Correlation between bone quality and microvascular damage in systemic sclerosis patients

Objectives. SSc patients are recognized as presenting an increased risk of altered bone mass. The aim of this study was to assess the bone quality, by trabecular bone score (TBS), in SSc patients in correlation with different levels of microvascular damage, as evaluated by nailfold videocapillaroscopy (NVC), and to compare the results regarding bone quality with RA patients and healthy subjects (CNT). Methods. Eighty-four SSc patients, 98 RA patients and 60 CNT, were studied. BMD (g/cm2) of the lumbar spine (L1-L4) was analysed by DXA scan. Lumbar spine bone quality was derived from each spine DXA examination using the TBS analysis. NVC patterns were analysed. Results. A total of 56/84 SSc patients (66%) as well as 78/98 RA patients (80%) showed bone loss at DXA and BMD was found to be significantly lower than in the CNT (P<0.001). Similarly, lumbar spine TBS was found to be significantly lower in SSc and RA patients than in CNT (P<0.001). TBS values were found to be lower in SSc with a late NVC pattern, compared with the active or early pattern (late vs active and early pattern, P<0.001). There was no statistically significant difference in the mean lumbar spine TBS between SSc and RA patients (P = 0.238). Conclusion. The data obtained showed significantly lower bone quality (lower TBS and BMD) in SSc and RA patients compared with CNT. The bone quality seemed lower in SSc patients with more altered microvasculature (late NVC pattern).