ESPE Abstracts

Background: Adipokines have been demonstrated to regulate bone metabolism and impact bone strength. Previous studies have investigated the potential influence of leptin and adiponectin on the risks of vertebral fracture (VF) and bone mineral density (BMD) in healthy children and postmenopausal women, however, the outcomes of these investigations remain controversy.

Objectives: To determine plasma leptin and adiponectin level between VF and non-VF in children and adolescent with systemic lupus erythematosus (SLE) receiving glucocorticoid (GC) therapy and to examine correlation between plasma leptin and adiponectin level with BMD in these patients.

Methods: In a cross-sectional study, forty-seven SLE patient aged 5-20 years, 5 with VF and 42 non-VF, along with 22 healthy control subjects were enrolled. Clinical characteristics, bone panels, BMD and body composition from dual energy X-ray absorptiometry were collected. The differences in leptin and adiponectin levels among VF, non-VF and control group were analyze by one way ANOVA. The correlation between leptin and adiponectin levels and BMD were evaluated using Pearson’s coefficient.

Results: Mean age of SLE patients was 15.1 ± 3.0 years. There were no significant differences in clinical characteristics and BMD between the VF and non-VF groups. However, the VF group exhibited significantly higher levels of elemental calcium supplement dosage and serum alkaline phosphatase, whereas the urine calcium to creatinine ratio was significant lower in comparison to the non-VF group. We found higher leptin levels in VF group compared to non-VF and control groups (21.03 ± 25.49 vs 15.28 ± 12.57 vs 6.79 ± 4.03 ng/mL, p 0.01) but no statistically significant difference observed between VF and non-VF group (p 0.31). Adiponectin levels did not show significant differences among the groups. A logistic regression was performed to ascertain the effects of height Z-score, elemental calcium supplement dosage, lean mass Z-score (LMZ), fat free mass index (FFMI), leptin level and total body (TB) BMD Z-score on the likelihood of participants having VF. The analysis revealed that patients with leptin levels > 12 ng/mL and TB BMD Z-score <-1 SD were 29.3 times more likely to have VF (p 0.049). Increase adiponectin level was negatively correlated with TB BMD Z-score (r -0.358, p 0.018) whereas no correlation was found between leptin and BMD.

Conclusion: Elevated leptin levels may pose a potential risk factor for VF in children and adolescents with SLE receiving GC therapy especially in those with a high leptin level combine with low TB BMD Z-score.