P173 Complex assessment of bone mineral density, fracture risk, vitamin D status and bone metabolism in hungarian systemic sclerosis patients

Career situation of first and presenting author Instructor. Introduction Osteoporosis has been associated with systemic sclerosis (SSc). Objectives We wished to determine bone alterations in SSc patients by conventional densitometry (DXA), peripheral quantitative computed tomography (pQCT) and bone biomarkers. Methods We included 44 SSc patients and 33 age-matched healthy controls. Lumbar spine and femoral neck bone mineral density (BMD) was assessed by DXA. Volumetric BMD was measured by pQCT at the radius. FRAX, 25-hydroxyvitamin-D 3 (25-OH-D 3 ), parathyroid hormone, osteocalcin, C-terminal collagen telopeptide and procollagen type I amino-terminal propeptide were also assessed. Results SSc patients had lower L2–4 BMD (0.880±0.108 vs. 0.996±0.181 g/cm 2 ; p=0.019) and femoral neck (FN) BMD (0.786±0.134 vs. 0.910±0.090 g/cm 2 ; p=0.007) by DXA. In SSc vs controls, pQCT indicated lower mean cortical (328.03±103.32 vs 487.06±42.45 mg/cm 3 ; p 3 ; p=0.037). Vitamin D 3 deficiency was more common in SSc vs controls (60.0% vs 39.3%; p=0.003). L2–4 (p=0.002) and FN BMD (p=0.015) positively correlated with BMI. pQCT assessments confirmed an inverse correlation between pulmonary manifestation and total (p=0.024), trabecular (p=0.035) and cortical density (p=0.015). Anti-Scl70 positivity inversely correlated with pQCT total density (p=0.015) and the presence of digital ulcers with cortical density (p=0.001). We also found that vertebral and FN BMD as determined by DXA significantly correlated with pQCT total, trabecular and cortical density (p Conclusions The results of our study suggest that bone loss in SSc patients may be associated with lower BMI, anti Scl70 positivity, and the presence of pulmonary manifestations and digital ulcers. Both DXA and pQCT are appropriate tools to evaluate the bone alterations in SSc patients. Acknowledgements This research was supported by Hungarian National Scientific Research Fund (OTKA) grant No. K 105073 (H.P.B. and Z.S.); by the European Union and the State of Hungary and co-financed by the European Social Fund in the framework of TAMOP-4.2.4.A/2-11/1-2012-0001 ‘National Excellence Program ’(Z.S.); by the European Union grants GINOP-2.3.2-15-2016-00015 and GINOP-2.3.2-15-2016-00050 (Z.S.). Disclosure of Interest None declared.