Osteoporosis and major fragility fractures (MOF) in sarcoidosis patients: association with disease severity

Background The reports on bone mineral loss or major osteoporosis fracture (MOF) in sarcoidosis are scarce and have conflicting outcomes. This study aimed to evaluate the prevalence and risk factors of MOF in sarcoidosis patients. Methods In a single-center cohort of 382 patients with sarcoidosis (55.8 +/- 11.6 years) we evaluated bone mineral density at lumbar spine, at femoral neck and at total hip and the presence of MOF. Lung function measurements including diffusion capacity for carbon monoxide (DLCO) were assessed. Chest X-rays were performed and radiological staging was done by Scadding score. Results Ninety patients (23.6%) with sarcoidosis have history of a MOF. BMD T-scores were lower in sarcoidosis with MOF with respect to those without MOF, but the difference was statistically significant only for BMD at femoral neck (p < 0.05). Moreover, BMD values at total hip was positively correlated with DLCO (%) (p < 0.001). Prevalence of MOF was higher in patients with sarcoidosis with lung parenchymal involvement (radiological stages 2-4) than in patients with sarcoidosis in chest X-ray stages 0 and 1 (28.3 vs 19.2% respectively, p < 0.05). Moreover, multiple regression analyses showed that X-ray Scadding score was positively associated with MOF. Conclusions This study shows that MOF represent a common and important complication in patients with moderate/severe sarcoidosis. The chest X-ray evaluation and the pulmonary function test could allow to define the risk of MOF in sarcoidosis patients.