Bone Abstracts

Purpose: Systemic sclerosis (SSc) is a rare inflammatory rheumatic disease that has been associated with an increased risk of low bone mineral density (BMD). However, data on risk factors associated with bone loss in SSc are scarce. The objective of this study was to investigate the prevalence of and the risk factors for low BMD in patients with SSc.

Methods: Cross-sectional data of 61 patients with SSc were collected. BMD in the lumbar spine, total hip and femoral neck was assessed using DXA. Osteoporosis and osteopenia were defined according to WHO definitions. SSc disease severity was defined by the Rodnan skin score and the Medsger disease severity score. Analysis for factors associated with BMD was performed through multiple linear regression analyses.

Results: Patients were on average 56.7±12.4 years old and 72% were female of whom 77% postmenopausal. BMD measurements revealed osteopenia or osteoporosis in at least one site in 67% of the patients, of whom 30% had osteoporosis. Low BMI and postmenopausal state were significantly associated with low BMD in all skeletal sites. No significant associations were found between age, disease severity, glucocorticoid treatment and BMD. Of the 30% of patients who had an indication for anti-osteoporosis treatment, 91% did not receive anti-osteoporosis medication.

Conclusions: A high frequency of osteoporosis or osteopenia (67%) was demonstrated in our patients with SSc. Low BMI and postmenopausal state were identified as the most important risk factors. No relationship between disease severity and BMD was found, which could be related to the sample size, although it can be argued that low BMI, at least partly, is a marker of disease severity. This study also shows a high frequency of undertreatment of osteoporosis in this patient group. These results underline the importance of monitoring and treatment of low BMD in SSc.