5 Contributors to BMD Decrease in Patients With MS Are Identified

Physical activity, depression, and symptomatic fatigue are the greatest independent contributors to the decrease in femoral neck bone mineral density (BMD) that patients with multiple sclerosis (MS) experience, according to a new study.

Disability and inflammation are 2 other independent contributors to the decrease in femoral neck BMD among patients with MS.

Using dual-energy x-ray absorptiometry, the researchers measured the femoral neck and lumbar spine BMD in 23 patients with MS and in 22 without MS.

The Expanded Disability Status Scale was used to measure disability, while the Multiple Sclerosis Functional Composite was used to measure functional capacity. Measurements of symptomatic fatigue and depression were obtained via questionnaires, and physical activity was measured via accelerometry. Bloodwork revealed the calcium, phosphate, vitamin D, N-terminal telopeptide, osteopontin, and cytokine markers of inflammation. Salivary cortisol and cardiac heart rate variability were also recorded.

Compared with those without MS, the participants with MS had lower BMD at the femoral neck as well as a smaller, statistically nonsignificant difference in BMD at the lumbar spine. Comparatively, participants with MS also had lower functional capacity, greater fatigue, greater depression, and decreased physical activity.

According to the researchers, 51% of the variance in femoral neck BMD could be attributed to disability (standardized estimate= -0.17), physical activity (standardized estimate=0.39), symptomatic fatigue (standardized estimate= -0.36), depression (standardized estimate= -0.30), and inflammatory markers (standardized estimate=0.27).

Inflammatory markers were also predictive of disability (standardized estimate=0.44) and physical activity (standardized estimate= -0.40). The results also showed that symptomatic fatigue and depression were correlated.

“Bone metabolism in [people with MS] is complex,” the researchers concluded. “Efforts to increase physical activity and address symptomatic fatigue and depression may improve bone mineral density in [people with MS]. Future research should investigate the mechanisms through which symptomatic fatigue and depression contribute to reduced BMD in [people with MS].”

—Colleen Murphy

Reference:

Cleland BT, Papanek P, Ingraham BA, et al. Determinants of low bone mineral density in people with multiple sclerosis: role of physical activity. Mult Scler Relat Disord. 2020;38:101864. https://doi.org/10.1016/j.msard.2019.101864.