Bone loss in children with Duchenne muscular dystrophy (DMD) worsens steadily with age and long-term steroid treatment, raising the chance of fractures, according to a study published recently in Osteoporosis International.
This new systematic review of research highlights that understanding how bone health changes over time can help guide future treatment and clinical trials aimed at protecting strength and mobility in this rare disease.
The review found that children with DMD who were treated with glucocorticoids, or steroids, had lower bone density in their spines, hips and legs as they aged. Steroids help slow the muscle weakness caused by the disease, but they also make bones more fragile. The study reported that for every year of age, spine bone density dropped by 0.25 standard deviations, while the hip and leg bones declined even faster.
“This comprehensive analysis of the natural history of BMD [bone mineral density] and the factors that influence it in DMD facilitates a better understanding of osteoporosis progression to support the improvement of bone strength among individuals with DMD,” explained this systematic review’s authors.
Read more about prognosis of DMD
These losses were not only numbers on a scan. The chance of breaking a bone rose significantly as bone density decreased. For every drop of one standard deviation in spine bone density, the risk of fracture increased by 21%. Bone loss sped up after age 11, making older children more vulnerable to painful breaks that limit independence.
This review drew on 41 studies covering 1,940 individuals worldwide, with most children between the ages of 6 and 15. Nearly three-quarters of the children were still able to walk, and most had not yet entered puberty when their bone health was measured. Steroid use was common, starting around age 7, with an average daily dose close to recommended levels. Even at these doses, long-term use was linked to steady bone weakening.
Bone health was most often measured using dual-energy X-ray absorptiometry, which showed clear trends. The lumbar spine was the most frequently studied site, but total body and femur scans revealed similar patterns of decline. The fastest losses were seen in the leg bones, with a drop of 0.41 standard deviations per year.
For patients and families, this means that broken bones are not only possible but likely as children with DMD get older. Researchers say that tracking these patterns is a key step toward developing ways to strengthen bones and prevent fractures, which could help preserve quality of life.
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