Omega 3 Fatty Acid Treatment for Pediatric Musculoskeletal Health

Medical treatments and disease pathophysiology can result in prolonged immobilization that places hospitalized infants and children at risk for serious musculoskeletal complications including bone loss, fragility fractures, and muscle atrophy. Patients at the highest risk for inpatient fracture include premature infants, children with cerebral palsy, spinal cord injury, neuromuscular disorders (e.g., Duchenne Muscular Dystrophy or Spinal Muscular Atrophy), lengthy post-operative immobilization such as esophageal atresia (EA), and prolonged use of parenteral nutrition (PN). These fractures can result in significant discomfort, increase medical costs, may require surgical intervention, and may result in long term deleterious effects on musculoskeletal health.

Omega-3 polyunsaturated fatty acids (O3PuFA) are important bio-mediators modulating bone formation and remodeling. We demonstrated that O3PuFA provide protection of bone microstructure by increasing the number of trabecular elements and subsequently strengthening the trabecular network in young mice. Human studies suggest an association between O3PuFA intake and increased bone mineral density (BMD) in adults, and we also demonstrated decreased fracture risk in infants. O3PuFA may reduce bone resorption by modulating inflammatory cytokines and inhibiting osteoclast differentiation and activity, and may also increase bone formation by increasing osteoblast differentiation and activity, which may provide the explanation for the observed skeletal benefits.

In this study, we propose the use of intravenous O3PuFA (Omegaven® , Fresenius Kabi, Bad Hamburg Germany) administration for the prevention of musculoskeletal complications due to immobilization in infants. Boston Children's Hospital (BCH) has more than 15 years' experience with this O3PuFA product, having treated more than 250 infants and children. Omegaven is currently under review by the FDA for treatment of infants with PN-associated liver disease.

The proposed study is a randomized, double blind clinical trial using comparing Omegaven® administration to the current standard of care (soybean-based lipid formulation, Intralipid®) on musculoskeletal health in high risk infants with EA admitted at BCH. Infants with EA have been observed to have dramatic bone loss and a very high fracture rate (over 40%) related to their prolonged post-operative immobilization; therefore, these patients represent the ideal model to evaluate this intervention. By targeting this particular patient population at such high risk for musculoskeletal complications and limited confounding factors, the effects of our intervention will have the highest probability of being identified if such a benefit does exist.

In this pilot study, thirty-two infants with EA will be randomized to either treatment arm for a four-week treatment period. Safety outcomes will include regular laboratory monitoring as per routine standard of care. Efficacy outcomes will include (1) computed tomography (CT) of the bilateral distal femurs at baseline and at 4 weeks, which will provide skeletal outcomes including volumetric bone density, bone geometry, and bone strength estimates, (2) serum and urine markers of bone turnover, and (3) incidence of fracture in the post-operative period. All subjects will continue to receive treatments according to standard of care regardless of group assignment, including physical therapy, nutritionist consult, fracture precautions, and regular laboratory monitoring per discretion of the primary medical team.