Multiple sclerosis is associated with low bone mineral density and osteoporosis

To compare measures of bone mineral density (BMD) between people with and without MS.

Using population-based administrative data from Manitoba, Canada, we identified people with MS who received BMD screening and controls who received BMD screening matched 5:1 on age, sex, region of residence, and date of BMD screening. We determined the BMD T-scores for the femoral neck, total hip, and lumbar spine and frequency of osteoporosis (defined as T-score -2.5 or lower). We compared the groups with respect to the femoral neck T-score using multivariable linear regression, adjusting for age, sex, region, disability, continuity of care, recent previous fracture, falls history, medication use, and comorbidities. We compared the odds of osteoporosis between groups using multivariable logistic regression analysis.

We identified 783 MS cases who underwent BMD screening and 3,915 matched controls. The mean (SD) femoral BMD T-score was lower in MS cases (-1.48 [1.08]) than in matched controls (-1.12 [0.98], p < 0.001), and the prevalence of osteoporosis was higher among the MS cases (range across BMD sites: 16%-26%) vs controls (6%-15%). MS was associated with a lower femoral neck BMD T-score after accounting for covariates (β = -0.24; 95% CI: -0.32 to -0.17) and more than 2-fold increased odds of osteoporosis (covariate-adjusted OR 2.41; 95% CI: 1.82-3.19).

People with MS have lower BMD and a higher prevalence of osteoporosis compared with people of similar age and sex without MS. These findings indicate the importance of addressing bone health as part of comprehensive MS care.