Worsening disability tied to loss of bone mineral density in MS
Researchers say study is first to show link
Worsening disability in people with multiple sclerosis (MS) is associated with a significantly greater likelihood of losing bone mineral density, which can lead to fractures, a study suggested.
“This study provides first evidence for the association of disability worsening and bone density reduction in [people with MS] over a short-term period,” the researchers wrote. Additional vigilance around bone health may be needed in MS patients whose disability is progressing to prevent fractures and improve quality of life, they added.
The study, “Short-Term Risk Factors for Bone Loss in Multiple Sclerosis: A Prospective Study and Literature Review,” was published in the European Journal of Neurology.
People with MS have a higher risk of having reduced bone mass and osteoporosis, a condition where the bones become fragile and more susceptible to fractures. Several factors may contribute to this, including reduced mobility due to disability and the use of medications like corticosteroids that can lower the amount of calcium and other minerals in the bones, referred to as bone mineral density.
Still, how bone health changes in people with MS remains poorly understood. Most studies that have looked at progressive bone loss have been small or focused on short observational periods.
Preventing osteoporosis
“Understanding the dynamics of bone health in [people with MS] is essential for developing targeted interventions to prevent osteoporosis and associated increased morbidity and mortality and to improve overall quality of life and health,” the researchers wrote.
The team, in Austria, examined bone health in 139 MS patients, ages 18-65, who were followed for at least two years. Participants’ bone mineral density in the lumbar spine and hip was assessed via an imaging technique called dual X-ray absorptiometry. These scans were performed done once at the start of the study and again after two years.
Over the course of the study, 73% of participants lost mineral density in the right hip bone. These participants lost a median of 3.5% of their bone minerals. This resulted in a significant difference between bone mineral density scores at the beginning compared with the end of the study. No significant bone mineral loss was observed in the lumbar spine.
The team then investigated whether factors such as age, vitamin D levels, smoking, body mass, menopausal status, gender, corticosteroid use, or disability worsening could be contributing to bone mineral density loss in these patients.
A statistical analysis identified disability worsening, defined as a sustained increase in Expanded Disability Status Scale (EDSS) scores lasting at least six months, as the only significant predictor of bone mineral density loss. Patients with disability worsening were seven times more likely to experience loss of bone mineral density.
The researchers suggested that participants with worsening disability may spend less time doing weight-bearing activities like walking, which are important for bone mineral density, potentially contributing to the effect seen in hip bones.
In the lumbar spine, the five vertebrae in the lower back — which are not considered weight-bearing bones — there was no change in bone mineral density, supporting the team’s hypothesis.
Whether participants took medications that could increase bone health (such as vitamin D supplements) and/or ones that could decrease bone health (such as corticosteroids) did not significantly affect the change in bone mineral density.
Eight patients also fractured bones between the first and last study visits. These participants were significantly older, had higher disability levels, and had lower hip bone mineral density than those without fractures, “indicating a link between lower [bone mineral density] and higher fracture risk,” the researchers wrote.
The researchers are pursuing a longer follow-up to see if additional trends in bone health appear. But they said their findings so far “underscore the need for active monitoring of [people with MS] with disability worsening to prevent bone loss and, thus, to reduce fracture risk.”
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