Effect of Oral Glutamine on Muscle Mass and Function in Duchenne Muscular Dystrophy

Glutamine inhibits whole body protein degradation in children with Duchenne Muscular Dystrophy (DMD). The effect is observed after 5 h oral glutamine administration and is also found when glutamine is given over a 10-day period. This multi-site national study aims to evaluate the functional benefit of long-term oral glutamine administration in 30 DMD children using a randomized double-blind placebo-controlled cross-over design. The study includes two 4-month periods: 1) a treatment period in which the subject receives oral glutamine (0.5 g/kg/d) and 2) a control period in which the subject receives a placebo. The order of treatment allocation is randomized. The two 4-month periods are separated by a 1 month wash-out period. The children are monitored every 2 months during period 1 (M0, M2, M4) and period 2 (M5, M7, M9) in the clinical investigation centres of Hospital Robert Debré in Paris and the CHR&U de Lille, as well as the clinical research centre of the CHU de Poitiers. Evidence of a functional benefit would involve evaluating the administration of glutamine over longer periods (as early as possible following diagnosis) among severely handicapped children and in other chronic pathologies associated with increased muscle protein catabolism. In DMD, such evidence would enable children to undergo gene therapy under improved physical condition.

Comparisons: Glutamine administration compared to placebo on the following outcome measures: walking speed on a standard course, work (kcal) and power (kcal/s) in relation to effort, body composition (bioelectrical impedance analysis and BIPHOTONIC absorptiometry), muscle mass (24-h urinary creatinine excretion), indices of protein degradation (CPK and 3-methyl histidine excretion) and biochemical parameters (electrolytes, fasting glucose, transaminases, insulin, IgfI, Igf-BPI).

Inclusion criteria

• Clinical diagnosis of Duchenne muscular dystrophy
• Able to walk >170 m
• Absence of hepatic insufficiency
• Absence of renal insufficiency

Exclusion criteria

• Dependent upon wheelchair
• Body weight >60kg
• Liver failure
• Kidney failure
• Surgery scheduled during the year following the first visit