Background In chronic inflammatory rheumatism and also in connective tissue diseases including rheumatoid arthritis and systemic erythematosus lupus, there is an increased risk of osteoporosis and osteoporotic fracture. In contrast, bone involvement in systemic sclerosis (SSc) is still debated. There is currently no recommendation for systematic research of osteoporosis in SSc.
Objectives The aim of our study was to investigate the existence of an increased prevalence of osteoporosis in patients with systemic sclerosis (SSc), to describe the qualitative alterations of bone tissue with the High-resolution peripheral quantitative computed tomography (HR-pQCT), comparing these patients to a group of healthy women, and to identify specific factors influencing SSc bone disease.
Methods We conducted a cross-sectional study of consecutively including patients with SSc and healthy women, matched on age, body mass index (BMI) and duration of menopause. Risk factors for osteoporosis was collected from all subjects. Bone mineral density (BMD) was measured at the lumbar spine, femoral neck and total hip by dual energy X-ray absorptiometry (DXA). The volumetric bone mineral density (vBMD) and bone microarchitecture parameters were measured by the HR-pQCT at the tibia and radius.
Results Thirty-three patients and 33 controls were included. The BMI of the patients was significantly lower (p<0.029). The prevalence of osteoporosis in postmenopausal patients was significantly higher than controls (42.8% versus 10.7%, p<0.05). After adjustment for BMI, BMD at the total hip was significantly lower in patients compared to controls (p<0.015). The HR-pQCT analysis showed a significant alteration of the trabecular compartment in patients, in particular a decrease in trabecular vBMD on both sites (p<0.01). In multivariate analysis, a low lean body mass, the presence of anti-centromere antibodies and older age were identified as independent factors for decreased BMD at the lumbar spine (R2=0.43;p=0.0009), decreased BMD at the femoral neck (R2=0.61;p<0.0001) and decreased BMD at the total hip (R2=0.73;p<0.0001). Digital ulcers were also identified as an independent factor for microarchitecture alteration.
Conclusions An increased prevalence of osteoporosis was found in patients with SSc. The HR-pQCT showed impaired trabecular bone compartment in patients. Low lean body mass, high age, digital ulcers and anti-centromere antibodies were identified as independent risk factors for bone damage.
Disclosure of Interest None declared