Increased risk for bone loss in women with systemic sclerosis: a comparative study with rheumatoid arthritis

To assess bone mass in women with systemic sclerosis (SSc) in comparison to age and sex-matched patients with rheumatoid arthritis (RA), and to evaluate factors influencing bone mineral density (BMD).

Patients were consecutively recruited and assessed for BMD at the lumbar spine and hip by dual-energy X-ray absorptiometry (DEXA) using a densitometer. In SSc, the extent of skin involvement, modified Rodnan skin thickness score (mRSS) and Medsger disease severity index were assessed.

Forty-three patients with SSc and 38 age-matched patients with RA were included. There was no difference in BMD measurements between patients with diffuse or limited SSc. Patients with SSc had similar risk factors associated with osteoporosis (OP) or low bone mass except for low body mass index (BMI) and low vitamin D levels compared to patients with RA. Lumbar spinal BMD and T score were similar between groups. Total hip and femoral neck BMD and T score at femoral neck and total hip were significantly lower in patient with SSc versus RA. There was significant association between mRSS, Medsger severity score (peripheral vascular involvement and skin) and femoral BMD.

There is an increased risk for bone loss in patients with SSc and the risk of OP is associated with disease severity, prolonged menopause and disease duration. The complex pathophysiology of bone metabolism as well as complex pathogenesis of the SSc pose some difficulty reaching clear-cut conclusions on the causal relationship between SSc and bone loss.