Multiple sclerosis (MS) is associated with low bone mineral density (BMD) and over 2-fold increased odds of developing osteoporosis, according to a study published in Neurology: Clinical Practice.

In this population-based, matched cohort study, investigators utilized administrative health claims to select people with MS (n=783) and matched controls (n=3915) who were registered in the bone mineral density database in Manitoba, Canada. The date of MS diagnosis was defined as the first demyelinating disease claim, and patients were identified based on ≥3 hospital, physician, or prescription claims for disease-modifying therapy. BMD had been measured using dual-energy X-ray absorptiometry.

Primary outcome was the femoral neck T-score, used to determine the proportion of participants with osteoporosis based on a value of ≥2.5 standard deviations below young adult normative values. Investigators also examined the lumbar spine T-score, total hip T-score, and the minimum T-score of the 3 sites to provide a more comprehensive skeletal assessment.

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Compared to matched controls, those with MS had lower mean BMD T-scores and mean standard deviation at the femoral neck (-1.48 [1.08] vs (-1.12 [0.98]), total hip (-1.18 [1.38] vs -0.63 [1.18]), lumbar spine (-1.04 [1.50] vs -0.88 [1.46]), and minimum score (-1.76 [1.20] vs -1.43 [1.11]). The range of across BMD sites showed the prevalence of osteoporosis was higher among patients with MS (16% to 26%) compared with controls (6% to 15%). Using multivariate linear regression analysis, the investigators confirmed that MS was associated with lower BMD T-score at the lower femoral neck (-0.24; 95% CI: -0.32 to -0.17) and more than 2-fold increased odds of osteoporosis (OR 2.41; 95% CI: 1.82-3.19).

This study was limited by the lack of a formally validated MS-specific measure of disability that would have enabled researchers to evaluate associations with fatigue, anticonvulsant use, and several comorbidities. Vitamin D status was not captured. The study population may not be representative of those in the entire MS population because only the individuals who underwent BMD screening were included in this analysis.

Researchers conclude that people with MS have more than a 2-fold increased odds of osteoporosis than individuals without MS. Based on these findings and the high rate of falls among people with MS, developing systematic approaches to BMD screening and optimizing bone health as part of comprehensive MS care is needed in clinical practice.

Several researchers acknowledge conflicts of interest. Please see reference for a full list of disclosures.

Reference

Bisson EJ, Finlayson ML, Ekuma O, Leslie WD, Marrie RA. Multiple sclerosis is associated with low bone mineral density and osteoporosis [published online May 30, 2019]. Neurol Clin Pract. doi: 10.1212/CPJ.0000000000000669