Background Vitamin D is involved in both innate and adaptive immunity and in the regulation of bone turnover1. High prevalence of vitamin D deficiency has been reported in autoimmune disease including Systemic Sclerosis (SSc)2. Vitamin D is recognized as one of the important causal factor for low bone mass due to its action on bone formation and mineralization3,4. Moreover SSc is characterized by vascular damage, immune and fibrotic changes that are further risk factors for bone mass loss.
Objectives The aim of this study was to evaluate possible correlation between 25(OH)D3 serum concentration and further bone mass loss in postmenopausal women with SSc in winter season.
Methods After informed consent 54 female SSc patients and 42 healthy controls (mean age 68.5±9.5 years), were enrolled in the study during routine screening programs, in winter time. The mean age of patients was 66.5±11 years, the mean disease duration calculated from onset of Raynaud phenomenon was 12±10 years. 25(OH)D3 serum levels were evaluated by radioimmunoassay. The Bone Mineral Density (BMD) of the lumbar spine and hip was measured by dual energy X-ray absorptiometry using a Lunar Prodigy (GE, USA)
Results 25(OH)D3 resulted significantly lower in SSc patients in comparison with controls (mean ± SD 16.1±11.7 vs 25.1±4.1 ng/ml p<0.01); whereas several bone metabolism markers like calcium (p=0.2), phosphorus (p=0.1) and bone alkaline phosphatase (p=0.1) serum levels were similar in both groups. BMD was significantly lower in SSc patients compared to control group at the level of femoral neck (mean ± SD 0.766±0.13 g/cm3 vs 0.896±0.3 g/cm3, p<0.001) and total femur (0.826±0.163 g/cm3 vs 0.948±0.136 g/cm3 p<0.002). Significantly lower BMD at lumbar spine was also observed in SSc patients (1.033±0.151 g/cm3 vs 1.132±0.200 g/cm3 p<0.003). Both BMD of femoral neck and total femur positively correlated with 25(OH)D3 concentrations (r=0.39, p<0.002; r=0.46, p<0.003, respectively).
Conclusions 25(OH)D3 serum concentration and BMD values are significantly lower in SSc postmenopausal patients than in postmenopausal controls, at least in winter time. A positive correlation between 25(OH)D3 serum levels and bone mass seem evident in SSc patients and deserve further analysis.
Cutolo M. et al. Autoimmun Rev 2011;11:84-87.
Caramaschi P. et al. Clin Rheumatol 2010;12:1419-25.
Lips P. et al. Journal of Internal Medicine 2006; 260:245–254.
Pelajo CF et al Autoimmun Rev 2010 9(7):507-510.
Disclosure of Interest None declared