Reduced Bone Mineral Density in Women with Multiple Sclerosis

Aim: The aim of this study was to compare the bone mineral density (BMD) and muscle mass in women with multiple sclerosis (MS) in an outpatient setting and control subjects, and to examine the effect of motor disability, muscle mass and/or glucocorticoids (GC) use on BMD. Methods: Body composition and BMD were measured by dual-energy X-ray absorptiometry in 250 MS women (153 premenopausal and 97 postmenopausal women) with EDSS (Expanded Disability Status Scale) 6.5 treated in an outpatient setting and in 193 controls. Results: Compared to controls, patients had significantly lower values for total body bone mineral content and BMD at all measured sites except for the distal radius. Patients with MS had significantly lower amount of total muscle mass as well as total leg muscle mass when compared to the control group. The EDSS score was negatively associated with BMD at the proximal femur in both premenopausal and postmenopausal women, while the deficit of total body muscle mass was significantly associated with a loss of BMD at the lumbar spine and whole body BMD in premenopausal women only. GC treatment was negatively associated with BMD at the lumbar spine in premenopausal women. Conclusion: The total body muscle mass was an important predictive factor for the total body BMD and the lumbar spine BMD in premenopausal women with MS. Further prospective studies are required to verify the protective effect of muscle mass on BMD in patients with MS and to assess the role of systemic factors modulating the bone-muscle relationship (e.g. vitamin D or estrogen deficiency).