Short-Term Risk Factors for Bone Loss in Multiple Sclerosis: A Prospective Study and Literature Review.

Background: Reduced bone mass and increased osteoporosis risk are common in people with multiple sclerosis (pwMS). The aim of the study was to identify risk factors for short-term bone loss in MS.

Methods: This prospective study included 139 pwMS (ages 18-65). Baseline data included demographics, body-mass index, physical activity, smoking, menopause status, 25-hydroxy vitamin D levels, and history of glucocorticoid use. Bone mineral density (BMD) was measured at baseline and after 2 years using dual-energy X-ray absorptiometry (DXA) for the lumbar spine and hip. Disability worsening was assessed by the Expanded Disability Status Scale (EDSS). Additionally, a literature review was conducted on longitudinal data regarding BMD in MS.

Results: Over the 2-year follow-up period, significant BMD loss was observed in the hip (baseline g/cm: median 0.898; IQR 0.808-1.014; 2-year follow-up: 0.882; 0.784-1.01; p < 0.001), but not in the lumbar spine. Overall, 101 (73.1%) experienced hip BMD loss, with a median decrease of 3.5%. Patients with disability worsening had an approximately 7-times higher risk of bone loss compared to those without disability worsening (p = 0.013). PwMS with fractures during the follow-up period had significantly lower hip BMD (0.760, 0.546-0.890 vs. 0.909, 0.828-1.015; p = 0.024), a higher EDSS score (4.4, 2.8-5.8 vs. 2.0, 1.0-4.0 vs. p = 0.026), and were older (59, 46-62 vs. 47, 37-54; p = 0.030) compared to those without fractures.

Conclusion: Disability worsening was identified as a risk factor for BMD loss. These findings underscore the need for active monitoring of pwMS with disability worsening to prevent bone loss and, thus, to reduce fracture risk.