Increased risk of osteoporosis and fracture in women with systemic sclerosis: A comparative study with rheumatoid arthritis

Objective To investigate whether women with systemic sclerosis (SSc) have an increased risk of osteoporosis (OP) and related fractures compared to a high-risk population with rheumatoid arthritis (RA) and also healthy controls, and to determine putative specific OP and fracture risk factors. Methods We performed a cross-sectional study with successive inclusion of age-matched healthy women and women with SSc and RA. Risk factors for OP and fracture were collected for all patients. Bone mineral density (BMD) was systematically measured at the lumbar spine and total hip region with dual x-ray absorptiometry. Results We included 71 women with SSc, 139 women with RA, and 227 healthy women. The prevalence of OP and fracture was similar in SSc and RA, and was for both diseases higher than in healthy controls (OP: 30% in SSc, 32% in RA, and 11% in controls; fracture: 35% in SSc, 33% in RA, and 10% in controls). Multivariate analysis identified age as a risk factor of OP in SSc. Age and low 25-hydroxyvitamin D (25[OH]D) levels were recognized as risk factors of fracture in SSc. In comparison, age and corticosteroid treatment were associated with OP in RA. Multivariate analysis confirmed age, OP, and low 25(OH)D levels as independent risk factors of fractures in RA. Conclusion The prevalence of OP and fracture in SSc was increased compared to healthy women and reached the high prevalence associated with RA. Age and vitamin D deficiency were identified as risk factors of fracture in SSc. Therefore, increasing the awareness and performance of BMD measurements together with the vitamin D supply in patients with SSc is warranted.