Optimizing Bone Health in Duchenne Muscular Dystrophy

Abstract

Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder characterized by progressive muscle weakness, with eventual loss of ambulation and premature death. The approved therapy with corticosteroids improves muscle strength, prolongs ambulation, and maintains pulmonary function. However, the osteoporotic impact of chronic corticosteroid use further impairs the underlying reduced bone mass seen in DMD, leading to increased fragility fractures of long bones and vertebrae. These serious sequelae adversely affect quality of life and can impact survival. The current clinical issues relating to bone health and bone health screening methods in DMD are presented in this review. Diagnostic studies, including biochemical markers of bone turnover and bone mineral density by dual energy X-ray absorptiometry (DXA), as well as spinal imaging using densitometric lateral spinal imaging, and treatment to optimize bone health in patients with DMD are discussed. Treatment with bisphosphonates offers a method to increase bone mass in these children; oral and intravenous bisphosphonates have been used successfully although treatment is typically reserved for children with fractures and/or bone pain with low bone mass by DXA.

Bone Density in the Obese Child: Clinical Considerations and Diagnostic Challenges

“…It is characterized by severe and persistent muscle weakness and loss of muscle mass, leading to immobility and long-term corticosteroid use is an approved and proven treatment[62]. A tendency toward obesity emerges by early adolescence; a cohort study of 252 steroid-naïve boys reported obesity in up to 54% of participants, followed by a decline in obesity in late adolescence[63].…”

“…A tendency toward obesity emerges by early adolescence; a cohort study of 252 steroid-naïve boys reported obesity in up to 54% of participants, followed by a decline in obesity in late adolescence[63]. Several prior studies have described deficiencies in aBMD in this population along with marked increase in fragility fractures[62, 64, 65]. These observed patterns in bone outcomes are due, to some degree, to immobility.…”

Zoledronic acid in pediatric metabolic bone disorders

“…Limited published data exist on the use of BPs for GIO in children. GIO is prevalent in children with Duchene muscular dystrophy treated with long term GCs and many studies have reported positive outcome (28,29). It is important to note that there is potential for recovery of bone density with reduced fracture risk to expected for age in children once GCs are discontinued (30,31).…”

Pain characterization in Duchenne muscular dystrophy

“…Duchenne muscular dystrophy is characterized by progressive muscle weakness, ambulation loss and premature death 3 . The lack of dystrophin results in degeneration of muscle fibers, which are replaced by fat and connective tissue 1 .…”