Bone fragility in sarcoidosis

Purpose: Few studies have suggested that sarcoidosis may be associated with low bone mineral density (BMD) and fragility fractures. However, studies on bone mineral loss or fractures in sarcoidosis are conflicting. This study aimed to evaluate: 1) the history of fragility fractures in patients with sarcoidosis; 2) the correlation of bone fragility with severity of sarcoidosis disease. Methods: We selected 252 sarcoidosis patients (54.7 ± 12.1 years) and age- and sex-matched healthy controls. We evaluated BMD at the lumbar spine (BMD-LS), femoral neck, and total hip (BMD-TH), and also the occurrence of any fracture. Forced expiratory volume in one second, forced vital capacity, and diffusion capacity for carbon monoxide (DLCO) were also assessed. Results: BMD T-scores were lower in sarcoidosis patients than in healthy controls, but the difference was statistically significant only for BMD-LS (p < 0.01) and BMD-TH (p < 0.05). Moreover, BMD-LS and BMD-TH values were significantly associated with DLCO (%) (p < 0.05). The prevalence of fragility fracture was higher in patients with sarcoidosis than in controls (30.6% vs. 12.3%). The sarcoidosis patients with a higher number of vertebral fractures (>3) also showed reduced values on pulmonary function test parameters, particularly DLCO (%). Conclusions: This study shows that fragility fractures are significantly more frequent in patients with sarcoidosis than in control subjects. Furthermore, a greater number of vertebral fractures was linked to worse pulmonary function tests.