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

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.

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.

Over the 2-year follow-up period, significant BMD loss was observed in the hip (baseline g/cm²: 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.

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.