Growth hormone therapy for children with Duchenne Muscular Dystrophy and glucocorticoid induced short stature.

Background: Duchenne Muscular Dystrophy (DMD) is the most common form of inherited muscle disease in childhood. DMD patients have severe growth retardation due to several reasons including chronic treatment with glucocorticoid (GC). Data regarding the efficacy and safety of Recombinant Growth Hormone (rGH) treatment in DMD patients is very limited. The aim of this study is to evaluate efficacy and safety of growth hormone treatment in 4 DMD boys with glucocorticoid induced growth failure.

Methods and Results: 4 prepubertal patients with DMD on high dose of GC (Deflazecort or Prednisone) at an age range between 12-13.6 years and significantly delayed bone age (8.5-11 years) were studied. rhGH was subcutaneously administered at a dose of 0.033 mg/kg/d for a duration of 12-18 months. Pretreatment annual growth rate of the 4 patients (0, 3,2.5, 1.5 cm/yr) improved during treatment (3.8, 7.8, 7.2, 3.3 cm/yr respectively). While height SD improved in 2 patients: -2.74 and -2.96 height SD to -2.52 and -2.64 height SD on rGH therapy, In the other two patients pretreatment continuous decline in height SD was arrested. Motor function decline was similar pre-growth hormone and during treatment. Cardiopulmonary function measured by ejection fraction and forced vital capacity was unchanged during the treatment period.

Conclusions: This report of growth hormone therapy in DMD patients revealed an improved prepubertal growth velocity without detrimental effects observed on neuromuscular and cardiopulmonary function. Larger randomized control studies are required to prove safety and efficacy of this treatment in DMD patients.