Bone Metabolism in a Large Cohort of Patients with Systemic Sclerosis

The aim of this study was to evaluate in a largesize cohort of SSc patients bone mineral density (BMD)and to analyze its possible determinants. 106 consecutiveoutpatients affected by SSc were enrolled and completelyevaluated for bone metabolism and SSc characteristics. Forthe statistical analysis, we preferred Z score to BMD orT score since the population was composed of patients ofdifferent ages and of both sexes. Mean neck Z score wassignificantly lower than 0. No significant differences werefound for other sites. Female patients were shown to have atotal femur and neck Z score significantly lower than 0(p = 0.028 and p\0.001, respectively). 13 % of patientshad at least one morphometric non-clinical vertebral fracture.In univariate analysis, total femur Z score was lowerin female (p = 0.050) and positively correlates with BMI(p = 0.001), neck Z score positively correlates with age(p = 0.016), and whole body Z score positively correlateswith BMI (p\0.001). No correlations were found forlumbar Z score. The multivariate analysis confirmed thepositive correlation between BMI and total femur andwhole body Z score and between age and neck femurZ score (p = 0.005, p\0.001 and p = 0.040, respectively).Lung involvement was shown to correlate with alower whole body Z score in multivariate analysis(p = 0.037). We found a modest risk of low BMD inpatients with SSc and the important protective role of BMI.Patients with lung involvement showed lower whole bodyZ score.