Bone Abstracts

Objectives: Vitamin D has an important effect on bone but there are no trials that directly address the boosting of serum levels of 25-hydroxyvitamin D (25OHD) in bone microarchitecture in Juvenile-onset Systemic Lupus patients (JoSLE). The aim of this study was to evaluate the effect of vitamin D supplementation on bone microarchitecture parameters using HR-pQCT in JoSLE patients.

Methods: This study was a randomized double-blind placebo-controlled 24-week trial (Clinical Trial Registry NCT01892748) conducted at the Hospital das Clínicas da Universidade de Sao Paulo, Brazil. Forty female JoSLE patients were randomized (1:1) to receive oral cholecalciferol 50,000 IU/week (JoSLE-VitD) or placebo (JoSLE-PL). Medications remained stable throughout the study. Serum levels of 25OHD were measured using radioimmunoassay. Bone microarchitecture and volumetric bone density were analysed using HR-pQCT at tibia site.

Results: At baseline, groups were similar regarding age, BMI, organ involvement, glucocorticoid dose, immunosuppressant use, serum levels of 25OHD and HR-pQCT parameters. After 24 weeks, higher 25OHD levels were observed in the JoSLE-VitD group compared to the JoSLE-PL [31.3(8.6) vs. 16.5(5.8) ng/ml, P<0.001]. An increase in trabecular number [ΔTb.N: 0.16(0.24) vs. 0.03(0.19), P=0.024] and a decrease in trabecular separation [ΔThSp: -0.045(0.067) vs. 0.001(0.009), P=0.017] were found in JoSLE-VitD group than in JoSLE-PL at tibia site. No differences were observed in other structural parameters [trabecular (Tb.Th) or cortical thickness (Ct.Th)], volumetric bone mineral densities, cortical porosity and biomechanical parameters (P>0.05).

Conclusion: This study suggests that cholecalciferol supplementation for 24 weeks could be effective in improving bone microarchitecture parameters, mainly trabecular number in JoSLE patients. The authors have declared no conflicts of interest

Disclosure: The authors declared no competing interests.