed no significant differences between two groups. TBS L1-L4 and TBS L1-L4 Z-scores were lower in the VF group than in the non-VF group, although not significantly: [1. 16 (1. 14-1. 40) vs. 1. 36 (1. 30-1. 42), P 0. 117; 0. 05 (-2. 12 to 0. 38) vs. 0. 09 (-0. 6 to 0. 5), P = 0. 370]. Both VF and non-VF groups had L1-L4 BMD Z-scores above -2: -1. 04 (-2. 57 to 0. 4) vs. 0. 26 (-1. 04 to 1. 02), P 0. 12. TBS L1-L4 Z-scores showed a moderate positive correlation with L1-L4 BMD Z-scores (r 0. 477, P 0. 001). TBS L1-L4 also exhibited moderate positive correlations with L1-L4 BMD (r 0. 686, P < 0. 001) and BMAD L1-L4 Z-scores (r 0. 488, P < 0. 001).

Conclusion: Lower TBS may indicate compromised bone microarchitecture, providing additional insight beyond BMD alone in childhood and adolescent patients with SLE.

Keywords: SLE, Adolescents, Glucocorticoid, Trabecular bone score